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