jquery.flot.crosshair.js (5601B)
1 /* Flot plugin for showing crosshairs when the mouse hovers over the plot. 2 3 Copyright (c) 2007-2013 IOLA and Ole Laursen. 4 Licensed under the MIT license. 5 6 The plugin supports these options: 7 8 crosshair: { 9 mode: null or "x" or "y" or "xy" 10 color: color 11 lineWidth: number 12 } 13 14 Set the mode to one of "x", "y" or "xy". The "x" mode enables a vertical 15 crosshair that lets you trace the values on the x axis, "y" enables a 16 horizontal crosshair and "xy" enables them both. "color" is the color of the 17 crosshair (default is "rgba(170, 0, 0, 0.80)"), "lineWidth" is the width of 18 the drawn lines (default is 1). 19 20 The plugin also adds four public methods: 21 22 - setCrosshair( pos ) 23 24 Set the position of the crosshair. Note that this is cleared if the user 25 moves the mouse. "pos" is in coordinates of the plot and should be on the 26 form { x: xpos, y: ypos } (you can use x2/x3/... if you're using multiple 27 axes), which is coincidentally the same format as what you get from a 28 "plothover" event. If "pos" is null, the crosshair is cleared. 29 30 - clearCrosshair() 31 32 Clear the crosshair. 33 34 - lockCrosshair(pos) 35 36 Cause the crosshair to lock to the current location, no longer updating if 37 the user moves the mouse. Optionally supply a position (passed on to 38 setCrosshair()) to move it to. 39 40 Example usage: 41 42 var myFlot = $.plot( $("#graph"), ..., { crosshair: { mode: "x" } } }; 43 $("#graph").bind( "plothover", function ( evt, position, item ) { 44 if ( item ) { 45 // Lock the crosshair to the data point being hovered 46 myFlot.lockCrosshair({ 47 x: item.datapoint[ 0 ], 48 y: item.datapoint[ 1 ] 49 }); 50 } else { 51 // Return normal crosshair operation 52 myFlot.unlockCrosshair(); 53 } 54 }); 55 56 - unlockCrosshair() 57 58 Free the crosshair to move again after locking it. 59 */ 60 61 (function ($) { 62 var options = { 63 crosshair: { 64 mode: null, // one of null, "x", "y" or "xy", 65 color: "rgba(170, 0, 0, 0.80)", 66 lineWidth: 1 67 } 68 }; 69 70 function init(plot) { 71 // position of crosshair in pixels 72 var crosshair = { x: -1, y: -1, locked: false }; 73 74 plot.setCrosshair = function setCrosshair(pos) { 75 if (!pos) 76 crosshair.x = -1; 77 else { 78 var o = plot.p2c(pos); 79 crosshair.x = Math.max(0, Math.min(o.left, plot.width())); 80 crosshair.y = Math.max(0, Math.min(o.top, plot.height())); 81 } 82 83 plot.triggerRedrawOverlay(); 84 }; 85 86 plot.clearCrosshair = plot.setCrosshair; // passes null for pos 87 88 plot.lockCrosshair = function lockCrosshair(pos) { 89 if (pos) 90 plot.setCrosshair(pos); 91 crosshair.locked = true; 92 }; 93 94 plot.unlockCrosshair = function unlockCrosshair() { 95 crosshair.locked = false; 96 }; 97 98 function onMouseOut(e) { 99 if (crosshair.locked) 100 return; 101 102 if (crosshair.x != -1) { 103 crosshair.x = -1; 104 plot.triggerRedrawOverlay(); 105 } 106 } 107 108 function onMouseMove(e) { 109 if (crosshair.locked) 110 return; 111 112 if (plot.getSelection && plot.getSelection()) { 113 crosshair.x = -1; // hide the crosshair while selecting 114 return; 115 } 116 117 var offset = plot.offset(); 118 crosshair.x = Math.max(0, Math.min(e.pageX - offset.left, plot.width())); 119 crosshair.y = Math.max(0, Math.min(e.pageY - offset.top, plot.height())); 120 plot.triggerRedrawOverlay(); 121 } 122 123 plot.hooks.bindEvents.push(function (plot, eventHolder) { 124 if (!plot.getOptions().crosshair.mode) 125 return; 126 127 eventHolder.mouseout(onMouseOut); 128 eventHolder.mousemove(onMouseMove); 129 }); 130 131 plot.hooks.drawOverlay.push(function (plot, ctx) { 132 var c = plot.getOptions().crosshair; 133 if (!c.mode) 134 return; 135 136 var plotOffset = plot.getPlotOffset(); 137 138 ctx.save(); 139 ctx.translate(plotOffset.left, plotOffset.top); 140 141 if (crosshair.x != -1) { 142 var adj = plot.getOptions().crosshair.lineWidth % 2 === 0 ? 0 : 0.5; 143 144 ctx.strokeStyle = c.color; 145 ctx.lineWidth = c.lineWidth; 146 ctx.lineJoin = "round"; 147 148 ctx.beginPath(); 149 if (c.mode.indexOf("x") != -1) { 150 var drawX = Math.round(crosshair.x) + adj; 151 ctx.moveTo(drawX, 0); 152 ctx.lineTo(drawX, plot.height()); 153 } 154 if (c.mode.indexOf("y") != -1) { 155 var drawY = Math.round(crosshair.y) + adj; 156 ctx.moveTo(0, drawY); 157 ctx.lineTo(plot.width(), drawY); 158 } 159 ctx.stroke(); 160 } 161 ctx.restore(); 162 }); 163 164 plot.hooks.shutdown.push(function (plot, eventHolder) { 165 eventHolder.unbind("mouseout", onMouseOut); 166 eventHolder.unbind("mousemove", onMouseMove); 167 }); 168 } 169 170 $.plot.plugins.push({ 171 init: init, 172 options: options, 173 name: 'crosshair', 174 version: '1.0' 175 }); 176 })(jQuery);