329 lines
9.8 KiB
JavaScript
Executable file
329 lines
9.8 KiB
JavaScript
Executable file
"use strict";
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module.exports = function(Chart) {
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var helpers = Chart.helpers;
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Chart.defaults.global.legend = {
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display: true,
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position: 'top',
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fullWidth: true, // marks that this box should take the full width of the canvas (pushing down other boxes)
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reverse: false,
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// a callback that will handle
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onClick: function(e, legendItem) {
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var dataset = this.chart.data.datasets[legendItem.datasetIndex];
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dataset.hidden = !dataset.hidden;
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// We hid a dataset ... rerender the chart
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this.chart.update();
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},
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labels: {
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boxWidth: 40,
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fontSize: Chart.defaults.global.defaultFontSize,
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fontStyle: Chart.defaults.global.defaultFontStyle,
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fontColor: Chart.defaults.global.defaultFontColor,
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fontFamily: Chart.defaults.global.defaultFontFamily,
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padding: 10,
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// Generates labels shown in the legend
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// Valid properties to return:
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// text : text to display
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// fillStyle : fill of coloured box
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// strokeStyle: stroke of coloured box
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// hidden : if this legend item refers to a hidden item
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// lineCap : cap style for line
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// lineDash
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// lineDashOffset :
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// lineJoin :
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// lineWidth :
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generateLabels: function(data) {
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return data.datasets.map(function(dataset, i) {
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return {
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text: dataset.label,
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fillStyle: dataset.backgroundColor,
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hidden: dataset.hidden,
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lineCap: dataset.borderCapStyle,
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lineDash: dataset.borderDash,
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lineDashOffset: dataset.borderDashOffset,
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lineJoin: dataset.borderJoinStyle,
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lineWidth: dataset.borderWidth,
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strokeStyle: dataset.borderColor,
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// Below is extra data used for toggling the datasets
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datasetIndex: i
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};
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}, this);
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}
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}
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};
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Chart.Legend = Chart.Element.extend({
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initialize: function(config) {
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helpers.extend(this, config);
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// Contains hit boxes for each dataset (in dataset order)
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this.legendHitBoxes = [];
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// Are we in doughnut mode which has a different data type
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this.doughnutMode = false;
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},
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// These methods are ordered by lifecyle. Utilities then follow.
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// Any function defined here is inherited by all legend types.
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// Any function can be extended by the legend type
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beforeUpdate: helpers.noop,
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update: function(maxWidth, maxHeight, margins) {
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// Update Lifecycle - Probably don't want to ever extend or overwrite this function ;)
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this.beforeUpdate();
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// Absorb the master measurements
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this.maxWidth = maxWidth;
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this.maxHeight = maxHeight;
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this.margins = margins;
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// Dimensions
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this.beforeSetDimensions();
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this.setDimensions();
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this.afterSetDimensions();
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// Labels
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this.beforeBuildLabels();
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this.buildLabels();
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this.afterBuildLabels();
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// Fit
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this.beforeFit();
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this.fit();
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this.afterFit();
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//
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this.afterUpdate();
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return this.minSize;
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},
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afterUpdate: helpers.noop,
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//
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beforeSetDimensions: helpers.noop,
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setDimensions: function() {
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// Set the unconstrained dimension before label rotation
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if (this.isHorizontal()) {
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// Reset position before calculating rotation
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this.width = this.maxWidth;
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this.left = 0;
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this.right = this.width;
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} else {
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this.height = this.maxHeight;
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// Reset position before calculating rotation
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this.top = 0;
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this.bottom = this.height;
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}
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// Reset padding
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this.paddingLeft = 0;
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this.paddingTop = 0;
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this.paddingRight = 0;
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this.paddingBottom = 0;
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// Reset minSize
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this.minSize = {
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width: 0,
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height: 0
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};
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},
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afterSetDimensions: helpers.noop,
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//
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beforeBuildLabels: helpers.noop,
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buildLabels: function() {
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this.legendItems = this.options.labels.generateLabels.call(this, this.chart.data);
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if(this.options.reverse){
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this.legendItems.reverse();
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}
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},
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afterBuildLabels: helpers.noop,
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//
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beforeFit: helpers.noop,
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fit: function() {
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var ctx = this.ctx;
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var labelFont = helpers.fontString(this.options.labels.fontSize, this.options.labels.fontStyle, this.options.labels.fontFamily);
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// Reset hit boxes
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this.legendHitBoxes = [];
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// Width
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if (this.isHorizontal()) {
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this.minSize.width = this.maxWidth; // fill all the width
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} else {
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this.minSize.width = this.options.display ? 10 : 0;
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}
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// height
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if (this.isHorizontal()) {
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this.minSize.height = this.options.display ? 10 : 0;
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} else {
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this.minSize.height = this.maxHeight; // fill all the height
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}
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// Increase sizes here
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if (this.options.display) {
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if (this.isHorizontal()) {
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// Labels
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// Width of each line of legend boxes. Labels wrap onto multiple lines when there are too many to fit on one
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this.lineWidths = [0];
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var totalHeight = this.legendItems.length ? this.options.labels.fontSize + (this.options.labels.padding) : 0;
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ctx.textAlign = "left";
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ctx.textBaseline = 'top';
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ctx.font = labelFont;
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helpers.each(this.legendItems, function(legendItem, i) {
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var width = this.options.labels.boxWidth + (this.options.labels.fontSize / 2) + ctx.measureText(legendItem.text).width;
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if (this.lineWidths[this.lineWidths.length - 1] + width + this.options.labels.padding >= this.width) {
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totalHeight += this.options.labels.fontSize + (this.options.labels.padding);
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this.lineWidths[this.lineWidths.length] = this.left;
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}
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// Store the hitbox width and height here. Final position will be updated in `draw`
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this.legendHitBoxes[i] = {
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left: 0,
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top: 0,
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width: width,
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height: this.options.labels.fontSize
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};
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this.lineWidths[this.lineWidths.length - 1] += width + this.options.labels.padding;
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}, this);
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this.minSize.height += totalHeight;
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} else {
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// TODO vertical
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}
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}
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this.width = this.minSize.width;
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this.height = this.minSize.height;
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},
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afterFit: helpers.noop,
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// Shared Methods
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isHorizontal: function() {
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return this.options.position === "top" || this.options.position === "bottom";
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},
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// Actualy draw the legend on the canvas
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draw: function() {
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if (this.options.display) {
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var ctx = this.ctx;
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var cursor = {
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x: this.left + ((this.width - this.lineWidths[0]) / 2),
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y: this.top + this.options.labels.padding,
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line: 0
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};
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var labelFont = helpers.fontString(this.options.labels.fontSize, this.options.labels.fontStyle, this.options.labels.fontFamily);
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// Horizontal
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if (this.isHorizontal()) {
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// Labels
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ctx.textAlign = "left";
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ctx.textBaseline = 'top';
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ctx.lineWidth = 0.5;
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ctx.strokeStyle = this.options.labels.fontColor; // for strikethrough effect
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ctx.fillStyle = this.options.labels.fontColor; // render in correct colour
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ctx.font = labelFont;
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helpers.each(this.legendItems, function(legendItem, i) {
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var textWidth = ctx.measureText(legendItem.text).width;
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var width = this.options.labels.boxWidth + (this.options.labels.fontSize / 2) + textWidth;
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if (cursor.x + width >= this.width) {
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cursor.y += this.options.labels.fontSize + (this.options.labels.padding);
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cursor.line++;
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cursor.x = this.left + ((this.width - this.lineWidths[cursor.line]) / 2);
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}
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// Set the ctx for the box
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ctx.save();
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var itemOrDefault = function(item, defaulVal) {
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return item !== undefined ? item : defaulVal;
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};
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ctx.fillStyle = itemOrDefault(legendItem.fillStyle, Chart.defaults.global.defaultColor);
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ctx.lineCap = itemOrDefault(legendItem.lineCap, Chart.defaults.global.elements.line.borderCapStyle);
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ctx.lineDashOffset = itemOrDefault(legendItem.lineDashOffset, Chart.defaults.global.elements.line.borderDashOffset);
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ctx.lineJoin = itemOrDefault(legendItem.lineJoin, Chart.defaults.global.elements.line.borderJoinStyle);
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ctx.lineWidth = itemOrDefault(legendItem.lineWidth, Chart.defaults.global.elements.line.borderWidth);
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ctx.strokeStyle = itemOrDefault(legendItem.strokeStyle, Chart.defaults.global.defaultColor);
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if (ctx.setLineDash) {
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// IE 9 and 10 do not support line dash
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ctx.setLineDash(itemOrDefault(legendItem.lineDash, Chart.defaults.global.elements.line.borderDash));
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}
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// Draw the box
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ctx.strokeRect(cursor.x, cursor.y, this.options.labels.boxWidth, this.options.labels.fontSize);
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ctx.fillRect(cursor.x, cursor.y, this.options.labels.boxWidth, this.options.labels.fontSize);
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ctx.restore();
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this.legendHitBoxes[i].left = cursor.x;
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this.legendHitBoxes[i].top = cursor.y;
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// Fill the actual label
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ctx.fillText(legendItem.text, this.options.labels.boxWidth + (this.options.labels.fontSize / 2) + cursor.x, cursor.y);
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if (legendItem.hidden) {
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// Strikethrough the text if hidden
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ctx.beginPath();
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ctx.lineWidth = 2;
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ctx.moveTo(this.options.labels.boxWidth + (this.options.labels.fontSize / 2) + cursor.x, cursor.y + (this.options.labels.fontSize / 2));
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ctx.lineTo(this.options.labels.boxWidth + (this.options.labels.fontSize / 2) + cursor.x + textWidth, cursor.y + (this.options.labels.fontSize / 2));
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ctx.stroke();
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}
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cursor.x += width + (this.options.labels.padding);
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}, this);
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} else {
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}
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}
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},
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// Handle an event
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handleEvent: function(e) {
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var position = helpers.getRelativePosition(e, this.chart.chart);
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if (position.x >= this.left && position.x <= this.right && position.y >= this.top && position.y <= this.bottom) {
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// See if we are touching one of the dataset boxes
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for (var i = 0; i < this.legendHitBoxes.length; ++i) {
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var hitBox = this.legendHitBoxes[i];
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if (position.x >= hitBox.left && position.x <= hitBox.left + hitBox.width && position.y >= hitBox.top && position.y <= hitBox.top + hitBox.height) {
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// Touching an element
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if (this.options.onClick) {
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this.options.onClick.call(this, e, this.legendItems[i]);
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}
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break;
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}
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}
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}
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}
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});
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};
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