shop.balmet.com

codemirror.js (363564B)

---

 // CodeMirror, copyright (c) by Marijn Haverbeke and others
 // Distributed under an MIT license: http://codemirror.net/LICENSE
 
 // This is CodeMirror (http://codemirror.net), a code editor
 // implemented in JavaScript on top of the browser's DOM.
 //
 // You can find some technical background for some of the code below
 // at http://marijnhaverbeke.nl/blog/#cm-internals .
 
 (function(mod) {
   if (typeof exports == "object" && typeof module == "object") // CommonJS
     module.exports = mod();
   else if (typeof define == "function" && define.amd) // AMD
     return define([], mod);
   else // Plain browser env
     (this || window).CodeMirror = mod();
 })(function() {
   "use strict";
 
   // BROWSER SNIFFING
 
   // Kludges for bugs and behavior differences that can't be feature
   // detected are enabled based on userAgent etc sniffing.
   var userAgent = navigator.userAgent;
   var platform = navigator.platform;
 
   var gecko = /gecko\/\d/i.test(userAgent);
   var ie_upto10 = /MSIE \d/.test(userAgent);
   var ie_11up = /Trident\/(?:[7-9]|\d{2,})\..*rv:(\d+)/.exec(userAgent);
   var ie = ie_upto10 || ie_11up;
   var ie_version = ie && (ie_upto10 ? document.documentMode || 6 : ie_11up[1]);
   var webkit = /WebKit\//.test(userAgent);
   var qtwebkit = webkit && /Qt\/\d+\.\d+/.test(userAgent);
   var chrome = /Chrome\//.test(userAgent);
   var presto = /Opera\//.test(userAgent);
   var safari = /Apple Computer/.test(navigator.vendor);
   var mac_geMountainLion = /Mac OS X 1\d\D([8-9]|\d\d)\D/.test(userAgent);
   var phantom = /PhantomJS/.test(userAgent);
 
   var ios = /AppleWebKit/.test(userAgent) && /Mobile\/\w+/.test(userAgent);
   // This is woefully incomplete. Suggestions for alternative methods welcome.
   var mobile = ios || /Android|webOS|BlackBerry|Opera Mini|Opera Mobi|IEMobile/i.test(userAgent);
   var mac = ios || /Mac/.test(platform);
   var chromeOS = /\bCrOS\b/.test(userAgent);
   var windows = /win/i.test(platform);
 
   var presto_version = presto && userAgent.match(/Version\/(\d*\.\d*)/);
   if (presto_version) presto_version = Number(presto_version[1]);
   if (presto_version && presto_version >= 15) { presto = false; webkit = true; }
   // Some browsers use the wrong event properties to signal cmd/ctrl on OS X
   var flipCtrlCmd = mac && (qtwebkit || presto && (presto_version == null || presto_version < 12.11));
   var captureRightClick = gecko || (ie && ie_version >= 9);
 
   // Optimize some code when these features are not used.
   var sawReadOnlySpans = false, sawCollapsedSpans = false;
 
   // EDITOR CONSTRUCTOR
 
   // A CodeMirror instance represents an editor. This is the object
   // that user code is usually dealing with.
 
   function CodeMirror(place, options) {
     if (!(this instanceof CodeMirror)) return new CodeMirror(place, options);
 
     this.options = options = options ? copyObj(options) : {};
     // Determine effective options based on given values and defaults.
     copyObj(defaults, options, false);
     setGuttersForLineNumbers(options);
 
     var doc = options.value;
     if (typeof doc == "string") doc = new Doc(doc, options.mode, null, options.lineSeparator);
     this.doc = doc;
 
     var input = new CodeMirror.inputStyles[options.inputStyle](this);
     var display = this.display = new Display(place, doc, input);
     display.wrapper.CodeMirror = this;
     updateGutters(this);
     themeChanged(this);
     if (options.lineWrapping)
       this.display.wrapper.className += " CodeMirror-wrap";
     if (options.autofocus && !mobile) display.input.focus();
     initScrollbars(this);
 
     this.state = {
       keyMaps: [],  // stores maps added by addKeyMap
       overlays: [], // highlighting overlays, as added by addOverlay
       modeGen: 0,   // bumped when mode/overlay changes, used to invalidate highlighting info
       overwrite: false,
       delayingBlurEvent: false,
       focused: false,
       suppressEdits: false, // used to disable editing during key handlers when in readOnly mode
       pasteIncoming: false, cutIncoming: false, // help recognize paste/cut edits in input.poll
       selectingText: false,
       draggingText: false,
       highlight: new Delayed(), // stores highlight worker timeout
       keySeq: null,  // Unfinished key sequence
       specialChars: null
     };
 
     var cm = this;
 
     // Override magic textarea content restore that IE sometimes does
     // on our hidden textarea on reload
     if (ie && ie_version < 11) setTimeout(function() { cm.display.input.reset(true); }, 20);
 
     registerEventHandlers(this);
     ensureGlobalHandlers();
 
     startOperation(this);
     this.curOp.forceUpdate = true;
     attachDoc(this, doc);
 
     if ((options.autofocus && !mobile) || cm.hasFocus())
       setTimeout(bind(onFocus, this), 20);
     else
       onBlur(this);
 
     for (var opt in optionHandlers) if (optionHandlers.hasOwnProperty(opt))
       optionHandlers[opt](this, options[opt], Init);
     maybeUpdateLineNumberWidth(this);
     if (options.finishInit) options.finishInit(this);
     for (var i = 0; i < initHooks.length; ++i) initHooks[i](this);
     endOperation(this);
     // Suppress optimizelegibility in Webkit, since it breaks text
     // measuring on line wrapping boundaries.
     if (webkit && options.lineWrapping &&
         getComputedStyle(display.lineDiv).textRendering == "optimizelegibility")
       display.lineDiv.style.textRendering = "auto";
   }
 
   // DISPLAY CONSTRUCTOR
 
   // The display handles the DOM integration, both for input reading
   // and content drawing. It holds references to DOM nodes and
   // display-related state.
 
   function Display(place, doc, input) {
     var d = this;
     this.input = input;
 
     // Covers bottom-right square when both scrollbars are present.
     d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler");
     d.scrollbarFiller.setAttribute("cm-not-content", "true");
     // Covers bottom of gutter when coverGutterNextToScrollbar is on
     // and h scrollbar is present.
     d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler");
     d.gutterFiller.setAttribute("cm-not-content", "true");
     // Will contain the actual code, positioned to cover the viewport.
     d.lineDiv = elt("div", null, "CodeMirror-code");
     // Elements are added to these to represent selection and cursors.
     d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1");
     d.cursorDiv = elt("div", null, "CodeMirror-cursors");
     // A visibility: hidden element used to find the size of things.
     d.measure = elt("div", null, "CodeMirror-measure");
     // When lines outside of the viewport are measured, they are drawn in this.
     d.lineMeasure = elt("div", null, "CodeMirror-measure");
     // Wraps everything that needs to exist inside the vertically-padded coordinate system
     d.lineSpace = elt("div", [d.measure, d.lineMeasure, d.selectionDiv, d.cursorDiv, d.lineDiv],
                       null, "position: relative; outline: none");
     // Moved around its parent to cover visible view.
     d.mover = elt("div", [elt("div", [d.lineSpace], "CodeMirror-lines")], null, "position: relative");
     // Set to the height of the document, allowing scrolling.
     d.sizer = elt("div", [d.mover], "CodeMirror-sizer");
     d.sizerWidth = null;
     // Behavior of elts with overflow: auto and padding is
     // inconsistent across browsers. This is used to ensure the
     // scrollable area is big enough.
     d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerGap + "px; width: 1px;");
     // Will contain the gutters, if any.
     d.gutters = elt("div", null, "CodeMirror-gutters");
     d.lineGutter = null;
     // Actual scrollable element.
     d.scroller = elt("div", [d.sizer, d.heightForcer, d.gutters], "CodeMirror-scroll");
     d.scroller.setAttribute("tabIndex", "-1");
     // The element in which the editor lives.
     d.wrapper = elt("div", [d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror");
 
     // Work around IE7 z-index bug (not perfect, hence IE7 not really being supported)
     if (ie && ie_version < 8) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0; }
     if (!webkit && !(gecko && mobile)) d.scroller.draggable = true;
 
     if (place) {
       if (place.appendChild) place.appendChild(d.wrapper);
       else place(d.wrapper);
     }
 
     // Current rendered range (may be bigger than the view window).
     d.viewFrom = d.viewTo = doc.first;
     d.reportedViewFrom = d.reportedViewTo = doc.first;
     // Information about the rendered lines.
     d.view = [];
     d.renderedView = null;
     // Holds info about a single rendered line when it was rendered
     // for measurement, while not in view.
     d.externalMeasured = null;
     // Empty space (in pixels) above the view
     d.viewOffset = 0;
     d.lastWrapHeight = d.lastWrapWidth = 0;
     d.updateLineNumbers = null;
 
     d.nativeBarWidth = d.barHeight = d.barWidth = 0;
     d.scrollbarsClipped = false;
 
     // Used to only resize the line number gutter when necessary (when
     // the amount of lines crosses a boundary that makes its width change)
     d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null;
     // Set to true when a non-horizontal-scrolling line widget is
     // added. As an optimization, line widget aligning is skipped when
     // this is false.
     d.alignWidgets = false;
 
     d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
 
     // Tracks the maximum line length so that the horizontal scrollbar
     // can be kept static when scrolling.
     d.maxLine = null;
     d.maxLineLength = 0;
     d.maxLineChanged = false;
 
     // Used for measuring wheel scrolling granularity
     d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null;
 
     // True when shift is held down.
     d.shift = false;
 
     // Used to track whether anything happened since the context menu
     // was opened.
     d.selForContextMenu = null;
 
     d.activeTouch = null;
 
     input.init(d);
   }
 
   // STATE UPDATES
 
   // Used to get the editor into a consistent state again when options change.
 
   function loadMode(cm) {
     cm.doc.mode = CodeMirror.getMode(cm.options, cm.doc.modeOption);
     resetModeState(cm);
   }
 
   function resetModeState(cm) {
     cm.doc.iter(function(line) {
       if (line.stateAfter) line.stateAfter = null;
       if (line.styles) line.styles = null;
     });
     cm.doc.frontier = cm.doc.first;
     startWorker(cm, 100);
     cm.state.modeGen++;
     if (cm.curOp) regChange(cm);
   }
 
   function wrappingChanged(cm) {
     if (cm.options.lineWrapping) {
       addClass(cm.display.wrapper, "CodeMirror-wrap");
       cm.display.sizer.style.minWidth = "";
       cm.display.sizerWidth = null;
     } else {
       rmClass(cm.display.wrapper, "CodeMirror-wrap");
       findMaxLine(cm);
     }
     estimateLineHeights(cm);
     regChange(cm);
     clearCaches(cm);
     setTimeout(function(){updateScrollbars(cm);}, 100);
   }
 
   // Returns a function that estimates the height of a line, to use as
   // first approximation until the line becomes visible (and is thus
   // properly measurable).
   function estimateHeight(cm) {
     var th = textHeight(cm.display), wrapping = cm.options.lineWrapping;
     var perLine = wrapping && Math.max(5, cm.display.scroller.clientWidth / charWidth(cm.display) - 3);
     return function(line) {
       if (lineIsHidden(cm.doc, line)) return 0;
 
       var widgetsHeight = 0;
       if (line.widgets) for (var i = 0; i < line.widgets.length; i++) {
         if (line.widgets[i].height) widgetsHeight += line.widgets[i].height;
       }
 
       if (wrapping)
         return widgetsHeight + (Math.ceil(line.text.length / perLine) || 1) * th;
       else
         return widgetsHeight + th;
     };
   }
 
   function estimateLineHeights(cm) {
     var doc = cm.doc, est = estimateHeight(cm);
     doc.iter(function(line) {
       var estHeight = est(line);
       if (estHeight != line.height) updateLineHeight(line, estHeight);
     });
   }
 
   function themeChanged(cm) {
     cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-s-\S+/g, "") +
       cm.options.theme.replace(/(^|\s)\s*/g, " cm-s-");
     clearCaches(cm);
   }
 
   function guttersChanged(cm) {
     updateGutters(cm);
     regChange(cm);
     setTimeout(function(){alignHorizontally(cm);}, 20);
   }
 
   // Rebuild the gutter elements, ensure the margin to the left of the
   // code matches their width.
   function updateGutters(cm) {
     var gutters = cm.display.gutters, specs = cm.options.gutters;
     removeChildren(gutters);
     for (var i = 0; i < specs.length; ++i) {
       var gutterClass = specs[i];
       var gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + gutterClass));
       if (gutterClass == "CodeMirror-linenumbers") {
         cm.display.lineGutter = gElt;
         gElt.style.width = (cm.display.lineNumWidth || 1) + "px";
       }
     }
     gutters.style.display = i ? "" : "none";
     updateGutterSpace(cm);
   }
 
   function updateGutterSpace(cm) {
     var width = cm.display.gutters.offsetWidth;
     cm.display.sizer.style.marginLeft = width + "px";
   }
 
   // Compute the character length of a line, taking into account
   // collapsed ranges (see markText) that might hide parts, and join
   // other lines onto it.
   function lineLength(line) {
     if (line.height == 0) return 0;
     var len = line.text.length, merged, cur = line;
     while (merged = collapsedSpanAtStart(cur)) {
       var found = merged.find(0, true);
       cur = found.from.line;
       len += found.from.ch - found.to.ch;
     }
     cur = line;
     while (merged = collapsedSpanAtEnd(cur)) {
       var found = merged.find(0, true);
       len -= cur.text.length - found.from.ch;
       cur = found.to.line;
       len += cur.text.length - found.to.ch;
     }
     return len;
   }
 
   // Find the longest line in the document.
   function findMaxLine(cm) {
     var d = cm.display, doc = cm.doc;
     d.maxLine = getLine(doc, doc.first);
     d.maxLineLength = lineLength(d.maxLine);
     d.maxLineChanged = true;
     doc.iter(function(line) {
       var len = lineLength(line);
       if (len > d.maxLineLength) {
         d.maxLineLength = len;
         d.maxLine = line;
       }
     });
   }
 
   // Make sure the gutters options contains the element
   // "CodeMirror-linenumbers" when the lineNumbers option is true.
   function setGuttersForLineNumbers(options) {
     var found = indexOf(options.gutters, "CodeMirror-linenumbers");
     if (found == -1 && options.lineNumbers) {
       options.gutters = options.gutters.concat(["CodeMirror-linenumbers"]);
     } else if (found > -1 && !options.lineNumbers) {
       options.gutters = options.gutters.slice(0);
       options.gutters.splice(found, 1);
     }
   }
 
   // SCROLLBARS
 
   // Prepare DOM reads needed to update the scrollbars. Done in one
   // shot to minimize update/measure roundtrips.
   function measureForScrollbars(cm) {
     var d = cm.display, gutterW = d.gutters.offsetWidth;
     var docH = Math.round(cm.doc.height + paddingVert(cm.display));
     return {
       clientHeight: d.scroller.clientHeight,
       viewHeight: d.wrapper.clientHeight,
       scrollWidth: d.scroller.scrollWidth, clientWidth: d.scroller.clientWidth,
       viewWidth: d.wrapper.clientWidth,
       barLeft: cm.options.fixedGutter ? gutterW : 0,
       docHeight: docH,
       scrollHeight: docH + scrollGap(cm) + d.barHeight,
       nativeBarWidth: d.nativeBarWidth,
       gutterWidth: gutterW
     };
   }
 
   function NativeScrollbars(place, scroll, cm) {
     this.cm = cm;
     var vert = this.vert = elt("div", [elt("div", null, null, "min-width: 1px")], "CodeMirror-vscrollbar");
     var horiz = this.horiz = elt("div", [elt("div", null, null, "height: 100%; min-height: 1px")], "CodeMirror-hscrollbar");
     place(vert); place(horiz);
 
     on(vert, "scroll", function() {
       if (vert.clientHeight) scroll(vert.scrollTop, "vertical");
     });
     on(horiz, "scroll", function() {
       if (horiz.clientWidth) scroll(horiz.scrollLeft, "horizontal");
     });
 
     this.checkedZeroWidth = false;
     // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
     if (ie && ie_version < 8) this.horiz.style.minHeight = this.vert.style.minWidth = "18px";
   }
 
   NativeScrollbars.prototype = copyObj({
     update: function(measure) {
       var needsH = measure.scrollWidth > measure.clientWidth + 1;
       var needsV = measure.scrollHeight > measure.clientHeight + 1;
       var sWidth = measure.nativeBarWidth;
 
       if (needsV) {
         this.vert.style.display = "block";
         this.vert.style.bottom = needsH ? sWidth + "px" : "0";
         var totalHeight = measure.viewHeight - (needsH ? sWidth : 0);
         // A bug in IE8 can cause this value to be negative, so guard it.
         this.vert.firstChild.style.height =
           Math.max(0, measure.scrollHeight - measure.clientHeight + totalHeight) + "px";
       } else {
         this.vert.style.display = "";
         this.vert.firstChild.style.height = "0";
       }
 
       if (needsH) {
         this.horiz.style.display = "block";
         this.horiz.style.right = needsV ? sWidth + "px" : "0";
         this.horiz.style.left = measure.barLeft + "px";
         var totalWidth = measure.viewWidth - measure.barLeft - (needsV ? sWidth : 0);
         this.horiz.firstChild.style.width =
           (measure.scrollWidth - measure.clientWidth + totalWidth) + "px";
       } else {
         this.horiz.style.display = "";
         this.horiz.firstChild.style.width = "0";
       }
 
       if (!this.checkedZeroWidth && measure.clientHeight > 0) {
         if (sWidth == 0) this.zeroWidthHack();
         this.checkedZeroWidth = true;
       }
 
       return {right: needsV ? sWidth : 0, bottom: needsH ? sWidth : 0};
     },
     setScrollLeft: function(pos) {
       if (this.horiz.scrollLeft != pos) this.horiz.scrollLeft = pos;
       if (this.disableHoriz) this.enableZeroWidthBar(this.horiz, this.disableHoriz);
     },
     setScrollTop: function(pos) {
       if (this.vert.scrollTop != pos) this.vert.scrollTop = pos;
       if (this.disableVert) this.enableZeroWidthBar(this.vert, this.disableVert);
     },
     zeroWidthHack: function() {
       var w = mac && !mac_geMountainLion ? "12px" : "18px";
       this.horiz.style.height = this.vert.style.width = w;
       this.horiz.style.pointerEvents = this.vert.style.pointerEvents = "none";
       this.disableHoriz = new Delayed;
       this.disableVert = new Delayed;
     },
     enableZeroWidthBar: function(bar, delay) {
       bar.style.pointerEvents = "auto";
       function maybeDisable() {
         // To find out whether the scrollbar is still visible, we
         // check whether the element under the pixel in the bottom
         // left corner of the scrollbar box is the scrollbar box
         // itself (when the bar is still visible) or its filler child
         // (when the bar is hidden). If it is still visible, we keep
         // it enabled, if it's hidden, we disable pointer events.
         var box = bar.getBoundingClientRect();
         var elt = document.elementFromPoint(box.left + 1, box.bottom - 1);
         if (elt != bar) bar.style.pointerEvents = "none";
         else delay.set(1000, maybeDisable);
       }
       delay.set(1000, maybeDisable);
     },
     clear: function() {
       var parent = this.horiz.parentNode;
       parent.removeChild(this.horiz);
       parent.removeChild(this.vert);
     }
   }, NativeScrollbars.prototype);
 
   function NullScrollbars() {}
 
   NullScrollbars.prototype = copyObj({
     update: function() { return {bottom: 0, right: 0}; },
     setScrollLeft: function() {},
     setScrollTop: function() {},
     clear: function() {}
   }, NullScrollbars.prototype);
 
   CodeMirror.scrollbarModel = {"native": NativeScrollbars, "null": NullScrollbars};
 
   function initScrollbars(cm) {
     if (cm.display.scrollbars) {
       cm.display.scrollbars.clear();
       if (cm.display.scrollbars.addClass)
         rmClass(cm.display.wrapper, cm.display.scrollbars.addClass);
     }
 
     cm.display.scrollbars = new CodeMirror.scrollbarModel[cm.options.scrollbarStyle](function(node) {
       cm.display.wrapper.insertBefore(node, cm.display.scrollbarFiller);
       // Prevent clicks in the scrollbars from killing focus
       on(node, "mousedown", function() {
         if (cm.state.focused) setTimeout(function() { cm.display.input.focus(); }, 0);
       });
       node.setAttribute("cm-not-content", "true");
     }, function(pos, axis) {
       if (axis == "horizontal") setScrollLeft(cm, pos);
       else setScrollTop(cm, pos);
     }, cm);
     if (cm.display.scrollbars.addClass)
       addClass(cm.display.wrapper, cm.display.scrollbars.addClass);
   }
 
   function updateScrollbars(cm, measure) {
     if (!measure) measure = measureForScrollbars(cm);
     var startWidth = cm.display.barWidth, startHeight = cm.display.barHeight;
     updateScrollbarsInner(cm, measure);
     for (var i = 0; i < 4 && startWidth != cm.display.barWidth || startHeight != cm.display.barHeight; i++) {
       if (startWidth != cm.display.barWidth && cm.options.lineWrapping)
         updateHeightsInViewport(cm);
       updateScrollbarsInner(cm, measureForScrollbars(cm));
       startWidth = cm.display.barWidth; startHeight = cm.display.barHeight;
     }
   }
 
   // Re-synchronize the fake scrollbars with the actual size of the
   // content.
   function updateScrollbarsInner(cm, measure) {
     var d = cm.display;
     var sizes = d.scrollbars.update(measure);
 
     d.sizer.style.paddingRight = (d.barWidth = sizes.right) + "px";
     d.sizer.style.paddingBottom = (d.barHeight = sizes.bottom) + "px";
     d.heightForcer.style.borderBottom = sizes.bottom + "px solid transparent"
 
     if (sizes.right && sizes.bottom) {
       d.scrollbarFiller.style.display = "block";
       d.scrollbarFiller.style.height = sizes.bottom + "px";
       d.scrollbarFiller.style.width = sizes.right + "px";
     } else d.scrollbarFiller.style.display = "";
     if (sizes.bottom && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {
       d.gutterFiller.style.display = "block";
       d.gutterFiller.style.height = sizes.bottom + "px";
       d.gutterFiller.style.width = measure.gutterWidth + "px";
     } else d.gutterFiller.style.display = "";
   }
 
   // Compute the lines that are visible in a given viewport (defaults
   // the the current scroll position). viewport may contain top,
   // height, and ensure (see op.scrollToPos) properties.
   function visibleLines(display, doc, viewport) {
     var top = viewport && viewport.top != null ? Math.max(0, viewport.top) : display.scroller.scrollTop;
     top = Math.floor(top - paddingTop(display));
     var bottom = viewport && viewport.bottom != null ? viewport.bottom : top + display.wrapper.clientHeight;
 
     var from = lineAtHeight(doc, top), to = lineAtHeight(doc, bottom);
     // Ensure is a {from: {line, ch}, to: {line, ch}} object, and
     // forces those lines into the viewport (if possible).
     if (viewport && viewport.ensure) {
       var ensureFrom = viewport.ensure.from.line, ensureTo = viewport.ensure.to.line;
       if (ensureFrom < from) {
         from = ensureFrom;
         to = lineAtHeight(doc, heightAtLine(getLine(doc, ensureFrom)) + display.wrapper.clientHeight);
       } else if (Math.min(ensureTo, doc.lastLine()) >= to) {
         from = lineAtHeight(doc, heightAtLine(getLine(doc, ensureTo)) - display.wrapper.clientHeight);
         to = ensureTo;
       }
     }
     return {from: from, to: Math.max(to, from + 1)};
   }
 
   // LINE NUMBERS
 
   // Re-align line numbers and gutter marks to compensate for
   // horizontal scrolling.
   function alignHorizontally(cm) {
     var display = cm.display, view = display.view;
     if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) return;
     var comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft;
     var gutterW = display.gutters.offsetWidth, left = comp + "px";
     for (var i = 0; i < view.length; i++) if (!view[i].hidden) {
       if (cm.options.fixedGutter && view[i].gutter)
         view[i].gutter.style.left = left;
       var align = view[i].alignable;
       if (align) for (var j = 0; j < align.length; j++)
         align[j].style.left = left;
     }
     if (cm.options.fixedGutter)
       display.gutters.style.left = (comp + gutterW) + "px";
   }
 
   // Used to ensure that the line number gutter is still the right
   // size for the current document size. Returns true when an update
   // is needed.
   function maybeUpdateLineNumberWidth(cm) {
     if (!cm.options.lineNumbers) return false;
     var doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display;
     if (last.length != display.lineNumChars) {
       var test = display.measure.appendChild(elt("div", [elt("div", last)],
                                                  "CodeMirror-linenumber CodeMirror-gutter-elt"));
       var innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW;
       display.lineGutter.style.width = "";
       display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding) + 1;
       display.lineNumWidth = display.lineNumInnerWidth + padding;
       display.lineNumChars = display.lineNumInnerWidth ? last.length : -1;
       display.lineGutter.style.width = display.lineNumWidth + "px";
       updateGutterSpace(cm);
       return true;
     }
     return false;
   }
 
   function lineNumberFor(options, i) {
     return String(options.lineNumberFormatter(i + options.firstLineNumber));
   }
 
   // Computes display.scroller.scrollLeft + display.gutters.offsetWidth,
   // but using getBoundingClientRect to get a sub-pixel-accurate
   // result.
   function compensateForHScroll(display) {
     return display.scroller.getBoundingClientRect().left - display.sizer.getBoundingClientRect().left;
   }
 
   // DISPLAY DRAWING
 
   function DisplayUpdate(cm, viewport, force) {
     var display = cm.display;
 
     this.viewport = viewport;
     // Store some values that we'll need later (but don't want to force a relayout for)
     this.visible = visibleLines(display, cm.doc, viewport);
     this.editorIsHidden = !display.wrapper.offsetWidth;
     this.wrapperHeight = display.wrapper.clientHeight;
     this.wrapperWidth = display.wrapper.clientWidth;
     this.oldDisplayWidth = displayWidth(cm);
     this.force = force;
     this.dims = getDimensions(cm);
     this.events = [];
   }
 
   DisplayUpdate.prototype.signal = function(emitter, type) {
     if (hasHandler(emitter, type))
       this.events.push(arguments);
   };
   DisplayUpdate.prototype.finish = function() {
     for (var i = 0; i < this.events.length; i++)
       signal.apply(null, this.events[i]);
   };
 
   function maybeClipScrollbars(cm) {
     var display = cm.display;
     if (!display.scrollbarsClipped && display.scroller.offsetWidth) {
       display.nativeBarWidth = display.scroller.offsetWidth - display.scroller.clientWidth;
       display.heightForcer.style.height = scrollGap(cm) + "px";
       display.sizer.style.marginBottom = -display.nativeBarWidth + "px";
       display.sizer.style.borderRightWidth = scrollGap(cm) + "px";
       display.scrollbarsClipped = true;
     }
   }
 
   // Does the actual updating of the line display. Bails out
   // (returning false) when there is nothing to be done and forced is
   // false.
   function updateDisplayIfNeeded(cm, update) {
     var display = cm.display, doc = cm.doc;
 
     if (update.editorIsHidden) {
       resetView(cm);
       return false;
     }
 
     // Bail out if the visible area is already rendered and nothing changed.
     if (!update.force &&
         update.visible.from >= display.viewFrom && update.visible.to <= display.viewTo &&
         (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo) &&
         display.renderedView == display.view && countDirtyView(cm) == 0)
       return false;
 
     if (maybeUpdateLineNumberWidth(cm)) {
       resetView(cm);
       update.dims = getDimensions(cm);
     }
 
     // Compute a suitable new viewport (from & to)
     var end = doc.first + doc.size;
     var from = Math.max(update.visible.from - cm.options.viewportMargin, doc.first);
     var to = Math.min(end, update.visible.to + cm.options.viewportMargin);
     if (display.viewFrom < from && from - display.viewFrom < 20) from = Math.max(doc.first, display.viewFrom);
     if (display.viewTo > to && display.viewTo - to < 20) to = Math.min(end, display.viewTo);
     if (sawCollapsedSpans) {
       from = visualLineNo(cm.doc, from);
       to = visualLineEndNo(cm.doc, to);
     }
 
     var different = from != display.viewFrom || to != display.viewTo ||
       display.lastWrapHeight != update.wrapperHeight || display.lastWrapWidth != update.wrapperWidth;
     adjustView(cm, from, to);
 
     display.viewOffset = heightAtLine(getLine(cm.doc, display.viewFrom));
     // Position the mover div to align with the current scroll position
     cm.display.mover.style.top = display.viewOffset + "px";
 
     var toUpdate = countDirtyView(cm);
     if (!different && toUpdate == 0 && !update.force && display.renderedView == display.view &&
         (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo))
       return false;
 
     // For big changes, we hide the enclosing element during the
     // update, since that speeds up the operations on most browsers.
     var focused = activeElt();
     if (toUpdate > 4) display.lineDiv.style.display = "none";
     patchDisplay(cm, display.updateLineNumbers, update.dims);
     if (toUpdate > 4) display.lineDiv.style.display = "";
     display.renderedView = display.view;
     // There might have been a widget with a focused element that got
     // hidden or updated, if so re-focus it.
     if (focused && activeElt() != focused && focused.offsetHeight) focused.focus();
 
     // Prevent selection and cursors from interfering with the scroll
     // width and height.
     removeChildren(display.cursorDiv);
     removeChildren(display.selectionDiv);
     display.gutters.style.height = display.sizer.style.minHeight = 0;
 
     if (different) {
       display.lastWrapHeight = update.wrapperHeight;
       display.lastWrapWidth = update.wrapperWidth;
       startWorker(cm, 400);
     }
 
     display.updateLineNumbers = null;
 
     return true;
   }
 
   function postUpdateDisplay(cm, update) {
     var viewport = update.viewport;
 
     for (var first = true;; first = false) {
       if (!first || !cm.options.lineWrapping || update.oldDisplayWidth == displayWidth(cm)) {
         // Clip forced viewport to actual scrollable area.
         if (viewport && viewport.top != null)
           viewport = {top: Math.min(cm.doc.height + paddingVert(cm.display) - displayHeight(cm), viewport.top)};
         // Updated line heights might result in the drawn area not
         // actually covering the viewport. Keep looping until it does.
         update.visible = visibleLines(cm.display, cm.doc, viewport);
         if (update.visible.from >= cm.display.viewFrom && update.visible.to <= cm.display.viewTo)
           break;
       }
       if (!updateDisplayIfNeeded(cm, update)) break;
       updateHeightsInViewport(cm);
       var barMeasure = measureForScrollbars(cm);
       updateSelection(cm);
       updateScrollbars(cm, barMeasure);
       setDocumentHeight(cm, barMeasure);
     }
 
     update.signal(cm, "update", cm);
     if (cm.display.viewFrom != cm.display.reportedViewFrom || cm.display.viewTo != cm.display.reportedViewTo) {
       update.signal(cm, "viewportChange", cm, cm.display.viewFrom, cm.display.viewTo);
       cm.display.reportedViewFrom = cm.display.viewFrom; cm.display.reportedViewTo = cm.display.viewTo;
     }
   }
 
   function updateDisplaySimple(cm, viewport) {
     var update = new DisplayUpdate(cm, viewport);
     if (updateDisplayIfNeeded(cm, update)) {
       updateHeightsInViewport(cm);
       postUpdateDisplay(cm, update);
       var barMeasure = measureForScrollbars(cm);
       updateSelection(cm);
       updateScrollbars(cm, barMeasure);
       setDocumentHeight(cm, barMeasure);
       update.finish();
     }
   }
 
   function setDocumentHeight(cm, measure) {
     cm.display.sizer.style.minHeight = measure.docHeight + "px";
     cm.display.heightForcer.style.top = measure.docHeight + "px";
     cm.display.gutters.style.height = (measure.docHeight + cm.display.barHeight + scrollGap(cm)) + "px";
   }
 
   // Read the actual heights of the rendered lines, and update their
   // stored heights to match.
   function updateHeightsInViewport(cm) {
     var display = cm.display;
     var prevBottom = display.lineDiv.offsetTop;
     for (var i = 0; i < display.view.length; i++) {
       var cur = display.view[i], height;
       if (cur.hidden) continue;
       if (ie && ie_version < 8) {
         var bot = cur.node.offsetTop + cur.node.offsetHeight;
         height = bot - prevBottom;
         prevBottom = bot;
       } else {
         var box = cur.node.getBoundingClientRect();
         height = box.bottom - box.top;
       }
       var diff = cur.line.height - height;
       if (height < 2) height = textHeight(display);
       if (diff > .001 || diff < -.001) {
         updateLineHeight(cur.line, height);
         updateWidgetHeight(cur.line);
         if (cur.rest) for (var j = 0; j < cur.rest.length; j++)
           updateWidgetHeight(cur.rest[j]);
       }
     }
   }
 
   // Read and store the height of line widgets associated with the
   // given line.
   function updateWidgetHeight(line) {
     if (line.widgets) for (var i = 0; i < line.widgets.length; ++i)
       line.widgets[i].height = line.widgets[i].node.parentNode.offsetHeight;
   }
 
   // Do a bulk-read of the DOM positions and sizes needed to draw the
   // view, so that we don't interleave reading and writing to the DOM.
   function getDimensions(cm) {
     var d = cm.display, left = {}, width = {};
     var gutterLeft = d.gutters.clientLeft;
     for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {
       left[cm.options.gutters[i]] = n.offsetLeft + n.clientLeft + gutterLeft;
       width[cm.options.gutters[i]] = n.clientWidth;
     }
     return {fixedPos: compensateForHScroll(d),
             gutterTotalWidth: d.gutters.offsetWidth,
             gutterLeft: left,
             gutterWidth: width,
             wrapperWidth: d.wrapper.clientWidth};
   }
 
   // Sync the actual display DOM structure with display.view, removing
   // nodes for lines that are no longer in view, and creating the ones
   // that are not there yet, and updating the ones that are out of
   // date.
   function patchDisplay(cm, updateNumbersFrom, dims) {
     var display = cm.display, lineNumbers = cm.options.lineNumbers;
     var container = display.lineDiv, cur = container.firstChild;
 
     function rm(node) {
       var next = node.nextSibling;
       // Works around a throw-scroll bug in OS X Webkit
       if (webkit && mac && cm.display.currentWheelTarget == node)
         node.style.display = "none";
       else
         node.parentNode.removeChild(node);
       return next;
     }
 
     var view = display.view, lineN = display.viewFrom;
     // Loop over the elements in the view, syncing cur (the DOM nodes
     // in display.lineDiv) with the view as we go.
     for (var i = 0; i < view.length; i++) {
       var lineView = view[i];
       if (lineView.hidden) {
       } else if (!lineView.node || lineView.node.parentNode != container) { // Not drawn yet
         var node = buildLineElement(cm, lineView, lineN, dims);
         container.insertBefore(node, cur);
       } else { // Already drawn
         while (cur != lineView.node) cur = rm(cur);
         var updateNumber = lineNumbers && updateNumbersFrom != null &&
           updateNumbersFrom <= lineN && lineView.lineNumber;
         if (lineView.changes) {
           if (indexOf(lineView.changes, "gutter") > -1) updateNumber = false;
           updateLineForChanges(cm, lineView, lineN, dims);
         }
         if (updateNumber) {
           removeChildren(lineView.lineNumber);
           lineView.lineNumber.appendChild(document.createTextNode(lineNumberFor(cm.options, lineN)));
         }
         cur = lineView.node.nextSibling;
       }
       lineN += lineView.size;
     }
     while (cur) cur = rm(cur);
   }
 
   // When an aspect of a line changes, a string is added to
   // lineView.changes. This updates the relevant part of the line's
   // DOM structure.
   function updateLineForChanges(cm, lineView, lineN, dims) {
     for (var j = 0; j < lineView.changes.length; j++) {
       var type = lineView.changes[j];
       if (type == "text") updateLineText(cm, lineView);
       else if (type == "gutter") updateLineGutter(cm, lineView, lineN, dims);
       else if (type == "class") updateLineClasses(lineView);
       else if (type == "widget") updateLineWidgets(cm, lineView, dims);
     }
     lineView.changes = null;
   }
 
   // Lines with gutter elements, widgets or a background class need to
   // be wrapped, and have the extra elements added to the wrapper div
   function ensureLineWrapped(lineView) {
     if (lineView.node == lineView.text) {
       lineView.node = elt("div", null, null, "position: relative");
       if (lineView.text.parentNode)
         lineView.text.parentNode.replaceChild(lineView.node, lineView.text);
       lineView.node.appendChild(lineView.text);
       if (ie && ie_version < 8) lineView.node.style.zIndex = 2;
     }
     return lineView.node;
   }
 
   function updateLineBackground(lineView) {
     var cls = lineView.bgClass ? lineView.bgClass + " " + (lineView.line.bgClass || "") : lineView.line.bgClass;
     if (cls) cls += " CodeMirror-linebackground";
     if (lineView.background) {
       if (cls) lineView.background.className = cls;
       else { lineView.background.parentNode.removeChild(lineView.background); lineView.background = null; }
     } else if (cls) {
       var wrap = ensureLineWrapped(lineView);
       lineView.background = wrap.insertBefore(elt("div", null, cls), wrap.firstChild);
     }
   }
 
   // Wrapper around buildLineContent which will reuse the structure
   // in display.externalMeasured when possible.
   function getLineContent(cm, lineView) {
     var ext = cm.display.externalMeasured;
     if (ext && ext.line == lineView.line) {
       cm.display.externalMeasured = null;
       lineView.measure = ext.measure;
       return ext.built;
     }
     return buildLineContent(cm, lineView);
   }
 
   // Redraw the line's text. Interacts with the background and text
   // classes because the mode may output tokens that influence these
   // classes.
   function updateLineText(cm, lineView) {
     var cls = lineView.text.className;
     var built = getLineContent(cm, lineView);
     if (lineView.text == lineView.node) lineView.node = built.pre;
     lineView.text.parentNode.replaceChild(built.pre, lineView.text);
     lineView.text = built.pre;
     if (built.bgClass != lineView.bgClass || built.textClass != lineView.textClass) {
       lineView.bgClass = built.bgClass;
       lineView.textClass = built.textClass;
       updateLineClasses(lineView);
     } else if (cls) {
       lineView.text.className = cls;
     }
   }
 
   function updateLineClasses(lineView) {
     updateLineBackground(lineView);
     if (lineView.line.wrapClass)
       ensureLineWrapped(lineView).className = lineView.line.wrapClass;
     else if (lineView.node != lineView.text)
       lineView.node.className = "";
     var textClass = lineView.textClass ? lineView.textClass + " " + (lineView.line.textClass || "") : lineView.line.textClass;
     lineView.text.className = textClass || "";
   }
 
   function updateLineGutter(cm, lineView, lineN, dims) {
     if (lineView.gutter) {
       lineView.node.removeChild(lineView.gutter);
       lineView.gutter = null;
     }
     if (lineView.gutterBackground) {
       lineView.node.removeChild(lineView.gutterBackground);
       lineView.gutterBackground = null;
     }
     if (lineView.line.gutterClass) {
       var wrap = ensureLineWrapped(lineView);
       lineView.gutterBackground = elt("div", null, "CodeMirror-gutter-background " + lineView.line.gutterClass,
                                       "left: " + (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) +
                                       "px; width: " + dims.gutterTotalWidth + "px");
       wrap.insertBefore(lineView.gutterBackground, lineView.text);
     }
     var markers = lineView.line.gutterMarkers;
     if (cm.options.lineNumbers || markers) {
       var wrap = ensureLineWrapped(lineView);
       var gutterWrap = lineView.gutter = elt("div", null, "CodeMirror-gutter-wrapper", "left: " +
                                              (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + "px");
       cm.display.input.setUneditable(gutterWrap);
       wrap.insertBefore(gutterWrap, lineView.text);
       if (lineView.line.gutterClass)
         gutterWrap.className += " " + lineView.line.gutterClass;
       if (cm.options.lineNumbers && (!markers || !markers["CodeMirror-linenumbers"]))
         lineView.lineNumber = gutterWrap.appendChild(
           elt("div", lineNumberFor(cm.options, lineN),
               "CodeMirror-linenumber CodeMirror-gutter-elt",
               "left: " + dims.gutterLeft["CodeMirror-linenumbers"] + "px; width: "
               + cm.display.lineNumInnerWidth + "px"));
       if (markers) for (var k = 0; k < cm.options.gutters.length; ++k) {
         var id = cm.options.gutters[k], found = markers.hasOwnProperty(id) && markers[id];
         if (found)
           gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt", "left: " +
                                      dims.gutterLeft[id] + "px; width: " + dims.gutterWidth[id] + "px"));
       }
     }
   }
 
   function updateLineWidgets(cm, lineView, dims) {
     if (lineView.alignable) lineView.alignable = null;
     for (var node = lineView.node.firstChild, next; node; node = next) {
       var next = node.nextSibling;
       if (node.className == "CodeMirror-linewidget")
         lineView.node.removeChild(node);
     }
     insertLineWidgets(cm, lineView, dims);
   }
 
   // Build a line's DOM representation from scratch
   function buildLineElement(cm, lineView, lineN, dims) {
     var built = getLineContent(cm, lineView);
     lineView.text = lineView.node = built.pre;
     if (built.bgClass) lineView.bgClass = built.bgClass;
     if (built.textClass) lineView.textClass = built.textClass;
 
     updateLineClasses(lineView);
     updateLineGutter(cm, lineView, lineN, dims);
     insertLineWidgets(cm, lineView, dims);
     return lineView.node;
   }
 
   // A lineView may contain multiple logical lines (when merged by
   // collapsed spans). The widgets for all of them need to be drawn.
   function insertLineWidgets(cm, lineView, dims) {
     insertLineWidgetsFor(cm, lineView.line, lineView, dims, true);
     if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)
       insertLineWidgetsFor(cm, lineView.rest[i], lineView, dims, false);
   }
 
   function insertLineWidgetsFor(cm, line, lineView, dims, allowAbove) {
     if (!line.widgets) return;
     var wrap = ensureLineWrapped(lineView);
     for (var i = 0, ws = line.widgets; i < ws.length; ++i) {
       var widget = ws[i], node = elt("div", [widget.node], "CodeMirror-linewidget");
       if (!widget.handleMouseEvents) node.setAttribute("cm-ignore-events", "true");
       positionLineWidget(widget, node, lineView, dims);
       cm.display.input.setUneditable(node);
       if (allowAbove && widget.above)
         wrap.insertBefore(node, lineView.gutter || lineView.text);
       else
         wrap.appendChild(node);
       signalLater(widget, "redraw");
     }
   }
 
   function positionLineWidget(widget, node, lineView, dims) {
     if (widget.noHScroll) {
       (lineView.alignable || (lineView.alignable = [])).push(node);
       var width = dims.wrapperWidth;
       node.style.left = dims.fixedPos + "px";
       if (!widget.coverGutter) {
         width -= dims.gutterTotalWidth;
         node.style.paddingLeft = dims.gutterTotalWidth + "px";
       }
       node.style.width = width + "px";
     }
     if (widget.coverGutter) {
       node.style.zIndex = 5;
       node.style.position = "relative";
       if (!widget.noHScroll) node.style.marginLeft = -dims.gutterTotalWidth + "px";
     }
   }
 
   // POSITION OBJECT
 
   // A Pos instance represents a position within the text.
   var Pos = CodeMirror.Pos = function(line, ch) {
     if (!(this instanceof Pos)) return new Pos(line, ch);
     this.line = line; this.ch = ch;
   };
 
   // Compare two positions, return 0 if they are the same, a negative
   // number when a is less, and a positive number otherwise.
   var cmp = CodeMirror.cmpPos = function(a, b) { return a.line - b.line || a.ch - b.ch; };
 
   function copyPos(x) {return Pos(x.line, x.ch);}
   function maxPos(a, b) { return cmp(a, b) < 0 ? b : a; }
   function minPos(a, b) { return cmp(a, b) < 0 ? a : b; }
 
   // INPUT HANDLING
 
   function ensureFocus(cm) {
     if (!cm.state.focused) { cm.display.input.focus(); onFocus(cm); }
   }
 
   // This will be set to a {lineWise: bool, text: [string]} object, so
   // that, when pasting, we know what kind of selections the copied
   // text was made out of.
   var lastCopied = null;
 
   function applyTextInput(cm, inserted, deleted, sel, origin) {
     var doc = cm.doc;
     cm.display.shift = false;
     if (!sel) sel = doc.sel;
 
     var paste = cm.state.pasteIncoming || origin == "paste";
     var textLines = doc.splitLines(inserted), multiPaste = null
     // When pasing N lines into N selections, insert one line per selection
     if (paste && sel.ranges.length > 1) {
       if (lastCopied && lastCopied.text.join("\n") == inserted) {
         if (sel.ranges.length % lastCopied.text.length == 0) {
           multiPaste = [];
           for (var i = 0; i < lastCopied.text.length; i++)
             multiPaste.push(doc.splitLines(lastCopied.text[i]));
         }
       } else if (textLines.length == sel.ranges.length) {
         multiPaste = map(textLines, function(l) { return [l]; });
       }
     }
 
     // Normal behavior is to insert the new text into every selection
     for (var i = sel.ranges.length - 1; i >= 0; i--) {
       var range = sel.ranges[i];
       var from = range.from(), to = range.to();
       if (range.empty()) {
         if (deleted && deleted > 0) // Handle deletion
           from = Pos(from.line, from.ch - deleted);
         else if (cm.state.overwrite && !paste) // Handle overwrite
           to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + lst(textLines).length));
         else if (lastCopied && lastCopied.lineWise && lastCopied.text.join("\n") == inserted)
           from = to = Pos(from.line, 0)
       }
       var updateInput = cm.curOp.updateInput;
       var changeEvent = {from: from, to: to, text: multiPaste ? multiPaste[i % multiPaste.length] : textLines,
                          origin: origin || (paste ? "paste" : cm.state.cutIncoming ? "cut" : "+input")};
       makeChange(cm.doc, changeEvent);
       signalLater(cm, "inputRead", cm, changeEvent);
     }
     if (inserted && !paste)
       triggerElectric(cm, inserted);
 
     ensureCursorVisible(cm);
     cm.curOp.updateInput = updateInput;
     cm.curOp.typing = true;
     cm.state.pasteIncoming = cm.state.cutIncoming = false;
   }
 
   function handlePaste(e, cm) {
     var pasted = e.clipboardData && e.clipboardData.getData("text/plain");
     if (pasted) {
       e.preventDefault();
       if (!cm.isReadOnly() && !cm.options.disableInput)
         runInOp(cm, function() { applyTextInput(cm, pasted, 0, null, "paste"); });
       return true;
     }
   }
 
   function triggerElectric(cm, inserted) {
     // When an 'electric' character is inserted, immediately trigger a reindent
     if (!cm.options.electricChars || !cm.options.smartIndent) return;
     var sel = cm.doc.sel;
 
     for (var i = sel.ranges.length - 1; i >= 0; i--) {
       var range = sel.ranges[i];
       if (range.head.ch > 100 || (i && sel.ranges[i - 1].head.line == range.head.line)) continue;
       var mode = cm.getModeAt(range.head);
       var indented = false;
       if (mode.electricChars) {
         for (var j = 0; j < mode.electricChars.length; j++)
           if (inserted.indexOf(mode.electricChars.charAt(j)) > -1) {
             indented = indentLine(cm, range.head.line, "smart");
             break;
           }
       } else if (mode.electricInput) {
         if (mode.electricInput.test(getLine(cm.doc, range.head.line).text.slice(0, range.head.ch)))
           indented = indentLine(cm, range.head.line, "smart");
       }
       if (indented) signalLater(cm, "electricInput", cm, range.head.line);
     }
   }
 
   function copyableRanges(cm) {
     var text = [], ranges = [];
     for (var i = 0; i < cm.doc.sel.ranges.length; i++) {
       var line = cm.doc.sel.ranges[i].head.line;
       var lineRange = {anchor: Pos(line, 0), head: Pos(line + 1, 0)};
       ranges.push(lineRange);
       text.push(cm.getRange(lineRange.anchor, lineRange.head));
     }
     return {text: text, ranges: ranges};
   }
 
   function disableBrowserMagic(field) {
     field.setAttribute("autocorrect", "off");
     field.setAttribute("autocapitalize", "off");
     field.setAttribute("spellcheck", "false");
   }
 
   // TEXTAREA INPUT STYLE
 
   function TextareaInput(cm) {
     this.cm = cm;
     // See input.poll and input.reset
     this.prevInput = "";
 
     // Flag that indicates whether we expect input to appear real soon
     // now (after some event like 'keypress' or 'input') and are
     // polling intensively.
     this.pollingFast = false;
     // Self-resetting timeout for the poller
     this.polling = new Delayed();
     // Tracks when input.reset has punted to just putting a short
     // string into the textarea instead of the full selection.
     this.inaccurateSelection = false;
     // Used to work around IE issue with selection being forgotten when focus moves away from textarea
     this.hasSelection = false;
     this.composing = null;
   };
 
   function hiddenTextarea() {
     var te = elt("textarea", null, null, "position: absolute; padding: 0; width: 1px; height: 1em; outline: none");
     var div = elt("div", [te], null, "overflow: hidden; position: relative; width: 3px; height: 0px;");
     // The textarea is kept positioned near the cursor to prevent the
     // fact that it'll be scrolled into view on input from scrolling
     // our fake cursor out of view. On webkit, when wrap=off, paste is
     // very slow. So make the area wide instead.
     if (webkit) te.style.width = "1000px";
     else te.setAttribute("wrap", "off");
     // If border: 0; -- iOS fails to open keyboard (issue #1287)
     if (ios) te.style.border = "1px solid black";
     disableBrowserMagic(te);
     return div;
   }
 
   TextareaInput.prototype = copyObj({
     init: function(display) {
       var input = this, cm = this.cm;
 
       // Wraps and hides input textarea
       var div = this.wrapper = hiddenTextarea();
       // The semihidden textarea that is focused when the editor is
       // focused, and receives input.
       var te = this.textarea = div.firstChild;
       display.wrapper.insertBefore(div, display.wrapper.firstChild);
 
       // Needed to hide big blue blinking cursor on Mobile Safari (doesn't seem to work in iOS 8 anymore)
       if (ios) te.style.width = "0px";
 
       on(te, "input", function() {
         if (ie && ie_version >= 9 && input.hasSelection) input.hasSelection = null;
         input.poll();
       });
 
       on(te, "paste", function(e) {
         if (signalDOMEvent(cm, e) || handlePaste(e, cm)) return
 
         cm.state.pasteIncoming = true;
         input.fastPoll();
       });
 
       function prepareCopyCut(e) {
         if (signalDOMEvent(cm, e)) return
         if (cm.somethingSelected()) {
           lastCopied = {lineWise: false, text: cm.getSelections()};
           if (input.inaccurateSelection) {
             input.prevInput = "";
             input.inaccurateSelection = false;
             te.value = lastCopied.text.join("\n");
             selectInput(te);
           }
         } else if (!cm.options.lineWiseCopyCut) {
           return;
         } else {
           var ranges = copyableRanges(cm);
           lastCopied = {lineWise: true, text: ranges.text};
           if (e.type == "cut") {
             cm.setSelections(ranges.ranges, null, sel_dontScroll);
           } else {
             input.prevInput = "";
             te.value = ranges.text.join("\n");
             selectInput(te);
           }
         }
         if (e.type == "cut") cm.state.cutIncoming = true;
       }
       on(te, "cut", prepareCopyCut);
       on(te, "copy", prepareCopyCut);
 
       on(display.scroller, "paste", function(e) {
         if (eventInWidget(display, e) || signalDOMEvent(cm, e)) return;
         cm.state.pasteIncoming = true;
         input.focus();
       });
 
       // Prevent normal selection in the editor (we handle our own)
       on(display.lineSpace, "selectstart", function(e) {
         if (!eventInWidget(display, e)) e_preventDefault(e);
       });
 
       on(te, "compositionstart", function() {
         var start = cm.getCursor("from");
         if (input.composing) input.composing.range.clear()
         input.composing = {
           start: start,
           range: cm.markText(start, cm.getCursor("to"), {className: "CodeMirror-composing"})
         };
       });
       on(te, "compositionend", function() {
         if (input.composing) {
           input.poll();
           input.composing.range.clear();
           input.composing = null;
         }
       });
     },
 
     prepareSelection: function() {
       // Redraw the selection and/or cursor
       var cm = this.cm, display = cm.display, doc = cm.doc;
       var result = prepareSelection(cm);
 
       // Move the hidden textarea near the cursor to prevent scrolling artifacts
       if (cm.options.moveInputWithCursor) {
         var headPos = cursorCoords(cm, doc.sel.primary().head, "div");
         var wrapOff = display.wrapper.getBoundingClientRect(), lineOff = display.lineDiv.getBoundingClientRect();
         result.teTop = Math.max(0, Math.min(display.wrapper.clientHeight - 10,
                                             headPos.top + lineOff.top - wrapOff.top));
         result.teLeft = Math.max(0, Math.min(display.wrapper.clientWidth - 10,
                                              headPos.left + lineOff.left - wrapOff.left));
       }
 
       return result;
     },
 
     showSelection: function(drawn) {
       var cm = this.cm, display = cm.display;
       removeChildrenAndAdd(display.cursorDiv, drawn.cursors);
       removeChildrenAndAdd(display.selectionDiv, drawn.selection);
       if (drawn.teTop != null) {
         this.wrapper.style.top = drawn.teTop + "px";
         this.wrapper.style.left = drawn.teLeft + "px";
       }
     },
 
     // Reset the input to correspond to the selection (or to be empty,
     // when not typing and nothing is selected)
     reset: function(typing) {
       if (this.contextMenuPending) return;
       var minimal, selected, cm = this.cm, doc = cm.doc;
       if (cm.somethingSelected()) {
         this.prevInput = "";
         var range = doc.sel.primary();
         minimal = hasCopyEvent &&
           (range.to().line - range.from().line > 100 || (selected = cm.getSelection()).length > 1000);
         var content = minimal ? "-" : selected || cm.getSelection();
         this.textarea.value = content;
         if (cm.state.focused) selectInput(this.textarea);
         if (ie && ie_version >= 9) this.hasSelection = content;
       } else if (!typing) {
         this.prevInput = this.textarea.value = "";
         if (ie && ie_version >= 9) this.hasSelection = null;
       }
       this.inaccurateSelection = minimal;
     },
 
     getField: function() { return this.textarea; },
 
     supportsTouch: function() { return false; },
 
     focus: function() {
       if (this.cm.options.readOnly != "nocursor" && (!mobile || activeElt() != this.textarea)) {
         try { this.textarea.focus(); }
         catch (e) {} // IE8 will throw if the textarea is display: none or not in DOM
       }
     },
 
     blur: function() { this.textarea.blur(); },
 
     resetPosition: function() {
       this.wrapper.style.top = this.wrapper.style.left = 0;
     },
 
     receivedFocus: function() { this.slowPoll(); },
 
     // Poll for input changes, using the normal rate of polling. This
     // runs as long as the editor is focused.
     slowPoll: function() {
       var input = this;
       if (input.pollingFast) return;
       input.polling.set(this.cm.options.pollInterval, function() {
         input.poll();
         if (input.cm.state.focused) input.slowPoll();
       });
     },
 
     // When an event has just come in that is likely to add or change
     // something in the input textarea, we poll faster, to ensure that
     // the change appears on the screen quickly.
     fastPoll: function() {
       var missed = false, input = this;
       input.pollingFast = true;
       function p() {
         var changed = input.poll();
         if (!changed && !missed) {missed = true; input.polling.set(60, p);}
         else {input.pollingFast = false; input.slowPoll();}
       }
       input.polling.set(20, p);
     },
 
     // Read input from the textarea, and update the document to match.
     // When something is selected, it is present in the textarea, and
     // selected (unless it is huge, in which case a placeholder is
     // used). When nothing is selected, the cursor sits after previously
     // seen text (can be empty), which is stored in prevInput (we must
     // not reset the textarea when typing, because that breaks IME).
     poll: function() {
       var cm = this.cm, input = this.textarea, prevInput = this.prevInput;
       // Since this is called a *lot*, try to bail out as cheaply as
       // possible when it is clear that nothing happened. hasSelection
       // will be the case when there is a lot of text in the textarea,
       // in which case reading its value would be expensive.
       if (this.contextMenuPending || !cm.state.focused ||
           (hasSelection(input) && !prevInput && !this.composing) ||
           cm.isReadOnly() || cm.options.disableInput || cm.state.keySeq)
         return false;
 
       var text = input.value;
       // If nothing changed, bail.
       if (text == prevInput && !cm.somethingSelected()) return false;
       // Work around nonsensical selection resetting in IE9/10, and
       // inexplicable appearance of private area unicode characters on
       // some key combos in Mac (#2689).
       if (ie && ie_version >= 9 && this.hasSelection === text ||
           mac && /[\uf700-\uf7ff]/.test(text)) {
         cm.display.input.reset();
         return false;
       }
 
       if (cm.doc.sel == cm.display.selForContextMenu) {
         var first = text.charCodeAt(0);
         if (first == 0x200b && !prevInput) prevInput = "\u200b";
         if (first == 0x21da) { this.reset(); return this.cm.execCommand("undo"); }
       }
       // Find the part of the input that is actually new
       var same = 0, l = Math.min(prevInput.length, text.length);
       while (same < l && prevInput.charCodeAt(same) == text.charCodeAt(same)) ++same;
 
       var self = this;
       runInOp(cm, function() {
         applyTextInput(cm, text.slice(same), prevInput.length - same,
                        null, self.composing ? "*compose" : null);
 
         // Don't leave long text in the textarea, since it makes further polling slow
         if (text.length > 1000 || text.indexOf("\n") > -1) input.value = self.prevInput = "";
         else self.prevInput = text;
 
         if (self.composing) {
           self.composing.range.clear();
           self.composing.range = cm.markText(self.composing.start, cm.getCursor("to"),
                                              {className: "CodeMirror-composing"});
         }
       });
       return true;
     },
 
     ensurePolled: function() {
       if (this.pollingFast && this.poll()) this.pollingFast = false;
     },
 
     onKeyPress: function() {
       if (ie && ie_version >= 9) this.hasSelection = null;
       this.fastPoll();
     },
 
     onContextMenu: function(e) {
       var input = this, cm = input.cm, display = cm.display, te = input.textarea;
       var pos = posFromMouse(cm, e), scrollPos = display.scroller.scrollTop;
       if (!pos || presto) return; // Opera is difficult.
 
       // Reset the current text selection only if the click is done outside of the selection
       // and 'resetSelectionOnContextMenu' option is true.
       var reset = cm.options.resetSelectionOnContextMenu;
       if (reset && cm.doc.sel.contains(pos) == -1)
         operation(cm, setSelection)(cm.doc, simpleSelection(pos), sel_dontScroll);
 
       var oldCSS = te.style.cssText, oldWrapperCSS = input.wrapper.style.cssText;
       input.wrapper.style.cssText = "position: absolute"
       var wrapperBox = input.wrapper.getBoundingClientRect()
       te.style.cssText = "position: absolute; width: 30px; height: 30px; top: " + (e.clientY - wrapperBox.top - 5) +
         "px; left: " + (e.clientX - wrapperBox.left - 5) + "px; z-index: 1000; background: " +
         (ie ? "rgba(255, 255, 255, .05)" : "transparent") +
         "; outline: none; border-width: 0; outline: none; overflow: hidden; opacity: .05; filter: alpha(opacity=5);";
       if (webkit) var oldScrollY = window.scrollY; // Work around Chrome issue (#2712)
       display.input.focus();
       if (webkit) window.scrollTo(null, oldScrollY);
       display.input.reset();
       // Adds "Select all" to context menu in FF
       if (!cm.somethingSelected()) te.value = input.prevInput = " ";
       input.contextMenuPending = true;
       display.selForContextMenu = cm.doc.sel;
       clearTimeout(display.detectingSelectAll);
 
       // Select-all will be greyed out if there's nothing to select, so
       // this adds a zero-width space so that we can later check whether
       // it got selected.
       function prepareSelectAllHack() {
         if (te.selectionStart != null) {
           var selected = cm.somethingSelected();
           var extval = "\u200b" + (selected ? te.value : "");
           te.value = "\u21da"; // Used to catch context-menu undo
           te.value = extval;
           input.prevInput = selected ? "" : "\u200b";
           te.selectionStart = 1; te.selectionEnd = extval.length;
           // Re-set this, in case some other handler touched the
           // selection in the meantime.
           display.selForContextMenu = cm.doc.sel;
         }
       }
       function rehide() {
         input.contextMenuPending = false;
         input.wrapper.style.cssText = oldWrapperCSS
         te.style.cssText = oldCSS;
         if (ie && ie_version < 9) display.scrollbars.setScrollTop(display.scroller.scrollTop = scrollPos);
 
         // Try to detect the user choosing select-all
         if (te.selectionStart != null) {
           if (!ie || (ie && ie_version < 9)) prepareSelectAllHack();
           var i = 0, poll = function() {
             if (display.selForContextMenu == cm.doc.sel && te.selectionStart == 0 &&
                 te.selectionEnd > 0 && input.prevInput == "\u200b")
               operation(cm, commands.selectAll)(cm);
             else if (i++ < 10) display.detectingSelectAll = setTimeout(poll, 500);
             else display.input.reset();
           };
           display.detectingSelectAll = setTimeout(poll, 200);
         }
       }
 
       if (ie && ie_version >= 9) prepareSelectAllHack();
       if (captureRightClick) {
         e_stop(e);
         var mouseup = function() {
           off(window, "mouseup", mouseup);
           setTimeout(rehide, 20);
         };
         on(window, "mouseup", mouseup);
       } else {
         setTimeout(rehide, 50);
       }
     },
 
     readOnlyChanged: function(val) {
       if (!val) this.reset();
     },
 
     setUneditable: nothing,
 
     needsContentAttribute: false
   }, TextareaInput.prototype);
 
   // CONTENTEDITABLE INPUT STYLE
 
   function ContentEditableInput(cm) {
     this.cm = cm;
     this.lastAnchorNode = this.lastAnchorOffset = this.lastFocusNode = this.lastFocusOffset = null;
     this.polling = new Delayed();
     this.gracePeriod = false;
   }
 
   ContentEditableInput.prototype = copyObj({
     init: function(display) {
       var input = this, cm = input.cm;
       var div = input.div = display.lineDiv;
       disableBrowserMagic(div);
 
       on(div, "paste", function(e) {
         if (!signalDOMEvent(cm, e)) handlePaste(e, cm);
       })
 
       on(div, "compositionstart", function(e) {
         var data = e.data;
         input.composing = {sel: cm.doc.sel, data: data, startData: data};
         if (!data) return;
         var prim = cm.doc.sel.primary();
         var line = cm.getLine(prim.head.line);
         var found = line.indexOf(data, Math.max(0, prim.head.ch - data.length));
         if (found > -1 && found <= prim.head.ch)
           input.composing.sel = simpleSelection(Pos(prim.head.line, found),
                                                 Pos(prim.head.line, found + data.length));
       });
       on(div, "compositionupdate", function(e) {
         input.composing.data = e.data;
       });
       on(div, "compositionend", function(e) {
         var ours = input.composing;
         if (!ours) return;
         if (e.data != ours.startData && !/\u200b/.test(e.data))
           ours.data = e.data;
         // Need a small delay to prevent other code (input event,
         // selection polling) from doing damage when fired right after
         // compositionend.
         setTimeout(function() {
           if (!ours.handled)
             input.applyComposition(ours);
           if (input.composing == ours)
             input.composing = null;
         }, 50);
       });
 
       on(div, "touchstart", function() {
         input.forceCompositionEnd();
       });
 
       on(div, "input", function() {
         if (input.composing) return;
         if (cm.isReadOnly() || !input.pollContent())
           runInOp(input.cm, function() {regChange(cm);});
       });
 
       function onCopyCut(e) {
         if (signalDOMEvent(cm, e)) return
         if (cm.somethingSelected()) {
           lastCopied = {lineWise: false, text: cm.getSelections()};
           if (e.type == "cut") cm.replaceSelection("", null, "cut");
         } else if (!cm.options.lineWiseCopyCut) {
           return;
         } else {
           var ranges = copyableRanges(cm);
           lastCopied = {lineWise: true, text: ranges.text};
           if (e.type == "cut") {
             cm.operation(function() {
               cm.setSelections(ranges.ranges, 0, sel_dontScroll);
               cm.replaceSelection("", null, "cut");
             });
           }
         }
         // iOS exposes the clipboard API, but seems to discard content inserted into it
         if (e.clipboardData && !ios) {
           e.preventDefault();
           e.clipboardData.clearData();
           e.clipboardData.setData("text/plain", lastCopied.text.join("\n"));
         } else {
           // Old-fashioned briefly-focus-a-textarea hack
           var kludge = hiddenTextarea(), te = kludge.firstChild;
           cm.display.lineSpace.insertBefore(kludge, cm.display.lineSpace.firstChild);
           te.value = lastCopied.text.join("\n");
           var hadFocus = document.activeElement;
           selectInput(te);
           setTimeout(function() {
             cm.display.lineSpace.removeChild(kludge);
             hadFocus.focus();
           }, 50);
         }
       }
       on(div, "copy", onCopyCut);
       on(div, "cut", onCopyCut);
     },
 
     prepareSelection: function() {
       var result = prepareSelection(this.cm, false);
       result.focus = this.cm.state.focused;
       return result;
     },
 
     showSelection: function(info, takeFocus) {
       if (!info || !this.cm.display.view.length) return;
       if (info.focus || takeFocus) this.showPrimarySelection();
       this.showMultipleSelections(info);
     },
 
     showPrimarySelection: function() {
       var sel = window.getSelection(), prim = this.cm.doc.sel.primary();
       var curAnchor = domToPos(this.cm, sel.anchorNode, sel.anchorOffset);
       var curFocus = domToPos(this.cm, sel.focusNode, sel.focusOffset);
       if (curAnchor && !curAnchor.bad && curFocus && !curFocus.bad &&
           cmp(minPos(curAnchor, curFocus), prim.from()) == 0 &&
           cmp(maxPos(curAnchor, curFocus), prim.to()) == 0)
         return;
 
       var start = posToDOM(this.cm, prim.from());
       var end = posToDOM(this.cm, prim.to());
       if (!start && !end) return;
 
       var view = this.cm.display.view;
       var old = sel.rangeCount && sel.getRangeAt(0);
       if (!start) {
         start = {node: view[0].measure.map[2], offset: 0};
       } else if (!end) { // FIXME dangerously hacky
         var measure = view[view.length - 1].measure;
         var map = measure.maps ? measure.maps[measure.maps.length - 1] : measure.map;
         end = {node: map[map.length - 1], offset: map[map.length - 2] - map[map.length - 3]};
       }
 
       try { var rng = range(start.node, start.offset, end.offset, end.node); }
       catch(e) {} // Our model of the DOM might be outdated, in which case the range we try to set can be impossible
       if (rng) {
         if (!gecko && this.cm.state.focused) {
           sel.collapse(start.node, start.offset);
           if (!rng.collapsed) sel.addRange(rng);
         } else {
           sel.removeAllRanges();
           sel.addRange(rng);
         }
         if (old && sel.anchorNode == null) sel.addRange(old);
         else if (gecko) this.startGracePeriod();
       }
       this.rememberSelection();
     },
 
     startGracePeriod: function() {
       var input = this;
       clearTimeout(this.gracePeriod);
       this.gracePeriod = setTimeout(function() {
         input.gracePeriod = false;
         if (input.selectionChanged())
           input.cm.operation(function() { input.cm.curOp.selectionChanged = true; });
       }, 20);
     },
 
     showMultipleSelections: function(info) {
       removeChildrenAndAdd(this.cm.display.cursorDiv, info.cursors);
       removeChildrenAndAdd(this.cm.display.selectionDiv, info.selection);
     },
 
     rememberSelection: function() {
       var sel = window.getSelection();
       this.lastAnchorNode = sel.anchorNode; this.lastAnchorOffset = sel.anchorOffset;
       this.lastFocusNode = sel.focusNode; this.lastFocusOffset = sel.focusOffset;
     },
 
     selectionInEditor: function() {
       var sel = window.getSelection();
       if (!sel.rangeCount) return false;
       var node = sel.getRangeAt(0).commonAncestorContainer;
       return contains(this.div, node);
     },
 
     focus: function() {
       if (this.cm.options.readOnly != "nocursor") this.div.focus();
     },
     blur: function() { this.div.blur(); },
     getField: function() { return this.div; },
 
     supportsTouch: function() { return true; },
 
     receivedFocus: function() {
       var input = this;
       if (this.selectionInEditor())
         this.pollSelection();
       else
         runInOp(this.cm, function() { input.cm.curOp.selectionChanged = true; });
 
       function poll() {
         if (input.cm.state.focused) {
           input.pollSelection();
           input.polling.set(input.cm.options.pollInterval, poll);
         }
       }
       this.polling.set(this.cm.options.pollInterval, poll);
     },
 
     selectionChanged: function() {
       var sel = window.getSelection();
       return sel.anchorNode != this.lastAnchorNode || sel.anchorOffset != this.lastAnchorOffset ||
         sel.focusNode != this.lastFocusNode || sel.focusOffset != this.lastFocusOffset;
     },
 
     pollSelection: function() {
       if (!this.composing && !this.gracePeriod && this.selectionChanged()) {
         var sel = window.getSelection(), cm = this.cm;
         this.rememberSelection();
         var anchor = domToPos(cm, sel.anchorNode, sel.anchorOffset);
         var head = domToPos(cm, sel.focusNode, sel.focusOffset);
         if (anchor && head) runInOp(cm, function() {
           setSelection(cm.doc, simpleSelection(anchor, head), sel_dontScroll);
           if (anchor.bad || head.bad) cm.curOp.selectionChanged = true;
         });
       }
     },
 
     pollContent: function() {
       var cm = this.cm, display = cm.display, sel = cm.doc.sel.primary();
       var from = sel.from(), to = sel.to();
       if (from.line < display.viewFrom || to.line > display.viewTo - 1) return false;
 
       var fromIndex;
       if (from.line == display.viewFrom || (fromIndex = findViewIndex(cm, from.line)) == 0) {
         var fromLine = lineNo(display.view[0].line);
         var fromNode = display.view[0].node;
       } else {
         var fromLine = lineNo(display.view[fromIndex].line);
         var fromNode = display.view[fromIndex - 1].node.nextSibling;
       }
       var toIndex = findViewIndex(cm, to.line);
       if (toIndex == display.view.length - 1) {
         var toLine = display.viewTo - 1;
         var toNode = display.lineDiv.lastChild;
       } else {
         var toLine = lineNo(display.view[toIndex + 1].line) - 1;
         var toNode = display.view[toIndex + 1].node.previousSibling;
       }
 
       var newText = cm.doc.splitLines(domTextBetween(cm, fromNode, toNode, fromLine, toLine));
       var oldText = getBetween(cm.doc, Pos(fromLine, 0), Pos(toLine, getLine(cm.doc, toLine).text.length));
       while (newText.length > 1 && oldText.length > 1) {
         if (lst(newText) == lst(oldText)) { newText.pop(); oldText.pop(); toLine--; }
         else if (newText[0] == oldText[0]) { newText.shift(); oldText.shift(); fromLine++; }
         else break;
       }
 
       var cutFront = 0, cutEnd = 0;
       var newTop = newText[0], oldTop = oldText[0], maxCutFront = Math.min(newTop.length, oldTop.length);
       while (cutFront < maxCutFront && newTop.charCodeAt(cutFront) == oldTop.charCodeAt(cutFront))
         ++cutFront;
       var newBot = lst(newText), oldBot = lst(oldText);
       var maxCutEnd = Math.min(newBot.length - (newText.length == 1 ? cutFront : 0),
                                oldBot.length - (oldText.length == 1 ? cutFront : 0));
       while (cutEnd < maxCutEnd &&
              newBot.charCodeAt(newBot.length - cutEnd - 1) == oldBot.charCodeAt(oldBot.length - cutEnd - 1))
         ++cutEnd;
 
       newText[newText.length - 1] = newBot.slice(0, newBot.length - cutEnd);
       newText[0] = newText[0].slice(cutFront);
 
       var chFrom = Pos(fromLine, cutFront);
       var chTo = Pos(toLine, oldText.length ? lst(oldText).length - cutEnd : 0);
       if (newText.length > 1 || newText[0] || cmp(chFrom, chTo)) {
         replaceRange(cm.doc, newText, chFrom, chTo, "+input");
         return true;
       }
     },
 
     ensurePolled: function() {
       this.forceCompositionEnd();
     },
     reset: function() {
       this.forceCompositionEnd();
     },
     forceCompositionEnd: function() {
       if (!this.composing || this.composing.handled) return;
       this.applyComposition(this.composing);
       this.composing.handled = true;
       this.div.blur();
       this.div.focus();
     },
     applyComposition: function(composing) {
       if (this.cm.isReadOnly())
         operation(this.cm, regChange)(this.cm)
       else if (composing.data && composing.data != composing.startData)
         operation(this.cm, applyTextInput)(this.cm, composing.data, 0, composing.sel);
     },
 
     setUneditable: function(node) {
       node.contentEditable = "false"
     },
 
     onKeyPress: function(e) {
       e.preventDefault();
       if (!this.cm.isReadOnly())
         operation(this.cm, applyTextInput)(this.cm, String.fromCharCode(e.charCode == null ? e.keyCode : e.charCode), 0);
     },
 
     readOnlyChanged: function(val) {
       this.div.contentEditable = String(val != "nocursor")
     },
 
     onContextMenu: nothing,
     resetPosition: nothing,
 
     needsContentAttribute: true
   }, ContentEditableInput.prototype);
 
   function posToDOM(cm, pos) {
     var view = findViewForLine(cm, pos.line);
     if (!view || view.hidden) return null;
     var line = getLine(cm.doc, pos.line);
     var info = mapFromLineView(view, line, pos.line);
 
     var order = getOrder(line), side = "left";
     if (order) {
       var partPos = getBidiPartAt(order, pos.ch);
       side = partPos % 2 ? "right" : "left";
     }
     var result = nodeAndOffsetInLineMap(info.map, pos.ch, side);
     result.offset = result.collapse == "right" ? result.end : result.start;
     return result;
   }
 
   function badPos(pos, bad) { if (bad) pos.bad = true; return pos; }
 
   function domToPos(cm, node, offset) {
     var lineNode;
     if (node == cm.display.lineDiv) {
       lineNode = cm.display.lineDiv.childNodes[offset];
       if (!lineNode) return badPos(cm.clipPos(Pos(cm.display.viewTo - 1)), true);
       node = null; offset = 0;
     } else {
       for (lineNode = node;; lineNode = lineNode.parentNode) {
         if (!lineNode || lineNode == cm.display.lineDiv) return null;
         if (lineNode.parentNode && lineNode.parentNode == cm.display.lineDiv) break;
       }
     }
     for (var i = 0; i < cm.display.view.length; i++) {
       var lineView = cm.display.view[i];
       if (lineView.node == lineNode)
         return locateNodeInLineView(lineView, node, offset);
     }
   }
 
   function locateNodeInLineView(lineView, node, offset) {
     var wrapper = lineView.text.firstChild, bad = false;
     if (!node || !contains(wrapper, node)) return badPos(Pos(lineNo(lineView.line), 0), true);
     if (node == wrapper) {
       bad = true;
       node = wrapper.childNodes[offset];
       offset = 0;
       if (!node) {
         var line = lineView.rest ? lst(lineView.rest) : lineView.line;
         return badPos(Pos(lineNo(line), line.text.length), bad);
       }
     }
 
     var textNode = node.nodeType == 3 ? node : null, topNode = node;
     if (!textNode && node.childNodes.length == 1 && node.firstChild.nodeType == 3) {
       textNode = node.firstChild;
       if (offset) offset = textNode.nodeValue.length;
     }
     while (topNode.parentNode != wrapper) topNode = topNode.parentNode;
     var measure = lineView.measure, maps = measure.maps;
 
     function find(textNode, topNode, offset) {
       for (var i = -1; i < (maps ? maps.length : 0); i++) {
         var map = i < 0 ? measure.map : maps[i];
         for (var j = 0; j < map.length; j += 3) {
           var curNode = map[j + 2];
           if (curNode == textNode || curNode == topNode) {
             var line = lineNo(i < 0 ? lineView.line : lineView.rest[i]);
             var ch = map[j] + offset;
             if (offset < 0 || curNode != textNode) ch = map[j + (offset ? 1 : 0)];
             return Pos(line, ch);
           }
         }
       }
     }
     var found = find(textNode, topNode, offset);
     if (found) return badPos(found, bad);
 
     // FIXME this is all really shaky. might handle the few cases it needs to handle, but likely to cause problems
     for (var after = topNode.nextSibling, dist = textNode ? textNode.nodeValue.length - offset : 0; after; after = after.nextSibling) {
       found = find(after, after.firstChild, 0);
       if (found)
         return badPos(Pos(found.line, found.ch - dist), bad);
       else
         dist += after.textContent.length;
     }
     for (var before = topNode.previousSibling, dist = offset; before; before = before.previousSibling) {
       found = find(before, before.firstChild, -1);
       if (found)
         return badPos(Pos(found.line, found.ch + dist), bad);
       else
         dist += after.textContent.length;
     }
   }
 
   function domTextBetween(cm, from, to, fromLine, toLine) {
     var text = "", closing = false, lineSep = cm.doc.lineSeparator();
     function recognizeMarker(id) { return function(marker) { return marker.id == id; }; }
     function walk(node) {
       if (node.nodeType == 1) {
         var cmText = node.getAttribute("cm-text");
         if (cmText != null) {
           if (cmText == "") cmText = node.textContent.replace(/\u200b/g, "");
           text += cmText;
           return;
         }
         var markerID = node.getAttribute("cm-marker"), range;
         if (markerID) {
           var found = cm.findMarks(Pos(fromLine, 0), Pos(toLine + 1, 0), recognizeMarker(+markerID));
           if (found.length && (range = found[0].find()))
             text += getBetween(cm.doc, range.from, range.to).join(lineSep);
           return;
         }
         if (node.getAttribute("contenteditable") == "false") return;
         for (var i = 0; i < node.childNodes.length; i++)
           walk(node.childNodes[i]);
         if (/^(pre|div|p)$/i.test(node.nodeName))
           closing = true;
       } else if (node.nodeType == 3) {
         var val = node.nodeValue;
         if (!val) return;
         if (closing) {
           text += lineSep;
           closing = false;
         }
         text += val;
       }
     }
     for (;;) {
       walk(from);
       if (from == to) break;
       from = from.nextSibling;
     }
     return text;
   }
 
   CodeMirror.inputStyles = {"textarea": TextareaInput, "contenteditable": ContentEditableInput};
 
   // SELECTION / CURSOR
 
   // Selection objects are immutable. A new one is created every time
   // the selection changes. A selection is one or more non-overlapping
   // (and non-touching) ranges, sorted, and an integer that indicates
   // which one is the primary selection (the one that's scrolled into
   // view, that getCursor returns, etc).
   function Selection(ranges, primIndex) {
     this.ranges = ranges;
     this.primIndex = primIndex;
   }
 
   Selection.prototype = {
     primary: function() { return this.ranges[this.primIndex]; },
     equals: function(other) {
       if (other == this) return true;
       if (other.primIndex != this.primIndex || other.ranges.length != this.ranges.length) return false;
       for (var i = 0; i < this.ranges.length; i++) {
         var here = this.ranges[i], there = other.ranges[i];
         if (cmp(here.anchor, there.anchor) != 0 || cmp(here.head, there.head) != 0) return false;
       }
       return true;
     },
     deepCopy: function() {
       for (var out = [], i = 0; i < this.ranges.length; i++)
         out[i] = new Range(copyPos(this.ranges[i].anchor), copyPos(this.ranges[i].head));
       return new Selection(out, this.primIndex);
     },
     somethingSelected: function() {
       for (var i = 0; i < this.ranges.length; i++)
         if (!this.ranges[i].empty()) return true;
       return false;
     },
     contains: function(pos, end) {
       if (!end) end = pos;
       for (var i = 0; i < this.ranges.length; i++) {
         var range = this.ranges[i];
         if (cmp(end, range.from()) >= 0 && cmp(pos, range.to()) <= 0)
           return i;
       }
       return -1;
     }
   };
 
   function Range(anchor, head) {
     this.anchor = anchor; this.head = head;
   }
 
   Range.prototype = {
     from: function() { return minPos(this.anchor, this.head); },
     to: function() { return maxPos(this.anchor, this.head); },
     empty: function() {
       return this.head.line == this.anchor.line && this.head.ch == this.anchor.ch;
     }
   };
 
   // Take an unsorted, potentially overlapping set of ranges, and
   // build a selection out of it. 'Consumes' ranges array (modifying
   // it).
   function normalizeSelection(ranges, primIndex) {
     var prim = ranges[primIndex];
     ranges.sort(function(a, b) { return cmp(a.from(), b.from()); });
     primIndex = indexOf(ranges, prim);
     for (var i = 1; i < ranges.length; i++) {
       var cur = ranges[i], prev = ranges[i - 1];
       if (cmp(prev.to(), cur.from()) >= 0) {
         var from = minPos(prev.from(), cur.from()), to = maxPos(prev.to(), cur.to());
         var inv = prev.empty() ? cur.from() == cur.head : prev.from() == prev.head;
         if (i <= primIndex) --primIndex;
         ranges.splice(--i, 2, new Range(inv ? to : from, inv ? from : to));
       }
     }
     return new Selection(ranges, primIndex);
   }
 
   function simpleSelection(anchor, head) {
     return new Selection([new Range(anchor, head || anchor)], 0);
   }
 
   // Most of the external API clips given positions to make sure they
   // actually exist within the document.
   function clipLine(doc, n) {return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1));}
   function clipPos(doc, pos) {
     if (pos.line < doc.first) return Pos(doc.first, 0);
     var last = doc.first + doc.size - 1;
     if (pos.line > last) return Pos(last, getLine(doc, last).text.length);
     return clipToLen(pos, getLine(doc, pos.line).text.length);
   }
   function clipToLen(pos, linelen) {
     var ch = pos.ch;
     if (ch == null || ch > linelen) return Pos(pos.line, linelen);
     else if (ch < 0) return Pos(pos.line, 0);
     else return pos;
   }
   function isLine(doc, l) {return l >= doc.first && l < doc.first + doc.size;}
   function clipPosArray(doc, array) {
     for (var out = [], i = 0; i < array.length; i++) out[i] = clipPos(doc, array[i]);
     return out;
   }
 
   // SELECTION UPDATES
 
   // The 'scroll' parameter given to many of these indicated whether
   // the new cursor position should be scrolled into view after
   // modifying the selection.
 
   // If shift is held or the extend flag is set, extends a range to
   // include a given position (and optionally a second position).
   // Otherwise, simply returns the range between the given positions.
   // Used for cursor motion and such.
   function extendRange(doc, range, head, other) {
     if (doc.cm && doc.cm.display.shift || doc.extend) {
       var anchor = range.anchor;
       if (other) {
         var posBefore = cmp(head, anchor) < 0;
         if (posBefore != (cmp(other, anchor) < 0)) {
           anchor = head;
           head = other;
         } else if (posBefore != (cmp(head, other) < 0)) {
           head = other;
         }
       }
       return new Range(anchor, head);
     } else {
       return new Range(other || head, head);
     }
   }
 
   // Extend the primary selection range, discard the rest.
   function extendSelection(doc, head, other, options) {
     setSelection(doc, new Selection([extendRange(doc, doc.sel.primary(), head, other)], 0), options);
   }
 
   // Extend all selections (pos is an array of selections with length
   // equal the number of selections)
   function extendSelections(doc, heads, options) {
     for (var out = [], i = 0; i < doc.sel.ranges.length; i++)
       out[i] = extendRange(doc, doc.sel.ranges[i], heads[i], null);
     var newSel = normalizeSelection(out, doc.sel.primIndex);
     setSelection(doc, newSel, options);
   }
 
   // Updates a single range in the selection.
   function replaceOneSelection(doc, i, range, options) {
     var ranges = doc.sel.ranges.slice(0);
     ranges[i] = range;
     setSelection(doc, normalizeSelection(ranges, doc.sel.primIndex), options);
   }
 
   // Reset the selection to a single range.
   function setSimpleSelection(doc, anchor, head, options) {
     setSelection(doc, simpleSelection(anchor, head), options);
   }
 
   // Give beforeSelectionChange handlers a change to influence a
   // selection update.
   function filterSelectionChange(doc, sel, options) {
     var obj = {
       ranges: sel.ranges,
       update: function(ranges) {
         this.ranges = [];
         for (var i = 0; i < ranges.length; i++)
           this.ranges[i] = new Range(clipPos(doc, ranges[i].anchor),
                                      clipPos(doc, ranges[i].head));
       },
       origin: options && options.origin
     };
     signal(doc, "beforeSelectionChange", doc, obj);
     if (doc.cm) signal(doc.cm, "beforeSelectionChange", doc.cm, obj);
     if (obj.ranges != sel.ranges) return normalizeSelection(obj.ranges, obj.ranges.length - 1);
     else return sel;
   }
 
   function setSelectionReplaceHistory(doc, sel, options) {
     var done = doc.history.done, last = lst(done);
     if (last && last.ranges) {
       done[done.length - 1] = sel;
       setSelectionNoUndo(doc, sel, options);
     } else {
       setSelection(doc, sel, options);
     }
   }
 
   // Set a new selection.
   function setSelection(doc, sel, options) {
     setSelectionNoUndo(doc, sel, options);
     addSelectionToHistory(doc, doc.sel, doc.cm ? doc.cm.curOp.id : NaN, options);
   }
 
   function setSelectionNoUndo(doc, sel, options) {
     if (hasHandler(doc, "beforeSelectionChange") || doc.cm && hasHandler(doc.cm, "beforeSelectionChange"))
       sel = filterSelectionChange(doc, sel, options);
 
     var bias = options && options.bias ||
       (cmp(sel.primary().head, doc.sel.primary().head) < 0 ? -1 : 1);
     setSelectionInner(doc, skipAtomicInSelection(doc, sel, bias, true));
 
     if (!(options && options.scroll === false) && doc.cm)
       ensureCursorVisible(doc.cm);
   }
 
   function setSelectionInner(doc, sel) {
     if (sel.equals(doc.sel)) return;
 
     doc.sel = sel;
 
     if (doc.cm) {
       doc.cm.curOp.updateInput = doc.cm.curOp.selectionChanged = true;
       signalCursorActivity(doc.cm);
     }
     signalLater(doc, "cursorActivity", doc);
   }
 
   // Verify that the selection does not partially select any atomic
   // marked ranges.
   function reCheckSelection(doc) {
     setSelectionInner(doc, skipAtomicInSelection(doc, doc.sel, null, false), sel_dontScroll);
   }
 
   // Return a selection that does not partially select any atomic
   // ranges.
   function skipAtomicInSelection(doc, sel, bias, mayClear) {
     var out;
     for (var i = 0; i < sel.ranges.length; i++) {
       var range = sel.ranges[i];
       var old = sel.ranges.length == doc.sel.ranges.length && doc.sel.ranges[i];
       var newAnchor = skipAtomic(doc, range.anchor, old && old.anchor, bias, mayClear);
       var newHead = skipAtomic(doc, range.head, old && old.head, bias, mayClear);
       if (out || newAnchor != range.anchor || newHead != range.head) {
         if (!out) out = sel.ranges.slice(0, i);
         out[i] = new Range(newAnchor, newHead);
       }
     }
     return out ? normalizeSelection(out, sel.primIndex) : sel;
   }
 
   function skipAtomicInner(doc, pos, oldPos, dir, mayClear) {
     var line = getLine(doc, pos.line);
     if (line.markedSpans) for (var i = 0; i < line.markedSpans.length; ++i) {
       var sp = line.markedSpans[i], m = sp.marker;
       if ((sp.from == null || (m.inclusiveLeft ? sp.from <= pos.ch : sp.from < pos.ch)) &&
           (sp.to == null || (m.inclusiveRight ? sp.to >= pos.ch : sp.to > pos.ch))) {
         if (mayClear) {
           signal(m, "beforeCursorEnter");
           if (m.explicitlyCleared) {
             if (!line.markedSpans) break;
             else {--i; continue;}
           }
         }
         if (!m.atomic) continue;
 
         if (oldPos) {
           var near = m.find(dir < 0 ? 1 : -1), diff;
           if (dir < 0 ? m.inclusiveRight : m.inclusiveLeft)
             near = movePos(doc, near, -dir, near && near.line == pos.line ? line : null);
           if (near && near.line == pos.line && (diff = cmp(near, oldPos)) && (dir < 0 ? diff < 0 : diff > 0))
             return skipAtomicInner(doc, near, pos, dir, mayClear);
         }
 
         var far = m.find(dir < 0 ? -1 : 1);
         if (dir < 0 ? m.inclusiveLeft : m.inclusiveRight)
           far = movePos(doc, far, dir, far.line == pos.line ? line : null);
         return far ? skipAtomicInner(doc, far, pos, dir, mayClear) : null;
       }
     }
     return pos;
   }
 
   // Ensure a given position is not inside an atomic range.
   function skipAtomic(doc, pos, oldPos, bias, mayClear) {
     var dir = bias || 1;
     var found = skipAtomicInner(doc, pos, oldPos, dir, mayClear) ||
         (!mayClear && skipAtomicInner(doc, pos, oldPos, dir, true)) ||
         skipAtomicInner(doc, pos, oldPos, -dir, mayClear) ||
         (!mayClear && skipAtomicInner(doc, pos, oldPos, -dir, true));
     if (!found) {
       doc.cantEdit = true;
       return Pos(doc.first, 0);
     }
     return found;
   }
 
   function movePos(doc, pos, dir, line) {
     if (dir < 0 && pos.ch == 0) {
       if (pos.line > doc.first) return clipPos(doc, Pos(pos.line - 1));
       else return null;
     } else if (dir > 0 && pos.ch == (line || getLine(doc, pos.line)).text.length) {
       if (pos.line < doc.first + doc.size - 1) return Pos(pos.line + 1, 0);
       else return null;
     } else {
       return new Pos(pos.line, pos.ch + dir);
     }
   }
 
   // SELECTION DRAWING
 
   function updateSelection(cm) {
     cm.display.input.showSelection(cm.display.input.prepareSelection());
   }
 
   function prepareSelection(cm, primary) {
     var doc = cm.doc, result = {};
     var curFragment = result.cursors = document.createDocumentFragment();
     var selFragment = result.selection = document.createDocumentFragment();
 
     for (var i = 0; i < doc.sel.ranges.length; i++) {
       if (primary === false && i == doc.sel.primIndex) continue;
       var range = doc.sel.ranges[i];
       if (range.from().line >= cm.display.viewTo || range.to().line < cm.display.viewFrom) continue;
       var collapsed = range.empty();
       if (collapsed || cm.options.showCursorWhenSelecting)
         drawSelectionCursor(cm, range.head, curFragment);
       if (!collapsed)
         drawSelectionRange(cm, range, selFragment);
     }
     return result;
   }
 
   // Draws a cursor for the given range
   function drawSelectionCursor(cm, head, output) {
     var pos = cursorCoords(cm, head, "div", null, null, !cm.options.singleCursorHeightPerLine);
 
     var cursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor"));
     cursor.style.left = pos.left + "px";
     cursor.style.top = pos.top + "px";
     cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + "px";
 
     if (pos.other) {
       // Secondary cursor, shown when on a 'jump' in bi-directional text
       var otherCursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor CodeMirror-secondarycursor"));
       otherCursor.style.display = "";
       otherCursor.style.left = pos.other.left + "px";
       otherCursor.style.top = pos.other.top + "px";
       otherCursor.style.height = (pos.other.bottom - pos.other.top) * .85 + "px";
     }
   }
 
   // Draws the given range as a highlighted selection
   function drawSelectionRange(cm, range, output) {
     var display = cm.display, doc = cm.doc;
     var fragment = document.createDocumentFragment();
     var padding = paddingH(cm.display), leftSide = padding.left;
     var rightSide = Math.max(display.sizerWidth, displayWidth(cm) - display.sizer.offsetLeft) - padding.right;
 
     function add(left, top, width, bottom) {
       if (top < 0) top = 0;
       top = Math.round(top);
       bottom = Math.round(bottom);
       fragment.appendChild(elt("div", null, "CodeMirror-selected", "position: absolute; left: " + left +
                                "px; top: " + top + "px; width: " + (width == null ? rightSide - left : width) +
                                "px; height: " + (bottom - top) + "px"));
     }
 
     function drawForLine(line, fromArg, toArg) {
       var lineObj = getLine(doc, line);
       var lineLen = lineObj.text.length;
       var start, end;
       function coords(ch, bias) {
         return charCoords(cm, Pos(line, ch), "div", lineObj, bias);
       }
 
       iterateBidiSections(getOrder(lineObj), fromArg || 0, toArg == null ? lineLen : toArg, function(from, to, dir) {
         var leftPos = coords(from, "left"), rightPos, left, right;
         if (from == to) {
           rightPos = leftPos;
           left = right = leftPos.left;
         } else {
           rightPos = coords(to - 1, "right");
           if (dir == "rtl") { var tmp = leftPos; leftPos = rightPos; rightPos = tmp; }
           left = leftPos.left;
           right = rightPos.right;
         }
         if (fromArg == null && from == 0) left = leftSide;
         if (rightPos.top - leftPos.top > 3) { // Different lines, draw top part
           add(left, leftPos.top, null, leftPos.bottom);
           left = leftSide;
           if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, null, rightPos.top);
         }
         if (toArg == null && to == lineLen) right = rightSide;
         if (!start || leftPos.top < start.top || leftPos.top == start.top && leftPos.left < start.left)
           start = leftPos;
         if (!end || rightPos.bottom > end.bottom || rightPos.bottom == end.bottom && rightPos.right > end.right)
           end = rightPos;
         if (left < leftSide + 1) left = leftSide;
         add(left, rightPos.top, right - left, rightPos.bottom);
       });
       return {start: start, end: end};
     }
 
     var sFrom = range.from(), sTo = range.to();
     if (sFrom.line == sTo.line) {
       drawForLine(sFrom.line, sFrom.ch, sTo.ch);
     } else {
       var fromLine = getLine(doc, sFrom.line), toLine = getLine(doc, sTo.line);
       var singleVLine = visualLine(fromLine) == visualLine(toLine);
       var leftEnd = drawForLine(sFrom.line, sFrom.ch, singleVLine ? fromLine.text.length + 1 : null).end;
       var rightStart = drawForLine(sTo.line, singleVLine ? 0 : null, sTo.ch).start;
       if (singleVLine) {
         if (leftEnd.top < rightStart.top - 2) {
           add(leftEnd.right, leftEnd.top, null, leftEnd.bottom);
           add(leftSide, rightStart.top, rightStart.left, rightStart.bottom);
         } else {
           add(leftEnd.right, leftEnd.top, rightStart.left - leftEnd.right, leftEnd.bottom);
         }
       }
       if (leftEnd.bottom < rightStart.top)
         add(leftSide, leftEnd.bottom, null, rightStart.top);
     }
 
     output.appendChild(fragment);
   }
 
   // Cursor-blinking
   function restartBlink(cm) {
     if (!cm.state.focused) return;
     var display = cm.display;
     clearInterval(display.blinker);
     var on = true;
     display.cursorDiv.style.visibility = "";
     if (cm.options.cursorBlinkRate > 0)
       display.blinker = setInterval(function() {
         display.cursorDiv.style.visibility = (on = !on) ? "" : "hidden";
       }, cm.options.cursorBlinkRate);
     else if (cm.options.cursorBlinkRate < 0)
       display.cursorDiv.style.visibility = "hidden";
   }
 
   // HIGHLIGHT WORKER
 
   function startWorker(cm, time) {
     if (cm.doc.mode.startState && cm.doc.frontier < cm.display.viewTo)
       cm.state.highlight.set(time, bind(highlightWorker, cm));
   }
 
   function highlightWorker(cm) {
     var doc = cm.doc;
     if (doc.frontier < doc.first) doc.frontier = doc.first;
     if (doc.frontier >= cm.display.viewTo) return;
     var end = +new Date + cm.options.workTime;
     var state = copyState(doc.mode, getStateBefore(cm, doc.frontier));
     var changedLines = [];
 
     doc.iter(doc.frontier, Math.min(doc.first + doc.size, cm.display.viewTo + 500), function(line) {
       if (doc.frontier >= cm.display.viewFrom) { // Visible
         var oldStyles = line.styles, tooLong = line.text.length > cm.options.maxHighlightLength;
         var highlighted = highlightLine(cm, line, tooLong ? copyState(doc.mode, state) : state, true);
         line.styles = highlighted.styles;
         var oldCls = line.styleClasses, newCls = highlighted.classes;
         if (newCls) line.styleClasses = newCls;
         else if (oldCls) line.styleClasses = null;
         var ischange = !oldStyles || oldStyles.length != line.styles.length ||
           oldCls != newCls && (!oldCls || !newCls || oldCls.bgClass != newCls.bgClass || oldCls.textClass != newCls.textClass);
         for (var i = 0; !ischange && i < oldStyles.length; ++i) ischange = oldStyles[i] != line.styles[i];
         if (ischange) changedLines.push(doc.frontier);
         line.stateAfter = tooLong ? state : copyState(doc.mode, state);
       } else {
         if (line.text.length <= cm.options.maxHighlightLength)
           processLine(cm, line.text, state);
         line.stateAfter = doc.frontier % 5 == 0 ? copyState(doc.mode, state) : null;
       }
       ++doc.frontier;
       if (+new Date > end) {
         startWorker(cm, cm.options.workDelay);
         return true;
       }
     });
     if (changedLines.length) runInOp(cm, function() {
       for (var i = 0; i < changedLines.length; i++)
         regLineChange(cm, changedLines[i], "text");
     });
   }
 
   // Finds the line to start with when starting a parse. Tries to
   // find a line with a stateAfter, so that it can start with a
   // valid state. If that fails, it returns the line with the
   // smallest indentation, which tends to need the least context to
   // parse correctly.
   function findStartLine(cm, n, precise) {
     var minindent, minline, doc = cm.doc;
     var lim = precise ? -1 : n - (cm.doc.mode.innerMode ? 1000 : 100);
     for (var search = n; search > lim; --search) {
       if (search <= doc.first) return doc.first;
       var line = getLine(doc, search - 1);
       if (line.stateAfter && (!precise || search <= doc.frontier)) return search;
       var indented = countColumn(line.text, null, cm.options.tabSize);
       if (minline == null || minindent > indented) {
         minline = search - 1;
         minindent = indented;
       }
     }
     return minline;
   }
 
   function getStateBefore(cm, n, precise) {
     var doc = cm.doc, display = cm.display;
     if (!doc.mode.startState) return true;
     var pos = findStartLine(cm, n, precise), state = pos > doc.first && getLine(doc, pos-1).stateAfter;
     if (!state) state = startState(doc.mode);
     else state = copyState(doc.mode, state);
     doc.iter(pos, n, function(line) {
       processLine(cm, line.text, state);
       var save = pos == n - 1 || pos % 5 == 0 || pos >= display.viewFrom && pos < display.viewTo;
       line.stateAfter = save ? copyState(doc.mode, state) : null;
       ++pos;
     });
     if (precise) doc.frontier = pos;
     return state;
   }
 
   // POSITION MEASUREMENT
 
   function paddingTop(display) {return display.lineSpace.offsetTop;}
   function paddingVert(display) {return display.mover.offsetHeight - display.lineSpace.offsetHeight;}
   function paddingH(display) {
     if (display.cachedPaddingH) return display.cachedPaddingH;
     var e = removeChildrenAndAdd(display.measure, elt("pre", "x"));
     var style = window.getComputedStyle ? window.getComputedStyle(e) : e.currentStyle;
     var data = {left: parseInt(style.paddingLeft), right: parseInt(style.paddingRight)};
     if (!isNaN(data.left) && !isNaN(data.right)) display.cachedPaddingH = data;
     return data;
   }
 
   function scrollGap(cm) { return scrollerGap - cm.display.nativeBarWidth; }
   function displayWidth(cm) {
     return cm.display.scroller.clientWidth - scrollGap(cm) - cm.display.barWidth;
   }
   function displayHeight(cm) {
     return cm.display.scroller.clientHeight - scrollGap(cm) - cm.display.barHeight;
   }
 
   // Ensure the lineView.wrapping.heights array is populated. This is
   // an array of bottom offsets for the lines that make up a drawn
   // line. When lineWrapping is on, there might be more than one
   // height.
   function ensureLineHeights(cm, lineView, rect) {
     var wrapping = cm.options.lineWrapping;
     var curWidth = wrapping && displayWidth(cm);
     if (!lineView.measure.heights || wrapping && lineView.measure.width != curWidth) {
       var heights = lineView.measure.heights = [];
       if (wrapping) {
         lineView.measure.width = curWidth;
         var rects = lineView.text.firstChild.getClientRects();
         for (var i = 0; i < rects.length - 1; i++) {
           var cur = rects[i], next = rects[i + 1];
           if (Math.abs(cur.bottom - next.bottom) > 2)
             heights.push((cur.bottom + next.top) / 2 - rect.top);
         }
       }
       heights.push(rect.bottom - rect.top);
     }
   }
 
   // Find a line map (mapping character offsets to text nodes) and a
   // measurement cache for the given line number. (A line view might
   // contain multiple lines when collapsed ranges are present.)
   function mapFromLineView(lineView, line, lineN) {
     if (lineView.line == line)
       return {map: lineView.measure.map, cache: lineView.measure.cache};
     for (var i = 0; i < lineView.rest.length; i++)
       if (lineView.rest[i] == line)
         return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i]};
     for (var i = 0; i < lineView.rest.length; i++)
       if (lineNo(lineView.rest[i]) > lineN)
         return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i], before: true};
   }
 
   // Render a line into the hidden node display.externalMeasured. Used
   // when measurement is needed for a line that's not in the viewport.
   function updateExternalMeasurement(cm, line) {
     line = visualLine(line);
     var lineN = lineNo(line);
     var view = cm.display.externalMeasured = new LineView(cm.doc, line, lineN);
     view.lineN = lineN;
     var built = view.built = buildLineContent(cm, view);
     view.text = built.pre;
     removeChildrenAndAdd(cm.display.lineMeasure, built.pre);
     return view;
   }
 
   // Get a {top, bottom, left, right} box (in line-local coordinates)
   // for a given character.
   function measureChar(cm, line, ch, bias) {
     return measureCharPrepared(cm, prepareMeasureForLine(cm, line), ch, bias);
   }
 
   // Find a line view that corresponds to the given line number.
   function findViewForLine(cm, lineN) {
     if (lineN >= cm.display.viewFrom && lineN < cm.display.viewTo)
       return cm.display.view[findViewIndex(cm, lineN)];
     var ext = cm.display.externalMeasured;
     if (ext && lineN >= ext.lineN && lineN < ext.lineN + ext.size)
       return ext;
   }
 
   // Measurement can be split in two steps, the set-up work that
   // applies to the whole line, and the measurement of the actual
   // character. Functions like coordsChar, that need to do a lot of
   // measurements in a row, can thus ensure that the set-up work is
   // only done once.
   function prepareMeasureForLine(cm, line) {
     var lineN = lineNo(line);
     var view = findViewForLine(cm, lineN);
     if (view && !view.text) {
       view = null;
     } else if (view && view.changes) {
       updateLineForChanges(cm, view, lineN, getDimensions(cm));
       cm.curOp.forceUpdate = true;
     }
     if (!view)
       view = updateExternalMeasurement(cm, line);
 
     var info = mapFromLineView(view, line, lineN);
     return {
       line: line, view: view, rect: null,
       map: info.map, cache: info.cache, before: info.before,
       hasHeights: false
     };
   }
 
   // Given a prepared measurement object, measures the position of an
   // actual character (or fetches it from the cache).
   function measureCharPrepared(cm, prepared, ch, bias, varHeight) {
     if (prepared.before) ch = -1;
     var key = ch + (bias || ""), found;
     if (prepared.cache.hasOwnProperty(key)) {
       found = prepared.cache[key];
     } else {
       if (!prepared.rect)
         prepared.rect = prepared.view.text.getBoundingClientRect();
       if (!prepared.hasHeights) {
         ensureLineHeights(cm, prepared.view, prepared.rect);
         prepared.hasHeights = true;
       }
       found = measureCharInner(cm, prepared, ch, bias);
       if (!found.bogus) prepared.cache[key] = found;
     }
     return {left: found.left, right: found.right,
             top: varHeight ? found.rtop : found.top,
             bottom: varHeight ? found.rbottom : found.bottom};
   }
 
   var nullRect = {left: 0, right: 0, top: 0, bottom: 0};
 
   function nodeAndOffsetInLineMap(map, ch, bias) {
     var node, start, end, collapse;
     // First, search the line map for the text node corresponding to,
     // or closest to, the target character.
     for (var i = 0; i < map.length; i += 3) {
       var mStart = map[i], mEnd = map[i + 1];
       if (ch < mStart) {
         start = 0; end = 1;
         collapse = "left";
       } else if (ch < mEnd) {
         start = ch - mStart;
         end = start + 1;
       } else if (i == map.length - 3 || ch == mEnd && map[i + 3] > ch) {
         end = mEnd - mStart;
         start = end - 1;
         if (ch >= mEnd) collapse = "right";
       }
       if (start != null) {
         node = map[i + 2];
         if (mStart == mEnd && bias == (node.insertLeft ? "left" : "right"))
           collapse = bias;
         if (bias == "left" && start == 0)
           while (i && map[i - 2] == map[i - 3] && map[i - 1].insertLeft) {
             node = map[(i -= 3) + 2];
             collapse = "left";
           }
         if (bias == "right" && start == mEnd - mStart)
           while (i < map.length - 3 && map[i + 3] == map[i + 4] && !map[i + 5].insertLeft) {
             node = map[(i += 3) + 2];
             collapse = "right";
           }
         break;
       }
     }
     return {node: node, start: start, end: end, collapse: collapse, coverStart: mStart, coverEnd: mEnd};
   }
 
   function measureCharInner(cm, prepared, ch, bias) {
     var place = nodeAndOffsetInLineMap(prepared.map, ch, bias);
     var node = place.node, start = place.start, end = place.end, collapse = place.collapse;
 
     var rect;
     if (node.nodeType == 3) { // If it is a text node, use a range to retrieve the coordinates.
       for (var i = 0; i < 4; i++) { // Retry a maximum of 4 times when nonsense rectangles are returned
         while (start && isExtendingChar(prepared.line.text.charAt(place.coverStart + start))) --start;
         while (place.coverStart + end < place.coverEnd && isExtendingChar(prepared.line.text.charAt(place.coverStart + end))) ++end;
         if (ie && ie_version < 9 && start == 0 && end == place.coverEnd - place.coverStart) {
           rect = node.parentNode.getBoundingClientRect();
         } else if (ie && cm.options.lineWrapping) {
           var rects = range(node, start, end).getClientRects();
           if (rects.length)
             rect = rects[bias == "right" ? rects.length - 1 : 0];
           else
             rect = nullRect;
         } else {
           rect = range(node, start, end).getBoundingClientRect() || nullRect;
         }
         if (rect.left || rect.right || start == 0) break;
         end = start;
         start = start - 1;
         collapse = "right";
       }
       if (ie && ie_version < 11) rect = maybeUpdateRectForZooming(cm.display.measure, rect);
     } else { // If it is a widget, simply get the box for the whole widget.
       if (start > 0) collapse = bias = "right";
       var rects;
       if (cm.options.lineWrapping && (rects = node.getClientRects()).length > 1)
         rect = rects[bias == "right" ? rects.length - 1 : 0];
       else
         rect = node.getBoundingClientRect();
     }
     if (ie && ie_version < 9 && !start && (!rect || !rect.left && !rect.right)) {
       var rSpan = node.parentNode.getClientRects()[0];
       if (rSpan)
         rect = {left: rSpan.left, right: rSpan.left + charWidth(cm.display), top: rSpan.top, bottom: rSpan.bottom};
       else
         rect = nullRect;
     }
 
     var rtop = rect.top - prepared.rect.top, rbot = rect.bottom - prepared.rect.top;
     var mid = (rtop + rbot) / 2;
     var heights = prepared.view.measure.heights;
     for (var i = 0; i < heights.length - 1; i++)
       if (mid < heights[i]) break;
     var top = i ? heights[i - 1] : 0, bot = heights[i];
     var result = {left: (collapse == "right" ? rect.right : rect.left) - prepared.rect.left,
                   right: (collapse == "left" ? rect.left : rect.right) - prepared.rect.left,
                   top: top, bottom: bot};
     if (!rect.left && !rect.right) result.bogus = true;
     if (!cm.options.singleCursorHeightPerLine) { result.rtop = rtop; result.rbottom = rbot; }
 
     return result;
   }
 
   // Work around problem with bounding client rects on ranges being
   // returned incorrectly when zoomed on IE10 and below.
   function maybeUpdateRectForZooming(measure, rect) {
     if (!window.screen || screen.logicalXDPI == null ||
         screen.logicalXDPI == screen.deviceXDPI || !hasBadZoomedRects(measure))
       return rect;
     var scaleX = screen.logicalXDPI / screen.deviceXDPI;
     var scaleY = screen.logicalYDPI / screen.deviceYDPI;
     return {left: rect.left * scaleX, right: rect.right * scaleX,
             top: rect.top * scaleY, bottom: rect.bottom * scaleY};
   }
 
   function clearLineMeasurementCacheFor(lineView) {
     if (lineView.measure) {
       lineView.measure.cache = {};
       lineView.measure.heights = null;
       if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)
         lineView.measure.caches[i] = {};
     }
   }
 
   function clearLineMeasurementCache(cm) {
     cm.display.externalMeasure = null;
     removeChildren(cm.display.lineMeasure);
     for (var i = 0; i < cm.display.view.length; i++)
       clearLineMeasurementCacheFor(cm.display.view[i]);
   }
 
   function clearCaches(cm) {
     clearLineMeasurementCache(cm);
     cm.display.cachedCharWidth = cm.display.cachedTextHeight = cm.display.cachedPaddingH = null;
     if (!cm.options.lineWrapping) cm.display.maxLineChanged = true;
     cm.display.lineNumChars = null;
   }
 
   function pageScrollX() { return window.pageXOffset || (document.documentElement || document.body).scrollLeft; }
   function pageScrollY() { return window.pageYOffset || (document.documentElement || document.body).scrollTop; }
 
   // Converts a {top, bottom, left, right} box from line-local
   // coordinates into another coordinate system. Context may be one of
   // "line", "div" (display.lineDiv), "local"/null (editor), "window",
   // or "page".
   function intoCoordSystem(cm, lineObj, rect, context) {
     if (lineObj.widgets) for (var i = 0; i < lineObj.widgets.length; ++i) if (lineObj.widgets[i].above) {
       var size = widgetHeight(lineObj.widgets[i]);
       rect.top += size; rect.bottom += size;
     }
     if (context == "line") return rect;
     if (!context) context = "local";
     var yOff = heightAtLine(lineObj);
     if (context == "local") yOff += paddingTop(cm.display);
     else yOff -= cm.display.viewOffset;
     if (context == "page" || context == "window") {
       var lOff = cm.display.lineSpace.getBoundingClientRect();
       yOff += lOff.top + (context == "window" ? 0 : pageScrollY());
       var xOff = lOff.left + (context == "window" ? 0 : pageScrollX());
       rect.left += xOff; rect.right += xOff;
     }
     rect.top += yOff; rect.bottom += yOff;
     return rect;
   }
 
   // Coverts a box from "div" coords to another coordinate system.
   // Context may be "window", "page", "div", or "local"/null.
   function fromCoordSystem(cm, coords, context) {
     if (context == "div") return coords;
     var left = coords.left, top = coords.top;
     // First move into "page" coordinate system
     if (context == "page") {
       left -= pageScrollX();
       top -= pageScrollY();
     } else if (context == "local" || !context) {
       var localBox = cm.display.sizer.getBoundingClientRect();
       left += localBox.left;
       top += localBox.top;
     }
 
     var lineSpaceBox = cm.display.lineSpace.getBoundingClientRect();
     return {left: left - lineSpaceBox.left, top: top - lineSpaceBox.top};
   }
 
   function charCoords(cm, pos, context, lineObj, bias) {
     if (!lineObj) lineObj = getLine(cm.doc, pos.line);
     return intoCoordSystem(cm, lineObj, measureChar(cm, lineObj, pos.ch, bias), context);
   }
 
   // Returns a box for a given cursor position, which may have an
   // 'other' property containing the position of the secondary cursor
   // on a bidi boundary.
   function cursorCoords(cm, pos, context, lineObj, preparedMeasure, varHeight) {
     lineObj = lineObj || getLine(cm.doc, pos.line);
     if (!preparedMeasure) preparedMeasure = prepareMeasureForLine(cm, lineObj);
     function get(ch, right) {
       var m = measureCharPrepared(cm, preparedMeasure, ch, right ? "right" : "left", varHeight);
       if (right) m.left = m.right; else m.right = m.left;
       return intoCoordSystem(cm, lineObj, m, context);
     }
     function getBidi(ch, partPos) {
       var part = order[partPos], right = part.level % 2;
       if (ch == bidiLeft(part) && partPos && part.level < order[partPos - 1].level) {
         part = order[--partPos];
         ch = bidiRight(part) - (part.level % 2 ? 0 : 1);
         right = true;
       } else if (ch == bidiRight(part) && partPos < order.length - 1 && part.level < order[partPos + 1].level) {
         part = order[++partPos];
         ch = bidiLeft(part) - part.level % 2;
         right = false;
       }
       if (right && ch == part.to && ch > part.from) return get(ch - 1);
       return get(ch, right);
     }
     var order = getOrder(lineObj), ch = pos.ch;
     if (!order) return get(ch);
     var partPos = getBidiPartAt(order, ch);
     var val = getBidi(ch, partPos);
     if (bidiOther != null) val.other = getBidi(ch, bidiOther);
     return val;
   }
 
   // Used to cheaply estimate the coordinates for a position. Used for
   // intermediate scroll updates.
   function estimateCoords(cm, pos) {
     var left = 0, pos = clipPos(cm.doc, pos);
     if (!cm.options.lineWrapping) left = charWidth(cm.display) * pos.ch;
     var lineObj = getLine(cm.doc, pos.line);
     var top = heightAtLine(lineObj) + paddingTop(cm.display);
     return {left: left, right: left, top: top, bottom: top + lineObj.height};
   }
 
   // Positions returned by coordsChar contain some extra information.
   // xRel is the relative x position of the input coordinates compared
   // to the found position (so xRel > 0 means the coordinates are to
   // the right of the character position, for example). When outside
   // is true, that means the coordinates lie outside the line's
   // vertical range.
   function PosWithInfo(line, ch, outside, xRel) {
     var pos = Pos(line, ch);
     pos.xRel = xRel;
     if (outside) pos.outside = true;
     return pos;
   }
 
   // Compute the character position closest to the given coordinates.
   // Input must be lineSpace-local ("div" coordinate system).
   function coordsChar(cm, x, y) {
     var doc = cm.doc;
     y += cm.display.viewOffset;
     if (y < 0) return PosWithInfo(doc.first, 0, true, -1);
     var lineN = lineAtHeight(doc, y), last = doc.first + doc.size - 1;
     if (lineN > last)
       return PosWithInfo(doc.first + doc.size - 1, getLine(doc, last).text.length, true, 1);
     if (x < 0) x = 0;
 
     var lineObj = getLine(doc, lineN);
     for (;;) {
       var found = coordsCharInner(cm, lineObj, lineN, x, y);
       var merged = collapsedSpanAtEnd(lineObj);
       var mergedPos = merged && merged.find(0, true);
       if (merged && (found.ch > mergedPos.from.ch || found.ch == mergedPos.from.ch && found.xRel > 0))
         lineN = lineNo(lineObj = mergedPos.to.line);
       else
         return found;
     }
   }
 
   function coordsCharInner(cm, lineObj, lineNo, x, y) {
     var innerOff = y - heightAtLine(lineObj);
     var wrongLine = false, adjust = 2 * cm.display.wrapper.clientWidth;
     var preparedMeasure = prepareMeasureForLine(cm, lineObj);
 
     function getX(ch) {
       var sp = cursorCoords(cm, Pos(lineNo, ch), "line", lineObj, preparedMeasure);
       wrongLine = true;
       if (innerOff > sp.bottom) return sp.left - adjust;
       else if (innerOff < sp.top) return sp.left + adjust;
       else wrongLine = false;
       return sp.left;
     }
 
     var bidi = getOrder(lineObj), dist = lineObj.text.length;
     var from = lineLeft(lineObj), to = lineRight(lineObj);
     var fromX = getX(from), fromOutside = wrongLine, toX = getX(to), toOutside = wrongLine;
 
     if (x > toX) return PosWithInfo(lineNo, to, toOutside, 1);
     // Do a binary search between these bounds.
     for (;;) {
       if (bidi ? to == from || to == moveVisually(lineObj, from, 1) : to - from <= 1) {
         var ch = x < fromX || x - fromX <= toX - x ? from : to;
         var xDiff = x - (ch == from ? fromX : toX);
         while (isExtendingChar(lineObj.text.charAt(ch))) ++ch;
         var pos = PosWithInfo(lineNo, ch, ch == from ? fromOutside : toOutside,
                               xDiff < -1 ? -1 : xDiff > 1 ? 1 : 0);
         return pos;
       }
       var step = Math.ceil(dist / 2), middle = from + step;
       if (bidi) {
         middle = from;
         for (var i = 0; i < step; ++i) middle = moveVisually(lineObj, middle, 1);
       }
       var middleX = getX(middle);
       if (middleX > x) {to = middle; toX = middleX; if (toOutside = wrongLine) toX += 1000; dist = step;}
       else {from = middle; fromX = middleX; fromOutside = wrongLine; dist -= step;}
     }
   }
 
   var measureText;
   // Compute the default text height.
   function textHeight(display) {
     if (display.cachedTextHeight != null) return display.cachedTextHeight;
     if (measureText == null) {
       measureText = elt("pre");
       // Measure a bunch of lines, for browsers that compute
       // fractional heights.
       for (var i = 0; i < 49; ++i) {
         measureText.appendChild(document.createTextNode("x"));
         measureText.appendChild(elt("br"));
       }
       measureText.appendChild(document.createTextNode("x"));
     }
     removeChildrenAndAdd(display.measure, measureText);
     var height = measureText.offsetHeight / 50;
     if (height > 3) display.cachedTextHeight = height;
     removeChildren(display.measure);
     return height || 1;
   }
 
   // Compute the default character width.
   function charWidth(display) {
     if (display.cachedCharWidth != null) return display.cachedCharWidth;
     var anchor = elt("span", "xxxxxxxxxx");
     var pre = elt("pre", [anchor]);
     removeChildrenAndAdd(display.measure, pre);
     var rect = anchor.getBoundingClientRect(), width = (rect.right - rect.left) / 10;
     if (width > 2) display.cachedCharWidth = width;
     return width || 10;
   }
 
   // OPERATIONS
 
   // Operations are used to wrap a series of changes to the editor
   // state in such a way that each change won't have to update the
   // cursor and display (which would be awkward, slow, and
   // error-prone). Instead, display updates are batched and then all
   // combined and executed at once.
 
   var operationGroup = null;
 
   var nextOpId = 0;
   // Start a new operation.
   function startOperation(cm) {
     cm.curOp = {
       cm: cm,
       viewChanged: false,      // Flag that indicates that lines might need to be redrawn
       startHeight: cm.doc.height, // Used to detect need to update scrollbar
       forceUpdate: false,      // Used to force a redraw
       updateInput: null,       // Whether to reset the input textarea
       typing: false,           // Whether this reset should be careful to leave existing text (for compositing)
       changeObjs: null,        // Accumulated changes, for firing change events
       cursorActivityHandlers: null, // Set of handlers to fire cursorActivity on
       cursorActivityCalled: 0, // Tracks which cursorActivity handlers have been called already
       selectionChanged: false, // Whether the selection needs to be redrawn
       updateMaxLine: false,    // Set when the widest line needs to be determined anew
       scrollLeft: null, scrollTop: null, // Intermediate scroll position, not pushed to DOM yet
       scrollToPos: null,       // Used to scroll to a specific position
       focus: false,
       id: ++nextOpId           // Unique ID
     };
     if (operationGroup) {
       operationGroup.ops.push(cm.curOp);
     } else {
       cm.curOp.ownsGroup = operationGroup = {
         ops: [cm.curOp],
         delayedCallbacks: []
       };
     }
   }
 
   function fireCallbacksForOps(group) {
     // Calls delayed callbacks and cursorActivity handlers until no
     // new ones appear
     var callbacks = group.delayedCallbacks, i = 0;
     do {
       for (; i < callbacks.length; i++)
         callbacks[i].call(null);
       for (var j = 0; j < group.ops.length; j++) {
         var op = group.ops[j];
         if (op.cursorActivityHandlers)
           while (op.cursorActivityCalled < op.cursorActivityHandlers.length)
             op.cursorActivityHandlers[op.cursorActivityCalled++].call(null, op.cm);
       }
     } while (i < callbacks.length);
   }
 
   // Finish an operation, updating the display and signalling delayed events
   function endOperation(cm) {
     var op = cm.curOp, group = op.ownsGroup;
     if (!group) return;
 
     try { fireCallbacksForOps(group); }
     finally {
       operationGroup = null;
       for (var i = 0; i < group.ops.length; i++)
         group.ops[i].cm.curOp = null;
       endOperations(group);
     }
   }
 
   // The DOM updates done when an operation finishes are batched so
   // that the minimum number of relayouts are required.
   function endOperations(group) {
     var ops = group.ops;
     for (var i = 0; i < ops.length; i++) // Read DOM
       endOperation_R1(ops[i]);
     for (var i = 0; i < ops.length; i++) // Write DOM (maybe)
       endOperation_W1(ops[i]);
     for (var i = 0; i < ops.length; i++) // Read DOM
       endOperation_R2(ops[i]);
     for (var i = 0; i < ops.length; i++) // Write DOM (maybe)
       endOperation_W2(ops[i]);
     for (var i = 0; i < ops.length; i++) // Read DOM
       endOperation_finish(ops[i]);
   }
 
   function endOperation_R1(op) {
     var cm = op.cm, display = cm.display;
     maybeClipScrollbars(cm);
     if (op.updateMaxLine) findMaxLine(cm);
 
     op.mustUpdate = op.viewChanged || op.forceUpdate || op.scrollTop != null ||
       op.scrollToPos && (op.scrollToPos.from.line < display.viewFrom ||
                          op.scrollToPos.to.line >= display.viewTo) ||
       display.maxLineChanged && cm.options.lineWrapping;
     op.update = op.mustUpdate &&
       new DisplayUpdate(cm, op.mustUpdate && {top: op.scrollTop, ensure: op.scrollToPos}, op.forceUpdate);
   }
 
   function endOperation_W1(op) {
     op.updatedDisplay = op.mustUpdate && updateDisplayIfNeeded(op.cm, op.update);
   }
 
   function endOperation_R2(op) {
     var cm = op.cm, display = cm.display;
     if (op.updatedDisplay) updateHeightsInViewport(cm);
 
     op.barMeasure = measureForScrollbars(cm);
 
     // If the max line changed since it was last measured, measure it,
     // and ensure the document's width matches it.
     // updateDisplay_W2 will use these properties to do the actual resizing
     if (display.maxLineChanged && !cm.options.lineWrapping) {
       op.adjustWidthTo = measureChar(cm, display.maxLine, display.maxLine.text.length).left + 3;
       cm.display.sizerWidth = op.adjustWidthTo;
       op.barMeasure.scrollWidth =
         Math.max(display.scroller.clientWidth, display.sizer.offsetLeft + op.adjustWidthTo + scrollGap(cm) + cm.display.barWidth);
       op.maxScrollLeft = Math.max(0, display.sizer.offsetLeft + op.adjustWidthTo - displayWidth(cm));
     }
 
     if (op.updatedDisplay || op.selectionChanged)
       op.preparedSelection = display.input.prepareSelection(op.focus);
   }
 
   function endOperation_W2(op) {
     var cm = op.cm;
 
     if (op.adjustWidthTo != null) {
       cm.display.sizer.style.minWidth = op.adjustWidthTo + "px";
       if (op.maxScrollLeft < cm.doc.scrollLeft)
         setScrollLeft(cm, Math.min(cm.display.scroller.scrollLeft, op.maxScrollLeft), true);
       cm.display.maxLineChanged = false;
     }
 
     var takeFocus = op.focus && op.focus == activeElt() && (!document.hasFocus || document.hasFocus())
     if (op.preparedSelection)
       cm.display.input.showSelection(op.preparedSelection, takeFocus);
     if (op.updatedDisplay || op.startHeight != cm.doc.height)
       updateScrollbars(cm, op.barMeasure);
     if (op.updatedDisplay)
       setDocumentHeight(cm, op.barMeasure);
 
     if (op.selectionChanged) restartBlink(cm);
 
     if (cm.state.focused && op.updateInput)
       cm.display.input.reset(op.typing);
     if (takeFocus) ensureFocus(op.cm);
   }
 
   function endOperation_finish(op) {
     var cm = op.cm, display = cm.display, doc = cm.doc;
 
     if (op.updatedDisplay) postUpdateDisplay(cm, op.update);
 
     // Abort mouse wheel delta measurement, when scrolling explicitly
     if (display.wheelStartX != null && (op.scrollTop != null || op.scrollLeft != null || op.scrollToPos))
       display.wheelStartX = display.wheelStartY = null;
 
     // Propagate the scroll position to the actual DOM scroller
     if (op.scrollTop != null && (display.scroller.scrollTop != op.scrollTop || op.forceScroll)) {
       doc.scrollTop = Math.max(0, Math.min(display.scroller.scrollHeight - display.scroller.clientHeight, op.scrollTop));
       display.scrollbars.setScrollTop(doc.scrollTop);
       display.scroller.scrollTop = doc.scrollTop;
     }
     if (op.scrollLeft != null && (display.scroller.scrollLeft != op.scrollLeft || op.forceScroll)) {
       doc.scrollLeft = Math.max(0, Math.min(display.scroller.scrollWidth - display.scroller.clientWidth, op.scrollLeft));
       display.scrollbars.setScrollLeft(doc.scrollLeft);
       display.scroller.scrollLeft = doc.scrollLeft;
       alignHorizontally(cm);
     }
     // If we need to scroll a specific position into view, do so.
     if (op.scrollToPos) {
       var coords = scrollPosIntoView(cm, clipPos(doc, op.scrollToPos.from),
                                      clipPos(doc, op.scrollToPos.to), op.scrollToPos.margin);
       if (op.scrollToPos.isCursor && cm.state.focused) maybeScrollWindow(cm, coords);
     }
 
     // Fire events for markers that are hidden/unidden by editing or
     // undoing
     var hidden = op.maybeHiddenMarkers, unhidden = op.maybeUnhiddenMarkers;
     if (hidden) for (var i = 0; i < hidden.length; ++i)
       if (!hidden[i].lines.length) signal(hidden[i], "hide");
     if (unhidden) for (var i = 0; i < unhidden.length; ++i)
       if (unhidden[i].lines.length) signal(unhidden[i], "unhide");
 
     if (display.wrapper.offsetHeight)
       doc.scrollTop = cm.display.scroller.scrollTop;
 
     // Fire change events, and delayed event handlers
     if (op.changeObjs)
       signal(cm, "changes", cm, op.changeObjs);
     if (op.update)
       op.update.finish();
   }
 
   // Run the given function in an operation
   function runInOp(cm, f) {
     if (cm.curOp) return f();
     startOperation(cm);
     try { return f(); }
     finally { endOperation(cm); }
   }
   // Wraps a function in an operation. Returns the wrapped function.
   function operation(cm, f) {
     return function() {
       if (cm.curOp) return f.apply(cm, arguments);
       startOperation(cm);
       try { return f.apply(cm, arguments); }
       finally { endOperation(cm); }
     };
   }
   // Used to add methods to editor and doc instances, wrapping them in
   // operations.
   function methodOp(f) {
     return function() {
       if (this.curOp) return f.apply(this, arguments);
       startOperation(this);
       try { return f.apply(this, arguments); }
       finally { endOperation(this); }
     };
   }
   function docMethodOp(f) {
     return function() {
       var cm = this.cm;
       if (!cm || cm.curOp) return f.apply(this, arguments);
       startOperation(cm);
       try { return f.apply(this, arguments); }
       finally { endOperation(cm); }
     };
   }
 
   // VIEW TRACKING
 
   // These objects are used to represent the visible (currently drawn)
   // part of the document. A LineView may correspond to multiple
   // logical lines, if those are connected by collapsed ranges.
   function LineView(doc, line, lineN) {
     // The starting line
     this.line = line;
     // Continuing lines, if any
     this.rest = visualLineContinued(line);
     // Number of logical lines in this visual line
     this.size = this.rest ? lineNo(lst(this.rest)) - lineN + 1 : 1;
     this.node = this.text = null;
     this.hidden = lineIsHidden(doc, line);
   }
 
   // Create a range of LineView objects for the given lines.
   function buildViewArray(cm, from, to) {
     var array = [], nextPos;
     for (var pos = from; pos < to; pos = nextPos) {
       var view = new LineView(cm.doc, getLine(cm.doc, pos), pos);
       nextPos = pos + view.size;
       array.push(view);
     }
     return array;
   }
 
   // Updates the display.view data structure for a given change to the
   // document. From and to are in pre-change coordinates. Lendiff is
   // the amount of lines added or subtracted by the change. This is
   // used for changes that span multiple lines, or change the way
   // lines are divided into visual lines. regLineChange (below)
   // registers single-line changes.
   function regChange(cm, from, to, lendiff) {
     if (from == null) from = cm.doc.first;
     if (to == null) to = cm.doc.first + cm.doc.size;
     if (!lendiff) lendiff = 0;
 
     var display = cm.display;
     if (lendiff && to < display.viewTo &&
         (display.updateLineNumbers == null || display.updateLineNumbers > from))
       display.updateLineNumbers = from;
 
     cm.curOp.viewChanged = true;
 
     if (from >= display.viewTo) { // Change after
       if (sawCollapsedSpans && visualLineNo(cm.doc, from) < display.viewTo)
         resetView(cm);
     } else if (to <= display.viewFrom) { // Change before
       if (sawCollapsedSpans && visualLineEndNo(cm.doc, to + lendiff) > display.viewFrom) {
         resetView(cm);
       } else {
         display.viewFrom += lendiff;
         display.viewTo += lendiff;
       }
     } else if (from <= display.viewFrom && to >= display.viewTo) { // Full overlap
       resetView(cm);
     } else if (from <= display.viewFrom) { // Top overlap
       var cut = viewCuttingPoint(cm, to, to + lendiff, 1);
       if (cut) {
         display.view = display.view.slice(cut.index);
         display.viewFrom = cut.lineN;
         display.viewTo += lendiff;
       } else {
         resetView(cm);
       }
     } else if (to >= display.viewTo) { // Bottom overlap
       var cut = viewCuttingPoint(cm, from, from, -1);
       if (cut) {
         display.view = display.view.slice(0, cut.index);
         display.viewTo = cut.lineN;
       } else {
         resetView(cm);
       }
     } else { // Gap in the middle
       var cutTop = viewCuttingPoint(cm, from, from, -1);
       var cutBot = viewCuttingPoint(cm, to, to + lendiff, 1);
       if (cutTop && cutBot) {
         display.view = display.view.slice(0, cutTop.index)
           .concat(buildViewArray(cm, cutTop.lineN, cutBot.lineN))
           .concat(display.view.slice(cutBot.index));
         display.viewTo += lendiff;
       } else {
         resetView(cm);
       }
     }
 
     var ext = display.externalMeasured;
     if (ext) {
       if (to < ext.lineN)
         ext.lineN += lendiff;
       else if (from < ext.lineN + ext.size)
         display.externalMeasured = null;
     }
   }
 
   // Register a change to a single line. Type must be one of "text",
   // "gutter", "class", "widget"
   function regLineChange(cm, line, type) {
     cm.curOp.viewChanged = true;
     var display = cm.display, ext = cm.display.externalMeasured;
     if (ext && line >= ext.lineN && line < ext.lineN + ext.size)
       display.externalMeasured = null;
 
     if (line < display.viewFrom || line >= display.viewTo) return;
     var lineView = display.view[findViewIndex(cm, line)];
     if (lineView.node == null) return;
     var arr = lineView.changes || (lineView.changes = []);
     if (indexOf(arr, type) == -1) arr.push(type);
   }
 
   // Clear the view.
   function resetView(cm) {
     cm.display.viewFrom = cm.display.viewTo = cm.doc.first;
     cm.display.view = [];
     cm.display.viewOffset = 0;
   }
 
   // Find the view element corresponding to a given line. Return null
   // when the line isn't visible.
   function findViewIndex(cm, n) {
     if (n >= cm.display.viewTo) return null;
     n -= cm.display.viewFrom;
     if (n < 0) return null;
     var view = cm.display.view;
     for (var i = 0; i < view.length; i++) {
       n -= view[i].size;
       if (n < 0) return i;
     }
   }
 
   function viewCuttingPoint(cm, oldN, newN, dir) {
     var index = findViewIndex(cm, oldN), diff, view = cm.display.view;
     if (!sawCollapsedSpans || newN == cm.doc.first + cm.doc.size)
       return {index: index, lineN: newN};
     for (var i = 0, n = cm.display.viewFrom; i < index; i++)
       n += view[i].size;
     if (n != oldN) {
       if (dir > 0) {
         if (index == view.length - 1) return null;
         diff = (n + view[index].size) - oldN;
         index++;
       } else {
         diff = n - oldN;
       }
       oldN += diff; newN += diff;
     }
     while (visualLineNo(cm.doc, newN) != newN) {
       if (index == (dir < 0 ? 0 : view.length - 1)) return null;
       newN += dir * view[index - (dir < 0 ? 1 : 0)].size;
       index += dir;
     }
     return {index: index, lineN: newN};
   }
 
   // Force the view to cover a given range, adding empty view element
   // or clipping off existing ones as needed.
   function adjustView(cm, from, to) {
     var display = cm.display, view = display.view;
     if (view.length == 0 || from >= display.viewTo || to <= display.viewFrom) {
       display.view = buildViewArray(cm, from, to);
       display.viewFrom = from;
     } else {
       if (display.viewFrom > from)
         display.view = buildViewArray(cm, from, display.viewFrom).concat(display.view);
       else if (display.viewFrom < from)
         display.view = display.view.slice(findViewIndex(cm, from));
       display.viewFrom = from;
       if (display.viewTo < to)
         display.view = display.view.concat(buildViewArray(cm, display.viewTo, to));
       else if (display.viewTo > to)
         display.view = display.view.slice(0, findViewIndex(cm, to));
     }
     display.viewTo = to;
   }
 
   // Count the number of lines in the view whose DOM representation is
   // out of date (or nonexistent).
   function countDirtyView(cm) {
     var view = cm.display.view, dirty = 0;
     for (var i = 0; i < view.length; i++) {
       var lineView = view[i];
       if (!lineView.hidden && (!lineView.node || lineView.changes)) ++dirty;
     }
     return dirty;
   }
 
   // EVENT HANDLERS
 
   // Attach the necessary event handlers when initializing the editor
   function registerEventHandlers(cm) {
     var d = cm.display;
     on(d.scroller, "mousedown", operation(cm, onMouseDown));
     // Older IE's will not fire a second mousedown for a double click
     if (ie && ie_version < 11)
       on(d.scroller, "dblclick", operation(cm, function(e) {
         if (signalDOMEvent(cm, e)) return;
         var pos = posFromMouse(cm, e);
         if (!pos || clickInGutter(cm, e) || eventInWidget(cm.display, e)) return;
         e_preventDefault(e);
         var word = cm.findWordAt(pos);
         extendSelection(cm.doc, word.anchor, word.head);
       }));
     else
       on(d.scroller, "dblclick", function(e) { signalDOMEvent(cm, e) || e_preventDefault(e); });
     // Some browsers fire contextmenu *after* opening the menu, at
     // which point we can't mess with it anymore. Context menu is
     // handled in onMouseDown for these browsers.
     if (!captureRightClick) on(d.scroller, "contextmenu", function(e) {onContextMenu(cm, e);});
 
     // Used to suppress mouse event handling when a touch happens
     var touchFinished, prevTouch = {end: 0};
     function finishTouch() {
       if (d.activeTouch) {
         touchFinished = setTimeout(function() {d.activeTouch = null;}, 1000);
         prevTouch = d.activeTouch;
         prevTouch.end = +new Date;
       }
     };
     function isMouseLikeTouchEvent(e) {
       if (e.touches.length != 1) return false;
       var touch = e.touches[0];
       return touch.radiusX <= 1 && touch.radiusY <= 1;
     }
     function farAway(touch, other) {
       if (other.left == null) return true;
       var dx = other.left - touch.left, dy = other.top - touch.top;
       return dx * dx + dy * dy > 20 * 20;
     }
     on(d.scroller, "touchstart", function(e) {
       if (!signalDOMEvent(cm, e) && !isMouseLikeTouchEvent(e)) {
         clearTimeout(touchFinished);
         var now = +new Date;
         d.activeTouch = {start: now, moved: false,
                          prev: now - prevTouch.end <= 300 ? prevTouch : null};
         if (e.touches.length == 1) {
           d.activeTouch.left = e.touches[0].pageX;
           d.activeTouch.top = e.touches[0].pageY;
         }
       }
     });
     on(d.scroller, "touchmove", function() {
       if (d.activeTouch) d.activeTouch.moved = true;
     });
     on(d.scroller, "touchend", function(e) {
       var touch = d.activeTouch;
       if (touch && !eventInWidget(d, e) && touch.left != null &&
           !touch.moved && new Date - touch.start < 300) {
         var pos = cm.coordsChar(d.activeTouch, "page"), range;
         if (!touch.prev || farAway(touch, touch.prev)) // Single tap
           range = new Range(pos, pos);
         else if (!touch.prev.prev || farAway(touch, touch.prev.prev)) // Double tap
           range = cm.findWordAt(pos);
         else // Triple tap
           range = new Range(Pos(pos.line, 0), clipPos(cm.doc, Pos(pos.line + 1, 0)));
         cm.setSelection(range.anchor, range.head);
         cm.focus();
         e_preventDefault(e);
       }
       finishTouch();
     });
     on(d.scroller, "touchcancel", finishTouch);
 
     // Sync scrolling between fake scrollbars and real scrollable
     // area, ensure viewport is updated when scrolling.
     on(d.scroller, "scroll", function() {
       if (d.scroller.clientHeight) {
         setScrollTop(cm, d.scroller.scrollTop);
         setScrollLeft(cm, d.scroller.scrollLeft, true);
         signal(cm, "scroll", cm);
       }
     });
 
     // Listen to wheel events in order to try and update the viewport on time.
     on(d.scroller, "mousewheel", function(e){onScrollWheel(cm, e);});
     on(d.scroller, "DOMMouseScroll", function(e){onScrollWheel(cm, e);});
 
     // Prevent wrapper from ever scrolling
     on(d.wrapper, "scroll", function() { d.wrapper.scrollTop = d.wrapper.scrollLeft = 0; });
 
     d.dragFunctions = {
       enter: function(e) {if (!signalDOMEvent(cm, e)) e_stop(e);},
       over: function(e) {if (!signalDOMEvent(cm, e)) { onDragOver(cm, e); e_stop(e); }},
       start: function(e){onDragStart(cm, e);},
       drop: operation(cm, onDrop),
       leave: function(e) {if (!signalDOMEvent(cm, e)) { clearDragCursor(cm); }}
     };
 
     var inp = d.input.getField();
     on(inp, "keyup", function(e) { onKeyUp.call(cm, e); });
     on(inp, "keydown", operation(cm, onKeyDown));
     on(inp, "keypress", operation(cm, onKeyPress));
     on(inp, "focus", bind(onFocus, cm));
     on(inp, "blur", bind(onBlur, cm));
   }
 
   function dragDropChanged(cm, value, old) {
     var wasOn = old && old != CodeMirror.Init;
     if (!value != !wasOn) {
       var funcs = cm.display.dragFunctions;
       var toggle = value ? on : off;
       toggle(cm.display.scroller, "dragstart", funcs.start);
       toggle(cm.display.scroller, "dragenter", funcs.enter);
       toggle(cm.display.scroller, "dragover", funcs.over);
       toggle(cm.display.scroller, "dragleave", funcs.leave);
       toggle(cm.display.scroller, "drop", funcs.drop);
     }
   }
 
   // Called when the window resizes
   function onResize(cm) {
     var d = cm.display;
     if (d.lastWrapHeight == d.wrapper.clientHeight && d.lastWrapWidth == d.wrapper.clientWidth)
       return;
     // Might be a text scaling operation, clear size caches.
     d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
     d.scrollbarsClipped = false;
     cm.setSize();
   }
 
   // MOUSE EVENTS
 
   // Return true when the given mouse event happened in a widget
   function eventInWidget(display, e) {
     for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {
       if (!n || (n.nodeType == 1 && n.getAttribute("cm-ignore-events") == "true") ||
           (n.parentNode == display.sizer && n != display.mover))
         return true;
     }
   }
 
   // Given a mouse event, find the corresponding position. If liberal
   // is false, it checks whether a gutter or scrollbar was clicked,
   // and returns null if it was. forRect is used by rectangular
   // selections, and tries to estimate a character position even for
   // coordinates beyond the right of the text.
   function posFromMouse(cm, e, liberal, forRect) {
     var display = cm.display;
     if (!liberal && e_target(e).getAttribute("cm-not-content") == "true") return null;
 
     var x, y, space = display.lineSpace.getBoundingClientRect();
     // Fails unpredictably on IE[67] when mouse is dragged around quickly.
     try { x = e.clientX - space.left; y = e.clientY - space.top; }
     catch (e) { return null; }
     var coords = coordsChar(cm, x, y), line;
     if (forRect && coords.xRel == 1 && (line = getLine(cm.doc, coords.line).text).length == coords.ch) {
       var colDiff = countColumn(line, line.length, cm.options.tabSize) - line.length;
       coords = Pos(coords.line, Math.max(0, Math.round((x - paddingH(cm.display).left) / charWidth(cm.display)) - colDiff));
     }
     return coords;
   }
 
   // A mouse down can be a single click, double click, triple click,
   // start of selection drag, start of text drag, new cursor
   // (ctrl-click), rectangle drag (alt-drag), or xwin
   // middle-click-paste. Or it might be a click on something we should
   // not interfere with, such as a scrollbar or widget.
   function onMouseDown(e) {
     var cm = this, display = cm.display;
     if (signalDOMEvent(cm, e) || display.activeTouch && display.input.supportsTouch()) return;
     display.shift = e.shiftKey;
 
     if (eventInWidget(display, e)) {
       if (!webkit) {
         // Briefly turn off draggability, to allow widgets to do
         // normal dragging things.
         display.scroller.draggable = false;
         setTimeout(function(){display.scroller.draggable = true;}, 100);
       }
       return;
     }
     if (clickInGutter(cm, e)) return;
     var start = posFromMouse(cm, e);
     window.focus();
 
     switch (e_button(e)) {
     case 1:
       // #3261: make sure, that we're not starting a second selection
       if (cm.state.selectingText)
         cm.state.selectingText(e);
       else if (start)
         leftButtonDown(cm, e, start);
       else if (e_target(e) == display.scroller)
         e_preventDefault(e);
       break;
     case 2:
       if (webkit) cm.state.lastMiddleDown = +new Date;
       if (start) extendSelection(cm.doc, start);
       setTimeout(function() {display.input.focus();}, 20);
       e_preventDefault(e);
       break;
     case 3:
       if (captureRightClick) onContextMenu(cm, e);
       else delayBlurEvent(cm);
       break;
     }
   }
 
   var lastClick, lastDoubleClick;
   function leftButtonDown(cm, e, start) {
     if (ie) setTimeout(bind(ensureFocus, cm), 0);
     else cm.curOp.focus = activeElt();
 
     var now = +new Date, type;
     if (lastDoubleClick && lastDoubleClick.time > now - 400 && cmp(lastDoubleClick.pos, start) == 0) {
       type = "triple";
     } else if (lastClick && lastClick.time > now - 400 && cmp(lastClick.pos, start) == 0) {
       type = "double";
       lastDoubleClick = {time: now, pos: start};
     } else {
       type = "single";
       lastClick = {time: now, pos: start};
     }
 
     var sel = cm.doc.sel, modifier = mac ? e.metaKey : e.ctrlKey, contained;
     if (cm.options.dragDrop && dragAndDrop && !cm.isReadOnly() &&
         type == "single" && (contained = sel.contains(start)) > -1 &&
         (cmp((contained = sel.ranges[contained]).from(), start) < 0 || start.xRel > 0) &&
         (cmp(contained.to(), start) > 0 || start.xRel < 0))
       leftButtonStartDrag(cm, e, start, modifier);
     else
       leftButtonSelect(cm, e, start, type, modifier);
   }
 
   // Start a text drag. When it ends, see if any dragging actually
   // happen, and treat as a click if it didn't.
   function leftButtonStartDrag(cm, e, start, modifier) {
     var display = cm.display, startTime = +new Date;
     var dragEnd = operation(cm, function(e2) {
       if (webkit) display.scroller.draggable = false;
       cm.state.draggingText = false;
       off(document, "mouseup", dragEnd);
       off(display.scroller, "drop", dragEnd);
       if (Math.abs(e.clientX - e2.clientX) + Math.abs(e.clientY - e2.clientY) < 10) {
         e_preventDefault(e2);
         if (!modifier && +new Date - 200 < startTime)
           extendSelection(cm.doc, start);
         // Work around unexplainable focus problem in IE9 (#2127) and Chrome (#3081)
         if (webkit || ie && ie_version == 9)
           setTimeout(function() {document.body.focus(); display.input.focus();}, 20);
         else
           display.input.focus();
       }
     });
     // Let the drag handler handle this.
     if (webkit) display.scroller.draggable = true;
     cm.state.draggingText = dragEnd;
     // IE's approach to draggable
     if (display.scroller.dragDrop) display.scroller.dragDrop();
     on(document, "mouseup", dragEnd);
     on(display.scroller, "drop", dragEnd);
   }
 
   // Normal selection, as opposed to text dragging.
   function leftButtonSelect(cm, e, start, type, addNew) {
     var display = cm.display, doc = cm.doc;
     e_preventDefault(e);
 
     var ourRange, ourIndex, startSel = doc.sel, ranges = startSel.ranges;
     if (addNew && !e.shiftKey) {
       ourIndex = doc.sel.contains(start);
       if (ourIndex > -1)
         ourRange = ranges[ourIndex];
       else
         ourRange = new Range(start, start);
     } else {
       ourRange = doc.sel.primary();
       ourIndex = doc.sel.primIndex;
     }
 
     if (chromeOS ? e.shiftKey && e.metaKey : e.altKey) {
       type = "rect";
       if (!addNew) ourRange = new Range(start, start);
       start = posFromMouse(cm, e, true, true);
       ourIndex = -1;
     } else if (type == "double") {
       var word = cm.findWordAt(start);
       if (cm.display.shift || doc.extend)
         ourRange = extendRange(doc, ourRange, word.anchor, word.head);
       else
         ourRange = word;
     } else if (type == "triple") {
       var line = new Range(Pos(start.line, 0), clipPos(doc, Pos(start.line + 1, 0)));
       if (cm.display.shift || doc.extend)
         ourRange = extendRange(doc, ourRange, line.anchor, line.head);
       else
         ourRange = line;
     } else {
       ourRange = extendRange(doc, ourRange, start);
     }
 
     if (!addNew) {
       ourIndex = 0;
       setSelection(doc, new Selection([ourRange], 0), sel_mouse);
       startSel = doc.sel;
     } else if (ourIndex == -1) {
       ourIndex = ranges.length;
       setSelection(doc, normalizeSelection(ranges.concat([ourRange]), ourIndex),
                    {scroll: false, origin: "*mouse"});
     } else if (ranges.length > 1 && ranges[ourIndex].empty() && type == "single" && !e.shiftKey) {
       setSelection(doc, normalizeSelection(ranges.slice(0, ourIndex).concat(ranges.slice(ourIndex + 1)), 0),
                    {scroll: false, origin: "*mouse"});
       startSel = doc.sel;
     } else {
       replaceOneSelection(doc, ourIndex, ourRange, sel_mouse);
     }
 
     var lastPos = start;
     function extendTo(pos) {
       if (cmp(lastPos, pos) == 0) return;
       lastPos = pos;
 
       if (type == "rect") {
         var ranges = [], tabSize = cm.options.tabSize;
         var startCol = countColumn(getLine(doc, start.line).text, start.ch, tabSize);
         var posCol = countColumn(getLine(doc, pos.line).text, pos.ch, tabSize);
         var left = Math.min(startCol, posCol), right = Math.max(startCol, posCol);
         for (var line = Math.min(start.line, pos.line), end = Math.min(cm.lastLine(), Math.max(start.line, pos.line));
              line <= end; line++) {
           var text = getLine(doc, line).text, leftPos = findColumn(text, left, tabSize);
           if (left == right)
             ranges.push(new Range(Pos(line, leftPos), Pos(line, leftPos)));
           else if (text.length > leftPos)
             ranges.push(new Range(Pos(line, leftPos), Pos(line, findColumn(text, right, tabSize))));
         }
         if (!ranges.length) ranges.push(new Range(start, start));
         setSelection(doc, normalizeSelection(startSel.ranges.slice(0, ourIndex).concat(ranges), ourIndex),
                      {origin: "*mouse", scroll: false});
         cm.scrollIntoView(pos);
       } else {
         var oldRange = ourRange;
         var anchor = oldRange.anchor, head = pos;
         if (type != "single") {
           if (type == "double")
             var range = cm.findWordAt(pos);
           else
             var range = new Range(Pos(pos.line, 0), clipPos(doc, Pos(pos.line + 1, 0)));
           if (cmp(range.anchor, anchor) > 0) {
             head = range.head;
             anchor = minPos(oldRange.from(), range.anchor);
           } else {
             head = range.anchor;
             anchor = maxPos(oldRange.to(), range.head);
           }
         }
         var ranges = startSel.ranges.slice(0);
         ranges[ourIndex] = new Range(clipPos(doc, anchor), head);
         setSelection(doc, normalizeSelection(ranges, ourIndex), sel_mouse);
       }
     }
 
     var editorSize = display.wrapper.getBoundingClientRect();
     // Used to ensure timeout re-tries don't fire when another extend
     // happened in the meantime (clearTimeout isn't reliable -- at
     // least on Chrome, the timeouts still happen even when cleared,
     // if the clear happens after their scheduled firing time).
     var counter = 0;
 
     function extend(e) {
       var curCount = ++counter;
       var cur = posFromMouse(cm, e, true, type == "rect");
       if (!cur) return;
       if (cmp(cur, lastPos) != 0) {
         cm.curOp.focus = activeElt();
         extendTo(cur);
         var visible = visibleLines(display, doc);
         if (cur.line >= visible.to || cur.line < visible.from)
           setTimeout(operation(cm, function(){if (counter == curCount) extend(e);}), 150);
       } else {
         var outside = e.clientY < editorSize.top ? -20 : e.clientY > editorSize.bottom ? 20 : 0;
         if (outside) setTimeout(operation(cm, function() {
           if (counter != curCount) return;
           display.scroller.scrollTop += outside;
           extend(e);
         }), 50);
       }
     }
 
     function done(e) {
       cm.state.selectingText = false;
       counter = Infinity;
       e_preventDefault(e);
       display.input.focus();
       off(document, "mousemove", move);
       off(document, "mouseup", up);
       doc.history.lastSelOrigin = null;
     }
 
     var move = operation(cm, function(e) {
       if (!e_button(e)) done(e);
       else extend(e);
     });
     var up = operation(cm, done);
     cm.state.selectingText = up;
     on(document, "mousemove", move);
     on(document, "mouseup", up);
   }
 
   // Determines whether an event happened in the gutter, and fires the
   // handlers for the corresponding event.
   function gutterEvent(cm, e, type, prevent) {
     try { var mX = e.clientX, mY = e.clientY; }
     catch(e) { return false; }
     if (mX >= Math.floor(cm.display.gutters.getBoundingClientRect().right)) return false;
     if (prevent) e_preventDefault(e);
 
     var display = cm.display;
     var lineBox = display.lineDiv.getBoundingClientRect();
 
     if (mY > lineBox.bottom || !hasHandler(cm, type)) return e_defaultPrevented(e);
     mY -= lineBox.top - display.viewOffset;
 
     for (var i = 0; i < cm.options.gutters.length; ++i) {
       var g = display.gutters.childNodes[i];
       if (g && g.getBoundingClientRect().right >= mX) {
         var line = lineAtHeight(cm.doc, mY);
         var gutter = cm.options.gutters[i];
         signal(cm, type, cm, line, gutter, e);
         return e_defaultPrevented(e);
       }
     }
   }
 
   function clickInGutter(cm, e) {
     return gutterEvent(cm, e, "gutterClick", true);
   }
 
   // Kludge to work around strange IE behavior where it'll sometimes
   // re-fire a series of drag-related events right after the drop (#1551)
   var lastDrop = 0;
 
   function onDrop(e) {
     var cm = this;
     clearDragCursor(cm);
     if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e))
       return;
     e_preventDefault(e);
     if (ie) lastDrop = +new Date;
     var pos = posFromMouse(cm, e, true), files = e.dataTransfer.files;
     if (!pos || cm.isReadOnly()) return;
     // Might be a file drop, in which case we simply extract the text
     // and insert it.
     if (files && files.length && window.FileReader && window.File) {
       var n = files.length, text = Array(n), read = 0;
       var loadFile = function(file, i) {
         if (cm.options.allowDropFileTypes &&
             indexOf(cm.options.allowDropFileTypes, file.type) == -1)
           return;
 
         var reader = new FileReader;
         reader.onload = operation(cm, function() {
           var content = reader.result;
           if (/[\x00-\x08\x0e-\x1f]{2}/.test(content)) content = "";
           text[i] = content;
           if (++read == n) {
             pos = clipPos(cm.doc, pos);
             var change = {from: pos, to: pos,
                           text: cm.doc.splitLines(text.join(cm.doc.lineSeparator())),
                           origin: "paste"};
             makeChange(cm.doc, change);
             setSelectionReplaceHistory(cm.doc, simpleSelection(pos, changeEnd(change)));
           }
         });
         reader.readAsText(file);
       };
       for (var i = 0; i < n; ++i) loadFile(files[i], i);
     } else { // Normal drop
       // Don't do a replace if the drop happened inside of the selected text.
       if (cm.state.draggingText && cm.doc.sel.contains(pos) > -1) {
         cm.state.draggingText(e);
         // Ensure the editor is re-focused
         setTimeout(function() {cm.display.input.focus();}, 20);
         return;
       }
       try {
         var text = e.dataTransfer.getData("Text");
         if (text) {
           if (cm.state.draggingText && !(mac ? e.altKey : e.ctrlKey))
             var selected = cm.listSelections();
           setSelectionNoUndo(cm.doc, simpleSelection(pos, pos));
           if (selected) for (var i = 0; i < selected.length; ++i)
             replaceRange(cm.doc, "", selected[i].anchor, selected[i].head, "drag");
           cm.replaceSelection(text, "around", "paste");
           cm.display.input.focus();
         }
       }
       catch(e){}
     }
   }
 
   function onDragStart(cm, e) {
     if (ie && (!cm.state.draggingText || +new Date - lastDrop < 100)) { e_stop(e); return; }
     if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) return;
 
     e.dataTransfer.setData("Text", cm.getSelection());
     e.dataTransfer.effectAllowed = "copyMove"
 
     // Use dummy image instead of default browsers image.
     // Recent Safari (~6.0.2) have a tendency to segfault when this happens, so we don't do it there.
     if (e.dataTransfer.setDragImage && !safari) {
       var img = elt("img", null, null, "position: fixed; left: 0; top: 0;");
       img.src = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";
       if (presto) {
         img.width = img.height = 1;
         cm.display.wrapper.appendChild(img);
         // Force a relayout, or Opera won't use our image for some obscure reason
         img._top = img.offsetTop;
       }
       e.dataTransfer.setDragImage(img, 0, 0);
       if (presto) img.parentNode.removeChild(img);
     }
   }
 
   function onDragOver(cm, e) {
     var pos = posFromMouse(cm, e);
     if (!pos) return;
     var frag = document.createDocumentFragment();
     drawSelectionCursor(cm, pos, frag);
     if (!cm.display.dragCursor) {
       cm.display.dragCursor = elt("div", null, "CodeMirror-cursors CodeMirror-dragcursors");
       cm.display.lineSpace.insertBefore(cm.display.dragCursor, cm.display.cursorDiv);
     }
     removeChildrenAndAdd(cm.display.dragCursor, frag);
   }
 
   function clearDragCursor(cm) {
     if (cm.display.dragCursor) {
       cm.display.lineSpace.removeChild(cm.display.dragCursor);
       cm.display.dragCursor = null;
     }
   }
 
   // SCROLL EVENTS
 
   // Sync the scrollable area and scrollbars, ensure the viewport
   // covers the visible area.
   function setScrollTop(cm, val) {
     if (Math.abs(cm.doc.scrollTop - val) < 2) return;
     cm.doc.scrollTop = val;
     if (!gecko) updateDisplaySimple(cm, {top: val});
     if (cm.display.scroller.scrollTop != val) cm.display.scroller.scrollTop = val;
     cm.display.scrollbars.setScrollTop(val);
     if (gecko) updateDisplaySimple(cm);
     startWorker(cm, 100);
   }
   // Sync scroller and scrollbar, ensure the gutter elements are
   // aligned.
   function setScrollLeft(cm, val, isScroller) {
     if (isScroller ? val == cm.doc.scrollLeft : Math.abs(cm.doc.scrollLeft - val) < 2) return;
     val = Math.min(val, cm.display.scroller.scrollWidth - cm.display.scroller.clientWidth);
     cm.doc.scrollLeft = val;
     alignHorizontally(cm);
     if (cm.display.scroller.scrollLeft != val) cm.display.scroller.scrollLeft = val;
     cm.display.scrollbars.setScrollLeft(val);
   }
 
   // Since the delta values reported on mouse wheel events are
   // unstandardized between browsers and even browser versions, and
   // generally horribly unpredictable, this code starts by measuring
   // the scroll effect that the first few mouse wheel events have,
   // and, from that, detects the way it can convert deltas to pixel
   // offsets afterwards.
   //
   // The reason we want to know the amount a wheel event will scroll
   // is that it gives us a chance to update the display before the
   // actual scrolling happens, reducing flickering.
 
   var wheelSamples = 0, wheelPixelsPerUnit = null;
   // Fill in a browser-detected starting value on browsers where we
   // know one. These don't have to be accurate -- the result of them
   // being wrong would just be a slight flicker on the first wheel
   // scroll (if it is large enough).
   if (ie) wheelPixelsPerUnit = -.53;
   else if (gecko) wheelPixelsPerUnit = 15;
   else if (chrome) wheelPixelsPerUnit = -.7;
   else if (safari) wheelPixelsPerUnit = -1/3;
 
   var wheelEventDelta = function(e) {
     var dx = e.wheelDeltaX, dy = e.wheelDeltaY;
     if (dx == null && e.detail && e.axis == e.HORIZONTAL_AXIS) dx = e.detail;
     if (dy == null && e.detail && e.axis == e.VERTICAL_AXIS) dy = e.detail;
     else if (dy == null) dy = e.wheelDelta;
     return {x: dx, y: dy};
   };
   CodeMirror.wheelEventPixels = function(e) {
     var delta = wheelEventDelta(e);
     delta.x *= wheelPixelsPerUnit;
     delta.y *= wheelPixelsPerUnit;
     return delta;
   };
 
   function onScrollWheel(cm, e) {
     var delta = wheelEventDelta(e), dx = delta.x, dy = delta.y;
 
     var display = cm.display, scroll = display.scroller;
     // Quit if there's nothing to scroll here
     var canScrollX = scroll.scrollWidth > scroll.clientWidth;
     var canScrollY = scroll.scrollHeight > scroll.clientHeight;
     if (!(dx && canScrollX || dy && canScrollY)) return;
 
     // Webkit browsers on OS X abort momentum scrolls when the target
     // of the scroll event is removed from the scrollable element.
     // This hack (see related code in patchDisplay) makes sure the
     // element is kept around.
     if (dy && mac && webkit) {
       outer: for (var cur = e.target, view = display.view; cur != scroll; cur = cur.parentNode) {
         for (var i = 0; i < view.length; i++) {
           if (view[i].node == cur) {
             cm.display.currentWheelTarget = cur;
             break outer;
           }
         }
       }
     }
 
     // On some browsers, horizontal scrolling will cause redraws to
     // happen before the gutter has been realigned, causing it to
     // wriggle around in a most unseemly way. When we have an
     // estimated pixels/delta value, we just handle horizontal
     // scrolling entirely here. It'll be slightly off from native, but
     // better than glitching out.
     if (dx && !gecko && !presto && wheelPixelsPerUnit != null) {
       if (dy && canScrollY)
         setScrollTop(cm, Math.max(0, Math.min(scroll.scrollTop + dy * wheelPixelsPerUnit, scroll.scrollHeight - scroll.clientHeight)));
       setScrollLeft(cm, Math.max(0, Math.min(scroll.scrollLeft + dx * wheelPixelsPerUnit, scroll.scrollWidth - scroll.clientWidth)));
       // Only prevent default scrolling if vertical scrolling is
       // actually possible. Otherwise, it causes vertical scroll
       // jitter on OSX trackpads when deltaX is small and deltaY
       // is large (issue #3579)
       if (!dy || (dy && canScrollY))
         e_preventDefault(e);
       display.wheelStartX = null; // Abort measurement, if in progress
       return;
     }
 
     // 'Project' the visible viewport to cover the area that is being
     // scrolled into view (if we know enough to estimate it).
     if (dy && wheelPixelsPerUnit != null) {
       var pixels = dy * wheelPixelsPerUnit;
       var top = cm.doc.scrollTop, bot = top + display.wrapper.clientHeight;
       if (pixels < 0) top = Math.max(0, top + pixels - 50);
       else bot = Math.min(cm.doc.height, bot + pixels + 50);
       updateDisplaySimple(cm, {top: top, bottom: bot});
     }
 
     if (wheelSamples < 20) {
       if (display.wheelStartX == null) {
         display.wheelStartX = scroll.scrollLeft; display.wheelStartY = scroll.scrollTop;
         display.wheelDX = dx; display.wheelDY = dy;
         setTimeout(function() {
           if (display.wheelStartX == null) return;
           var movedX = scroll.scrollLeft - display.wheelStartX;
           var movedY = scroll.scrollTop - display.wheelStartY;
           var sample = (movedY && display.wheelDY && movedY / display.wheelDY) ||
             (movedX && display.wheelDX && movedX / display.wheelDX);
           display.wheelStartX = display.wheelStartY = null;
           if (!sample) return;
           wheelPixelsPerUnit = (wheelPixelsPerUnit * wheelSamples + sample) / (wheelSamples + 1);
           ++wheelSamples;
         }, 200);
       } else {
         display.wheelDX += dx; display.wheelDY += dy;
       }
     }
   }
 
   // KEY EVENTS
 
   // Run a handler that was bound to a key.
   function doHandleBinding(cm, bound, dropShift) {
     if (typeof bound == "string") {
       bound = commands[bound];
       if (!bound) return false;
     }
     // Ensure previous input has been read, so that the handler sees a
     // consistent view of the document
     cm.display.input.ensurePolled();
     var prevShift = cm.display.shift, done = false;
     try {
       if (cm.isReadOnly()) cm.state.suppressEdits = true;
       if (dropShift) cm.display.shift = false;
       done = bound(cm) != Pass;
     } finally {
       cm.display.shift = prevShift;
       cm.state.suppressEdits = false;
     }
     return done;
   }
 
   function lookupKeyForEditor(cm, name, handle) {
     for (var i = 0; i < cm.state.keyMaps.length; i++) {
       var result = lookupKey(name, cm.state.keyMaps[i], handle, cm);
       if (result) return result;
     }
     return (cm.options.extraKeys && lookupKey(name, cm.options.extraKeys, handle, cm))
       || lookupKey(name, cm.options.keyMap, handle, cm);
   }
 
   var stopSeq = new Delayed;
   function dispatchKey(cm, name, e, handle) {
     var seq = cm.state.keySeq;
     if (seq) {
       if (isModifierKey(name)) return "handled";
       stopSeq.set(50, function() {
         if (cm.state.keySeq == seq) {
           cm.state.keySeq = null;
           cm.display.input.reset();
         }
       });
       name = seq + " " + name;
     }
     var result = lookupKeyForEditor(cm, name, handle);
 
     if (result == "multi")
       cm.state.keySeq = name;
     if (result == "handled")
       signalLater(cm, "keyHandled", cm, name, e);
 
     if (result == "handled" || result == "multi") {
       e_preventDefault(e);
       restartBlink(cm);
     }
 
     if (seq && !result && /\'$/.test(name)) {
       e_preventDefault(e);
       return true;
     }
     return !!result;
   }
 
   // Handle a key from the keydown event.
   function handleKeyBinding(cm, e) {
     var name = keyName(e, true);
     if (!name) return false;
 
     if (e.shiftKey && !cm.state.keySeq) {
       // First try to resolve full name (including 'Shift-'). Failing
       // that, see if there is a cursor-motion command (starting with
       // 'go') bound to the keyname without 'Shift-'.
       return dispatchKey(cm, "Shift-" + name, e, function(b) {return doHandleBinding(cm, b, true);})
           || dispatchKey(cm, name, e, function(b) {
                if (typeof b == "string" ? /^go[A-Z]/.test(b) : b.motion)
                  return doHandleBinding(cm, b);
              });
     } else {
       return dispatchKey(cm, name, e, function(b) { return doHandleBinding(cm, b); });
     }
   }
 
   // Handle a key from the keypress event
   function handleCharBinding(cm, e, ch) {
     return dispatchKey(cm, "'" + ch + "'", e,
                        function(b) { return doHandleBinding(cm, b, true); });
   }
 
   var lastStoppedKey = null;
   function onKeyDown(e) {
     var cm = this;
     cm.curOp.focus = activeElt();
     if (signalDOMEvent(cm, e)) return;
     // IE does strange things with escape.
     if (ie && ie_version < 11 && e.keyCode == 27) e.returnValue = false;
     var code = e.keyCode;
     cm.display.shift = code == 16 || e.shiftKey;
     var handled = handleKeyBinding(cm, e);
     if (presto) {
       lastStoppedKey = handled ? code : null;
       // Opera has no cut event... we try to at least catch the key combo
       if (!handled && code == 88 && !hasCopyEvent && (mac ? e.metaKey : e.ctrlKey))
         cm.replaceSelection("", null, "cut");
     }
 
     // Turn mouse into crosshair when Alt is held on Mac.
     if (code == 18 && !/\bCodeMirror-crosshair\b/.test(cm.display.lineDiv.className))
       showCrossHair(cm);
   }
 
   function showCrossHair(cm) {
     var lineDiv = cm.display.lineDiv;
     addClass(lineDiv, "CodeMirror-crosshair");
 
     function up(e) {
       if (e.keyCode == 18 || !e.altKey) {
         rmClass(lineDiv, "CodeMirror-crosshair");
         off(document, "keyup", up);
         off(document, "mouseover", up);
       }
     }
     on(document, "keyup", up);
     on(document, "mouseover", up);
   }
 
   function onKeyUp(e) {
     if (e.keyCode == 16) this.doc.sel.shift = false;
     signalDOMEvent(this, e);
   }
 
   function onKeyPress(e) {
     var cm = this;
     if (eventInWidget(cm.display, e) || signalDOMEvent(cm, e) || e.ctrlKey && !e.altKey || mac && e.metaKey) return;
     var keyCode = e.keyCode, charCode = e.charCode;
     if (presto && keyCode == lastStoppedKey) {lastStoppedKey = null; e_preventDefault(e); return;}
     if ((presto && (!e.which || e.which < 10)) && handleKeyBinding(cm, e)) return;
     var ch = String.fromCharCode(charCode == null ? keyCode : charCode);
     if (handleCharBinding(cm, e, ch)) return;
     cm.display.input.onKeyPress(e);
   }
 
   // FOCUS/BLUR EVENTS
 
   function delayBlurEvent(cm) {
     cm.state.delayingBlurEvent = true;
     setTimeout(function() {
       if (cm.state.delayingBlurEvent) {
         cm.state.delayingBlurEvent = false;
         onBlur(cm);
       }
     }, 100);
   }
 
   function onFocus(cm) {
     if (cm.state.delayingBlurEvent) cm.state.delayingBlurEvent = false;
 
     if (cm.options.readOnly == "nocursor") return;
     if (!cm.state.focused) {
       signal(cm, "focus", cm);
       cm.state.focused = true;
       addClass(cm.display.wrapper, "CodeMirror-focused");
       // This test prevents this from firing when a context
       // menu is closed (since the input reset would kill the
       // select-all detection hack)
       if (!cm.curOp && cm.display.selForContextMenu != cm.doc.sel) {
         cm.display.input.reset();
         if (webkit) setTimeout(function() { cm.display.input.reset(true); }, 20); // Issue #1730
       }
       cm.display.input.receivedFocus();
     }
     restartBlink(cm);
   }
   function onBlur(cm) {
     if (cm.state.delayingBlurEvent) return;
 
     if (cm.state.focused) {
       signal(cm, "blur", cm);
       cm.state.focused = false;
       rmClass(cm.display.wrapper, "CodeMirror-focused");
     }
     clearInterval(cm.display.blinker);
     setTimeout(function() {if (!cm.state.focused) cm.display.shift = false;}, 150);
   }
 
   // CONTEXT MENU HANDLING
 
   // To make the context menu work, we need to briefly unhide the
   // textarea (making it as unobtrusive as possible) to let the
   // right-click take effect on it.
   function onContextMenu(cm, e) {
     if (eventInWidget(cm.display, e) || contextMenuInGutter(cm, e)) return;
     if (signalDOMEvent(cm, e, "contextmenu")) return;
     cm.display.input.onContextMenu(e);
   }
 
   function contextMenuInGutter(cm, e) {
     if (!hasHandler(cm, "gutterContextMenu")) return false;
     return gutterEvent(cm, e, "gutterContextMenu", false);
   }
 
   // UPDATING
 
   // Compute the position of the end of a change (its 'to' property
   // refers to the pre-change end).
   var changeEnd = CodeMirror.changeEnd = function(change) {
     if (!change.text) return change.to;
     return Pos(change.from.line + change.text.length - 1,
                lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0));
   };
 
   // Adjust a position to refer to the post-change position of the
   // same text, or the end of the change if the change covers it.
   function adjustForChange(pos, change) {
     if (cmp(pos, change.from) < 0) return pos;
     if (cmp(pos, change.to) <= 0) return changeEnd(change);
 
     var line = pos.line + change.text.length - (change.to.line - change.from.line) - 1, ch = pos.ch;
     if (pos.line == change.to.line) ch += changeEnd(change).ch - change.to.ch;
     return Pos(line, ch);
   }
 
   function computeSelAfterChange(doc, change) {
     var out = [];
     for (var i = 0; i < doc.sel.ranges.length; i++) {
       var range = doc.sel.ranges[i];
       out.push(new Range(adjustForChange(range.anchor, change),
                          adjustForChange(range.head, change)));
     }
     return normalizeSelection(out, doc.sel.primIndex);
   }
 
   function offsetPos(pos, old, nw) {
     if (pos.line == old.line)
       return Pos(nw.line, pos.ch - old.ch + nw.ch);
     else
       return Pos(nw.line + (pos.line - old.line), pos.ch);
   }
 
   // Used by replaceSelections to allow moving the selection to the
   // start or around the replaced test. Hint may be "start" or "around".
   function computeReplacedSel(doc, changes, hint) {
     var out = [];
     var oldPrev = Pos(doc.first, 0), newPrev = oldPrev;
     for (var i = 0; i < changes.length; i++) {
       var change = changes[i];
       var from = offsetPos(change.from, oldPrev, newPrev);
       var to = offsetPos(changeEnd(change), oldPrev, newPrev);
       oldPrev = change.to;
       newPrev = to;
       if (hint == "around") {
         var range = doc.sel.ranges[i], inv = cmp(range.head, range.anchor) < 0;
         out[i] = new Range(inv ? to : from, inv ? from : to);
       } else {
         out[i] = new Range(from, from);
       }
     }
     return new Selection(out, doc.sel.primIndex);
   }
 
   // Allow "beforeChange" event handlers to influence a change
   function filterChange(doc, change, update) {
     var obj = {
       canceled: false,
       from: change.from,
       to: change.to,
       text: change.text,
       origin: change.origin,
       cancel: function() { this.canceled = true; }
     };
     if (update) obj.update = function(from, to, text, origin) {
       if (from) this.from = clipPos(doc, from);
       if (to) this.to = clipPos(doc, to);
       if (text) this.text = text;
       if (origin !== undefined) this.origin = origin;
     };
     signal(doc, "beforeChange", doc, obj);
     if (doc.cm) signal(doc.cm, "beforeChange", doc.cm, obj);
 
     if (obj.canceled) return null;
     return {from: obj.from, to: obj.to, text: obj.text, origin: obj.origin};
   }
 
   // Apply a change to a document, and add it to the document's
   // history, and propagating it to all linked documents.
   function makeChange(doc, change, ignoreReadOnly) {
     if (doc.cm) {
       if (!doc.cm.curOp) return operation(doc.cm, makeChange)(doc, change, ignoreReadOnly);
       if (doc.cm.state.suppressEdits) return;
     }
 
     if (hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange")) {
       change = filterChange(doc, change, true);
       if (!change) return;
     }
 
     // Possibly split or suppress the update based on the presence
     // of read-only spans in its range.
     var split = sawReadOnlySpans && !ignoreReadOnly && removeReadOnlyRanges(doc, change.from, change.to);
     if (split) {
       for (var i = split.length - 1; i >= 0; --i)
         makeChangeInner(doc, {from: split[i].from, to: split[i].to, text: i ? [""] : change.text});
     } else {
       makeChangeInner(doc, change);
     }
   }
 
   function makeChangeInner(doc, change) {
     if (change.text.length == 1 && change.text[0] == "" && cmp(change.from, change.to) == 0) return;
     var selAfter = computeSelAfterChange(doc, change);
     addChangeToHistory(doc, change, selAfter, doc.cm ? doc.cm.curOp.id : NaN);
 
     makeChangeSingleDoc(doc, change, selAfter, stretchSpansOverChange(doc, change));
     var rebased = [];
 
     linkedDocs(doc, function(doc, sharedHist) {
       if (!sharedHist && indexOf(rebased, doc.history) == -1) {
         rebaseHist(doc.history, change);
         rebased.push(doc.history);
       }
       makeChangeSingleDoc(doc, change, null, stretchSpansOverChange(doc, change));
     });
   }
 
   // Revert a change stored in a document's history.
   function makeChangeFromHistory(doc, type, allowSelectionOnly) {
     if (doc.cm && doc.cm.state.suppressEdits) return;
 
     var hist = doc.history, event, selAfter = doc.sel;
     var source = type == "undo" ? hist.done : hist.undone, dest = type == "undo" ? hist.undone : hist.done;
 
     // Verify that there is a useable event (so that ctrl-z won't
     // needlessly clear selection events)
     for (var i = 0; i < source.length; i++) {
       event = source[i];
       if (allowSelectionOnly ? event.ranges && !event.equals(doc.sel) : !event.ranges)
         break;
     }
     if (i == source.length) return;
     hist.lastOrigin = hist.lastSelOrigin = null;
 
     for (;;) {
       event = source.pop();
       if (event.ranges) {
         pushSelectionToHistory(event, dest);
         if (allowSelectionOnly && !event.equals(doc.sel)) {
           setSelection(doc, event, {clearRedo: false});
           return;
         }
         selAfter = event;
       }
       else break;
     }
 
     // Build up a reverse change object to add to the opposite history
     // stack (redo when undoing, and vice versa).
     var antiChanges = [];
     pushSelectionToHistory(selAfter, dest);
     dest.push({changes: antiChanges, generation: hist.generation});
     hist.generation = event.generation || ++hist.maxGeneration;
 
     var filter = hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange");
 
     for (var i = event.changes.length - 1; i >= 0; --i) {
       var change = event.changes[i];
       change.origin = type;
       if (filter && !filterChange(doc, change, false)) {
         source.length = 0;
         return;
       }
 
       antiChanges.push(historyChangeFromChange(doc, change));
 
       var after = i ? computeSelAfterChange(doc, change) : lst(source);
       makeChangeSingleDoc(doc, change, after, mergeOldSpans(doc, change));
       if (!i && doc.cm) doc.cm.scrollIntoView({from: change.from, to: changeEnd(change)});
       var rebased = [];
 
       // Propagate to the linked documents
       linkedDocs(doc, function(doc, sharedHist) {
         if (!sharedHist && indexOf(rebased, doc.history) == -1) {
           rebaseHist(doc.history, change);
           rebased.push(doc.history);
         }
         makeChangeSingleDoc(doc, change, null, mergeOldSpans(doc, change));
       });
     }
   }
 
   // Sub-views need their line numbers shifted when text is added
   // above or below them in the parent document.
   function shiftDoc(doc, distance) {
     if (distance == 0) return;
     doc.first += distance;
     doc.sel = new Selection(map(doc.sel.ranges, function(range) {
       return new Range(Pos(range.anchor.line + distance, range.anchor.ch),
                        Pos(range.head.line + distance, range.head.ch));
     }), doc.sel.primIndex);
     if (doc.cm) {
       regChange(doc.cm, doc.first, doc.first - distance, distance);
       for (var d = doc.cm.display, l = d.viewFrom; l < d.viewTo; l++)
         regLineChange(doc.cm, l, "gutter");
     }
   }
 
   // More lower-level change function, handling only a single document
   // (not linked ones).
   function makeChangeSingleDoc(doc, change, selAfter, spans) {
     if (doc.cm && !doc.cm.curOp)
       return operation(doc.cm, makeChangeSingleDoc)(doc, change, selAfter, spans);
 
     if (change.to.line < doc.first) {
       shiftDoc(doc, change.text.length - 1 - (change.to.line - change.from.line));
       return;
     }
     if (change.from.line > doc.lastLine()) return;
 
     // Clip the change to the size of this doc
     if (change.from.line < doc.first) {
       var shift = change.text.length - 1 - (doc.first - change.from.line);
       shiftDoc(doc, shift);
       change = {from: Pos(doc.first, 0), to: Pos(change.to.line + shift, change.to.ch),
                 text: [lst(change.text)], origin: change.origin};
     }
     var last = doc.lastLine();
     if (change.to.line > last) {
       change = {from: change.from, to: Pos(last, getLine(doc, last).text.length),
                 text: [change.text[0]], origin: change.origin};
     }
 
     change.removed = getBetween(doc, change.from, change.to);
 
     if (!selAfter) selAfter = computeSelAfterChange(doc, change);
     if (doc.cm) makeChangeSingleDocInEditor(doc.cm, change, spans);
     else updateDoc(doc, change, spans);
     setSelectionNoUndo(doc, selAfter, sel_dontScroll);
   }
 
   // Handle the interaction of a change to a document with the editor
   // that this document is part of.
   function makeChangeSingleDocInEditor(cm, change, spans) {
     var doc = cm.doc, display = cm.display, from = change.from, to = change.to;
 
     var recomputeMaxLength = false, checkWidthStart = from.line;
     if (!cm.options.lineWrapping) {
       checkWidthStart = lineNo(visualLine(getLine(doc, from.line)));
       doc.iter(checkWidthStart, to.line + 1, function(line) {
         if (line == display.maxLine) {
           recomputeMaxLength = true;
           return true;
         }
       });
     }
 
     if (doc.sel.contains(change.from, change.to) > -1)
       signalCursorActivity(cm);
 
     updateDoc(doc, change, spans, estimateHeight(cm));
 
     if (!cm.options.lineWrapping) {
       doc.iter(checkWidthStart, from.line + change.text.length, function(line) {
         var len = lineLength(line);
         if (len > display.maxLineLength) {
           display.maxLine = line;
           display.maxLineLength = len;
           display.maxLineChanged = true;
           recomputeMaxLength = false;
         }
       });
       if (recomputeMaxLength) cm.curOp.updateMaxLine = true;
     }
 
     // Adjust frontier, schedule worker
     doc.frontier = Math.min(doc.frontier, from.line);
     startWorker(cm, 400);
 
     var lendiff = change.text.length - (to.line - from.line) - 1;
     // Remember that these lines changed, for updating the display
     if (change.full)
       regChange(cm);
     else if (from.line == to.line && change.text.length == 1 && !isWholeLineUpdate(cm.doc, change))
       regLineChange(cm, from.line, "text");
     else
       regChange(cm, from.line, to.line + 1, lendiff);
 
     var changesHandler = hasHandler(cm, "changes"), changeHandler = hasHandler(cm, "change");
     if (changeHandler || changesHandler) {
       var obj = {
         from: from, to: to,
         text: change.text,
         removed: change.removed,
         origin: change.origin
       };
       if (changeHandler) signalLater(cm, "change", cm, obj);
       if (changesHandler) (cm.curOp.changeObjs || (cm.curOp.changeObjs = [])).push(obj);
     }
     cm.display.selForContextMenu = null;
   }
 
   function replaceRange(doc, code, from, to, origin) {
     if (!to) to = from;
     if (cmp(to, from) < 0) { var tmp = to; to = from; from = tmp; }
     if (typeof code == "string") code = doc.splitLines(code);
     makeChange(doc, {from: from, to: to, text: code, origin: origin});
   }
 
   // SCROLLING THINGS INTO VIEW
 
   // If an editor sits on the top or bottom of the window, partially
   // scrolled out of view, this ensures that the cursor is visible.
   function maybeScrollWindow(cm, coords) {
     if (signalDOMEvent(cm, "scrollCursorIntoView")) return;
 
     var display = cm.display, box = display.sizer.getBoundingClientRect(), doScroll = null;
     if (coords.top + box.top < 0) doScroll = true;
     else if (coords.bottom + box.top > (window.innerHeight || document.documentElement.clientHeight)) doScroll = false;
     if (doScroll != null && !phantom) {
       var scrollNode = elt("div", "\u200b", null, "position: absolute; top: " +
                            (coords.top - display.viewOffset - paddingTop(cm.display)) + "px; height: " +
                            (coords.bottom - coords.top + scrollGap(cm) + display.barHeight) + "px; left: " +
                            coords.left + "px; width: 2px;");
       cm.display.lineSpace.appendChild(scrollNode);
       scrollNode.scrollIntoView(doScroll);
       cm.display.lineSpace.removeChild(scrollNode);
     }
   }
 
   // Scroll a given position into view (immediately), verifying that
   // it actually became visible (as line heights are accurately
   // measured, the position of something may 'drift' during drawing).
   function scrollPosIntoView(cm, pos, end, margin) {
     if (margin == null) margin = 0;
     for (var limit = 0; limit < 5; limit++) {
       var changed = false, coords = cursorCoords(cm, pos);
       var endCoords = !end || end == pos ? coords : cursorCoords(cm, end);
       var scrollPos = calculateScrollPos(cm, Math.min(coords.left, endCoords.left),
                                          Math.min(coords.top, endCoords.top) - margin,
                                          Math.max(coords.left, endCoords.left),
                                          Math.max(coords.bottom, endCoords.bottom) + margin);
       var startTop = cm.doc.scrollTop, startLeft = cm.doc.scrollLeft;
       if (scrollPos.scrollTop != null) {
         setScrollTop(cm, scrollPos.scrollTop);
         if (Math.abs(cm.doc.scrollTop - startTop) > 1) changed = true;
       }
       if (scrollPos.scrollLeft != null) {
         setScrollLeft(cm, scrollPos.scrollLeft);
         if (Math.abs(cm.doc.scrollLeft - startLeft) > 1) changed = true;
       }
       if (!changed) break;
     }
     return coords;
   }
 
   // Scroll a given set of coordinates into view (immediately).
   function scrollIntoView(cm, x1, y1, x2, y2) {
     var scrollPos = calculateScrollPos(cm, x1, y1, x2, y2);
     if (scrollPos.scrollTop != null) setScrollTop(cm, scrollPos.scrollTop);
     if (scrollPos.scrollLeft != null) setScrollLeft(cm, scrollPos.scrollLeft);
   }
 
   // Calculate a new scroll position needed to scroll the given
   // rectangle into view. Returns an object with scrollTop and
   // scrollLeft properties. When these are undefined, the
   // vertical/horizontal position does not need to be adjusted.
   function calculateScrollPos(cm, x1, y1, x2, y2) {
     var display = cm.display, snapMargin = textHeight(cm.display);
     if (y1 < 0) y1 = 0;
     var screentop = cm.curOp && cm.curOp.scrollTop != null ? cm.curOp.scrollTop : display.scroller.scrollTop;
     var screen = displayHeight(cm), result = {};
     if (y2 - y1 > screen) y2 = y1 + screen;
     var docBottom = cm.doc.height + paddingVert(display);
     var atTop = y1 < snapMargin, atBottom = y2 > docBottom - snapMargin;
     if (y1 < screentop) {
       result.scrollTop = atTop ? 0 : y1;
     } else if (y2 > screentop + screen) {
       var newTop = Math.min(y1, (atBottom ? docBottom : y2) - screen);
       if (newTop != screentop) result.scrollTop = newTop;
     }
 
     var screenleft = cm.curOp && cm.curOp.scrollLeft != null ? cm.curOp.scrollLeft : display.scroller.scrollLeft;
     var screenw = displayWidth(cm) - (cm.options.fixedGutter ? display.gutters.offsetWidth : 0);
     var tooWide = x2 - x1 > screenw;
     if (tooWide) x2 = x1 + screenw;
     if (x1 < 10)
       result.scrollLeft = 0;
     else if (x1 < screenleft)
       result.scrollLeft = Math.max(0, x1 - (tooWide ? 0 : 10));
     else if (x2 > screenw + screenleft - 3)
       result.scrollLeft = x2 + (tooWide ? 0 : 10) - screenw;
     return result;
   }
 
   // Store a relative adjustment to the scroll position in the current
   // operation (to be applied when the operation finishes).
   function addToScrollPos(cm, left, top) {
     if (left != null || top != null) resolveScrollToPos(cm);
     if (left != null)
       cm.curOp.scrollLeft = (cm.curOp.scrollLeft == null ? cm.doc.scrollLeft : cm.curOp.scrollLeft) + left;
     if (top != null)
       cm.curOp.scrollTop = (cm.curOp.scrollTop == null ? cm.doc.scrollTop : cm.curOp.scrollTop) + top;
   }
 
   // Make sure that at the end of the operation the current cursor is
   // shown.
   function ensureCursorVisible(cm) {
     resolveScrollToPos(cm);
     var cur = cm.getCursor(), from = cur, to = cur;
     if (!cm.options.lineWrapping) {
       from = cur.ch ? Pos(cur.line, cur.ch - 1) : cur;
       to = Pos(cur.line, cur.ch + 1);
     }
     cm.curOp.scrollToPos = {from: from, to: to, margin: cm.options.cursorScrollMargin, isCursor: true};
   }
 
   // When an operation has its scrollToPos property set, and another
   // scroll action is applied before the end of the operation, this
   // 'simulates' scrolling that position into view in a cheap way, so
   // that the effect of intermediate scroll commands is not ignored.
   function resolveScrollToPos(cm) {
     var range = cm.curOp.scrollToPos;
     if (range) {
       cm.curOp.scrollToPos = null;
       var from = estimateCoords(cm, range.from), to = estimateCoords(cm, range.to);
       var sPos = calculateScrollPos(cm, Math.min(from.left, to.left),
                                     Math.min(from.top, to.top) - range.margin,
                                     Math.max(from.right, to.right),
                                     Math.max(from.bottom, to.bottom) + range.margin);
       cm.scrollTo(sPos.scrollLeft, sPos.scrollTop);
     }
   }
 
   // API UTILITIES
 
   // Indent the given line. The how parameter can be "smart",
   // "add"/null, "subtract", or "prev". When aggressive is false
   // (typically set to true for forced single-line indents), empty
   // lines are not indented, and places where the mode returns Pass
   // are left alone.
   function indentLine(cm, n, how, aggressive) {
     var doc = cm.doc, state;
     if (how == null) how = "add";
     if (how == "smart") {
       // Fall back to "prev" when the mode doesn't have an indentation
       // method.
       if (!doc.mode.indent) how = "prev";
       else state = getStateBefore(cm, n);
     }
 
     var tabSize = cm.options.tabSize;
     var line = getLine(doc, n), curSpace = countColumn(line.text, null, tabSize);
     if (line.stateAfter) line.stateAfter = null;
     var curSpaceString = line.text.match(/^\s*/)[0], indentation;
     if (!aggressive && !/\S/.test(line.text)) {
       indentation = 0;
       how = "not";
     } else if (how == "smart") {
       indentation = doc.mode.indent(state, line.text.slice(curSpaceString.length), line.text);
       if (indentation == Pass || indentation > 150) {
         if (!aggressive) return;
         how = "prev";
       }
     }
     if (how == "prev") {
       if (n > doc.first) indentation = countColumn(getLine(doc, n-1).text, null, tabSize);
       else indentation = 0;
     } else if (how == "add") {
       indentation = curSpace + cm.options.indentUnit;
     } else if (how == "subtract") {
       indentation = curSpace - cm.options.indentUnit;
     } else if (typeof how == "number") {
       indentation = curSpace + how;
     }
     indentation = Math.max(0, indentation);
 
     var indentString = "", pos = 0;
     if (cm.options.indentWithTabs)
       for (var i = Math.floor(indentation / tabSize); i; --i) {pos += tabSize; indentString += "\t";}
     if (pos < indentation) indentString += spaceStr(indentation - pos);
 
     if (indentString != curSpaceString) {
       replaceRange(doc, indentString, Pos(n, 0), Pos(n, curSpaceString.length), "+input");
       line.stateAfter = null;
       return true;
     } else {
       // Ensure that, if the cursor was in the whitespace at the start
       // of the line, it is moved to the end of that space.
       for (var i = 0; i < doc.sel.ranges.length; i++) {
         var range = doc.sel.ranges[i];
         if (range.head.line == n && range.head.ch < curSpaceString.length) {
           var pos = Pos(n, curSpaceString.length);
           replaceOneSelection(doc, i, new Range(pos, pos));
           break;
         }
       }
     }
   }
 
   // Utility for applying a change to a line by handle or number,
   // returning the number and optionally registering the line as
   // changed.
   function changeLine(doc, handle, changeType, op) {
     var no = handle, line = handle;
     if (typeof handle == "number") line = getLine(doc, clipLine(doc, handle));
     else no = lineNo(handle);
     if (no == null) return null;
     if (op(line, no) && doc.cm) regLineChange(doc.cm, no, changeType);
     return line;
   }
 
   // Helper for deleting text near the selection(s), used to implement
   // backspace, delete, and similar functionality.
   function deleteNearSelection(cm, compute) {
     var ranges = cm.doc.sel.ranges, kill = [];
     // Build up a set of ranges to kill first, merging overlapping
     // ranges.
     for (var i = 0; i < ranges.length; i++) {
       var toKill = compute(ranges[i]);
       while (kill.length && cmp(toKill.from, lst(kill).to) <= 0) {
         var replaced = kill.pop();
         if (cmp(replaced.from, toKill.from) < 0) {
           toKill.from = replaced.from;
           break;
         }
       }
       kill.push(toKill);
     }
     // Next, remove those actual ranges.
     runInOp(cm, function() {
       for (var i = kill.length - 1; i >= 0; i--)
         replaceRange(cm.doc, "", kill[i].from, kill[i].to, "+delete");
       ensureCursorVisible(cm);
     });
   }
 
   // Used for horizontal relative motion. Dir is -1 or 1 (left or
   // right), unit can be "char", "column" (like char, but doesn't
   // cross line boundaries), "word" (across next word), or "group" (to
   // the start of next group of word or non-word-non-whitespace
   // chars). The visually param controls whether, in right-to-left
   // text, direction 1 means to move towards the next index in the
   // string, or towards the character to the right of the current
   // position. The resulting position will have a hitSide=true
   // property if it reached the end of the document.
   function findPosH(doc, pos, dir, unit, visually) {
     var line = pos.line, ch = pos.ch, origDir = dir;
     var lineObj = getLine(doc, line);
     function findNextLine() {
       var l = line + dir;
       if (l < doc.first || l >= doc.first + doc.size) return false
       line = l;
       return lineObj = getLine(doc, l);
     }
     function moveOnce(boundToLine) {
       var next = (visually ? moveVisually : moveLogically)(lineObj, ch, dir, true);
       if (next == null) {
         if (!boundToLine && findNextLine()) {
           if (visually) ch = (dir < 0 ? lineRight : lineLeft)(lineObj);
           else ch = dir < 0 ? lineObj.text.length : 0;
         } else return false
       } else ch = next;
       return true;
     }
 
     if (unit == "char") {
       moveOnce()
     } else if (unit == "column") {
       moveOnce(true)
     } else if (unit == "word" || unit == "group") {
       var sawType = null, group = unit == "group";
       var helper = doc.cm && doc.cm.getHelper(pos, "wordChars");
       for (var first = true;; first = false) {
         if (dir < 0 && !moveOnce(!first)) break;
         var cur = lineObj.text.charAt(ch) || "\n";
         var type = isWordChar(cur, helper) ? "w"
           : group && cur == "\n" ? "n"
           : !group || /\s/.test(cur) ? null
           : "p";
         if (group && !first && !type) type = "s";
         if (sawType && sawType != type) {
           if (dir < 0) {dir = 1; moveOnce();}
           break;
         }
 
         if (type) sawType = type;
         if (dir > 0 && !moveOnce(!first)) break;
       }
     }
     var result = skipAtomic(doc, Pos(line, ch), pos, origDir, true);
     if (!cmp(pos, result)) result.hitSide = true;
     return result;
   }
 
   // For relative vertical movement. Dir may be -1 or 1. Unit can be
   // "page" or "line". The resulting position will have a hitSide=true
   // property if it reached the end of the document.
   function findPosV(cm, pos, dir, unit) {
     var doc = cm.doc, x = pos.left, y;
     if (unit == "page") {
       var pageSize = Math.min(cm.display.wrapper.clientHeight, window.innerHeight || document.documentElement.clientHeight);
       y = pos.top + dir * (pageSize - (dir < 0 ? 1.5 : .5) * textHeight(cm.display));
     } else if (unit == "line") {
       y = dir > 0 ? pos.bottom + 3 : pos.top - 3;
     }
     for (;;) {
       var target = coordsChar(cm, x, y);
       if (!target.outside) break;
       if (dir < 0 ? y <= 0 : y >= doc.height) { target.hitSide = true; break; }
       y += dir * 5;
     }
     return target;
   }
 
   // EDITOR METHODS
 
   // The publicly visible API. Note that methodOp(f) means
   // 'wrap f in an operation, performed on its `this` parameter'.
 
   // This is not the complete set of editor methods. Most of the
   // methods defined on the Doc type are also injected into
   // CodeMirror.prototype, for backwards compatibility and
   // convenience.
 
   CodeMirror.prototype = {
     constructor: CodeMirror,
     focus: function(){window.focus(); this.display.input.focus();},
 
     setOption: function(option, value) {
       var options = this.options, old = options[option];
       if (options[option] == value && option != "mode") return;
       options[option] = value;
       if (optionHandlers.hasOwnProperty(option))
         operation(this, optionHandlers[option])(this, value, old);
     },
 
     getOption: function(option) {return this.options[option];},
     getDoc: function() {return this.doc;},
 
     addKeyMap: function(map, bottom) {
       this.state.keyMaps[bottom ? "push" : "unshift"](getKeyMap(map));
     },
     removeKeyMap: function(map) {
       var maps = this.state.keyMaps;
       for (var i = 0; i < maps.length; ++i)
         if (maps[i] == map || maps[i].name == map) {
           maps.splice(i, 1);
           return true;
         }
     },
 
     addOverlay: methodOp(function(spec, options) {
       var mode = spec.token ? spec : CodeMirror.getMode(this.options, spec);
       if (mode.startState) throw new Error("Overlays may not be stateful.");
       this.state.overlays.push({mode: mode, modeSpec: spec, opaque: options && options.opaque});
       this.state.modeGen++;
       regChange(this);
     }),
     removeOverlay: methodOp(function(spec) {
       var overlays = this.state.overlays;
       for (var i = 0; i < overlays.length; ++i) {
         var cur = overlays[i].modeSpec;
         if (cur == spec || typeof spec == "string" && cur.name == spec) {
           overlays.splice(i, 1);
           this.state.modeGen++;
           regChange(this);
           return;
         }
       }
     }),
 
     indentLine: methodOp(function(n, dir, aggressive) {
       if (typeof dir != "string" && typeof dir != "number") {
         if (dir == null) dir = this.options.smartIndent ? "smart" : "prev";
         else dir = dir ? "add" : "subtract";
       }
       if (isLine(this.doc, n)) indentLine(this, n, dir, aggressive);
     }),
     indentSelection: methodOp(function(how) {
       var ranges = this.doc.sel.ranges, end = -1;
       for (var i = 0; i < ranges.length; i++) {
         var range = ranges[i];
         if (!range.empty()) {
           var from = range.from(), to = range.to();
           var start = Math.max(end, from.line);
           end = Math.min(this.lastLine(), to.line - (to.ch ? 0 : 1)) + 1;
           for (var j = start; j < end; ++j)
             indentLine(this, j, how);
           var newRanges = this.doc.sel.ranges;
           if (from.ch == 0 && ranges.length == newRanges.length && newRanges[i].from().ch > 0)
             replaceOneSelection(this.doc, i, new Range(from, newRanges[i].to()), sel_dontScroll);
         } else if (range.head.line > end) {
           indentLine(this, range.head.line, how, true);
           end = range.head.line;
           if (i == this.doc.sel.primIndex) ensureCursorVisible(this);
         }
       }
     }),
 
     // Fetch the parser token for a given character. Useful for hacks
     // that want to inspect the mode state (say, for completion).
     getTokenAt: function(pos, precise) {
       return takeToken(this, pos, precise);
     },
 
     getLineTokens: function(line, precise) {
       return takeToken(this, Pos(line), precise, true);
     },
 
     getTokenTypeAt: function(pos) {
       pos = clipPos(this.doc, pos);
       var styles = getLineStyles(this, getLine(this.doc, pos.line));
       var before = 0, after = (styles.length - 1) / 2, ch = pos.ch;
       var type;
       if (ch == 0) type = styles[2];
       else for (;;) {
         var mid = (before + after) >> 1;
         if ((mid ? styles[mid * 2 - 1] : 0) >= ch) after = mid;
         else if (styles[mid * 2 + 1] < ch) before = mid + 1;
         else { type = styles[mid * 2 + 2]; break; }
       }
       var cut = type ? type.indexOf("cm-overlay ") : -1;
       return cut < 0 ? type : cut == 0 ? null : type.slice(0, cut - 1);
     },
 
     getModeAt: function(pos) {
       var mode = this.doc.mode;
       if (!mode.innerMode) return mode;
       return CodeMirror.innerMode(mode, this.getTokenAt(pos).state).mode;
     },
 
     getHelper: function(pos, type) {
       return this.getHelpers(pos, type)[0];
     },
 
     getHelpers: function(pos, type) {
       var found = [];
       if (!helpers.hasOwnProperty(type)) return found;
       var help = helpers[type], mode = this.getModeAt(pos);
       if (typeof mode[type] == "string") {
         if (help[mode[type]]) found.push(help[mode[type]]);
       } else if (mode[type]) {
         for (var i = 0; i < mode[type].length; i++) {
           var val = help[mode[type][i]];
           if (val) found.push(val);
         }
       } else if (mode.helperType && help[mode.helperType]) {
         found.push(help[mode.helperType]);
       } else if (help[mode.name]) {
         found.push(help[mode.name]);
       }
       for (var i = 0; i < help._global.length; i++) {
         var cur = help._global[i];
         if (cur.pred(mode, this) && indexOf(found, cur.val) == -1)
           found.push(cur.val);
       }
       return found;
     },
 
     getStateAfter: function(line, precise) {
       var doc = this.doc;
       line = clipLine(doc, line == null ? doc.first + doc.size - 1: line);
       return getStateBefore(this, line + 1, precise);
     },
 
     cursorCoords: function(start, mode) {
       var pos, range = this.doc.sel.primary();
       if (start == null) pos = range.head;
       else if (typeof start == "object") pos = clipPos(this.doc, start);
       else pos = start ? range.from() : range.to();
       return cursorCoords(this, pos, mode || "page");
     },
 
     charCoords: function(pos, mode) {
       return charCoords(this, clipPos(this.doc, pos), mode || "page");
     },
 
     coordsChar: function(coords, mode) {
       coords = fromCoordSystem(this, coords, mode || "page");
       return coordsChar(this, coords.left, coords.top);
     },
 
     lineAtHeight: function(height, mode) {
       height = fromCoordSystem(this, {top: height, left: 0}, mode || "page").top;
       return lineAtHeight(this.doc, height + this.display.viewOffset);
     },
     heightAtLine: function(line, mode) {
       var end = false, lineObj;
       if (typeof line == "number") {
         var last = this.doc.first + this.doc.size - 1;
         if (line < this.doc.first) line = this.doc.first;
         else if (line > last) { line = last; end = true; }
         lineObj = getLine(this.doc, line);
       } else {
         lineObj = line;
       }
       return intoCoordSystem(this, lineObj, {top: 0, left: 0}, mode || "page").top +
         (end ? this.doc.height - heightAtLine(lineObj) : 0);
     },
 
     defaultTextHeight: function() { return textHeight(this.display); },
     defaultCharWidth: function() { return charWidth(this.display); },
 
     setGutterMarker: methodOp(function(line, gutterID, value) {
       return changeLine(this.doc, line, "gutter", function(line) {
         var markers = line.gutterMarkers || (line.gutterMarkers = {});
         markers[gutterID] = value;
         if (!value && isEmpty(markers)) line.gutterMarkers = null;
         return true;
       });
     }),
 
     clearGutter: methodOp(function(gutterID) {
       var cm = this, doc = cm.doc, i = doc.first;
       doc.iter(function(line) {
         if (line.gutterMarkers && line.gutterMarkers[gutterID]) {
           line.gutterMarkers[gutterID] = null;
           regLineChange(cm, i, "gutter");
           if (isEmpty(line.gutterMarkers)) line.gutterMarkers = null;
         }
         ++i;
       });
     }),
 
     lineInfo: function(line) {
       if (typeof line == "number") {
         if (!isLine(this.doc, line)) return null;
         var n = line;
         line = getLine(this.doc, line);
         if (!line) return null;
       } else {
         var n = lineNo(line);
         if (n == null) return null;
       }
       return {line: n, handle: line, text: line.text, gutterMarkers: line.gutterMarkers,
               textClass: line.textClass, bgClass: line.bgClass, wrapClass: line.wrapClass,
               widgets: line.widgets};
     },
 
     getViewport: function() { return {from: this.display.viewFrom, to: this.display.viewTo};},
 
     addWidget: function(pos, node, scroll, vert, horiz) {
       var display = this.display;
       pos = cursorCoords(this, clipPos(this.doc, pos));
       var top = pos.bottom, left = pos.left;
       node.style.position = "absolute";
       node.setAttribute("cm-ignore-events", "true");
       this.display.input.setUneditable(node);
       display.sizer.appendChild(node);
       if (vert == "over") {
         top = pos.top;
       } else if (vert == "above" || vert == "near") {
         var vspace = Math.max(display.wrapper.clientHeight, this.doc.height),
         hspace = Math.max(display.sizer.clientWidth, display.lineSpace.clientWidth);
         // Default to positioning above (if specified and possible); otherwise default to positioning below
         if ((vert == 'above' || pos.bottom + node.offsetHeight > vspace) && pos.top > node.offsetHeight)
           top = pos.top - node.offsetHeight;
         else if (pos.bottom + node.offsetHeight <= vspace)
           top = pos.bottom;
         if (left + node.offsetWidth > hspace)
           left = hspace - node.offsetWidth;
       }
       node.style.top = top + "px";
       node.style.left = node.style.right = "";
       if (horiz == "right") {
         left = display.sizer.clientWidth - node.offsetWidth;
         node.style.right = "0px";
       } else {
         if (horiz == "left") left = 0;
         else if (horiz == "middle") left = (display.sizer.clientWidth - node.offsetWidth) / 2;
         node.style.left = left + "px";
       }
       if (scroll)
         scrollIntoView(this, left, top, left + node.offsetWidth, top + node.offsetHeight);
     },
 
     triggerOnKeyDown: methodOp(onKeyDown),
     triggerOnKeyPress: methodOp(onKeyPress),
     triggerOnKeyUp: onKeyUp,
 
     execCommand: function(cmd) {
       if (commands.hasOwnProperty(cmd))
         return commands[cmd].call(null, this);
     },
 
     triggerElectric: methodOp(function(text) { triggerElectric(this, text); }),
 
     findPosH: function(from, amount, unit, visually) {
       var dir = 1;
       if (amount < 0) { dir = -1; amount = -amount; }
       for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {
         cur = findPosH(this.doc, cur, dir, unit, visually);
         if (cur.hitSide) break;
       }
       return cur;
     },
 
     moveH: methodOp(function(dir, unit) {
       var cm = this;
       cm.extendSelectionsBy(function(range) {
         if (cm.display.shift || cm.doc.extend || range.empty())
           return findPosH(cm.doc, range.head, dir, unit, cm.options.rtlMoveVisually);
         else
           return dir < 0 ? range.from() : range.to();
       }, sel_move);
     }),
 
     deleteH: methodOp(function(dir, unit) {
       var sel = this.doc.sel, doc = this.doc;
       if (sel.somethingSelected())
         doc.replaceSelection("", null, "+delete");
       else
         deleteNearSelection(this, function(range) {
           var other = findPosH(doc, range.head, dir, unit, false);
           return dir < 0 ? {from: other, to: range.head} : {from: range.head, to: other};
         });
     }),
 
     findPosV: function(from, amount, unit, goalColumn) {
       var dir = 1, x = goalColumn;
       if (amount < 0) { dir = -1; amount = -amount; }
       for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {
         var coords = cursorCoords(this, cur, "div");
         if (x == null) x = coords.left;
         else coords.left = x;
         cur = findPosV(this, coords, dir, unit);
         if (cur.hitSide) break;
       }
       return cur;
     },
 
     moveV: methodOp(function(dir, unit) {
       var cm = this, doc = this.doc, goals = [];
       var collapse = !cm.display.shift && !doc.extend && doc.sel.somethingSelected();
       doc.extendSelectionsBy(function(range) {
         if (collapse)
           return dir < 0 ? range.from() : range.to();
         var headPos = cursorCoords(cm, range.head, "div");
         if (range.goalColumn != null) headPos.left = range.goalColumn;
         goals.push(headPos.left);
         var pos = findPosV(cm, headPos, dir, unit);
         if (unit == "page" && range == doc.sel.primary())
           addToScrollPos(cm, null, charCoords(cm, pos, "div").top - headPos.top);
         return pos;
       }, sel_move);
       if (goals.length) for (var i = 0; i < doc.sel.ranges.length; i++)
         doc.sel.ranges[i].goalColumn = goals[i];
     }),
 
     // Find the word at the given position (as returned by coordsChar).
     findWordAt: function(pos) {
       var doc = this.doc, line = getLine(doc, pos.line).text;
       var start = pos.ch, end = pos.ch;
       if (line) {
         var helper = this.getHelper(pos, "wordChars");
         if ((pos.xRel < 0 || end == line.length) && start) --start; else ++end;
         var startChar = line.charAt(start);
         var check = isWordChar(startChar, helper)
           ? function(ch) { return isWordChar(ch, helper); }
           : /\s/.test(startChar) ? function(ch) {return /\s/.test(ch);}
           : function(ch) {return !/\s/.test(ch) && !isWordChar(ch);};
         while (start > 0 && check(line.charAt(start - 1))) --start;
         while (end < line.length && check(line.charAt(end))) ++end;
       }
       return new Range(Pos(pos.line, start), Pos(pos.line, end));
     },
 
     toggleOverwrite: function(value) {
       if (value != null && value == this.state.overwrite) return;
       if (this.state.overwrite = !this.state.overwrite)
         addClass(this.display.cursorDiv, "CodeMirror-overwrite");
       else
         rmClass(this.display.cursorDiv, "CodeMirror-overwrite");
 
       signal(this, "overwriteToggle", this, this.state.overwrite);
     },
     hasFocus: function() { return this.display.input.getField() == activeElt(); },
     isReadOnly: function() { return !!(this.options.readOnly || this.doc.cantEdit); },
 
     scrollTo: methodOp(function(x, y) {
       if (x != null || y != null) resolveScrollToPos(this);
       if (x != null) this.curOp.scrollLeft = x;
       if (y != null) this.curOp.scrollTop = y;
     }),
     getScrollInfo: function() {
       var scroller = this.display.scroller;
       return {left: scroller.scrollLeft, top: scroller.scrollTop,
               height: scroller.scrollHeight - scrollGap(this) - this.display.barHeight,
               width: scroller.scrollWidth - scrollGap(this) - this.display.barWidth,
               clientHeight: displayHeight(this), clientWidth: displayWidth(this)};
     },
 
     scrollIntoView: methodOp(function(range, margin) {
       if (range == null) {
         range = {from: this.doc.sel.primary().head, to: null};
         if (margin == null) margin = this.options.cursorScrollMargin;
       } else if (typeof range == "number") {
         range = {from: Pos(range, 0), to: null};
       } else if (range.from == null) {
         range = {from: range, to: null};
       }
       if (!range.to) range.to = range.from;
       range.margin = margin || 0;
 
       if (range.from.line != null) {
         resolveScrollToPos(this);
         this.curOp.scrollToPos = range;
       } else {
         var sPos = calculateScrollPos(this, Math.min(range.from.left, range.to.left),
                                       Math.min(range.from.top, range.to.top) - range.margin,
                                       Math.max(range.from.right, range.to.right),
                                       Math.max(range.from.bottom, range.to.bottom) + range.margin);
         this.scrollTo(sPos.scrollLeft, sPos.scrollTop);
       }
     }),
 
     setSize: methodOp(function(width, height) {
       var cm = this;
       function interpret(val) {
         return typeof val == "number" || /^\d+$/.test(String(val)) ? val + "px" : val;
       }
       if (width != null) cm.display.wrapper.style.width = interpret(width);
       if (height != null) cm.display.wrapper.style.height = interpret(height);
       if (cm.options.lineWrapping) clearLineMeasurementCache(this);
       var lineNo = cm.display.viewFrom;
       cm.doc.iter(lineNo, cm.display.viewTo, function(line) {
         if (line.widgets) for (var i = 0; i < line.widgets.length; i++)
           if (line.widgets[i].noHScroll) { regLineChange(cm, lineNo, "widget"); break; }
         ++lineNo;
       });
       cm.curOp.forceUpdate = true;
       signal(cm, "refresh", this);
     }),
 
     operation: function(f){return runInOp(this, f);},
 
     refresh: methodOp(function() {
       var oldHeight = this.display.cachedTextHeight;
       regChange(this);
       this.curOp.forceUpdate = true;
       clearCaches(this);
       this.scrollTo(this.doc.scrollLeft, this.doc.scrollTop);
       updateGutterSpace(this);
       if (oldHeight == null || Math.abs(oldHeight - textHeight(this.display)) > .5)
         estimateLineHeights(this);
       signal(this, "refresh", this);
     }),
 
     swapDoc: methodOp(function(doc) {
       var old = this.doc;
       old.cm = null;
       attachDoc(this, doc);
       clearCaches(this);
       this.display.input.reset();
       this.scrollTo(doc.scrollLeft, doc.scrollTop);
       this.curOp.forceScroll = true;
       signalLater(this, "swapDoc", this, old);
       return old;
     }),
 
     getInputField: function(){return this.display.input.getField();},
     getWrapperElement: function(){return this.display.wrapper;},
     getScrollerElement: function(){return this.display.scroller;},
     getGutterElement: function(){return this.display.gutters;}
   };
   eventMixin(CodeMirror);
 
   // OPTION DEFAULTS
 
   // The default configuration options.
   var defaults = CodeMirror.defaults = {};
   // Functions to run when options are changed.
   var optionHandlers = CodeMirror.optionHandlers = {};
 
   function option(name, deflt, handle, notOnInit) {
     CodeMirror.defaults[name] = deflt;
     if (handle) optionHandlers[name] =
       notOnInit ? function(cm, val, old) {if (old != Init) handle(cm, val, old);} : handle;
   }
 
   // Passed to option handlers when there is no old value.
   var Init = CodeMirror.Init = {toString: function(){return "CodeMirror.Init";}};
 
   // These two are, on init, called from the constructor because they
   // have to be initialized before the editor can start at all.
   option("value", "", function(cm, val) {
     cm.setValue(val);
   }, true);
   option("mode", null, function(cm, val) {
     cm.doc.modeOption = val;
     loadMode(cm);
   }, true);
 
   option("indentUnit", 2, loadMode, true);
   option("indentWithTabs", false);
   option("smartIndent", true);
   option("tabSize", 4, function(cm) {
     resetModeState(cm);
     clearCaches(cm);
     regChange(cm);
   }, true);
   option("lineSeparator", null, function(cm, val) {
     cm.doc.lineSep = val;
     if (!val) return;
     var newBreaks = [], lineNo = cm.doc.first;
     cm.doc.iter(function(line) {
       for (var pos = 0;;) {
         var found = line.text.indexOf(val, pos);
         if (found == -1) break;
         pos = found + val.length;
         newBreaks.push(Pos(lineNo, found));
       }
       lineNo++;
     });
     for (var i = newBreaks.length - 1; i >= 0; i--)
       replaceRange(cm.doc, val, newBreaks[i], Pos(newBreaks[i].line, newBreaks[i].ch + val.length))
   });
   option("specialChars", /[\u0000-\u001f\u007f\u00ad\u200b-\u200f\u2028\u2029\ufeff]/g, function(cm, val, old) {
     cm.state.specialChars = new RegExp(val.source + (val.test("\t") ? "" : "|\t"), "g");
     if (old != CodeMirror.Init) cm.refresh();
   });
   option("specialCharPlaceholder", defaultSpecialCharPlaceholder, function(cm) {cm.refresh();}, true);
   option("electricChars", true);
   option("inputStyle", mobile ? "contenteditable" : "textarea", function() {
     throw new Error("inputStyle can not (yet) be changed in a running editor"); // FIXME
   }, true);
   option("rtlMoveVisually", !windows);
   option("wholeLineUpdateBefore", true);
 
   option("theme", "default", function(cm) {
     themeChanged(cm);
     guttersChanged(cm);
   }, true);
   option("keyMap", "default", function(cm, val, old) {
     var next = getKeyMap(val);
     var prev = old != CodeMirror.Init && getKeyMap(old);
     if (prev && prev.detach) prev.detach(cm, next);
     if (next.attach) next.attach(cm, prev || null);
   });
   option("extraKeys", null);
 
   option("lineWrapping", false, wrappingChanged, true);
   option("gutters", [], function(cm) {
     setGuttersForLineNumbers(cm.options);
     guttersChanged(cm);
   }, true);
   option("fixedGutter", true, function(cm, val) {
     cm.display.gutters.style.left = val ? compensateForHScroll(cm.display) + "px" : "0";
     cm.refresh();
   }, true);
   option("coverGutterNextToScrollbar", false, function(cm) {updateScrollbars(cm);}, true);
   option("scrollbarStyle", "native", function(cm) {
     initScrollbars(cm);
     updateScrollbars(cm);
     cm.display.scrollbars.setScrollTop(cm.doc.scrollTop);
     cm.display.scrollbars.setScrollLeft(cm.doc.scrollLeft);
   }, true);
   option("lineNumbers", false, function(cm) {
     setGuttersForLineNumbers(cm.options);
     guttersChanged(cm);
   }, true);
   option("firstLineNumber", 1, guttersChanged, true);
   option("lineNumberFormatter", function(integer) {return integer;}, guttersChanged, true);
   option("showCursorWhenSelecting", false, updateSelection, true);
 
   option("resetSelectionOnContextMenu", true);
   option("lineWiseCopyCut", true);
 
   option("readOnly", false, function(cm, val) {
     if (val == "nocursor") {
       onBlur(cm);
       cm.display.input.blur();
       cm.display.disabled = true;
     } else {
       cm.display.disabled = false;
     }
     cm.display.input.readOnlyChanged(val)
   });
   option("disableInput", false, function(cm, val) {if (!val) cm.display.input.reset();}, true);
   option("dragDrop", true, dragDropChanged);
   option("allowDropFileTypes", null);
 
   option("cursorBlinkRate", 530);
   option("cursorScrollMargin", 0);
   option("cursorHeight", 1, updateSelection, true);
   option("singleCursorHeightPerLine", true, updateSelection, true);
   option("workTime", 100);
   option("workDelay", 100);
   option("flattenSpans", true, resetModeState, true);
   option("addModeClass", false, resetModeState, true);
   option("pollInterval", 100);
   option("undoDepth", 200, function(cm, val){cm.doc.history.undoDepth = val;});
   option("historyEventDelay", 1250);
   option("viewportMargin", 10, function(cm){cm.refresh();}, true);
   option("maxHighlightLength", 10000, resetModeState, true);
   option("moveInputWithCursor", true, function(cm, val) {
     if (!val) cm.display.input.resetPosition();
   });
 
   option("tabindex", null, function(cm, val) {
     cm.display.input.getField().tabIndex = val || "";
   });
   option("autofocus", null);
 
   // MODE DEFINITION AND QUERYING
 
   // Known modes, by name and by MIME
   var modes = CodeMirror.modes = {}, mimeModes = CodeMirror.mimeModes = {};
 
   // Extra arguments are stored as the mode's dependencies, which is
   // used by (legacy) mechanisms like loadmode.js to automatically
   // load a mode. (Preferred mechanism is the require/define calls.)
   CodeMirror.defineMode = function(name, mode) {
     if (!CodeMirror.defaults.mode && name != "null") CodeMirror.defaults.mode = name;
     if (arguments.length > 2)
       mode.dependencies = Array.prototype.slice.call(arguments, 2);
     modes[name] = mode;
   };
 
   CodeMirror.defineMIME = function(mime, spec) {
     mimeModes[mime] = spec;
   };
 
   // Given a MIME type, a {name, ...options} config object, or a name
   // string, return a mode config object.
   CodeMirror.resolveMode = function(spec) {
     if (typeof spec == "string" && mimeModes.hasOwnProperty(spec)) {
       spec = mimeModes[spec];
     } else if (spec && typeof spec.name == "string" && mimeModes.hasOwnProperty(spec.name)) {
       var found = mimeModes[spec.name];
       if (typeof found == "string") found = {name: found};
       spec = createObj(found, spec);
       spec.name = found.name;
     } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+xml$/.test(spec)) {
       return CodeMirror.resolveMode("application/xml");
     }
     if (typeof spec == "string") return {name: spec};
     else return spec || {name: "null"};
   };
 
   // Given a mode spec (anything that resolveMode accepts), find and
   // initialize an actual mode object.
   CodeMirror.getMode = function(options, spec) {
     var spec = CodeMirror.resolveMode(spec);
     var mfactory = modes[spec.name];
     if (!mfactory) return CodeMirror.getMode(options, "text/plain");
     var modeObj = mfactory(options, spec);
     if (modeExtensions.hasOwnProperty(spec.name)) {
       var exts = modeExtensions[spec.name];
       for (var prop in exts) {
         if (!exts.hasOwnProperty(prop)) continue;
         if (modeObj.hasOwnProperty(prop)) modeObj["_" + prop] = modeObj[prop];
         modeObj[prop] = exts[prop];
       }
     }
     modeObj.name = spec.name;
     if (spec.helperType) modeObj.helperType = spec.helperType;
     if (spec.modeProps) for (var prop in spec.modeProps)
       modeObj[prop] = spec.modeProps[prop];
 
     return modeObj;
   };
 
   // Minimal default mode.
   CodeMirror.defineMode("null", function() {
     return {token: function(stream) {stream.skipToEnd();}};
   });
   CodeMirror.defineMIME("text/plain", "null");
 
   // This can be used to attach properties to mode objects from
   // outside the actual mode definition.
   var modeExtensions = CodeMirror.modeExtensions = {};
   CodeMirror.extendMode = function(mode, properties) {
     var exts = modeExtensions.hasOwnProperty(mode) ? modeExtensions[mode] : (modeExtensions[mode] = {});
     copyObj(properties, exts);
   };
 
   // EXTENSIONS
 
   CodeMirror.defineExtension = function(name, func) {
     CodeMirror.prototype[name] = func;
   };
   CodeMirror.defineDocExtension = function(name, func) {
     Doc.prototype[name] = func;
   };
   CodeMirror.defineOption = option;
 
   var initHooks = [];
   CodeMirror.defineInitHook = function(f) {initHooks.push(f);};
 
   var helpers = CodeMirror.helpers = {};
   CodeMirror.registerHelper = function(type, name, value) {
     if (!helpers.hasOwnProperty(type)) helpers[type] = CodeMirror[type] = {_global: []};
     helpers[type][name] = value;
   };
   CodeMirror.registerGlobalHelper = function(type, name, predicate, value) {
     CodeMirror.registerHelper(type, name, value);
     helpers[type]._global.push({pred: predicate, val: value});
   };
 
   // MODE STATE HANDLING
 
   // Utility functions for working with state. Exported because nested
   // modes need to do this for their inner modes.
 
   var copyState = CodeMirror.copyState = function(mode, state) {
     if (state === true) return state;
     if (mode.copyState) return mode.copyState(state);
     var nstate = {};
     for (var n in state) {
       var val = state[n];
       if (val instanceof Array) val = val.concat([]);
       nstate[n] = val;
     }
     return nstate;
   };
 
   var startState = CodeMirror.startState = function(mode, a1, a2) {
     return mode.startState ? mode.startState(a1, a2) : true;
   };
 
   // Given a mode and a state (for that mode), find the inner mode and
   // state at the position that the state refers to.
   CodeMirror.innerMode = function(mode, state) {
     while (mode.innerMode) {
       var info = mode.innerMode(state);
       if (!info || info.mode == mode) break;
       state = info.state;
       mode = info.mode;
     }
     return info || {mode: mode, state: state};
   };
 
   // STANDARD COMMANDS
 
   // Commands are parameter-less actions that can be performed on an
   // editor, mostly used for keybindings.
   var commands = CodeMirror.commands = {
     selectAll: function(cm) {cm.setSelection(Pos(cm.firstLine(), 0), Pos(cm.lastLine()), sel_dontScroll);},
     singleSelection: function(cm) {
       cm.setSelection(cm.getCursor("anchor"), cm.getCursor("head"), sel_dontScroll);
     },
     killLine: function(cm) {
       deleteNearSelection(cm, function(range) {
         if (range.empty()) {
           var len = getLine(cm.doc, range.head.line).text.length;
           if (range.head.ch == len && range.head.line < cm.lastLine())
             return {from: range.head, to: Pos(range.head.line + 1, 0)};
           else
             return {from: range.head, to: Pos(range.head.line, len)};
         } else {
           return {from: range.from(), to: range.to()};
         }
       });
     },
     deleteLine: function(cm) {
       deleteNearSelection(cm, function(range) {
         return {from: Pos(range.from().line, 0),
                 to: clipPos(cm.doc, Pos(range.to().line + 1, 0))};
       });
     },
     delLineLeft: function(cm) {
       deleteNearSelection(cm, function(range) {
         return {from: Pos(range.from().line, 0), to: range.from()};
       });
     },
     delWrappedLineLeft: function(cm) {
       deleteNearSelection(cm, function(range) {
         var top = cm.charCoords(range.head, "div").top + 5;
         var leftPos = cm.coordsChar({left: 0, top: top}, "div");
         return {from: leftPos, to: range.from()};
       });
     },
     delWrappedLineRight: function(cm) {
       deleteNearSelection(cm, function(range) {
         var top = cm.charCoords(range.head, "div").top + 5;
         var rightPos = cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div");
         return {from: range.from(), to: rightPos };
       });
     },
     undo: function(cm) {cm.undo();},
     redo: function(cm) {cm.redo();},
     undoSelection: function(cm) {cm.undoSelection();},
     redoSelection: function(cm) {cm.redoSelection();},
     goDocStart: function(cm) {cm.extendSelection(Pos(cm.firstLine(), 0));},
     goDocEnd: function(cm) {cm.extendSelection(Pos(cm.lastLine()));},
     goLineStart: function(cm) {
       cm.extendSelectionsBy(function(range) { return lineStart(cm, range.head.line); },
                             {origin: "+move", bias: 1});
     },
     goLineStartSmart: function(cm) {
       cm.extendSelectionsBy(function(range) {
         return lineStartSmart(cm, range.head);
       }, {origin: "+move", bias: 1});
     },
     goLineEnd: function(cm) {
       cm.extendSelectionsBy(function(range) { return lineEnd(cm, range.head.line); },
                             {origin: "+move", bias: -1});
     },
     goLineRight: function(cm) {
       cm.extendSelectionsBy(function(range) {
         var top = cm.charCoords(range.head, "div").top + 5;
         return cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div");
       }, sel_move);
     },
     goLineLeft: function(cm) {
       cm.extendSelectionsBy(function(range) {
         var top = cm.charCoords(range.head, "div").top + 5;
         return cm.coordsChar({left: 0, top: top}, "div");
       }, sel_move);
     },
     goLineLeftSmart: function(cm) {
       cm.extendSelectionsBy(function(range) {
         var top = cm.charCoords(range.head, "div").top + 5;
         var pos = cm.coordsChar({left: 0, top: top}, "div");
         if (pos.ch < cm.getLine(pos.line).search(/\S/)) return lineStartSmart(cm, range.head);
         return pos;
       }, sel_move);
     },
     goLineUp: function(cm) {cm.moveV(-1, "line");},
     goLineDown: function(cm) {cm.moveV(1, "line");},
     goPageUp: function(cm) {cm.moveV(-1, "page");},
     goPageDown: function(cm) {cm.moveV(1, "page");},
     goCharLeft: function(cm) {cm.moveH(-1, "char");},
     goCharRight: function(cm) {cm.moveH(1, "char");},
     goColumnLeft: function(cm) {cm.moveH(-1, "column");},
     goColumnRight: function(cm) {cm.moveH(1, "column");},
     goWordLeft: function(cm) {cm.moveH(-1, "word");},
     goGroupRight: function(cm) {cm.moveH(1, "group");},
     goGroupLeft: function(cm) {cm.moveH(-1, "group");},
     goWordRight: function(cm) {cm.moveH(1, "word");},
     delCharBefore: function(cm) {cm.deleteH(-1, "char");},
     delCharAfter: function(cm) {cm.deleteH(1, "char");},
     delWordBefore: function(cm) {cm.deleteH(-1, "word");},
     delWordAfter: function(cm) {cm.deleteH(1, "word");},
     delGroupBefore: function(cm) {cm.deleteH(-1, "group");},
     delGroupAfter: function(cm) {cm.deleteH(1, "group");},
     indentAuto: function(cm) {cm.indentSelection("smart");},
     indentMore: function(cm) {cm.indentSelection("add");},
     indentLess: function(cm) {cm.indentSelection("subtract");},
     insertTab: function(cm) {cm.replaceSelection("\t");},
     insertSoftTab: function(cm) {
       var spaces = [], ranges = cm.listSelections(), tabSize = cm.options.tabSize;
       for (var i = 0; i < ranges.length; i++) {
         var pos = ranges[i].from();
         var col = countColumn(cm.getLine(pos.line), pos.ch, tabSize);
         spaces.push(spaceStr(tabSize - col % tabSize));
       }
       cm.replaceSelections(spaces);
     },
     defaultTab: function(cm) {
       if (cm.somethingSelected()) cm.indentSelection("add");
       else cm.execCommand("insertTab");
     },
     transposeChars: function(cm) {
       runInOp(cm, function() {
         var ranges = cm.listSelections(), newSel = [];
         for (var i = 0; i < ranges.length; i++) {
           var cur = ranges[i].head, line = getLine(cm.doc, cur.line).text;
           if (line) {
             if (cur.ch == line.length) cur = new Pos(cur.line, cur.ch - 1);
             if (cur.ch > 0) {
               cur = new Pos(cur.line, cur.ch + 1);
               cm.replaceRange(line.charAt(cur.ch - 1) + line.charAt(cur.ch - 2),
                               Pos(cur.line, cur.ch - 2), cur, "+transpose");
             } else if (cur.line > cm.doc.first) {
               var prev = getLine(cm.doc, cur.line - 1).text;
               if (prev)
                 cm.replaceRange(line.charAt(0) + cm.doc.lineSeparator() +
                                 prev.charAt(prev.length - 1),
                                 Pos(cur.line - 1, prev.length - 1), Pos(cur.line, 1), "+transpose");
             }
           }
           newSel.push(new Range(cur, cur));
         }
         cm.setSelections(newSel);
       });
     },
     newlineAndIndent: function(cm) {
       runInOp(cm, function() {
         var len = cm.listSelections().length;
         for (var i = 0; i < len; i++) {
           var range = cm.listSelections()[i];
           cm.replaceRange(cm.doc.lineSeparator(), range.anchor, range.head, "+input");
           cm.indentLine(range.from().line + 1, null, true);
         }
         ensureCursorVisible(cm);
       });
     },
     openLine: function(cm) {cm.replaceSelection("\n", "start")},
     toggleOverwrite: function(cm) {cm.toggleOverwrite();}
   };
 
 
   // STANDARD KEYMAPS
 
   var keyMap = CodeMirror.keyMap = {};
 
   keyMap.basic = {
     "Left": "goCharLeft", "Right": "goCharRight", "Up": "goLineUp", "Down": "goLineDown",
     "End": "goLineEnd", "Home": "goLineStartSmart", "PageUp": "goPageUp", "PageDown": "goPageDown",
     "Delete": "delCharAfter", "Backspace": "delCharBefore", "Shift-Backspace": "delCharBefore",
     "Tab": "defaultTab", "Shift-Tab": "indentAuto",
     "Enter": "newlineAndIndent", "Insert": "toggleOverwrite",
     "Esc": "singleSelection"
   };
   // Note that the save and find-related commands aren't defined by
   // default. User code or addons can define them. Unknown commands
   // are simply ignored.
   keyMap.pcDefault = {
     "Ctrl-A": "selectAll", "Ctrl-D": "deleteLine", "Ctrl-Z": "undo", "Shift-Ctrl-Z": "redo", "Ctrl-Y": "redo",
     "Ctrl-Home": "goDocStart", "Ctrl-End": "goDocEnd", "Ctrl-Up": "goLineUp", "Ctrl-Down": "goLineDown",
     "Ctrl-Left": "goGroupLeft", "Ctrl-Right": "goGroupRight", "Alt-Left": "goLineStart", "Alt-Right": "goLineEnd",
     "Ctrl-Backspace": "delGroupBefore", "Ctrl-Delete": "delGroupAfter", "Ctrl-S": "save", "Ctrl-F": "find",
     "Ctrl-G": "findNext", "Shift-Ctrl-G": "findPrev", "Shift-Ctrl-F": "replace", "Shift-Ctrl-R": "replaceAll",
     "Ctrl-[": "indentLess", "Ctrl-]": "indentMore",
     "Ctrl-U": "undoSelection", "Shift-Ctrl-U": "redoSelection", "Alt-U": "redoSelection",
     fallthrough: "basic"
   };
   // Very basic readline/emacs-style bindings, which are standard on Mac.
   keyMap.emacsy = {
     "Ctrl-F": "goCharRight", "Ctrl-B": "goCharLeft", "Ctrl-P": "goLineUp", "Ctrl-N": "goLineDown",
     "Alt-F": "goWordRight", "Alt-B": "goWordLeft", "Ctrl-A": "goLineStart", "Ctrl-E": "goLineEnd",
     "Ctrl-V": "goPageDown", "Shift-Ctrl-V": "goPageUp", "Ctrl-D": "delCharAfter", "Ctrl-H": "delCharBefore",
     "Alt-D": "delWordAfter", "Alt-Backspace": "delWordBefore", "Ctrl-K": "killLine", "Ctrl-T": "transposeChars",
     "Ctrl-O": "openLine"
   };
   keyMap.macDefault = {
     "Cmd-A": "selectAll", "Cmd-D": "deleteLine", "Cmd-Z": "undo", "Shift-Cmd-Z": "redo", "Cmd-Y": "redo",
     "Cmd-Home": "goDocStart", "Cmd-Up": "goDocStart", "Cmd-End": "goDocEnd", "Cmd-Down": "goDocEnd", "Alt-Left": "goGroupLeft",
     "Alt-Right": "goGroupRight", "Cmd-Left": "goLineLeft", "Cmd-Right": "goLineRight", "Alt-Backspace": "delGroupBefore",
     "Ctrl-Alt-Backspace": "delGroupAfter", "Alt-Delete": "delGroupAfter", "Cmd-S": "save", "Cmd-F": "find",
     "Cmd-G": "findNext", "Shift-Cmd-G": "findPrev", "Cmd-Alt-F": "replace", "Shift-Cmd-Alt-F": "replaceAll",
     "Cmd-[": "indentLess", "Cmd-]": "indentMore", "Cmd-Backspace": "delWrappedLineLeft", "Cmd-Delete": "delWrappedLineRight",
     "Cmd-U": "undoSelection", "Shift-Cmd-U": "redoSelection", "Ctrl-Up": "goDocStart", "Ctrl-Down": "goDocEnd",
     fallthrough: ["basic", "emacsy"]
   };
   keyMap["default"] = mac ? keyMap.macDefault : keyMap.pcDefault;
 
   // KEYMAP DISPATCH
 
   function normalizeKeyName(name) {
     var parts = name.split(/-(?!$)/), name = parts[parts.length - 1];
     var alt, ctrl, shift, cmd;
     for (var i = 0; i < parts.length - 1; i++) {
       var mod = parts[i];
       if (/^(cmd|meta|m)$/i.test(mod)) cmd = true;
       else if (/^a(lt)?$/i.test(mod)) alt = true;
       else if (/^(c|ctrl|control)$/i.test(mod)) ctrl = true;
       else if (/^s(hift)$/i.test(mod)) shift = true;
       else throw new Error("Unrecognized modifier name: " + mod);
     }
     if (alt) name = "Alt-" + name;
     if (ctrl) name = "Ctrl-" + name;
     if (cmd) name = "Cmd-" + name;
     if (shift) name = "Shift-" + name;
     return name;
   }
 
   // This is a kludge to keep keymaps mostly working as raw objects
   // (backwards compatibility) while at the same time support features
   // like normalization and multi-stroke key bindings. It compiles a
   // new normalized keymap, and then updates the old object to reflect
   // this.
   CodeMirror.normalizeKeyMap = function(keymap) {
     var copy = {};
     for (var keyname in keymap) if (keymap.hasOwnProperty(keyname)) {
       var value = keymap[keyname];
       if (/^(name|fallthrough|(de|at)tach)$/.test(keyname)) continue;
       if (value == "...") { delete keymap[keyname]; continue; }
 
       var keys = map(keyname.split(" "), normalizeKeyName);
       for (var i = 0; i < keys.length; i++) {
         var val, name;
         if (i == keys.length - 1) {
           name = keys.join(" ");
           val = value;
         } else {
           name = keys.slice(0, i + 1).join(" ");
           val = "...";
         }
         var prev = copy[name];
         if (!prev) copy[name] = val;
         else if (prev != val) throw new Error("Inconsistent bindings for " + name);
       }
       delete keymap[keyname];
     }
     for (var prop in copy) keymap[prop] = copy[prop];
     return keymap;
   };
 
   var lookupKey = CodeMirror.lookupKey = function(key, map, handle, context) {
     map = getKeyMap(map);
     var found = map.call ? map.call(key, context) : map[key];
     if (found === false) return "nothing";
     if (found === "...") return "multi";
     if (found != null && handle(found)) return "handled";
 
     if (map.fallthrough) {
       if (Object.prototype.toString.call(map.fallthrough) != "[object Array]")
         return lookupKey(key, map.fallthrough, handle, context);
       for (var i = 0; i < map.fallthrough.length; i++) {
         var result = lookupKey(key, map.fallthrough[i], handle, context);
         if (result) return result;
       }
     }
   };
 
   // Modifier key presses don't count as 'real' key presses for the
   // purpose of keymap fallthrough.
   var isModifierKey = CodeMirror.isModifierKey = function(value) {
     var name = typeof value == "string" ? value : keyNames[value.keyCode];
     return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod";
   };
 
   // Look up the name of a key as indicated by an event object.
   var keyName = CodeMirror.keyName = function(event, noShift) {
     if (presto && event.keyCode == 34 && event["char"]) return false;
     var base = keyNames[event.keyCode], name = base;
     if (name == null || event.altGraphKey) return false;
     if (event.altKey && base != "Alt") name = "Alt-" + name;
     if ((flipCtrlCmd ? event.metaKey : event.ctrlKey) && base != "Ctrl") name = "Ctrl-" + name;
     if ((flipCtrlCmd ? event.ctrlKey : event.metaKey) && base != "Cmd") name = "Cmd-" + name;
     if (!noShift && event.shiftKey && base != "Shift") name = "Shift-" + name;
     return name;
   };
 
   function getKeyMap(val) {
     return typeof val == "string" ? keyMap[val] : val;
   }
 
   // FROMTEXTAREA
 
   CodeMirror.fromTextArea = function(textarea, options) {
     options = options ? copyObj(options) : {};
     options.value = textarea.value;
     if (!options.tabindex && textarea.tabIndex)
       options.tabindex = textarea.tabIndex;
     if (!options.placeholder && textarea.placeholder)
       options.placeholder = textarea.placeholder;
     // Set autofocus to true if this textarea is focused, or if it has
     // autofocus and no other element is focused.
     if (options.autofocus == null) {
       var hasFocus = activeElt();
       options.autofocus = hasFocus == textarea ||
         textarea.getAttribute("autofocus") != null && hasFocus == document.body;
     }
 
     function save() {textarea.value = cm.getValue();}
     if (textarea.form) {
       on(textarea.form, "submit", save);
       // Deplorable hack to make the submit method do the right thing.
       if (!options.leaveSubmitMethodAlone) {
         var form = textarea.form, realSubmit = form.submit;
         try {
           var wrappedSubmit = form.submit = function() {
             save();
             form.submit = realSubmit;
             form.submit();
             form.submit = wrappedSubmit;
           };
         } catch(e) {}
       }
     }
 
     options.finishInit = function(cm) {
       cm.save = save;
       cm.getTextArea = function() { return textarea; };
       cm.toTextArea = function() {
         cm.toTextArea = isNaN; // Prevent this from being ran twice
         save();
         textarea.parentNode.removeChild(cm.getWrapperElement());
         textarea.style.display = "";
         if (textarea.form) {
           off(textarea.form, "submit", save);
           if (typeof textarea.form.submit == "function")
             textarea.form.submit = realSubmit;
         }
       };
     };
 
     textarea.style.display = "none";
     var cm = CodeMirror(function(node) {
       textarea.parentNode.insertBefore(node, textarea.nextSibling);
     }, options);
     return cm;
   };
 
   // STRING STREAM
 
   // Fed to the mode parsers, provides helper functions to make
   // parsers more succinct.
 
   var StringStream = CodeMirror.StringStream = function(string, tabSize) {
     this.pos = this.start = 0;
     this.string = string;
     this.tabSize = tabSize || 8;
     this.lastColumnPos = this.lastColumnValue = 0;
     this.lineStart = 0;
   };
 
   StringStream.prototype = {
     eol: function() {return this.pos >= this.string.length;},
     sol: function() {return this.pos == this.lineStart;},
     peek: function() {return this.string.charAt(this.pos) || undefined;},
     next: function() {
       if (this.pos < this.string.length)
         return this.string.charAt(this.pos++);
     },
     eat: function(match) {
       var ch = this.string.charAt(this.pos);
       if (typeof match == "string") var ok = ch == match;
       else var ok = ch && (match.test ? match.test(ch) : match(ch));
       if (ok) {++this.pos; return ch;}
     },
     eatWhile: function(match) {
       var start = this.pos;
       while (this.eat(match)){}
       return this.pos > start;
     },
     eatSpace: function() {
       var start = this.pos;
       while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) ++this.pos;
       return this.pos > start;
     },
     skipToEnd: function() {this.pos = this.string.length;},
     skipTo: function(ch) {
       var found = this.string.indexOf(ch, this.pos);
       if (found > -1) {this.pos = found; return true;}
     },
     backUp: function(n) {this.pos -= n;},
     column: function() {
       if (this.lastColumnPos < this.start) {
         this.lastColumnValue = countColumn(this.string, this.start, this.tabSize, this.lastColumnPos, this.lastColumnValue);
         this.lastColumnPos = this.start;
       }
       return this.lastColumnValue - (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0);
     },
     indentation: function() {
       return countColumn(this.string, null, this.tabSize) -
         (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0);
     },
     match: function(pattern, consume, caseInsensitive) {
       if (typeof pattern == "string") {
         var cased = function(str) {return caseInsensitive ? str.toLowerCase() : str;};
         var substr = this.string.substr(this.pos, pattern.length);
         if (cased(substr) == cased(pattern)) {
           if (consume !== false) this.pos += pattern.length;
           return true;
         }
       } else {
         var match = this.string.slice(this.pos).match(pattern);
         if (match && match.index > 0) return null;
         if (match && consume !== false) this.pos += match[0].length;
         return match;
       }
     },
     current: function(){return this.string.slice(this.start, this.pos);},
     hideFirstChars: function(n, inner) {
       this.lineStart += n;
       try { return inner(); }
       finally { this.lineStart -= n; }
     }
   };
 
   // TEXTMARKERS
 
   // Created with markText and setBookmark methods. A TextMarker is a
   // handle that can be used to clear or find a marked position in the
   // document. Line objects hold arrays (markedSpans) containing
   // {from, to, marker} object pointing to such marker objects, and
   // indicating that such a marker is present on that line. Multiple
   // lines may point to the same marker when it spans across lines.
   // The spans will have null for their from/to properties when the
   // marker continues beyond the start/end of the line. Markers have
   // links back to the lines they currently touch.
 
   var nextMarkerId = 0;
 
   var TextMarker = CodeMirror.TextMarker = function(doc, type) {
     this.lines = [];
     this.type = type;
     this.doc = doc;
     this.id = ++nextMarkerId;
   };
   eventMixin(TextMarker);
 
   // Clear the marker.
   TextMarker.prototype.clear = function() {
     if (this.explicitlyCleared) return;
     var cm = this.doc.cm, withOp = cm && !cm.curOp;
     if (withOp) startOperation(cm);
     if (hasHandler(this, "clear")) {
       var found = this.find();
       if (found) signalLater(this, "clear", found.from, found.to);
     }
     var min = null, max = null;
     for (var i = 0; i < this.lines.length; ++i) {
       var line = this.lines[i];
       var span = getMarkedSpanFor(line.markedSpans, this);
       if (cm && !this.collapsed) regLineChange(cm, lineNo(line), "text");
       else if (cm) {
         if (span.to != null) max = lineNo(line);
         if (span.from != null) min = lineNo(line);
       }
       line.markedSpans = removeMarkedSpan(line.markedSpans, span);
       if (span.from == null && this.collapsed && !lineIsHidden(this.doc, line) && cm)
         updateLineHeight(line, textHeight(cm.display));
     }
     if (cm && this.collapsed && !cm.options.lineWrapping) for (var i = 0; i < this.lines.length; ++i) {
       var visual = visualLine(this.lines[i]), len = lineLength(visual);
       if (len > cm.display.maxLineLength) {
         cm.display.maxLine = visual;
         cm.display.maxLineLength = len;
         cm.display.maxLineChanged = true;
       }
     }
 
     if (min != null && cm && this.collapsed) regChange(cm, min, max + 1);
     this.lines.length = 0;
     this.explicitlyCleared = true;
     if (this.atomic && this.doc.cantEdit) {
       this.doc.cantEdit = false;
       if (cm) reCheckSelection(cm.doc);
     }
     if (cm) signalLater(cm, "markerCleared", cm, this);
     if (withOp) endOperation(cm);
     if (this.parent) this.parent.clear();
   };
 
   // Find the position of the marker in the document. Returns a {from,
   // to} object by default. Side can be passed to get a specific side
   // -- 0 (both), -1 (left), or 1 (right). When lineObj is true, the
   // Pos objects returned contain a line object, rather than a line
   // number (used to prevent looking up the same line twice).
   TextMarker.prototype.find = function(side, lineObj) {
     if (side == null && this.type == "bookmark") side = 1;
     var from, to;
     for (var i = 0; i < this.lines.length; ++i) {
       var line = this.lines[i];
       var span = getMarkedSpanFor(line.markedSpans, this);
       if (span.from != null) {
         from = Pos(lineObj ? line : lineNo(line), span.from);
         if (side == -1) return from;
       }
       if (span.to != null) {
         to = Pos(lineObj ? line : lineNo(line), span.to);
         if (side == 1) return to;
       }
     }
     return from && {from: from, to: to};
   };
 
   // Signals that the marker's widget changed, and surrounding layout
   // should be recomputed.
   TextMarker.prototype.changed = function() {
     var pos = this.find(-1, true), widget = this, cm = this.doc.cm;
     if (!pos || !cm) return;
     runInOp(cm, function() {
       var line = pos.line, lineN = lineNo(pos.line);
       var view = findViewForLine(cm, lineN);
       if (view) {
         clearLineMeasurementCacheFor(view);
         cm.curOp.selectionChanged = cm.curOp.forceUpdate = true;
       }
       cm.curOp.updateMaxLine = true;
       if (!lineIsHidden(widget.doc, line) && widget.height != null) {
         var oldHeight = widget.height;
         widget.height = null;
         var dHeight = widgetHeight(widget) - oldHeight;
         if (dHeight)
           updateLineHeight(line, line.height + dHeight);
       }
     });
   };
 
   TextMarker.prototype.attachLine = function(line) {
     if (!this.lines.length && this.doc.cm) {
       var op = this.doc.cm.curOp;
       if (!op.maybeHiddenMarkers || indexOf(op.maybeHiddenMarkers, this) == -1)
         (op.maybeUnhiddenMarkers || (op.maybeUnhiddenMarkers = [])).push(this);
     }
     this.lines.push(line);
   };
   TextMarker.prototype.detachLine = function(line) {
     this.lines.splice(indexOf(this.lines, line), 1);
     if (!this.lines.length && this.doc.cm) {
       var op = this.doc.cm.curOp;
       (op.maybeHiddenMarkers || (op.maybeHiddenMarkers = [])).push(this);
     }
   };
 
   // Collapsed markers have unique ids, in order to be able to order
   // them, which is needed for uniquely determining an outer marker
   // when they overlap (they may nest, but not partially overlap).
   var nextMarkerId = 0;
 
   // Create a marker, wire it up to the right lines, and
   function markText(doc, from, to, options, type) {
     // Shared markers (across linked documents) are handled separately
     // (markTextShared will call out to this again, once per
     // document).
     if (options && options.shared) return markTextShared(doc, from, to, options, type);
     // Ensure we are in an operation.
     if (doc.cm && !doc.cm.curOp) return operation(doc.cm, markText)(doc, from, to, options, type);
 
     var marker = new TextMarker(doc, type), diff = cmp(from, to);
     if (options) copyObj(options, marker, false);
     // Don't connect empty markers unless clearWhenEmpty is false
     if (diff > 0 || diff == 0 && marker.clearWhenEmpty !== false)
       return marker;
     if (marker.replacedWith) {
       // Showing up as a widget implies collapsed (widget replaces text)
       marker.collapsed = true;
       marker.widgetNode = elt("span", [marker.replacedWith], "CodeMirror-widget");
       if (!options.handleMouseEvents) marker.widgetNode.setAttribute("cm-ignore-events", "true");
       if (options.insertLeft) marker.widgetNode.insertLeft = true;
     }
     if (marker.collapsed) {
       if (conflictingCollapsedRange(doc, from.line, from, to, marker) ||
           from.line != to.line && conflictingCollapsedRange(doc, to.line, from, to, marker))
         throw new Error("Inserting collapsed marker partially overlapping an existing one");
       sawCollapsedSpans = true;
     }
 
     if (marker.addToHistory)
       addChangeToHistory(doc, {from: from, to: to, origin: "markText"}, doc.sel, NaN);
 
     var curLine = from.line, cm = doc.cm, updateMaxLine;
     doc.iter(curLine, to.line + 1, function(line) {
       if (cm && marker.collapsed && !cm.options.lineWrapping && visualLine(line) == cm.display.maxLine)
         updateMaxLine = true;
       if (marker.collapsed && curLine != from.line) updateLineHeight(line, 0);
       addMarkedSpan(line, new MarkedSpan(marker,
                                          curLine == from.line ? from.ch : null,
                                          curLine == to.line ? to.ch : null));
       ++curLine;
     });
     // lineIsHidden depends on the presence of the spans, so needs a second pass
     if (marker.collapsed) doc.iter(from.line, to.line + 1, function(line) {
       if (lineIsHidden(doc, line)) updateLineHeight(line, 0);
     });
 
     if (marker.clearOnEnter) on(marker, "beforeCursorEnter", function() { marker.clear(); });
 
     if (marker.readOnly) {
       sawReadOnlySpans = true;
       if (doc.history.done.length || doc.history.undone.length)
         doc.clearHistory();
     }
     if (marker.collapsed) {
       marker.id = ++nextMarkerId;
       marker.atomic = true;
     }
     if (cm) {
       // Sync editor state
       if (updateMaxLine) cm.curOp.updateMaxLine = true;
       if (marker.collapsed)
         regChange(cm, from.line, to.line + 1);
       else if (marker.className || marker.title || marker.startStyle || marker.endStyle || marker.css)
         for (var i = from.line; i <= to.line; i++) regLineChange(cm, i, "text");
       if (marker.atomic) reCheckSelection(cm.doc);
       signalLater(cm, "markerAdded", cm, marker);
     }
     return marker;
   }
 
   // SHARED TEXTMARKERS
 
   // A shared marker spans multiple linked documents. It is
   // implemented as a meta-marker-object controlling multiple normal
   // markers.
   var SharedTextMarker = CodeMirror.SharedTextMarker = function(markers, primary) {
     this.markers = markers;
     this.primary = primary;
     for (var i = 0; i < markers.length; ++i)
       markers[i].parent = this;
   };
   eventMixin(SharedTextMarker);
 
   SharedTextMarker.prototype.clear = function() {
     if (this.explicitlyCleared) return;
     this.explicitlyCleared = true;
     for (var i = 0; i < this.markers.length; ++i)
       this.markers[i].clear();
     signalLater(this, "clear");
   };
   SharedTextMarker.prototype.find = function(side, lineObj) {
     return this.primary.find(side, lineObj);
   };
 
   function markTextShared(doc, from, to, options, type) {
     options = copyObj(options);
     options.shared = false;
     var markers = [markText(doc, from, to, options, type)], primary = markers[0];
     var widget = options.widgetNode;
     linkedDocs(doc, function(doc) {
       if (widget) options.widgetNode = widget.cloneNode(true);
       markers.push(markText(doc, clipPos(doc, from), clipPos(doc, to), options, type));
       for (var i = 0; i < doc.linked.length; ++i)
         if (doc.linked[i].isParent) return;
       primary = lst(markers);
     });
     return new SharedTextMarker(markers, primary);
   }
 
   function findSharedMarkers(doc) {
     return doc.findMarks(Pos(doc.first, 0), doc.clipPos(Pos(doc.lastLine())),
                          function(m) { return m.parent; });
   }
 
   function copySharedMarkers(doc, markers) {
     for (var i = 0; i < markers.length; i++) {
       var marker = markers[i], pos = marker.find();
       var mFrom = doc.clipPos(pos.from), mTo = doc.clipPos(pos.to);
       if (cmp(mFrom, mTo)) {
         var subMark = markText(doc, mFrom, mTo, marker.primary, marker.primary.type);
         marker.markers.push(subMark);
         subMark.parent = marker;
       }
     }
   }
 
   function detachSharedMarkers(markers) {
     for (var i = 0; i < markers.length; i++) {
       var marker = markers[i], linked = [marker.primary.doc];;
       linkedDocs(marker.primary.doc, function(d) { linked.push(d); });
       for (var j = 0; j < marker.markers.length; j++) {
         var subMarker = marker.markers[j];
         if (indexOf(linked, subMarker.doc) == -1) {
           subMarker.parent = null;
           marker.markers.splice(j--, 1);
         }
       }
     }
   }
 
   // TEXTMARKER SPANS
 
   function MarkedSpan(marker, from, to) {
     this.marker = marker;
     this.from = from; this.to = to;
   }
 
   // Search an array of spans for a span matching the given marker.
   function getMarkedSpanFor(spans, marker) {
     if (spans) for (var i = 0; i < spans.length; ++i) {
       var span = spans[i];
       if (span.marker == marker) return span;
     }
   }
   // Remove a span from an array, returning undefined if no spans are
   // left (we don't store arrays for lines without spans).
   function removeMarkedSpan(spans, span) {
     for (var r, i = 0; i < spans.length; ++i)
       if (spans[i] != span) (r || (r = [])).push(spans[i]);
     return r;
   }
   // Add a span to a line.
   function addMarkedSpan(line, span) {
     line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span];
     span.marker.attachLine(line);
   }
 
   // Used for the algorithm that adjusts markers for a change in the
   // document. These functions cut an array of spans at a given
   // character position, returning an array of remaining chunks (or
   // undefined if nothing remains).
   function markedSpansBefore(old, startCh, isInsert) {
     if (old) for (var i = 0, nw; i < old.length; ++i) {
       var span = old[i], marker = span.marker;
       var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= startCh : span.from < startCh);
       if (startsBefore || span.from == startCh && marker.type == "bookmark" && (!isInsert || !span.marker.insertLeft)) {
         var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= startCh : span.to > startCh);
         (nw || (nw = [])).push(new MarkedSpan(marker, span.from, endsAfter ? null : span.to));
       }
     }
     return nw;
   }
   function markedSpansAfter(old, endCh, isInsert) {
     if (old) for (var i = 0, nw; i < old.length; ++i) {
       var span = old[i], marker = span.marker;
       var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= endCh : span.to > endCh);
       if (endsAfter || span.from == endCh && marker.type == "bookmark" && (!isInsert || span.marker.insertLeft)) {
         var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= endCh : span.from < endCh);
         (nw || (nw = [])).push(new MarkedSpan(marker, startsBefore ? null : span.from - endCh,
                                               span.to == null ? null : span.to - endCh));
       }
     }
     return nw;
   }
 
   // Given a change object, compute the new set of marker spans that
   // cover the line in which the change took place. Removes spans
   // entirely within the change, reconnects spans belonging to the
   // same marker that appear on both sides of the change, and cuts off
   // spans partially within the change. Returns an array of span
   // arrays with one element for each line in (after) the change.
   function stretchSpansOverChange(doc, change) {
     if (change.full) return null;
     var oldFirst = isLine(doc, change.from.line) && getLine(doc, change.from.line).markedSpans;
     var oldLast = isLine(doc, change.to.line) && getLine(doc, change.to.line).markedSpans;
     if (!oldFirst && !oldLast) return null;
 
     var startCh = change.from.ch, endCh = change.to.ch, isInsert = cmp(change.from, change.to) == 0;
     // Get the spans that 'stick out' on both sides
     var first = markedSpansBefore(oldFirst, startCh, isInsert);
     var last = markedSpansAfter(oldLast, endCh, isInsert);
 
     // Next, merge those two ends
     var sameLine = change.text.length == 1, offset = lst(change.text).length + (sameLine ? startCh : 0);
     if (first) {
       // Fix up .to properties of first
       for (var i = 0; i < first.length; ++i) {
         var span = first[i];
         if (span.to == null) {
           var found = getMarkedSpanFor(last, span.marker);
           if (!found) span.to = startCh;
           else if (sameLine) span.to = found.to == null ? null : found.to + offset;
         }
       }
     }
     if (last) {
       // Fix up .from in last (or move them into first in case of sameLine)
       for (var i = 0; i < last.length; ++i) {
         var span = last[i];
         if (span.to != null) span.to += offset;
         if (span.from == null) {
           var found = getMarkedSpanFor(first, span.marker);
           if (!found) {
             span.from = offset;
             if (sameLine) (first || (first = [])).push(span);
           }
         } else {
           span.from += offset;
           if (sameLine) (first || (first = [])).push(span);
         }
       }
     }
     // Make sure we didn't create any zero-length spans
     if (first) first = clearEmptySpans(first);
     if (last && last != first) last = clearEmptySpans(last);
 
     var newMarkers = [first];
     if (!sameLine) {
       // Fill gap with whole-line-spans
       var gap = change.text.length - 2, gapMarkers;
       if (gap > 0 && first)
         for (var i = 0; i < first.length; ++i)
           if (first[i].to == null)
             (gapMarkers || (gapMarkers = [])).push(new MarkedSpan(first[i].marker, null, null));
       for (var i = 0; i < gap; ++i)
         newMarkers.push(gapMarkers);
       newMarkers.push(last);
     }
     return newMarkers;
   }
 
   // Remove spans that are empty and don't have a clearWhenEmpty
   // option of false.
   function clearEmptySpans(spans) {
     for (var i = 0; i < spans.length; ++i) {
       var span = spans[i];
       if (span.from != null && span.from == span.to && span.marker.clearWhenEmpty !== false)
         spans.splice(i--, 1);
     }
     if (!spans.length) return null;
     return spans;
   }
 
   // Used for un/re-doing changes from the history. Combines the
   // result of computing the existing spans with the set of spans that
   // existed in the history (so that deleting around a span and then
   // undoing brings back the span).
   function mergeOldSpans(doc, change) {
     var old = getOldSpans(doc, change);
     var stretched = stretchSpansOverChange(doc, change);
     if (!old) return stretched;
     if (!stretched) return old;
 
     for (var i = 0; i < old.length; ++i) {
       var oldCur = old[i], stretchCur = stretched[i];
       if (oldCur && stretchCur) {
         spans: for (var j = 0; j < stretchCur.length; ++j) {
           var span = stretchCur[j];
           for (var k = 0; k < oldCur.length; ++k)
             if (oldCur[k].marker == span.marker) continue spans;
           oldCur.push(span);
         }
       } else if (stretchCur) {
         old[i] = stretchCur;
       }
     }
     return old;
   }
 
   // Used to 'clip' out readOnly ranges when making a change.
   function removeReadOnlyRanges(doc, from, to) {
     var markers = null;
     doc.iter(from.line, to.line + 1, function(line) {
       if (line.markedSpans) for (var i = 0; i < line.markedSpans.length; ++i) {
         var mark = line.markedSpans[i].marker;
         if (mark.readOnly && (!markers || indexOf(markers, mark) == -1))
           (markers || (markers = [])).push(mark);
       }
     });
     if (!markers) return null;
     var parts = [{from: from, to: to}];
     for (var i = 0; i < markers.length; ++i) {
       var mk = markers[i], m = mk.find(0);
       for (var j = 0; j < parts.length; ++j) {
         var p = parts[j];
         if (cmp(p.to, m.from) < 0 || cmp(p.from, m.to) > 0) continue;
         var newParts = [j, 1], dfrom = cmp(p.from, m.from), dto = cmp(p.to, m.to);
         if (dfrom < 0 || !mk.inclusiveLeft && !dfrom)
           newParts.push({from: p.from, to: m.from});
         if (dto > 0 || !mk.inclusiveRight && !dto)
           newParts.push({from: m.to, to: p.to});
         parts.splice.apply(parts, newParts);
         j += newParts.length - 1;
       }
     }
     return parts;
   }
 
   // Connect or disconnect spans from a line.
   function detachMarkedSpans(line) {
     var spans = line.markedSpans;
     if (!spans) return;
     for (var i = 0; i < spans.length; ++i)
       spans[i].marker.detachLine(line);
     line.markedSpans = null;
   }
   function attachMarkedSpans(line, spans) {
     if (!spans) return;
     for (var i = 0; i < spans.length; ++i)
       spans[i].marker.attachLine(line);
     line.markedSpans = spans;
   }
 
   // Helpers used when computing which overlapping collapsed span
   // counts as the larger one.
   function extraLeft(marker) { return marker.inclusiveLeft ? -1 : 0; }
   function extraRight(marker) { return marker.inclusiveRight ? 1 : 0; }
 
   // Returns a number indicating which of two overlapping collapsed
   // spans is larger (and thus includes the other). Falls back to
   // comparing ids when the spans cover exactly the same range.
   function compareCollapsedMarkers(a, b) {
     var lenDiff = a.lines.length - b.lines.length;
     if (lenDiff != 0) return lenDiff;
     var aPos = a.find(), bPos = b.find();
     var fromCmp = cmp(aPos.from, bPos.from) || extraLeft(a) - extraLeft(b);
     if (fromCmp) return -fromCmp;
     var toCmp = cmp(aPos.to, bPos.to) || extraRight(a) - extraRight(b);
     if (toCmp) return toCmp;
     return b.id - a.id;
   }
 
   // Find out whether a line ends or starts in a collapsed span. If
   // so, return the marker for that span.
   function collapsedSpanAtSide(line, start) {
     var sps = sawCollapsedSpans && line.markedSpans, found;
     if (sps) for (var sp, i = 0; i < sps.length; ++i) {
       sp = sps[i];
       if (sp.marker.collapsed && (start ? sp.from : sp.to) == null &&
           (!found || compareCollapsedMarkers(found, sp.marker) < 0))
         found = sp.marker;
     }
     return found;
   }
   function collapsedSpanAtStart(line) { return collapsedSpanAtSide(line, true); }
   function collapsedSpanAtEnd(line) { return collapsedSpanAtSide(line, false); }
 
   // Test whether there exists a collapsed span that partially
   // overlaps (covers the start or end, but not both) of a new span.
   // Such overlap is not allowed.
   function conflictingCollapsedRange(doc, lineNo, from, to, marker) {
     var line = getLine(doc, lineNo);
     var sps = sawCollapsedSpans && line.markedSpans;
     if (sps) for (var i = 0; i < sps.length; ++i) {
       var sp = sps[i];
       if (!sp.marker.collapsed) continue;
       var found = sp.marker.find(0);
       var fromCmp = cmp(found.from, from) || extraLeft(sp.marker) - extraLeft(marker);
       var toCmp = cmp(found.to, to) || extraRight(sp.marker) - extraRight(marker);
       if (fromCmp >= 0 && toCmp <= 0 || fromCmp <= 0 && toCmp >= 0) continue;
       if (fromCmp <= 0 && (sp.marker.inclusiveRight && marker.inclusiveLeft ? cmp(found.to, from) >= 0 : cmp(found.to, from) > 0) ||
           fromCmp >= 0 && (sp.marker.inclusiveRight && marker.inclusiveLeft ? cmp(found.from, to) <= 0 : cmp(found.from, to) < 0))
         return true;
     }
   }
 
   // A visual line is a line as drawn on the screen. Folding, for
   // example, can cause multiple logical lines to appear on the same
   // visual line. This finds the start of the visual line that the
   // given line is part of (usually that is the line itself).
   function visualLine(line) {
     var merged;
     while (merged = collapsedSpanAtStart(line))
       line = merged.find(-1, true).line;
     return line;
   }
 
   // Returns an array of logical lines that continue the visual line
   // started by the argument, or undefined if there are no such lines.
   function visualLineContinued(line) {
     var merged, lines;
     while (merged = collapsedSpanAtEnd(line)) {
       line = merged.find(1, true).line;
       (lines || (lines = [])).push(line);
     }
     return lines;
   }
 
   // Get the line number of the start of the visual line that the
   // given line number is part of.
   function visualLineNo(doc, lineN) {
     var line = getLine(doc, lineN), vis = visualLine(line);
     if (line == vis) return lineN;
     return lineNo(vis);
   }
   // Get the line number of the start of the next visual line after
   // the given line.
   function visualLineEndNo(doc, lineN) {
     if (lineN > doc.lastLine()) return lineN;
     var line = getLine(doc, lineN), merged;
     if (!lineIsHidden(doc, line)) return lineN;
     while (merged = collapsedSpanAtEnd(line))
       line = merged.find(1, true).line;
     return lineNo(line) + 1;
   }
 
   // Compute whether a line is hidden. Lines count as hidden when they
   // are part of a visual line that starts with another line, or when
   // they are entirely covered by collapsed, non-widget span.
   function lineIsHidden(doc, line) {
     var sps = sawCollapsedSpans && line.markedSpans;
     if (sps) for (var sp, i = 0; i < sps.length; ++i) {
       sp = sps[i];
       if (!sp.marker.collapsed) continue;
       if (sp.from == null) return true;
       if (sp.marker.widgetNode) continue;
       if (sp.from == 0 && sp.marker.inclusiveLeft && lineIsHiddenInner(doc, line, sp))
         return true;
     }
   }
   function lineIsHiddenInner(doc, line, span) {
     if (span.to == null) {
       var end = span.marker.find(1, true);
       return lineIsHiddenInner(doc, end.line, getMarkedSpanFor(end.line.markedSpans, span.marker));
     }
     if (span.marker.inclusiveRight && span.to == line.text.length)
       return true;
     for (var sp, i = 0; i < line.markedSpans.length; ++i) {
       sp = line.markedSpans[i];
       if (sp.marker.collapsed && !sp.marker.widgetNode && sp.from == span.to &&
           (sp.to == null || sp.to != span.from) &&
           (sp.marker.inclusiveLeft || span.marker.inclusiveRight) &&
           lineIsHiddenInner(doc, line, sp)) return true;
     }
   }
 
   // LINE WIDGETS
 
   // Line widgets are block elements displayed above or below a line.
 
   var LineWidget = CodeMirror.LineWidget = function(doc, node, options) {
     if (options) for (var opt in options) if (options.hasOwnProperty(opt))
       this[opt] = options[opt];
     this.doc = doc;
     this.node = node;
   };
   eventMixin(LineWidget);
 
   function adjustScrollWhenAboveVisible(cm, line, diff) {
     if (heightAtLine(line) < ((cm.curOp && cm.curOp.scrollTop) || cm.doc.scrollTop))
       addToScrollPos(cm, null, diff);
   }
 
   LineWidget.prototype.clear = function() {
     var cm = this.doc.cm, ws = this.line.widgets, line = this.line, no = lineNo(line);
     if (no == null || !ws) return;
     for (var i = 0; i < ws.length; ++i) if (ws[i] == this) ws.splice(i--, 1);
     if (!ws.length) line.widgets = null;
     var height = widgetHeight(this);
     updateLineHeight(line, Math.max(0, line.height - height));
     if (cm) runInOp(cm, function() {
       adjustScrollWhenAboveVisible(cm, line, -height);
       regLineChange(cm, no, "widget");
     });
   };
   LineWidget.prototype.changed = function() {
     var oldH = this.height, cm = this.doc.cm, line = this.line;
     this.height = null;
     var diff = widgetHeight(this) - oldH;
     if (!diff) return;
     updateLineHeight(line, line.height + diff);
     if (cm) runInOp(cm, function() {
       cm.curOp.forceUpdate = true;
       adjustScrollWhenAboveVisible(cm, line, diff);
     });
   };
 
   function widgetHeight(widget) {
     if (widget.height != null) return widget.height;
     var cm = widget.doc.cm;
     if (!cm) return 0;
     if (!contains(document.body, widget.node)) {
       var parentStyle = "position: relative;";
       if (widget.coverGutter)
         parentStyle += "margin-left: -" + cm.display.gutters.offsetWidth + "px;";
       if (widget.noHScroll)
         parentStyle += "width: " + cm.display.wrapper.clientWidth + "px;";
       removeChildrenAndAdd(cm.display.measure, elt("div", [widget.node], null, parentStyle));
     }
     return widget.height = widget.node.parentNode.offsetHeight;
   }
 
   function addLineWidget(doc, handle, node, options) {
     var widget = new LineWidget(doc, node, options);
     var cm = doc.cm;
     if (cm && widget.noHScroll) cm.display.alignWidgets = true;
     changeLine(doc, handle, "widget", function(line) {
       var widgets = line.widgets || (line.widgets = []);
       if (widget.insertAt == null) widgets.push(widget);
       else widgets.splice(Math.min(widgets.length - 1, Math.max(0, widget.insertAt)), 0, widget);
       widget.line = line;
       if (cm && !lineIsHidden(doc, line)) {
         var aboveVisible = heightAtLine(line) < doc.scrollTop;
         updateLineHeight(line, line.height + widgetHeight(widget));
         if (aboveVisible) addToScrollPos(cm, null, widget.height);
         cm.curOp.forceUpdate = true;
       }
       return true;
     });
     return widget;
   }
 
   // LINE DATA STRUCTURE
 
   // Line objects. These hold state related to a line, including
   // highlighting info (the styles array).
   var Line = CodeMirror.Line = function(text, markedSpans, estimateHeight) {
     this.text = text;
     attachMarkedSpans(this, markedSpans);
     this.height = estimateHeight ? estimateHeight(this) : 1;
   };
   eventMixin(Line);
   Line.prototype.lineNo = function() { return lineNo(this); };
 
   // Change the content (text, markers) of a line. Automatically
   // invalidates cached information and tries to re-estimate the
   // line's height.
   function updateLine(line, text, markedSpans, estimateHeight) {
     line.text = text;
     if (line.stateAfter) line.stateAfter = null;
     if (line.styles) line.styles = null;
     if (line.order != null) line.order = null;
     detachMarkedSpans(line);
     attachMarkedSpans(line, markedSpans);
     var estHeight = estimateHeight ? estimateHeight(line) : 1;
     if (estHeight != line.height) updateLineHeight(line, estHeight);
   }
 
   // Detach a line from the document tree and its markers.
   function cleanUpLine(line) {
     line.parent = null;
     detachMarkedSpans(line);
   }
 
   function extractLineClasses(type, output) {
     if (type) for (;;) {
       var lineClass = type.match(/(?:^|\s+)line-(background-)?(\S+)/);
       if (!lineClass) break;
       type = type.slice(0, lineClass.index) + type.slice(lineClass.index + lineClass[0].length);
       var prop = lineClass[1] ? "bgClass" : "textClass";
       if (output[prop] == null)
         output[prop] = lineClass[2];
       else if (!(new RegExp("(?:^|\s)" + lineClass[2] + "(?:$|\s)")).test(output[prop]))
         output[prop] += " " + lineClass[2];
     }
     return type;
   }
 
   function callBlankLine(mode, state) {
     if (mode.blankLine) return mode.blankLine(state);
     if (!mode.innerMode) return;
     var inner = CodeMirror.innerMode(mode, state);
     if (inner.mode.blankLine) return inner.mode.blankLine(inner.state);
   }
 
   function readToken(mode, stream, state, inner) {
     for (var i = 0; i < 10; i++) {
       if (inner) inner[0] = CodeMirror.innerMode(mode, state).mode;
       var style = mode.token(stream, state);
       if (stream.pos > stream.start) return style;
     }
     throw new Error("Mode " + mode.name + " failed to advance stream.");
   }
 
   // Utility for getTokenAt and getLineTokens
   function takeToken(cm, pos, precise, asArray) {
     function getObj(copy) {
       return {start: stream.start, end: stream.pos,
               string: stream.current(),
               type: style || null,
               state: copy ? copyState(doc.mode, state) : state};
     }
 
     var doc = cm.doc, mode = doc.mode, style;
     pos = clipPos(doc, pos);
     var line = getLine(doc, pos.line), state = getStateBefore(cm, pos.line, precise);
     var stream = new StringStream(line.text, cm.options.tabSize), tokens;
     if (asArray) tokens = [];
     while ((asArray || stream.pos < pos.ch) && !stream.eol()) {
       stream.start = stream.pos;
       style = readToken(mode, stream, state);
       if (asArray) tokens.push(getObj(true));
     }
     return asArray ? tokens : getObj();
   }
 
   // Run the given mode's parser over a line, calling f for each token.
   function runMode(cm, text, mode, state, f, lineClasses, forceToEnd) {
     var flattenSpans = mode.flattenSpans;
     if (flattenSpans == null) flattenSpans = cm.options.flattenSpans;
     var curStart = 0, curStyle = null;
     var stream = new StringStream(text, cm.options.tabSize), style;
     var inner = cm.options.addModeClass && [null];
     if (text == "") extractLineClasses(callBlankLine(mode, state), lineClasses);
     while (!stream.eol()) {
       if (stream.pos > cm.options.maxHighlightLength) {
         flattenSpans = false;
         if (forceToEnd) processLine(cm, text, state, stream.pos);
         stream.pos = text.length;
         style = null;
       } else {
         style = extractLineClasses(readToken(mode, stream, state, inner), lineClasses);
       }
       if (inner) {
         var mName = inner[0].name;
         if (mName) style = "m-" + (style ? mName + " " + style : mName);
       }
       if (!flattenSpans || curStyle != style) {
         while (curStart < stream.start) {
           curStart = Math.min(stream.start, curStart + 50000);
           f(curStart, curStyle);
         }
         curStyle = style;
       }
       stream.start = stream.pos;
     }
     while (curStart < stream.pos) {
       // Webkit seems to refuse to render text nodes longer than 57444 characters
       var pos = Math.min(stream.pos, curStart + 50000);
       f(pos, curStyle);
       curStart = pos;
     }
   }
 
   // Compute a style array (an array starting with a mode generation
   // -- for invalidation -- followed by pairs of end positions and
   // style strings), which is used to highlight the tokens on the
   // line.
   function highlightLine(cm, line, state, forceToEnd) {
     // A styles array always starts with a number identifying the
     // mode/overlays that it is based on (for easy invalidation).
     var st = [cm.state.modeGen], lineClasses = {};
     // Compute the base array of styles
     runMode(cm, line.text, cm.doc.mode, state, function(end, style) {
       st.push(end, style);
     }, lineClasses, forceToEnd);
 
     // Run overlays, adjust style array.
     for (var o = 0; o < cm.state.overlays.length; ++o) {
       var overlay = cm.state.overlays[o], i = 1, at = 0;
       runMode(cm, line.text, overlay.mode, true, function(end, style) {
         var start = i;
         // Ensure there's a token end at the current position, and that i points at it
         while (at < end) {
           var i_end = st[i];
           if (i_end > end)
             st.splice(i, 1, end, st[i+1], i_end);
           i += 2;
           at = Math.min(end, i_end);
         }
         if (!style) return;
         if (overlay.opaque) {
           st.splice(start, i - start, end, "cm-overlay " + style);
           i = start + 2;
         } else {
           for (; start < i; start += 2) {
             var cur = st[start+1];
             st[start+1] = (cur ? cur + " " : "") + "cm-overlay " + style;
           }
         }
       }, lineClasses);
     }
 
     return {styles: st, classes: lineClasses.bgClass || lineClasses.textClass ? lineClasses : null};
   }
 
   function getLineStyles(cm, line, updateFrontier) {
     if (!line.styles || line.styles[0] != cm.state.modeGen) {
       var state = getStateBefore(cm, lineNo(line));
       var result = highlightLine(cm, line, line.text.length > cm.options.maxHighlightLength ? copyState(cm.doc.mode, state) : state);
       line.stateAfter = state;
       line.styles = result.styles;
       if (result.classes) line.styleClasses = result.classes;
       else if (line.styleClasses) line.styleClasses = null;
       if (updateFrontier === cm.doc.frontier) cm.doc.frontier++;
     }
     return line.styles;
   }
 
   // Lightweight form of highlight -- proceed over this line and
   // update state, but don't save a style array. Used for lines that
   // aren't currently visible.
   function processLine(cm, text, state, startAt) {
     var mode = cm.doc.mode;
     var stream = new StringStream(text, cm.options.tabSize);
     stream.start = stream.pos = startAt || 0;
     if (text == "") callBlankLine(mode, state);
     while (!stream.eol()) {
       readToken(mode, stream, state);
       stream.start = stream.pos;
     }
   }
 
   // Convert a style as returned by a mode (either null, or a string
   // containing one or more styles) to a CSS style. This is cached,
   // and also looks for line-wide styles.
   var styleToClassCache = {}, styleToClassCacheWithMode = {};
   function interpretTokenStyle(style, options) {
     if (!style || /^\s*$/.test(style)) return null;
     var cache = options.addModeClass ? styleToClassCacheWithMode : styleToClassCache;
     return cache[style] ||
       (cache[style] = style.replace(/\S+/g, "cm-$&"));
   }
 
   // Render the DOM representation of the text of a line. Also builds
   // up a 'line map', which points at the DOM nodes that represent
   // specific stretches of text, and is used by the measuring code.
   // The returned object contains the DOM node, this map, and
   // information about line-wide styles that were set by the mode.
   function buildLineContent(cm, lineView) {
     // The padding-right forces the element to have a 'border', which
     // is needed on Webkit to be able to get line-level bounding
     // rectangles for it (in measureChar).
     var content = elt("span", null, null, webkit ? "padding-right: .1px" : null);
     var builder = {pre: elt("pre", [content], "CodeMirror-line"), content: content,
                    col: 0, pos: 0, cm: cm,
                    splitSpaces: (ie || webkit) && cm.getOption("lineWrapping")};
     lineView.measure = {};
 
     // Iterate over the logical lines that make up this visual line.
     for (var i = 0; i <= (lineView.rest ? lineView.rest.length : 0); i++) {
       var line = i ? lineView.rest[i - 1] : lineView.line, order;
       builder.pos = 0;
       builder.addToken = buildToken;
       // Optionally wire in some hacks into the token-rendering
       // algorithm, to deal with browser quirks.
       if (hasBadBidiRects(cm.display.measure) && (order = getOrder(line)))
         builder.addToken = buildTokenBadBidi(builder.addToken, order);
       builder.map = [];
       var allowFrontierUpdate = lineView != cm.display.externalMeasured && lineNo(line);
       insertLineContent(line, builder, getLineStyles(cm, line, allowFrontierUpdate));
       if (line.styleClasses) {
         if (line.styleClasses.bgClass)
           builder.bgClass = joinClasses(line.styleClasses.bgClass, builder.bgClass || "");
         if (line.styleClasses.textClass)
           builder.textClass = joinClasses(line.styleClasses.textClass, builder.textClass || "");
       }
 
       // Ensure at least a single node is present, for measuring.
       if (builder.map.length == 0)
         builder.map.push(0, 0, builder.content.appendChild(zeroWidthElement(cm.display.measure)));
 
       // Store the map and a cache object for the current logical line
       if (i == 0) {
         lineView.measure.map = builder.map;
         lineView.measure.cache = {};
       } else {
         (lineView.measure.maps || (lineView.measure.maps = [])).push(builder.map);
         (lineView.measure.caches || (lineView.measure.caches = [])).push({});
       }
     }
 
     // See issue #2901
     if (webkit) {
       var last = builder.content.lastChild
       if (/\bcm-tab\b/.test(last.className) || (last.querySelector && last.querySelector(".cm-tab")))
         builder.content.className = "cm-tab-wrap-hack";
     }
 
     signal(cm, "renderLine", cm, lineView.line, builder.pre);
     if (builder.pre.className)
       builder.textClass = joinClasses(builder.pre.className, builder.textClass || "");
 
     return builder;
   }
 
   function defaultSpecialCharPlaceholder(ch) {
     var token = elt("span", "\u2022", "cm-invalidchar");
     token.title = "\\u" + ch.charCodeAt(0).toString(16);
     token.setAttribute("aria-label", token.title);
     return token;
   }
 
   // Build up the DOM representation for a single token, and add it to
   // the line map. Takes care to render special characters separately.
   function buildToken(builder, text, style, startStyle, endStyle, title, css) {
     if (!text) return;
     var displayText = builder.splitSpaces ? text.replace(/ {3,}/g, splitSpaces) : text;
     var special = builder.cm.state.specialChars, mustWrap = false;
     if (!special.test(text)) {
       builder.col += text.length;
       var content = document.createTextNode(displayText);
       builder.map.push(builder.pos, builder.pos + text.length, content);
       if (ie && ie_version < 9) mustWrap = true;
       builder.pos += text.length;
     } else {
       var content = document.createDocumentFragment(), pos = 0;
       while (true) {
         special.lastIndex = pos;
         var m = special.exec(text);
         var skipped = m ? m.index - pos : text.length - pos;
         if (skipped) {
           var txt = document.createTextNode(displayText.slice(pos, pos + skipped));
           if (ie && ie_version < 9) content.appendChild(elt("span", [txt]));
           else content.appendChild(txt);
           builder.map.push(builder.pos, builder.pos + skipped, txt);
           builder.col += skipped;
           builder.pos += skipped;
         }
         if (!m) break;
         pos += skipped + 1;
         if (m[0] == "\t") {
           var tabSize = builder.cm.options.tabSize, tabWidth = tabSize - builder.col % tabSize;
           var txt = content.appendChild(elt("span", spaceStr(tabWidth), "cm-tab"));
           txt.setAttribute("role", "presentation");
           txt.setAttribute("cm-text", "\t");
           builder.col += tabWidth;
         } else if (m[0] == "\r" || m[0] == "\n") {
           var txt = content.appendChild(elt("span", m[0] == "\r" ? "\u240d" : "\u2424", "cm-invalidchar"));
           txt.setAttribute("cm-text", m[0]);
           builder.col += 1;
         } else {
           var txt = builder.cm.options.specialCharPlaceholder(m[0]);
           txt.setAttribute("cm-text", m[0]);
           if (ie && ie_version < 9) content.appendChild(elt("span", [txt]));
           else content.appendChild(txt);
           builder.col += 1;
         }
         builder.map.push(builder.pos, builder.pos + 1, txt);
         builder.pos++;
       }
     }
     if (style || startStyle || endStyle || mustWrap || css) {
       var fullStyle = style || "";
       if (startStyle) fullStyle += startStyle;
       if (endStyle) fullStyle += endStyle;
       var token = elt("span", [content], fullStyle, css);
       if (title) token.title = title;
       return builder.content.appendChild(token);
     }
     builder.content.appendChild(content);
   }
 
   function splitSpaces(old) {
     var out = " ";
     for (var i = 0; i < old.length - 2; ++i) out += i % 2 ? " " : "\u00a0";
     out += " ";
     return out;
   }
 
   // Work around nonsense dimensions being reported for stretches of
   // right-to-left text.
   function buildTokenBadBidi(inner, order) {
     return function(builder, text, style, startStyle, endStyle, title, css) {
       style = style ? style + " cm-force-border" : "cm-force-border";
       var start = builder.pos, end = start + text.length;
       for (;;) {
         // Find the part that overlaps with the start of this text
         for (var i = 0; i < order.length; i++) {
           var part = order[i];
           if (part.to > start && part.from <= start) break;
         }
         if (part.to >= end) return inner(builder, text, style, startStyle, endStyle, title, css);
         inner(builder, text.slice(0, part.to - start), style, startStyle, null, title, css);
         startStyle = null;
         text = text.slice(part.to - start);
         start = part.to;
       }
     };
   }
 
   function buildCollapsedSpan(builder, size, marker, ignoreWidget) {
     var widget = !ignoreWidget && marker.widgetNode;
     if (widget) builder.map.push(builder.pos, builder.pos + size, widget);
     if (!ignoreWidget && builder.cm.display.input.needsContentAttribute) {
       if (!widget)
         widget = builder.content.appendChild(document.createElement("span"));
       widget.setAttribute("cm-marker", marker.id);
     }
     if (widget) {
       builder.cm.display.input.setUneditable(widget);
       builder.content.appendChild(widget);
     }
     builder.pos += size;
   }
 
   // Outputs a number of spans to make up a line, taking highlighting
   // and marked text into account.
   function insertLineContent(line, builder, styles) {
     var spans = line.markedSpans, allText = line.text, at = 0;
     if (!spans) {
       for (var i = 1; i < styles.length; i+=2)
         builder.addToken(builder, allText.slice(at, at = styles[i]), interpretTokenStyle(styles[i+1], builder.cm.options));
       return;
     }
 
     var len = allText.length, pos = 0, i = 1, text = "", style, css;
     var nextChange = 0, spanStyle, spanEndStyle, spanStartStyle, title, collapsed;
     for (;;) {
       if (nextChange == pos) { // Update current marker set
         spanStyle = spanEndStyle = spanStartStyle = title = css = "";
         collapsed = null; nextChange = Infinity;
         var foundBookmarks = [], endStyles
         for (var j = 0; j < spans.length; ++j) {
           var sp = spans[j], m = sp.marker;
           if (m.type == "bookmark" && sp.from == pos && m.widgetNode) {
             foundBookmarks.push(m);
           } else if (sp.from <= pos && (sp.to == null || sp.to > pos || m.collapsed && sp.to == pos && sp.from == pos)) {
             if (sp.to != null && sp.to != pos && nextChange > sp.to) {
               nextChange = sp.to;
               spanEndStyle = "";
             }
             if (m.className) spanStyle += " " + m.className;
             if (m.css) css = (css ? css + ";" : "") + m.css;
             if (m.startStyle && sp.from == pos) spanStartStyle += " " + m.startStyle;
             if (m.endStyle && sp.to == nextChange) (endStyles || (endStyles = [])).push(m.endStyle, sp.to)
             if (m.title && !title) title = m.title;
             if (m.collapsed && (!collapsed || compareCollapsedMarkers(collapsed.marker, m) < 0))
               collapsed = sp;
           } else if (sp.from > pos && nextChange > sp.from) {
             nextChange = sp.from;
           }
         }
         if (endStyles) for (var j = 0; j < endStyles.length; j += 2)
           if (endStyles[j + 1] == nextChange) spanEndStyle += " " + endStyles[j]
 
         if (!collapsed || collapsed.from == pos) for (var j = 0; j < foundBookmarks.length; ++j)
           buildCollapsedSpan(builder, 0, foundBookmarks[j]);
         if (collapsed && (collapsed.from || 0) == pos) {
           buildCollapsedSpan(builder, (collapsed.to == null ? len + 1 : collapsed.to) - pos,
                              collapsed.marker, collapsed.from == null);
           if (collapsed.to == null) return;
           if (collapsed.to == pos) collapsed = false;
         }
       }
       if (pos >= len) break;
 
       var upto = Math.min(len, nextChange);
       while (true) {
         if (text) {
           var end = pos + text.length;
           if (!collapsed) {
             var tokenText = end > upto ? text.slice(0, upto - pos) : text;
             builder.addToken(builder, tokenText, style ? style + spanStyle : spanStyle,
                              spanStartStyle, pos + tokenText.length == nextChange ? spanEndStyle : "", title, css);
           }
           if (end >= upto) {text = text.slice(upto - pos); pos = upto; break;}
           pos = end;
           spanStartStyle = "";
         }
         text = allText.slice(at, at = styles[i++]);
         style = interpretTokenStyle(styles[i++], builder.cm.options);
       }
     }
   }
 
   // DOCUMENT DATA STRUCTURE
 
   // By default, updates that start and end at the beginning of a line
   // are treated specially, in order to make the association of line
   // widgets and marker elements with the text behave more intuitive.
   function isWholeLineUpdate(doc, change) {
     return change.from.ch == 0 && change.to.ch == 0 && lst(change.text) == "" &&
       (!doc.cm || doc.cm.options.wholeLineUpdateBefore);
   }
 
   // Perform a change on the document data structure.
   function updateDoc(doc, change, markedSpans, estimateHeight) {
     function spansFor(n) {return markedSpans ? markedSpans[n] : null;}
     function update(line, text, spans) {
       updateLine(line, text, spans, estimateHeight);
       signalLater(line, "change", line, change);
     }
     function linesFor(start, end) {
       for (var i = start, result = []; i < end; ++i)
         result.push(new Line(text[i], spansFor(i), estimateHeight));
       return result;
     }
 
     var from = change.from, to = change.to, text = change.text;
     var firstLine = getLine(doc, from.line), lastLine = getLine(doc, to.line);
     var lastText = lst(text), lastSpans = spansFor(text.length - 1), nlines = to.line - from.line;
 
     // Adjust the line structure
     if (change.full) {
       doc.insert(0, linesFor(0, text.length));
       doc.remove(text.length, doc.size - text.length);
     } else if (isWholeLineUpdate(doc, change)) {
       // This is a whole-line replace. Treated specially to make
       // sure line objects move the way they are supposed to.
       var added = linesFor(0, text.length - 1);
       update(lastLine, lastLine.text, lastSpans);
       if (nlines) doc.remove(from.line, nlines);
       if (added.length) doc.insert(from.line, added);
     } else if (firstLine == lastLine) {
       if (text.length == 1) {
         update(firstLine, firstLine.text.slice(0, from.ch) + lastText + firstLine.text.slice(to.ch), lastSpans);
       } else {
         var added = linesFor(1, text.length - 1);
         added.push(new Line(lastText + firstLine.text.slice(to.ch), lastSpans, estimateHeight));
         update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
         doc.insert(from.line + 1, added);
       }
     } else if (text.length == 1) {
       update(firstLine, firstLine.text.slice(0, from.ch) + text[0] + lastLine.text.slice(to.ch), spansFor(0));
       doc.remove(from.line + 1, nlines);
     } else {
       update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
       update(lastLine, lastText + lastLine.text.slice(to.ch), lastSpans);
       var added = linesFor(1, text.length - 1);
       if (nlines > 1) doc.remove(from.line + 1, nlines - 1);
       doc.insert(from.line + 1, added);
     }
 
     signalLater(doc, "change", doc, change);
   }
 
   // The document is represented as a BTree consisting of leaves, with
   // chunk of lines in them, and branches, with up to ten leaves or
   // other branch nodes below them. The top node is always a branch
   // node, and is the document object itself (meaning it has
   // additional methods and properties).
   //
   // All nodes have parent links. The tree is used both to go from
   // line numbers to line objects, and to go from objects to numbers.
   // It also indexes by height, and is used to convert between height
   // and line object, and to find the total height of the document.
   //
   // See also http://marijnhaverbeke.nl/blog/codemirror-line-tree.html
 
   function LeafChunk(lines) {
     this.lines = lines;
     this.parent = null;
     for (var i = 0, height = 0; i < lines.length; ++i) {
       lines[i].parent = this;
       height += lines[i].height;
     }
     this.height = height;
   }
 
   LeafChunk.prototype = {
     chunkSize: function() { return this.lines.length; },
     // Remove the n lines at offset 'at'.
     removeInner: function(at, n) {
       for (var i = at, e = at + n; i < e; ++i) {
         var line = this.lines[i];
         this.height -= line.height;
         cleanUpLine(line);
         signalLater(line, "delete");
       }
       this.lines.splice(at, n);
     },
     // Helper used to collapse a small branch into a single leaf.
     collapse: function(lines) {
       lines.push.apply(lines, this.lines);
     },
     // Insert the given array of lines at offset 'at', count them as
     // having the given height.
     insertInner: function(at, lines, height) {
       this.height += height;
       this.lines = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at));
       for (var i = 0; i < lines.length; ++i) lines[i].parent = this;
     },
     // Used to iterate over a part of the tree.
     iterN: function(at, n, op) {
       for (var e = at + n; at < e; ++at)
         if (op(this.lines[at])) return true;
     }
   };
 
   function BranchChunk(children) {
     this.children = children;
     var size = 0, height = 0;
     for (var i = 0; i < children.length; ++i) {
       var ch = children[i];
       size += ch.chunkSize(); height += ch.height;
       ch.parent = this;
     }
     this.size = size;
     this.height = height;
     this.parent = null;
   }
 
   BranchChunk.prototype = {
     chunkSize: function() { return this.size; },
     removeInner: function(at, n) {
       this.size -= n;
       for (var i = 0; i < this.children.length; ++i) {
         var child = this.children[i], sz = child.chunkSize();
         if (at < sz) {
           var rm = Math.min(n, sz - at), oldHeight = child.height;
           child.removeInner(at, rm);
           this.height -= oldHeight - child.height;
           if (sz == rm) { this.children.splice(i--, 1); child.parent = null; }
           if ((n -= rm) == 0) break;
           at = 0;
         } else at -= sz;
       }
       // If the result is smaller than 25 lines, ensure that it is a
       // single leaf node.
       if (this.size - n < 25 &&
           (this.children.length > 1 || !(this.children[0] instanceof LeafChunk))) {
         var lines = [];
         this.collapse(lines);
         this.children = [new LeafChunk(lines)];
         this.children[0].parent = this;
       }
     },
     collapse: function(lines) {
       for (var i = 0; i < this.children.length; ++i) this.children[i].collapse(lines);
     },
     insertInner: function(at, lines, height) {
       this.size += lines.length;
       this.height += height;
       for (var i = 0; i < this.children.length; ++i) {
         var child = this.children[i], sz = child.chunkSize();
         if (at <= sz) {
           child.insertInner(at, lines, height);
           if (child.lines && child.lines.length > 50) {
             // To avoid memory thrashing when child.lines is huge (e.g. first view of a large file), it's never spliced.
             // Instead, small slices are taken. They're taken in order because sequential memory accesses are fastest.
             var remaining = child.lines.length % 25 + 25
             for (var pos = remaining; pos < child.lines.length;) {
               var leaf = new LeafChunk(child.lines.slice(pos, pos += 25));
               child.height -= leaf.height;
               this.children.splice(++i, 0, leaf);
               leaf.parent = this;
             }
             child.lines = child.lines.slice(0, remaining);
             this.maybeSpill();
           }
           break;
         }
         at -= sz;
       }
     },
     // When a node has grown, check whether it should be split.
     maybeSpill: function() {
       if (this.children.length <= 10) return;
       var me = this;
       do {
         var spilled = me.children.splice(me.children.length - 5, 5);
         var sibling = new BranchChunk(spilled);
         if (!me.parent) { // Become the parent node
           var copy = new BranchChunk(me.children);
           copy.parent = me;
           me.children = [copy, sibling];
           me = copy;
        } else {
           me.size -= sibling.size;
           me.height -= sibling.height;
           var myIndex = indexOf(me.parent.children, me);
           me.parent.children.splice(myIndex + 1, 0, sibling);
         }
         sibling.parent = me.parent;
       } while (me.children.length > 10);
       me.parent.maybeSpill();
     },
     iterN: function(at, n, op) {
       for (var i = 0; i < this.children.length; ++i) {
         var child = this.children[i], sz = child.chunkSize();
         if (at < sz) {
           var used = Math.min(n, sz - at);
           if (child.iterN(at, used, op)) return true;
           if ((n -= used) == 0) break;
           at = 0;
         } else at -= sz;
       }
     }
   };
 
   var nextDocId = 0;
   var Doc = CodeMirror.Doc = function(text, mode, firstLine, lineSep) {
     if (!(this instanceof Doc)) return new Doc(text, mode, firstLine, lineSep);
     if (firstLine == null) firstLine = 0;
 
     BranchChunk.call(this, [new LeafChunk([new Line("", null)])]);
     this.first = firstLine;
     this.scrollTop = this.scrollLeft = 0;
     this.cantEdit = false;
     this.cleanGeneration = 1;
     this.frontier = firstLine;
     var start = Pos(firstLine, 0);
     this.sel = simpleSelection(start);
     this.history = new History(null);
     this.id = ++nextDocId;
     this.modeOption = mode;
     this.lineSep = lineSep;
     this.extend = false;
 
     if (typeof text == "string") text = this.splitLines(text);
     updateDoc(this, {from: start, to: start, text: text});
     setSelection(this, simpleSelection(start), sel_dontScroll);
   };
 
   Doc.prototype = createObj(BranchChunk.prototype, {
     constructor: Doc,
     // Iterate over the document. Supports two forms -- with only one
     // argument, it calls that for each line in the document. With
     // three, it iterates over the range given by the first two (with
     // the second being non-inclusive).
     iter: function(from, to, op) {
       if (op) this.iterN(from - this.first, to - from, op);
       else this.iterN(this.first, this.first + this.size, from);
     },
 
     // Non-public interface for adding and removing lines.
     insert: function(at, lines) {
       var height = 0;
       for (var i = 0; i < lines.length; ++i) height += lines[i].height;
       this.insertInner(at - this.first, lines, height);
     },
     remove: function(at, n) { this.removeInner(at - this.first, n); },
 
     // From here, the methods are part of the public interface. Most
     // are also available from CodeMirror (editor) instances.
 
     getValue: function(lineSep) {
       var lines = getLines(this, this.first, this.first + this.size);
       if (lineSep === false) return lines;
       return lines.join(lineSep || this.lineSeparator());
     },
     setValue: docMethodOp(function(code) {
       var top = Pos(this.first, 0), last = this.first + this.size - 1;
       makeChange(this, {from: top, to: Pos(last, getLine(this, last).text.length),
                         text: this.splitLines(code), origin: "setValue", full: true}, true);
       setSelection(this, simpleSelection(top));
     }),
     replaceRange: function(code, from, to, origin) {
       from = clipPos(this, from);
       to = to ? clipPos(this, to) : from;
       replaceRange(this, code, from, to, origin);
     },
     getRange: function(from, to, lineSep) {
       var lines = getBetween(this, clipPos(this, from), clipPos(this, to));
       if (lineSep === false) return lines;
       return lines.join(lineSep || this.lineSeparator());
     },
 
     getLine: function(line) {var l = this.getLineHandle(line); return l && l.text;},
 
     getLineHandle: function(line) {if (isLine(this, line)) return getLine(this, line);},
     getLineNumber: function(line) {return lineNo(line);},
 
     getLineHandleVisualStart: function(line) {
       if (typeof line == "number") line = getLine(this, line);
       return visualLine(line);
     },
 
     lineCount: function() {return this.size;},
     firstLine: function() {return this.first;},
     lastLine: function() {return this.first + this.size - 1;},
 
     clipPos: function(pos) {return clipPos(this, pos);},
 
     getCursor: function(start) {
       var range = this.sel.primary(), pos;
       if (start == null || start == "head") pos = range.head;
       else if (start == "anchor") pos = range.anchor;
       else if (start == "end" || start == "to" || start === false) pos = range.to();
       else pos = range.from();
       return pos;
     },
     listSelections: function() { return this.sel.ranges; },
     somethingSelected: function() {return this.sel.somethingSelected();},
 
     setCursor: docMethodOp(function(line, ch, options) {
       setSimpleSelection(this, clipPos(this, typeof line == "number" ? Pos(line, ch || 0) : line), null, options);
     }),
     setSelection: docMethodOp(function(anchor, head, options) {
       setSimpleSelection(this, clipPos(this, anchor), clipPos(this, head || anchor), options);
     }),
     extendSelection: docMethodOp(function(head, other, options) {
       extendSelection(this, clipPos(this, head), other && clipPos(this, other), options);
     }),
     extendSelections: docMethodOp(function(heads, options) {
       extendSelections(this, clipPosArray(this, heads), options);
     }),
     extendSelectionsBy: docMethodOp(function(f, options) {
       var heads = map(this.sel.ranges, f);
       extendSelections(this, clipPosArray(this, heads), options);
     }),
     setSelections: docMethodOp(function(ranges, primary, options) {
       if (!ranges.length) return;
       for (var i = 0, out = []; i < ranges.length; i++)
         out[i] = new Range(clipPos(this, ranges[i].anchor),
                            clipPos(this, ranges[i].head));
       if (primary == null) primary = Math.min(ranges.length - 1, this.sel.primIndex);
       setSelection(this, normalizeSelection(out, primary), options);
     }),
     addSelection: docMethodOp(function(anchor, head, options) {
       var ranges = this.sel.ranges.slice(0);
       ranges.push(new Range(clipPos(this, anchor), clipPos(this, head || anchor)));
       setSelection(this, normalizeSelection(ranges, ranges.length - 1), options);
     }),
 
     getSelection: function(lineSep) {
       var ranges = this.sel.ranges, lines;
       for (var i = 0; i < ranges.length; i++) {
         var sel = getBetween(this, ranges[i].from(), ranges[i].to());
         lines = lines ? lines.concat(sel) : sel;
       }
       if (lineSep === false) return lines;
       else return lines.join(lineSep || this.lineSeparator());
     },
     getSelections: function(lineSep) {
       var parts = [], ranges = this.sel.ranges;
       for (var i = 0; i < ranges.length; i++) {
         var sel = getBetween(this, ranges[i].from(), ranges[i].to());
         if (lineSep !== false) sel = sel.join(lineSep || this.lineSeparator());
         parts[i] = sel;
       }
       return parts;
     },
     replaceSelection: function(code, collapse, origin) {
       var dup = [];
       for (var i = 0; i < this.sel.ranges.length; i++)
         dup[i] = code;
       this.replaceSelections(dup, collapse, origin || "+input");
     },
     replaceSelections: docMethodOp(function(code, collapse, origin) {
       var changes = [], sel = this.sel;
       for (var i = 0; i < sel.ranges.length; i++) {
         var range = sel.ranges[i];
         changes[i] = {from: range.from(), to: range.to(), text: this.splitLines(code[i]), origin: origin};
       }
       var newSel = collapse && collapse != "end" && computeReplacedSel(this, changes, collapse);
       for (var i = changes.length - 1; i >= 0; i--)
         makeChange(this, changes[i]);
       if (newSel) setSelectionReplaceHistory(this, newSel);
       else if (this.cm) ensureCursorVisible(this.cm);
     }),
     undo: docMethodOp(function() {makeChangeFromHistory(this, "undo");}),
     redo: docMethodOp(function() {makeChangeFromHistory(this, "redo");}),
     undoSelection: docMethodOp(function() {makeChangeFromHistory(this, "undo", true);}),
     redoSelection: docMethodOp(function() {makeChangeFromHistory(this, "redo", true);}),
 
     setExtending: function(val) {this.extend = val;},
     getExtending: function() {return this.extend;},
 
     historySize: function() {
       var hist = this.history, done = 0, undone = 0;
       for (var i = 0; i < hist.done.length; i++) if (!hist.done[i].ranges) ++done;
       for (var i = 0; i < hist.undone.length; i++) if (!hist.undone[i].ranges) ++undone;
       return {undo: done, redo: undone};
     },
     clearHistory: function() {this.history = new History(this.history.maxGeneration);},
 
     markClean: function() {
       this.cleanGeneration = this.changeGeneration(true);
     },
     changeGeneration: function(forceSplit) {
       if (forceSplit)
         this.history.lastOp = this.history.lastSelOp = this.history.lastOrigin = null;
       return this.history.generation;
     },
     isClean: function (gen) {
       return this.history.generation == (gen || this.cleanGeneration);
     },
 
     getHistory: function() {
       return {done: copyHistoryArray(this.history.done),
               undone: copyHistoryArray(this.history.undone)};
     },
     setHistory: function(histData) {
       var hist = this.history = new History(this.history.maxGeneration);
       hist.done = copyHistoryArray(histData.done.slice(0), null, true);
       hist.undone = copyHistoryArray(histData.undone.slice(0), null, true);
     },
 
     addLineClass: docMethodOp(function(handle, where, cls) {
       return changeLine(this, handle, where == "gutter" ? "gutter" : "class", function(line) {
         var prop = where == "text" ? "textClass"
                  : where == "background" ? "bgClass"
                  : where == "gutter" ? "gutterClass" : "wrapClass";
         if (!line[prop]) line[prop] = cls;
         else if (classTest(cls).test(line[prop])) return false;
         else line[prop] += " " + cls;
         return true;
       });
     }),
     removeLineClass: docMethodOp(function(handle, where, cls) {
       return changeLine(this, handle, where == "gutter" ? "gutter" : "class", function(line) {
         var prop = where == "text" ? "textClass"
                  : where == "background" ? "bgClass"
                  : where == "gutter" ? "gutterClass" : "wrapClass";
         var cur = line[prop];
         if (!cur) return false;
         else if (cls == null) line[prop] = null;
         else {
           var found = cur.match(classTest(cls));
           if (!found) return false;
           var end = found.index + found[0].length;
           line[prop] = cur.slice(0, found.index) + (!found.index || end == cur.length ? "" : " ") + cur.slice(end) || null;
         }
         return true;
       });
     }),
 
     addLineWidget: docMethodOp(function(handle, node, options) {
       return addLineWidget(this, handle, node, options);
     }),
     removeLineWidget: function(widget) { widget.clear(); },
 
     markText: function(from, to, options) {
       return markText(this, clipPos(this, from), clipPos(this, to), options, options && options.type || "range");
     },
     setBookmark: function(pos, options) {
       var realOpts = {replacedWith: options && (options.nodeType == null ? options.widget : options),
                       insertLeft: options && options.insertLeft,
                       clearWhenEmpty: false, shared: options && options.shared,
                       handleMouseEvents: options && options.handleMouseEvents};
       pos = clipPos(this, pos);
       return markText(this, pos, pos, realOpts, "bookmark");
     },
     findMarksAt: function(pos) {
       pos = clipPos(this, pos);
       var markers = [], spans = getLine(this, pos.line).markedSpans;
       if (spans) for (var i = 0; i < spans.length; ++i) {
         var span = spans[i];
         if ((span.from == null || span.from <= pos.ch) &&
             (span.to == null || span.to >= pos.ch))
           markers.push(span.marker.parent || span.marker);
       }
       return markers;
     },
     findMarks: function(from, to, filter) {
       from = clipPos(this, from); to = clipPos(this, to);
       var found = [], lineNo = from.line;
       this.iter(from.line, to.line + 1, function(line) {
         var spans = line.markedSpans;
         if (spans) for (var i = 0; i < spans.length; i++) {
           var span = spans[i];
           if (!(span.to != null && lineNo == from.line && from.ch >= span.to ||
                 span.from == null && lineNo != from.line ||
                 span.from != null && lineNo == to.line && span.from >= to.ch) &&
               (!filter || filter(span.marker)))
             found.push(span.marker.parent || span.marker);
         }
         ++lineNo;
       });
       return found;
     },
     getAllMarks: function() {
       var markers = [];
       this.iter(function(line) {
         var sps = line.markedSpans;
         if (sps) for (var i = 0; i < sps.length; ++i)
           if (sps[i].from != null) markers.push(sps[i].marker);
       });
       return markers;
     },
 
     posFromIndex: function(off) {
       var ch, lineNo = this.first, sepSize = this.lineSeparator().length;
       this.iter(function(line) {
         var sz = line.text.length + sepSize;
         if (sz > off) { ch = off; return true; }
         off -= sz;
         ++lineNo;
       });
       return clipPos(this, Pos(lineNo, ch));
     },
     indexFromPos: function (coords) {
       coords = clipPos(this, coords);
       var index = coords.ch;
       if (coords.line < this.first || coords.ch < 0) return 0;
       var sepSize = this.lineSeparator().length;
       this.iter(this.first, coords.line, function (line) {
         index += line.text.length + sepSize;
       });
       return index;
     },
 
     copy: function(copyHistory) {
       var doc = new Doc(getLines(this, this.first, this.first + this.size),
                         this.modeOption, this.first, this.lineSep);
       doc.scrollTop = this.scrollTop; doc.scrollLeft = this.scrollLeft;
       doc.sel = this.sel;
       doc.extend = false;
       if (copyHistory) {
         doc.history.undoDepth = this.history.undoDepth;
         doc.setHistory(this.getHistory());
       }
       return doc;
     },
 
     linkedDoc: function(options) {
       if (!options) options = {};
       var from = this.first, to = this.first + this.size;
       if (options.from != null && options.from > from) from = options.from;
       if (options.to != null && options.to < to) to = options.to;
       var copy = new Doc(getLines(this, from, to), options.mode || this.modeOption, from, this.lineSep);
       if (options.sharedHist) copy.history = this.history;
       (this.linked || (this.linked = [])).push({doc: copy, sharedHist: options.sharedHist});
       copy.linked = [{doc: this, isParent: true, sharedHist: options.sharedHist}];
       copySharedMarkers(copy, findSharedMarkers(this));
       return copy;
     },
     unlinkDoc: function(other) {
       if (other instanceof CodeMirror) other = other.doc;
       if (this.linked) for (var i = 0; i < this.linked.length; ++i) {
         var link = this.linked[i];
         if (link.doc != other) continue;
         this.linked.splice(i, 1);
         other.unlinkDoc(this);
         detachSharedMarkers(findSharedMarkers(this));
         break;
       }
       // If the histories were shared, split them again
       if (other.history == this.history) {
         var splitIds = [other.id];
         linkedDocs(other, function(doc) {splitIds.push(doc.id);}, true);
         other.history = new History(null);
         other.history.done = copyHistoryArray(this.history.done, splitIds);
         other.history.undone = copyHistoryArray(this.history.undone, splitIds);
       }
     },
     iterLinkedDocs: function(f) {linkedDocs(this, f);},
 
     getMode: function() {return this.mode;},
     getEditor: function() {return this.cm;},
 
     splitLines: function(str) {
       if (this.lineSep) return str.split(this.lineSep);
       return splitLinesAuto(str);
     },
     lineSeparator: function() { return this.lineSep || "\n"; }
   });
 
   // Public alias.
   Doc.prototype.eachLine = Doc.prototype.iter;
 
   // Set up methods on CodeMirror's prototype to redirect to the editor's document.
   var dontDelegate = "iter insert remove copy getEditor constructor".split(" ");
   for (var prop in Doc.prototype) if (Doc.prototype.hasOwnProperty(prop) && indexOf(dontDelegate, prop) < 0)
     CodeMirror.prototype[prop] = (function(method) {
       return function() {return method.apply(this.doc, arguments);};
     })(Doc.prototype[prop]);
 
   eventMixin(Doc);
 
   // Call f for all linked documents.
   function linkedDocs(doc, f, sharedHistOnly) {
     function propagate(doc, skip, sharedHist) {
       if (doc.linked) for (var i = 0; i < doc.linked.length; ++i) {
         var rel = doc.linked[i];
         if (rel.doc == skip) continue;
         var shared = sharedHist && rel.sharedHist;
         if (sharedHistOnly && !shared) continue;
         f(rel.doc, shared);
         propagate(rel.doc, doc, shared);
       }
     }
     propagate(doc, null, true);
   }
 
   // Attach a document to an editor.
   function attachDoc(cm, doc) {
     if (doc.cm) throw new Error("This document is already in use.");
     cm.doc = doc;
     doc.cm = cm;
     estimateLineHeights(cm);
     loadMode(cm);
     if (!cm.options.lineWrapping) findMaxLine(cm);
     cm.options.mode = doc.modeOption;
     regChange(cm);
   }
 
   // LINE UTILITIES
 
   // Find the line object corresponding to the given line number.
   function getLine(doc, n) {
     n -= doc.first;
     if (n < 0 || n >= doc.size) throw new Error("There is no line " + (n + doc.first) + " in the document.");
     for (var chunk = doc; !chunk.lines;) {
       for (var i = 0;; ++i) {
         var child = chunk.children[i], sz = child.chunkSize();
         if (n < sz) { chunk = child; break; }
         n -= sz;
       }
     }
     return chunk.lines[n];
   }
 
   // Get the part of a document between two positions, as an array of
   // strings.
   function getBetween(doc, start, end) {
     var out = [], n = start.line;
     doc.iter(start.line, end.line + 1, function(line) {
       var text = line.text;
       if (n == end.line) text = text.slice(0, end.ch);
       if (n == start.line) text = text.slice(start.ch);
       out.push(text);
       ++n;
     });
     return out;
   }
   // Get the lines between from and to, as array of strings.
   function getLines(doc, from, to) {
     var out = [];
     doc.iter(from, to, function(line) { out.push(line.text); });
     return out;
   }
 
   // Update the height of a line, propagating the height change
   // upwards to parent nodes.
   function updateLineHeight(line, height) {
     var diff = height - line.height;
     if (diff) for (var n = line; n; n = n.parent) n.height += diff;
   }
 
   // Given a line object, find its line number by walking up through
   // its parent links.
   function lineNo(line) {
     if (line.parent == null) return null;
     var cur = line.parent, no = indexOf(cur.lines, line);
     for (var chunk = cur.parent; chunk; cur = chunk, chunk = chunk.parent) {
       for (var i = 0;; ++i) {
         if (chunk.children[i] == cur) break;
         no += chunk.children[i].chunkSize();
       }
     }
     return no + cur.first;
   }
 
   // Find the line at the given vertical position, using the height
   // information in the document tree.
   function lineAtHeight(chunk, h) {
     var n = chunk.first;
     outer: do {
       for (var i = 0; i < chunk.children.length; ++i) {
         var child = chunk.children[i], ch = child.height;
         if (h < ch) { chunk = child; continue outer; }
         h -= ch;
         n += child.chunkSize();
       }
       return n;
     } while (!chunk.lines);
     for (var i = 0; i < chunk.lines.length; ++i) {
       var line = chunk.lines[i], lh = line.height;
       if (h < lh) break;
       h -= lh;
     }
     return n + i;
   }
 
 
   // Find the height above the given line.
   function heightAtLine(lineObj) {
     lineObj = visualLine(lineObj);
 
     var h = 0, chunk = lineObj.parent;
     for (var i = 0; i < chunk.lines.length; ++i) {
       var line = chunk.lines[i];
       if (line == lineObj) break;
       else h += line.height;
     }
     for (var p = chunk.parent; p; chunk = p, p = chunk.parent) {
       for (var i = 0; i < p.children.length; ++i) {
         var cur = p.children[i];
         if (cur == chunk) break;
         else h += cur.height;
       }
     }
     return h;
   }
 
   // Get the bidi ordering for the given line (and cache it). Returns
   // false for lines that are fully left-to-right, and an array of
   // BidiSpan objects otherwise.
   function getOrder(line) {
     var order = line.order;
     if (order == null) order = line.order = bidiOrdering(line.text);
     return order;
   }
 
   // HISTORY
 
   function History(startGen) {
     // Arrays of change events and selections. Doing something adds an
     // event to done and clears undo. Undoing moves events from done
     // to undone, redoing moves them in the other direction.
     this.done = []; this.undone = [];
     this.undoDepth = Infinity;
     // Used to track when changes can be merged into a single undo
     // event
     this.lastModTime = this.lastSelTime = 0;
     this.lastOp = this.lastSelOp = null;
     this.lastOrigin = this.lastSelOrigin = null;
     // Used by the isClean() method
     this.generation = this.maxGeneration = startGen || 1;
   }
 
   // Create a history change event from an updateDoc-style change
   // object.
   function historyChangeFromChange(doc, change) {
     var histChange = {from: copyPos(change.from), to: changeEnd(change), text: getBetween(doc, change.from, change.to)};
     attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);
     linkedDocs(doc, function(doc) {attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);}, true);
     return histChange;
   }
 
   // Pop all selection events off the end of a history array. Stop at
   // a change event.
   function clearSelectionEvents(array) {
     while (array.length) {
       var last = lst(array);
       if (last.ranges) array.pop();
       else break;
     }
   }
 
   // Find the top change event in the history. Pop off selection
   // events that are in the way.
   function lastChangeEvent(hist, force) {
     if (force) {
       clearSelectionEvents(hist.done);
       return lst(hist.done);
     } else if (hist.done.length && !lst(hist.done).ranges) {
       return lst(hist.done);
     } else if (hist.done.length > 1 && !hist.done[hist.done.length - 2].ranges) {
       hist.done.pop();
       return lst(hist.done);
     }
   }
 
   // Register a change in the history. Merges changes that are within
   // a single operation, ore are close together with an origin that
   // allows merging (starting with "+") into a single event.
   function addChangeToHistory(doc, change, selAfter, opId) {
     var hist = doc.history;
     hist.undone.length = 0;
     var time = +new Date, cur;
 
     if ((hist.lastOp == opId ||
          hist.lastOrigin == change.origin && change.origin &&
          ((change.origin.charAt(0) == "+" && doc.cm && hist.lastModTime > time - doc.cm.options.historyEventDelay) ||
           change.origin.charAt(0) == "*")) &&
         (cur = lastChangeEvent(hist, hist.lastOp == opId))) {
       // Merge this change into the last event
       var last = lst(cur.changes);
       if (cmp(change.from, change.to) == 0 && cmp(change.from, last.to) == 0) {
         // Optimized case for simple insertion -- don't want to add
         // new changesets for every character typed
         last.to = changeEnd(change);
       } else {
         // Add new sub-event
         cur.changes.push(historyChangeFromChange(doc, change));
       }
     } else {
       // Can not be merged, start a new event.
       var before = lst(hist.done);
       if (!before || !before.ranges)
         pushSelectionToHistory(doc.sel, hist.done);
       cur = {changes: [historyChangeFromChange(doc, change)],
              generation: hist.generation};
       hist.done.push(cur);
       while (hist.done.length > hist.undoDepth) {
         hist.done.shift();
         if (!hist.done[0].ranges) hist.done.shift();
       }
     }
     hist.done.push(selAfter);
     hist.generation = ++hist.maxGeneration;
     hist.lastModTime = hist.lastSelTime = time;
     hist.lastOp = hist.lastSelOp = opId;
     hist.lastOrigin = hist.lastSelOrigin = change.origin;
 
     if (!last) signal(doc, "historyAdded");
   }
 
   function selectionEventCanBeMerged(doc, origin, prev, sel) {
     var ch = origin.charAt(0);
     return ch == "*" ||
       ch == "+" &&
       prev.ranges.length == sel.ranges.length &&
       prev.somethingSelected() == sel.somethingSelected() &&
       new Date - doc.history.lastSelTime <= (doc.cm ? doc.cm.options.historyEventDelay : 500);
   }
 
   // Called whenever the selection changes, sets the new selection as
   // the pending selection in the history, and pushes the old pending
   // selection into the 'done' array when it was significantly
   // different (in number of selected ranges, emptiness, or time).
   function addSelectionToHistory(doc, sel, opId, options) {
     var hist = doc.history, origin = options && options.origin;
 
     // A new event is started when the previous origin does not match
     // the current, or the origins don't allow matching. Origins
     // starting with * are always merged, those starting with + are
     // merged when similar and close together in time.
     if (opId == hist.lastSelOp ||
         (origin && hist.lastSelOrigin == origin &&
          (hist.lastModTime == hist.lastSelTime && hist.lastOrigin == origin ||
           selectionEventCanBeMerged(doc, origin, lst(hist.done), sel))))
       hist.done[hist.done.length - 1] = sel;
     else
       pushSelectionToHistory(sel, hist.done);
 
     hist.lastSelTime = +new Date;
     hist.lastSelOrigin = origin;
     hist.lastSelOp = opId;
     if (options && options.clearRedo !== false)
       clearSelectionEvents(hist.undone);
   }
 
   function pushSelectionToHistory(sel, dest) {
     var top = lst(dest);
     if (!(top && top.ranges && top.equals(sel)))
       dest.push(sel);
   }
 
   // Used to store marked span information in the history.
   function attachLocalSpans(doc, change, from, to) {
     var existing = change["spans_" + doc.id], n = 0;
     doc.iter(Math.max(doc.first, from), Math.min(doc.first + doc.size, to), function(line) {
       if (line.markedSpans)
         (existing || (existing = change["spans_" + doc.id] = {}))[n] = line.markedSpans;
       ++n;
     });
   }
 
   // When un/re-doing restores text containing marked spans, those
   // that have been explicitly cleared should not be restored.
   function removeClearedSpans(spans) {
     if (!spans) return null;
     for (var i = 0, out; i < spans.length; ++i) {
       if (spans[i].marker.explicitlyCleared) { if (!out) out = spans.slice(0, i); }
       else if (out) out.push(spans[i]);
     }
     return !out ? spans : out.length ? out : null;
   }
 
   // Retrieve and filter the old marked spans stored in a change event.
   function getOldSpans(doc, change) {
     var found = change["spans_" + doc.id];
     if (!found) return null;
     for (var i = 0, nw = []; i < change.text.length; ++i)
       nw.push(removeClearedSpans(found[i]));
     return nw;
   }
 
   // Used both to provide a JSON-safe object in .getHistory, and, when
   // detaching a document, to split the history in two
   function copyHistoryArray(events, newGroup, instantiateSel) {
     for (var i = 0, copy = []; i < events.length; ++i) {
       var event = events[i];
       if (event.ranges) {
         copy.push(instantiateSel ? Selection.prototype.deepCopy.call(event) : event);
         continue;
       }
       var changes = event.changes, newChanges = [];
       copy.push({changes: newChanges});
       for (var j = 0; j < changes.length; ++j) {
         var change = changes[j], m;
         newChanges.push({from: change.from, to: change.to, text: change.text});
         if (newGroup) for (var prop in change) if (m = prop.match(/^spans_(\d+)$/)) {
           if (indexOf(newGroup, Number(m[1])) > -1) {
             lst(newChanges)[prop] = change[prop];
             delete change[prop];
           }
         }
       }
     }
     return copy;
   }
 
   // Rebasing/resetting history to deal with externally-sourced changes
 
   function rebaseHistSelSingle(pos, from, to, diff) {
     if (to < pos.line) {
       pos.line += diff;
     } else if (from < pos.line) {
       pos.line = from;
       pos.ch = 0;
     }
   }
 
   // Tries to rebase an array of history events given a change in the
   // document. If the change touches the same lines as the event, the
   // event, and everything 'behind' it, is discarded. If the change is
   // before the event, the event's positions are updated. Uses a
   // copy-on-write scheme for the positions, to avoid having to
   // reallocate them all on every rebase, but also avoid problems with
   // shared position objects being unsafely updated.
   function rebaseHistArray(array, from, to, diff) {
     for (var i = 0; i < array.length; ++i) {
       var sub = array[i], ok = true;
       if (sub.ranges) {
         if (!sub.copied) { sub = array[i] = sub.deepCopy(); sub.copied = true; }
         for (var j = 0; j < sub.ranges.length; j++) {
           rebaseHistSelSingle(sub.ranges[j].anchor, from, to, diff);
           rebaseHistSelSingle(sub.ranges[j].head, from, to, diff);
         }
         continue;
       }
       for (var j = 0; j < sub.changes.length; ++j) {
         var cur = sub.changes[j];
         if (to < cur.from.line) {
           cur.from = Pos(cur.from.line + diff, cur.from.ch);
           cur.to = Pos(cur.to.line + diff, cur.to.ch);
         } else if (from <= cur.to.line) {
           ok = false;
           break;
         }
       }
       if (!ok) {
         array.splice(0, i + 1);
         i = 0;
       }
     }
   }
 
   function rebaseHist(hist, change) {
     var from = change.from.line, to = change.to.line, diff = change.text.length - (to - from) - 1;
     rebaseHistArray(hist.done, from, to, diff);
     rebaseHistArray(hist.undone, from, to, diff);
   }
 
   // EVENT UTILITIES
 
   // Due to the fact that we still support jurassic IE versions, some
   // compatibility wrappers are needed.
 
   var e_preventDefault = CodeMirror.e_preventDefault = function(e) {
     if (e.preventDefault) e.preventDefault();
     else e.returnValue = false;
   };
   var e_stopPropagation = CodeMirror.e_stopPropagation = function(e) {
     if (e.stopPropagation) e.stopPropagation();
     else e.cancelBubble = true;
   };
   function e_defaultPrevented(e) {
     return e.defaultPrevented != null ? e.defaultPrevented : e.returnValue == false;
   }
   var e_stop = CodeMirror.e_stop = function(e) {e_preventDefault(e); e_stopPropagation(e);};
 
   function e_target(e) {return e.target || e.srcElement;}
   function e_button(e) {
     var b = e.which;
     if (b == null) {
       if (e.button & 1) b = 1;
       else if (e.button & 2) b = 3;
       else if (e.button & 4) b = 2;
     }
     if (mac && e.ctrlKey && b == 1) b = 3;
     return b;
   }
 
   // EVENT HANDLING
 
   // Lightweight event framework. on/off also work on DOM nodes,
   // registering native DOM handlers.
 
   var on = CodeMirror.on = function(emitter, type, f) {
     if (emitter.addEventListener)
       emitter.addEventListener(type, f, false);
     else if (emitter.attachEvent)
       emitter.attachEvent("on" + type, f);
     else {
       var map = emitter._handlers || (emitter._handlers = {});
       var arr = map[type] || (map[type] = []);
       arr.push(f);
     }
   };
 
   var noHandlers = []
   function getHandlers(emitter, type, copy) {
     var arr = emitter._handlers && emitter._handlers[type]
     if (copy) return arr && arr.length > 0 ? arr.slice() : noHandlers
     else return arr || noHandlers
   }
 
   var off = CodeMirror.off = function(emitter, type, f) {
     if (emitter.removeEventListener)
       emitter.removeEventListener(type, f, false);
     else if (emitter.detachEvent)
       emitter.detachEvent("on" + type, f);
     else {
       var handlers = getHandlers(emitter, type, false)
       for (var i = 0; i < handlers.length; ++i)
         if (handlers[i] == f) { handlers.splice(i, 1); break; }
     }
   };
 
   var signal = CodeMirror.signal = function(emitter, type /*, values...*/) {
     var handlers = getHandlers(emitter, type, true)
     if (!handlers.length) return;
     var args = Array.prototype.slice.call(arguments, 2);
     for (var i = 0; i < handlers.length; ++i) handlers[i].apply(null, args);
   };
 
   var orphanDelayedCallbacks = null;
 
   // Often, we want to signal events at a point where we are in the
   // middle of some work, but don't want the handler to start calling
   // other methods on the editor, which might be in an inconsistent
   // state or simply not expect any other events to happen.
   // signalLater looks whether there are any handlers, and schedules
   // them to be executed when the last operation ends, or, if no
   // operation is active, when a timeout fires.
   function signalLater(emitter, type /*, values...*/) {
     var arr = getHandlers(emitter, type, false)
     if (!arr.length) return;
     var args = Array.prototype.slice.call(arguments, 2), list;
     if (operationGroup) {
       list = operationGroup.delayedCallbacks;
     } else if (orphanDelayedCallbacks) {
       list = orphanDelayedCallbacks;
     } else {
       list = orphanDelayedCallbacks = [];
       setTimeout(fireOrphanDelayed, 0);
     }
     function bnd(f) {return function(){f.apply(null, args);};};
     for (var i = 0; i < arr.length; ++i)
       list.push(bnd(arr[i]));
   }
 
   function fireOrphanDelayed() {
     var delayed = orphanDelayedCallbacks;
     orphanDelayedCallbacks = null;
     for (var i = 0; i < delayed.length; ++i) delayed[i]();
   }
 
   // The DOM events that CodeMirror handles can be overridden by
   // registering a (non-DOM) handler on the editor for the event name,
   // and preventDefault-ing the event in that handler.
   function signalDOMEvent(cm, e, override) {
     if (typeof e == "string")
       e = {type: e, preventDefault: function() { this.defaultPrevented = true; }};
     signal(cm, override || e.type, cm, e);
     return e_defaultPrevented(e) || e.codemirrorIgnore;
   }
 
   function signalCursorActivity(cm) {
     var arr = cm._handlers && cm._handlers.cursorActivity;
     if (!arr) return;
     var set = cm.curOp.cursorActivityHandlers || (cm.curOp.cursorActivityHandlers = []);
     for (var i = 0; i < arr.length; ++i) if (indexOf(set, arr[i]) == -1)
       set.push(arr[i]);
   }
 
   function hasHandler(emitter, type) {
     return getHandlers(emitter, type).length > 0
   }
 
   // Add on and off methods to a constructor's prototype, to make
   // registering events on such objects more convenient.
   function eventMixin(ctor) {
     ctor.prototype.on = function(type, f) {on(this, type, f);};
     ctor.prototype.off = function(type, f) {off(this, type, f);};
   }
 
   // MISC UTILITIES
 
   // Number of pixels added to scroller and sizer to hide scrollbar
   var scrollerGap = 30;
 
   // Returned or thrown by various protocols to signal 'I'm not
   // handling this'.
   var Pass = CodeMirror.Pass = {toString: function(){return "CodeMirror.Pass";}};
 
   // Reused option objects for setSelection & friends
   var sel_dontScroll = {scroll: false}, sel_mouse = {origin: "*mouse"}, sel_move = {origin: "+move"};
 
   function Delayed() {this.id = null;}
   Delayed.prototype.set = function(ms, f) {
     clearTimeout(this.id);
     this.id = setTimeout(f, ms);
   };
 
   // Counts the column offset in a string, taking tabs into account.
   // Used mostly to find indentation.
   var countColumn = CodeMirror.countColumn = function(string, end, tabSize, startIndex, startValue) {
     if (end == null) {
       end = string.search(/[^\s\u00a0]/);
       if (end == -1) end = string.length;
     }
     for (var i = startIndex || 0, n = startValue || 0;;) {
       var nextTab = string.indexOf("\t", i);
       if (nextTab < 0 || nextTab >= end)
         return n + (end - i);
       n += nextTab - i;
       n += tabSize - (n % tabSize);
       i = nextTab + 1;
     }
   };
 
   // The inverse of countColumn -- find the offset that corresponds to
   // a particular column.
   var findColumn = CodeMirror.findColumn = function(string, goal, tabSize) {
     for (var pos = 0, col = 0;;) {
       var nextTab = string.indexOf("\t", pos);
       if (nextTab == -1) nextTab = string.length;
       var skipped = nextTab - pos;
       if (nextTab == string.length || col + skipped >= goal)
         return pos + Math.min(skipped, goal - col);
       col += nextTab - pos;
       col += tabSize - (col % tabSize);
       pos = nextTab + 1;
       if (col >= goal) return pos;
     }
   }
 
   var spaceStrs = [""];
   function spaceStr(n) {
     while (spaceStrs.length <= n)
       spaceStrs.push(lst(spaceStrs) + " ");
     return spaceStrs[n];
   }
 
   function lst(arr) { return arr[arr.length-1]; }
 
   var selectInput = function(node) { node.select(); };
   if (ios) // Mobile Safari apparently has a bug where select() is broken.
     selectInput = function(node) { node.selectionStart = 0; node.selectionEnd = node.value.length; };
   else if (ie) // Suppress mysterious IE10 errors
     selectInput = function(node) { try { node.select(); } catch(_e) {} };
 
   function indexOf(array, elt) {
     for (var i = 0; i < array.length; ++i)
       if (array[i] == elt) return i;
     return -1;
   }
   function map(array, f) {
     var out = [];
     for (var i = 0; i < array.length; i++) out[i] = f(array[i], i);
     return out;
   }
 
   function nothing() {}
 
   function createObj(base, props) {
     var inst;
     if (Object.create) {
       inst = Object.create(base);
     } else {
       nothing.prototype = base;
       inst = new nothing();
     }
     if (props) copyObj(props, inst);
     return inst;
   };
 
   function copyObj(obj, target, overwrite) {
     if (!target) target = {};
     for (var prop in obj)
       if (obj.hasOwnProperty(prop) && (overwrite !== false || !target.hasOwnProperty(prop)))
         target[prop] = obj[prop];
     return target;
   }
 
   function bind(f) {
     var args = Array.prototype.slice.call(arguments, 1);
     return function(){return f.apply(null, args);};
   }
 
   var nonASCIISingleCaseWordChar = /[\u00df\u0587\u0590-\u05f4\u0600-\u06ff\u3040-\u309f\u30a0-\u30ff\u3400-\u4db5\u4e00-\u9fcc\uac00-\ud7af]/;
   var isWordCharBasic = CodeMirror.isWordChar = function(ch) {
     return /\w/.test(ch) || ch > "\x80" &&
       (ch.toUpperCase() != ch.toLowerCase() || nonASCIISingleCaseWordChar.test(ch));
   };
   function isWordChar(ch, helper) {
     if (!helper) return isWordCharBasic(ch);
     if (helper.source.indexOf("\\w") > -1 && isWordCharBasic(ch)) return true;
     return helper.test(ch);
   }
 
   function isEmpty(obj) {
     for (var n in obj) if (obj.hasOwnProperty(n) && obj[n]) return false;
     return true;
   }
 
   // Extending unicode characters. A series of a non-extending char +
   // any number of extending chars is treated as a single unit as far
   // as editing and measuring is concerned. This is not fully correct,
   // since some scripts/fonts/browsers also treat other configurations
   // of code points as a group.
   var extendingChars = /[\u0300-\u036f\u0483-\u0489\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u064b-\u065e\u0670\u06d6-\u06dc\u06de-\u06e4\u06e7\u06e8\u06ea-\u06ed\u0711\u0730-\u074a\u07a6-\u07b0\u07eb-\u07f3\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0900-\u0902\u093c\u0941-\u0948\u094d\u0951-\u0955\u0962\u0963\u0981\u09bc\u09be\u09c1-\u09c4\u09cd\u09d7\u09e2\u09e3\u0a01\u0a02\u0a3c\u0a41\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a70\u0a71\u0a75\u0a81\u0a82\u0abc\u0ac1-\u0ac5\u0ac7\u0ac8\u0acd\u0ae2\u0ae3\u0b01\u0b3c\u0b3e\u0b3f\u0b41-\u0b44\u0b4d\u0b56\u0b57\u0b62\u0b63\u0b82\u0bbe\u0bc0\u0bcd\u0bd7\u0c3e-\u0c40\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62\u0c63\u0cbc\u0cbf\u0cc2\u0cc6\u0ccc\u0ccd\u0cd5\u0cd6\u0ce2\u0ce3\u0d3e\u0d41-\u0d44\u0d4d\u0d57\u0d62\u0d63\u0dca\u0dcf\u0dd2-\u0dd4\u0dd6\u0ddf\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0eb1\u0eb4-\u0eb9\u0ebb\u0ebc\u0ec8-\u0ecd\u0f18\u0f19\u0f35\u0f37\u0f39\u0f71-\u0f7e\u0f80-\u0f84\u0f86\u0f87\u0f90-\u0f97\u0f99-\u0fbc\u0fc6\u102d-\u1030\u1032-\u1037\u1039\u103a\u103d\u103e\u1058\u1059\u105e-\u1060\u1071-\u1074\u1082\u1085\u1086\u108d\u109d\u135f\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17b7-\u17bd\u17c6\u17c9-\u17d3\u17dd\u180b-\u180d\u18a9\u1920-\u1922\u1927\u1928\u1932\u1939-\u193b\u1a17\u1a18\u1a56\u1a58-\u1a5e\u1a60\u1a62\u1a65-\u1a6c\u1a73-\u1a7c\u1a7f\u1b00-\u1b03\u1b34\u1b36-\u1b3a\u1b3c\u1b42\u1b6b-\u1b73\u1b80\u1b81\u1ba2-\u1ba5\u1ba8\u1ba9\u1c2c-\u1c33\u1c36\u1c37\u1cd0-\u1cd2\u1cd4-\u1ce0\u1ce2-\u1ce8\u1ced\u1dc0-\u1de6\u1dfd-\u1dff\u200c\u200d\u20d0-\u20f0\u2cef-\u2cf1\u2de0-\u2dff\u302a-\u302f\u3099\u309a\ua66f-\ua672\ua67c\ua67d\ua6f0\ua6f1\ua802\ua806\ua80b\ua825\ua826\ua8c4\ua8e0-\ua8f1\ua926-\ua92d\ua947-\ua951\ua980-\ua982\ua9b3\ua9b6-\ua9b9\ua9bc\uaa29-\uaa2e\uaa31\uaa32\uaa35\uaa36\uaa43\uaa4c\uaab0\uaab2-\uaab4\uaab7\uaab8\uaabe\uaabf\uaac1\uabe5\uabe8\uabed\udc00-\udfff\ufb1e\ufe00-\ufe0f\ufe20-\ufe26\uff9e\uff9f]/;
   function isExtendingChar(ch) { return ch.charCodeAt(0) >= 768 && extendingChars.test(ch); }
 
   // DOM UTILITIES
 
   function elt(tag, content, className, style) {
     var e = document.createElement(tag);
     if (className) e.className = className;
     if (style) e.style.cssText = style;
     if (typeof content == "string") e.appendChild(document.createTextNode(content));
     else if (content) for (var i = 0; i < content.length; ++i) e.appendChild(content[i]);
     return e;
   }
 
   var range;
   if (document.createRange) range = function(node, start, end, endNode) {
     var r = document.createRange();
     r.setEnd(endNode || node, end);
     r.setStart(node, start);
     return r;
   };
   else range = function(node, start, end) {
     var r = document.body.createTextRange();
     try { r.moveToElementText(node.parentNode); }
     catch(e) { return r; }
     r.collapse(true);
     r.moveEnd("character", end);
     r.moveStart("character", start);
     return r;
   };
 
   function removeChildren(e) {
     for (var count = e.childNodes.length; count > 0; --count)
       e.removeChild(e.firstChild);
     return e;
   }
 
   function removeChildrenAndAdd(parent, e) {
     return removeChildren(parent).appendChild(e);
   }
 
   var contains = CodeMirror.contains = function(parent, child) {
     if (child.nodeType == 3) // Android browser always returns false when child is a textnode
       child = child.parentNode;
     if (parent.contains)
       return parent.contains(child);
     do {
       if (child.nodeType == 11) child = child.host;
       if (child == parent) return true;
     } while (child = child.parentNode);
   };
 
   function activeElt() {
     var activeElement = document.activeElement;
     while (activeElement && activeElement.root && activeElement.root.activeElement)
       activeElement = activeElement.root.activeElement;
     return activeElement;
   }
   // Older versions of IE throws unspecified error when touching
   // document.activeElement in some cases (during loading, in iframe)
   if (ie && ie_version < 11) activeElt = function() {
     try { return document.activeElement; }
     catch(e) { return document.body; }
   };
 
   function classTest(cls) { return new RegExp("(^|\\s)" + cls + "(?:$|\\s)\\s*"); }
   var rmClass = CodeMirror.rmClass = function(node, cls) {
     var current = node.className;
     var match = classTest(cls).exec(current);
     if (match) {
       var after = current.slice(match.index + match[0].length);
       node.className = current.slice(0, match.index) + (after ? match[1] + after : "");
     }
   };
   var addClass = CodeMirror.addClass = function(node, cls) {
     var current = node.className;
     if (!classTest(cls).test(current)) node.className += (current ? " " : "") + cls;
   };
   function joinClasses(a, b) {
     var as = a.split(" ");
     for (var i = 0; i < as.length; i++)
       if (as[i] && !classTest(as[i]).test(b)) b += " " + as[i];
     return b;
   }
 
   // WINDOW-WIDE EVENTS
 
   // These must be handled carefully, because naively registering a
   // handler for each editor will cause the editors to never be
   // garbage collected.
 
   function forEachCodeMirror(f) {
     if (!document.body.getElementsByClassName) return;
     var byClass = document.body.getElementsByClassName("CodeMirror");
     for (var i = 0; i < byClass.length; i++) {
       var cm = byClass[i].CodeMirror;
       if (cm) f(cm);
     }
   }
 
   var globalsRegistered = false;
   function ensureGlobalHandlers() {
     if (globalsRegistered) return;
     registerGlobalHandlers();
     globalsRegistered = true;
   }
   function registerGlobalHandlers() {
     // When the window resizes, we need to refresh active editors.
     var resizeTimer;
     on(window, "resize", function() {
       if (resizeTimer == null) resizeTimer = setTimeout(function() {
         resizeTimer = null;
         forEachCodeMirror(onResize);
       }, 100);
     });
     // When the window loses focus, we want to show the editor as blurred
     on(window, "blur", function() {
       forEachCodeMirror(onBlur);
     });
   }
 
   // FEATURE DETECTION
 
   // Detect drag-and-drop
   var dragAndDrop = function() {
     // There is *some* kind of drag-and-drop support in IE6-8, but I
     // couldn't get it to work yet.
     if (ie && ie_version < 9) return false;
     var div = elt('div');
     return "draggable" in div || "dragDrop" in div;
   }();
 
   var zwspSupported;
   function zeroWidthElement(measure) {
     if (zwspSupported == null) {
       var test = elt("span", "\u200b");
       removeChildrenAndAdd(measure, elt("span", [test, document.createTextNode("x")]));
       if (measure.firstChild.offsetHeight != 0)
         zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !(ie && ie_version < 8);
     }
     var node = zwspSupported ? elt("span", "\u200b") :
       elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px");
     node.setAttribute("cm-text", "");
     return node;
   }
 
   // Feature-detect IE's crummy client rect reporting for bidi text
   var badBidiRects;
   function hasBadBidiRects(measure) {
     if (badBidiRects != null) return badBidiRects;
     var txt = removeChildrenAndAdd(measure, document.createTextNode("A\u062eA"));
     var r0 = range(txt, 0, 1).getBoundingClientRect();
     if (!r0 || r0.left == r0.right) return false; // Safari returns null in some cases (#2780)
     var r1 = range(txt, 1, 2).getBoundingClientRect();
     return badBidiRects = (r1.right - r0.right < 3);
   }
 
   // See if "".split is the broken IE version, if so, provide an
   // alternative way to split lines.
   var splitLinesAuto = CodeMirror.splitLines = "\n\nb".split(/\n/).length != 3 ? function(string) {
     var pos = 0, result = [], l = string.length;
     while (pos <= l) {
       var nl = string.indexOf("\n", pos);
       if (nl == -1) nl = string.length;
       var line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl);
       var rt = line.indexOf("\r");
       if (rt != -1) {
         result.push(line.slice(0, rt));
         pos += rt + 1;
       } else {
         result.push(line);
         pos = nl + 1;
       }
     }
     return result;
   } : function(string){return string.split(/\r\n?|\n/);};
 
   var hasSelection = window.getSelection ? function(te) {
     try { return te.selectionStart != te.selectionEnd; }
     catch(e) { return false; }
   } : function(te) {
     try {var range = te.ownerDocument.selection.createRange();}
     catch(e) {}
     if (!range || range.parentElement() != te) return false;
     return range.compareEndPoints("StartToEnd", range) != 0;
   };
 
   var hasCopyEvent = (function() {
     var e = elt("div");
     if ("oncopy" in e) return true;
     e.setAttribute("oncopy", "return;");
     return typeof e.oncopy == "function";
   })();
 
   var badZoomedRects = null;
   function hasBadZoomedRects(measure) {
     if (badZoomedRects != null) return badZoomedRects;
     var node = removeChildrenAndAdd(measure, elt("span", "x"));
     var normal = node.getBoundingClientRect();
     var fromRange = range(node, 0, 1).getBoundingClientRect();
     return badZoomedRects = Math.abs(normal.left - fromRange.left) > 1;
   }
 
   // KEY NAMES
 
   var keyNames = CodeMirror.keyNames = {
     3: "Enter", 8: "Backspace", 9: "Tab", 13: "Enter", 16: "Shift", 17: "Ctrl", 18: "Alt",
     19: "Pause", 20: "CapsLock", 27: "Esc", 32: "Space", 33: "PageUp", 34: "PageDown", 35: "End",
     36: "Home", 37: "Left", 38: "Up", 39: "Right", 40: "Down", 44: "PrintScrn", 45: "Insert",
     46: "Delete", 59: ";", 61: "=", 91: "Mod", 92: "Mod", 93: "Mod",
     106: "*", 107: "=", 109: "-", 110: ".", 111: "/", 127: "Delete",
     173: "-", 186: ";", 187: "=", 188: ",", 189: "-", 190: ".", 191: "/", 192: "`", 219: "[", 220: "\\",
     221: "]", 222: "'", 63232: "Up", 63233: "Down", 63234: "Left", 63235: "Right", 63272: "Delete",
     63273: "Home", 63275: "End", 63276: "PageUp", 63277: "PageDown", 63302: "Insert"
   };
   (function() {
     // Number keys
     for (var i = 0; i < 10; i++) keyNames[i + 48] = keyNames[i + 96] = String(i);
     // Alphabetic keys
     for (var i = 65; i <= 90; i++) keyNames[i] = String.fromCharCode(i);
     // Function keys
     for (var i = 1; i <= 12; i++) keyNames[i + 111] = keyNames[i + 63235] = "F" + i;
   })();
 
   // BIDI HELPERS
 
   function iterateBidiSections(order, from, to, f) {
     if (!order) return f(from, to, "ltr");
     var found = false;
     for (var i = 0; i < order.length; ++i) {
       var part = order[i];
       if (part.from < to && part.to > from || from == to && part.to == from) {
         f(Math.max(part.from, from), Math.min(part.to, to), part.level == 1 ? "rtl" : "ltr");
         found = true;
       }
     }
     if (!found) f(from, to, "ltr");
   }
 
   function bidiLeft(part) { return part.level % 2 ? part.to : part.from; }
   function bidiRight(part) { return part.level % 2 ? part.from : part.to; }
 
   function lineLeft(line) { var order = getOrder(line); return order ? bidiLeft(order[0]) : 0; }
   function lineRight(line) {
     var order = getOrder(line);
     if (!order) return line.text.length;
     return bidiRight(lst(order));
   }
 
   function lineStart(cm, lineN) {
     var line = getLine(cm.doc, lineN);
     var visual = visualLine(line);
     if (visual != line) lineN = lineNo(visual);
     var order = getOrder(visual);
     var ch = !order ? 0 : order[0].level % 2 ? lineRight(visual) : lineLeft(visual);
     return Pos(lineN, ch);
   }
   function lineEnd(cm, lineN) {
     var merged, line = getLine(cm.doc, lineN);
     while (merged = collapsedSpanAtEnd(line)) {
       line = merged.find(1, true).line;
       lineN = null;
     }
     var order = getOrder(line);
     var ch = !order ? line.text.length : order[0].level % 2 ? lineLeft(line) : lineRight(line);
     return Pos(lineN == null ? lineNo(line) : lineN, ch);
   }
   function lineStartSmart(cm, pos) {
     var start = lineStart(cm, pos.line);
     var line = getLine(cm.doc, start.line);
     var order = getOrder(line);
     if (!order || order[0].level == 0) {
       var firstNonWS = Math.max(0, line.text.search(/\S/));
       var inWS = pos.line == start.line && pos.ch <= firstNonWS && pos.ch;
       return Pos(start.line, inWS ? 0 : firstNonWS);
     }
     return start;
   }
 
   function compareBidiLevel(order, a, b) {
     var linedir = order[0].level;
     if (a == linedir) return true;
     if (b == linedir) return false;
     return a < b;
   }
   var bidiOther;
   function getBidiPartAt(order, pos) {
     bidiOther = null;
     for (var i = 0, found; i < order.length; ++i) {
       var cur = order[i];
       if (cur.from < pos && cur.to > pos) return i;
       if ((cur.from == pos || cur.to == pos)) {
         if (found == null) {
           found = i;
         } else if (compareBidiLevel(order, cur.level, order[found].level)) {
           if (cur.from != cur.to) bidiOther = found;
           return i;
         } else {
           if (cur.from != cur.to) bidiOther = i;
           return found;
         }
       }
     }
     return found;
   }
 
   function moveInLine(line, pos, dir, byUnit) {
     if (!byUnit) return pos + dir;
     do pos += dir;
     while (pos > 0 && isExtendingChar(line.text.charAt(pos)));
     return pos;
   }
 
   // This is needed in order to move 'visually' through bi-directional
   // text -- i.e., pressing left should make the cursor go left, even
   // when in RTL text. The tricky part is the 'jumps', where RTL and
   // LTR text touch each other. This often requires the cursor offset
   // to move more than one unit, in order to visually move one unit.
   function moveVisually(line, start, dir, byUnit) {
     var bidi = getOrder(line);
     if (!bidi) return moveLogically(line, start, dir, byUnit);
     var pos = getBidiPartAt(bidi, start), part = bidi[pos];
     var target = moveInLine(line, start, part.level % 2 ? -dir : dir, byUnit);
 
     for (;;) {
       if (target > part.from && target < part.to) return target;
       if (target == part.from || target == part.to) {
         if (getBidiPartAt(bidi, target) == pos) return target;
         part = bidi[pos += dir];
         return (dir > 0) == part.level % 2 ? part.to : part.from;
       } else {
         part = bidi[pos += dir];
         if (!part) return null;
         if ((dir > 0) == part.level % 2)
           target = moveInLine(line, part.to, -1, byUnit);
         else
           target = moveInLine(line, part.from, 1, byUnit);
       }
     }
   }
 
   function moveLogically(line, start, dir, byUnit) {
     var target = start + dir;
     if (byUnit) while (target > 0 && isExtendingChar(line.text.charAt(target))) target += dir;
     return target < 0 || target > line.text.length ? null : target;
   }
 
   // Bidirectional ordering algorithm
   // See http://unicode.org/reports/tr9/tr9-13.html for the algorithm
   // that this (partially) implements.
 
   // One-char codes used for character types:
   // L (L):   Left-to-Right
   // R (R):   Right-to-Left
   // r (AL):  Right-to-Left Arabic
   // 1 (EN):  European Number
   // + (ES):  European Number Separator
   // % (ET):  European Number Terminator
   // n (AN):  Arabic Number
   // , (CS):  Common Number Separator
   // m (NSM): Non-Spacing Mark
   // b (BN):  Boundary Neutral
   // s (B):   Paragraph Separator
   // t (S):   Segment Separator
   // w (WS):  Whitespace
   // N (ON):  Other Neutrals
 
   // Returns null if characters are ordered as they appear
   // (left-to-right), or an array of sections ({from, to, level}
   // objects) in the order in which they occur visually.
   var bidiOrdering = (function() {
     // Character types for codepoints 0 to 0xff
     var lowTypes = "bbbbbbbbbtstwsbbbbbbbbbbbbbbssstwNN%%%NNNNNN,N,N1111111111NNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNbbbbbbsbbbbbbbbbbbbbbbbbbbbbbbbbb,N%%%%NNNNLNNNNN%%11NLNNN1LNNNNNLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLN";
     // Character types for codepoints 0x600 to 0x6ff
     var arabicTypes = "rrrrrrrrrrrr,rNNmmmmmmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmrrrrrrrnnnnnnnnnn%nnrrrmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmmmmmmNmmmm";
     function charType(code) {
       if (code <= 0xf7) return lowTypes.charAt(code);
       else if (0x590 <= code && code <= 0x5f4) return "R";
       else if (0x600 <= code && code <= 0x6ed) return arabicTypes.charAt(code - 0x600);
       else if (0x6ee <= code && code <= 0x8ac) return "r";
       else if (0x2000 <= code && code <= 0x200b) return "w";
       else if (code == 0x200c) return "b";
       else return "L";
     }
 
     var bidiRE = /[\u0590-\u05f4\u0600-\u06ff\u0700-\u08ac]/;
     var isNeutral = /[stwN]/, isStrong = /[LRr]/, countsAsLeft = /[Lb1n]/, countsAsNum = /[1n]/;
     // Browsers seem to always treat the boundaries of block elements as being L.
     var outerType = "L";
 
     function BidiSpan(level, from, to) {
       this.level = level;
       this.from = from; this.to = to;
     }
 
     return function(str) {
       if (!bidiRE.test(str)) return false;
       var len = str.length, types = [];
       for (var i = 0, type; i < len; ++i)
         types.push(type = charType(str.charCodeAt(i)));
 
       // W1. Examine each non-spacing mark (NSM) in the level run, and
       // change the type of the NSM to the type of the previous
       // character. If the NSM is at the start of the level run, it will
       // get the type of sor.
       for (var i = 0, prev = outerType; i < len; ++i) {
         var type = types[i];
         if (type == "m") types[i] = prev;
         else prev = type;
       }
 
       // W2. Search backwards from each instance of a European number
       // until the first strong type (R, L, AL, or sor) is found. If an
       // AL is found, change the type of the European number to Arabic
       // number.
       // W3. Change all ALs to R.
       for (var i = 0, cur = outerType; i < len; ++i) {
         var type = types[i];
         if (type == "1" && cur == "r") types[i] = "n";
         else if (isStrong.test(type)) { cur = type; if (type == "r") types[i] = "R"; }
       }
 
       // W4. A single European separator between two European numbers
       // changes to a European number. A single common separator between
       // two numbers of the same type changes to that type.
       for (var i = 1, prev = types[0]; i < len - 1; ++i) {
         var type = types[i];
         if (type == "+" && prev == "1" && types[i+1] == "1") types[i] = "1";
         else if (type == "," && prev == types[i+1] &&
                  (prev == "1" || prev == "n")) types[i] = prev;
         prev = type;
       }
 
       // W5. A sequence of European terminators adjacent to European
       // numbers changes to all European numbers.
       // W6. Otherwise, separators and terminators change to Other
       // Neutral.
       for (var i = 0; i < len; ++i) {
         var type = types[i];
         if (type == ",") types[i] = "N";
         else if (type == "%") {
           for (var end = i + 1; end < len && types[end] == "%"; ++end) {}
           var replace = (i && types[i-1] == "!") || (end < len && types[end] == "1") ? "1" : "N";
           for (var j = i; j < end; ++j) types[j] = replace;
           i = end - 1;
         }
       }
 
       // W7. Search backwards from each instance of a European number
       // until the first strong type (R, L, or sor) is found. If an L is
       // found, then change the type of the European number to L.
       for (var i = 0, cur = outerType; i < len; ++i) {
         var type = types[i];
         if (cur == "L" && type == "1") types[i] = "L";
         else if (isStrong.test(type)) cur = type;
       }
 
       // N1. A sequence of neutrals takes the direction of the
       // surrounding strong text if the text on both sides has the same
       // direction. European and Arabic numbers act as if they were R in
       // terms of their influence on neutrals. Start-of-level-run (sor)
       // and end-of-level-run (eor) are used at level run boundaries.
       // N2. Any remaining neutrals take the embedding direction.
       for (var i = 0; i < len; ++i) {
         if (isNeutral.test(types[i])) {
           for (var end = i + 1; end < len && isNeutral.test(types[end]); ++end) {}
           var before = (i ? types[i-1] : outerType) == "L";
           var after = (end < len ? types[end] : outerType) == "L";
           var replace = before || after ? "L" : "R";
           for (var j = i; j < end; ++j) types[j] = replace;
           i = end - 1;
         }
       }
 
       // Here we depart from the documented algorithm, in order to avoid
       // building up an actual levels array. Since there are only three
       // levels (0, 1, 2) in an implementation that doesn't take
       // explicit embedding into account, we can build up the order on
       // the fly, without following the level-based algorithm.
       var order = [], m;
       for (var i = 0; i < len;) {
         if (countsAsLeft.test(types[i])) {
           var start = i;
           for (++i; i < len && countsAsLeft.test(types[i]); ++i) {}
           order.push(new BidiSpan(0, start, i));
         } else {
           var pos = i, at = order.length;
           for (++i; i < len && types[i] != "L"; ++i) {}
           for (var j = pos; j < i;) {
             if (countsAsNum.test(types[j])) {
               if (pos < j) order.splice(at, 0, new BidiSpan(1, pos, j));
               var nstart = j;
               for (++j; j < i && countsAsNum.test(types[j]); ++j) {}
               order.splice(at, 0, new BidiSpan(2, nstart, j));
               pos = j;
             } else ++j;
           }
           if (pos < i) order.splice(at, 0, new BidiSpan(1, pos, i));
         }
       }
       if (order[0].level == 1 && (m = str.match(/^\s+/))) {
         order[0].from = m[0].length;
         order.unshift(new BidiSpan(0, 0, m[0].length));
       }
       if (lst(order).level == 1 && (m = str.match(/\s+$/))) {
         lst(order).to -= m[0].length;
         order.push(new BidiSpan(0, len - m[0].length, len));
       }
       if (order[0].level == 2)
         order.unshift(new BidiSpan(1, order[0].to, order[0].to));
       if (order[0].level != lst(order).level)
         order.push(new BidiSpan(order[0].level, len, len));
 
       return order;
     };
   })();
 
   // THE END
 
   CodeMirror.version = "5.15.3";
 
   return CodeMirror;
 });