/**
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* This is an experimental Highcharts module that draws long data series on a canvas
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* in order to increase performance of the initial load time and tooltip responsiveness.
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*
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* Compatible with HTML5 canvas compatible browsers (not IE < 9).
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*
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* Author: Torstein Honsi
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*
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*
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* Development plan
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* - Column range.
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* - Heatmap.
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* - Treemap.
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* - Check how it works with Highstock and data grouping.
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* - Check inverted charts.
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* - Check reversed axes.
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* - Chart callback should be async after last series is drawn. (But not necessarily, we don't do
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that with initial series animation).
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* - Cache full-size image so we don't have to redraw on hide/show and zoom up. But k-d-tree still
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* needs to be built.
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* - Test IE9 and IE10.
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* - Stacking is not perhaps not correct since it doesn't use the translation given in
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* the translate method. If this gets to complicated, a possible way out would be to
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* have a simplified renderCanvas method that simply draws the areaPath on a canvas.
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*
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* If this module is taken in as part of the core
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* - All the loading logic should be merged with core. Update styles in the core.
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* - Most of the method wraps should probably be added directly in parent methods.
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*
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* Notes for boost mode
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* - Area lines are not drawn
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* - Point markers are not drawn
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* - Zones and negativeColor don't work
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* - Columns are always one pixel wide. Don't set the threshold too low.
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*
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* Optimizing tips for users
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* - For scatter plots, use a marker.radius of 1 or less. It results in a rectangle being drawn, which is
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* considerably faster than a circle.
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* - Set extremes (min, max) explicitly on the axes in order for Highcharts to avoid computing extremes.
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* - Set enableMouseTracking to false on the series to improve total rendering time.
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* - The default threshold is set based on one series. If you have multiple, dense series, the combined
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* number of points drawn gets higher, and you may want to set the threshold lower in order to
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* use optimizations.
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*/
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/*global document, Highcharts, HighchartsAdapter, setTimeout */
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(function (H, HA) {
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'use strict';
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var noop = function () { return undefined; },
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Color = H.Color,
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Series = H.Series,
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seriesTypes = H.seriesTypes,
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each = H.each,
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extend = H.extend,
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addEvent = HA.addEvent,
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fireEvent = HA.fireEvent,
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merge = H.merge,
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pick = H.pick,
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wrap = H.wrap,
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plotOptions = H.getOptions().plotOptions,
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CHUNK_SIZE = 50000;
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function eachAsync(arr, fn, callback, chunkSize, i) {
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i = i || 0;
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chunkSize = chunkSize || CHUNK_SIZE;
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each(arr.slice(i, i + chunkSize), fn);
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if (i + chunkSize < arr.length) {
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setTimeout(function () {
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eachAsync(arr, fn, callback, chunkSize, i + chunkSize);
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});
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} else if (callback) {
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callback();
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}
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}
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// Set default options
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each(['area', 'arearange', 'column', 'line', 'scatter'], function (type) {
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if (plotOptions[type]) {
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plotOptions[type].boostThreshold = 5000;
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}
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});
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/**
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* Override a bunch of methods the same way. If the number of points is below the threshold,
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* run the original method. If not, check for a canvas version or do nothing.
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*/
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each(['translate', 'generatePoints', 'drawTracker', 'drawPoints', 'render'], function (method) {
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function branch(proceed) {
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var letItPass = this.options.stacking && (method === 'translate' || method === 'generatePoints');
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if ((this.processedXData || this.options.data).length < (this.options.boostThreshold || Number.MAX_VALUE) ||
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letItPass) {
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// Clear image
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if (method === 'render' && this.image) {
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this.image.attr({ href: '' });
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this.animate = null; // We're zooming in, don't run animation
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}
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proceed.call(this);
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// If a canvas version of the method exists, like renderCanvas(), run
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} else if (this[method + 'Canvas']) {
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this[method + 'Canvas']();
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}
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}
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wrap(Series.prototype, method, branch);
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// A special case for some types - its translate method is already wrapped
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if (method === 'translate') {
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if (seriesTypes.column) {
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wrap(seriesTypes.column.prototype, method, branch);
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}
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if (seriesTypes.arearange) {
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wrap(seriesTypes.arearange.prototype, method, branch);
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}
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}
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});
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/**
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* Do not compute extremes when min and max are set.
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* If we use this in the core, we can add the hook to hasExtremes to the methods directly.
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*/
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wrap(Series.prototype, 'getExtremes', function (proceed) {
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if (!this.hasExtremes()) {
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proceed.apply(this, Array.prototype.slice.call(arguments, 1));
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}
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});
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wrap(Series.prototype, 'setData', function (proceed) {
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if (!this.hasExtremes(true)) {
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proceed.apply(this, Array.prototype.slice.call(arguments, 1));
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}
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});
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wrap(Series.prototype, 'processData', function (proceed) {
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if (!this.hasExtremes(true)) {
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proceed.apply(this, Array.prototype.slice.call(arguments, 1));
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}
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});
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H.extend(Series.prototype, {
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pointRange: 0,
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hasExtremes: function (checkX) {
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var options = this.options,
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data = options.data,
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xAxis = this.xAxis.options,
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yAxis = this.yAxis.options;
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return data.length > (options.boostThreshold || Number.MAX_VALUE) && typeof yAxis.min === 'number' && typeof yAxis.max === 'number' &&
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(!checkX || (typeof xAxis.min === 'number' && typeof xAxis.max === 'number'));
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},
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/**
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* If implemented in the core, parts of this can probably be shared with other similar
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* methods in Highcharts.
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*/
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destroyGraphics: function () {
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var series = this,
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points = this.points,
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point,
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i;
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for (i = 0; i < points.length; i = i + 1) {
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point = points[i];
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if (point && point.graphic) {
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point.graphic = point.graphic.destroy();
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}
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}
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each(['graph', 'area'], function (prop) {
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if (series[prop]) {
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series[prop] = series[prop].destroy();
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}
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});
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},
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/**
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* Create a hidden canvas to draw the graph on. The contents is later copied over
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* to an SVG image element.
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*/
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getContext: function () {
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var width = this.chart.plotWidth,
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height = this.chart.plotHeight;
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if (!this.canvas) {
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this.canvas = document.createElement('canvas');
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this.image = this.chart.renderer.image('', 0, 0, width, height).add(this.group);
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this.ctx = this.canvas.getContext('2d');
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} else {
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this.ctx.clearRect(0, 0, width, height);
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}
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this.canvas.setAttribute('width', width);
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this.canvas.setAttribute('height', height);
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this.image.attr({
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width: width,
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height: height
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});
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return this.ctx;
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},
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/**
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* Draw the canvas image inside an SVG image
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*/
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canvasToSVG: function () {
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this.image.attr({ href: this.canvas.toDataURL('image/png') });
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},
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cvsLineTo: function (ctx, clientX, plotY) {
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ctx.lineTo(clientX, plotY);
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},
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renderCanvas: function () {
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var series = this,
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options = series.options,
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chart = series.chart,
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xAxis = this.xAxis,
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yAxis = this.yAxis,
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ctx,
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i,
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c = 0,
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xData = series.processedXData,
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yData = series.processedYData,
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rawData = options.data,
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xExtremes = xAxis.getExtremes(),
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xMin = xExtremes.min,
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xMax = xExtremes.max,
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yExtremes = yAxis.getExtremes(),
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yMin = yExtremes.min,
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yMax = yExtremes.max,
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pointTaken = {},
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lastClientX,
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sampling = !!series.sampling,
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points,
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r = options.marker && options.marker.radius,
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cvsDrawPoint = this.cvsDrawPoint,
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cvsLineTo = options.lineWidth ? this.cvsLineTo : false,
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cvsMarker = r <= 1 ? this.cvsMarkerSquare : this.cvsMarkerCircle,
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enableMouseTracking = options.enableMouseTracking !== false,
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lastPoint,
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threshold = options.threshold,
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yBottom = yAxis.getThreshold(threshold),
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hasThreshold = typeof threshold === 'number',
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translatedThreshold = yBottom,
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doFill = this.fill,
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isRange = series.pointArrayMap && series.pointArrayMap.join(',') === 'low,high',
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isStacked = !!options.stacking,
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cropStart = series.cropStart || 0,
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loadingOptions = chart.options.loading,
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requireSorting = series.requireSorting,
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wasNull,
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connectNulls = options.connectNulls,
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useRaw = !xData,
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minVal,
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maxVal,
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minI,
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maxI,
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fillColor = series.fillOpacity ?
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new Color(series.color).setOpacity(pick(options.fillOpacity, 0.75)).get() :
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series.color,
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stroke = function () {
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if (doFill) {
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ctx.fillStyle = fillColor;
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ctx.fill();
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} else {
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ctx.strokeStyle = series.color;
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ctx.lineWidth = options.lineWidth;
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ctx.stroke();
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}
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},
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drawPoint = function (clientX, plotY, yBottom) {
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if (c === 0) {
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ctx.beginPath();
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}
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if (wasNull) {
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ctx.moveTo(clientX, plotY);
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} else {
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if (cvsDrawPoint) {
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cvsDrawPoint(ctx, clientX, plotY, yBottom, lastPoint);
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} else if (cvsLineTo) {
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cvsLineTo(ctx, clientX, plotY);
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} else if (cvsMarker) {
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cvsMarker(ctx, clientX, plotY, r);
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}
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}
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// We need to stroke the line for every 1000 pixels. It will crash the browser
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// memory use if we stroke too infrequently.
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c = c + 1;
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if (c === 1000) {
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stroke();
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c = 0;
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}
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// Area charts need to keep track of the last point
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lastPoint = {
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clientX: clientX,
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plotY: plotY,
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yBottom: yBottom
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};
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},
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addKDPoint = function (clientX, plotY, i) {
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// The k-d tree requires series points. Reduce the amount of points, since the time to build the
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// tree increases exponentially.
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if (enableMouseTracking && !pointTaken[clientX + ',' + plotY]) {
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points.push({
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clientX: clientX,
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plotX: clientX,
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plotY: plotY,
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i: cropStart + i
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});
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pointTaken[clientX + ',' + plotY] = true;
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}
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};
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// If we are zooming out from SVG mode, destroy the graphics
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if (this.points) {
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this.destroyGraphics();
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}
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// The group
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series.plotGroup(
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'group',
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'series',
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series.visible ? 'visible' : 'hidden',
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options.zIndex,
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chart.seriesGroup
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);
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series.getAttribs();
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series.markerGroup = series.group;
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addEvent(series, 'destroy', function () {
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series.markerGroup = null;
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});
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points = this.points = [];
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ctx = this.getContext();
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series.buildKDTree = noop; // Do not start building while drawing
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// Display a loading indicator
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if (rawData.length > 99999) {
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chart.options.loading = merge(loadingOptions, {
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labelStyle: {
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backgroundColor: 'rgba(255,255,255,0.75)',
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padding: '1em',
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borderRadius: '0.5em'
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},
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style: {
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backgroundColor: 'none',
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opacity: 1
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}
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});
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chart.showLoading('Drawing...');
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chart.options.loading = loadingOptions; // reset
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if (chart.loadingShown === true) {
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chart.loadingShown = 1;
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} else {
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chart.loadingShown = chart.loadingShown + 1;
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}
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}
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// Loop over the points
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i = 0;
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eachAsync(isStacked ? series.data : (xData || rawData), function (d) {
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var x,
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y,
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clientX,
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plotY,
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isNull,
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low,
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isYInside = true;
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if (useRaw) {
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x = d[0];
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y = d[1];
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} else {
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x = d;
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y = yData[i];
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}
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// Resolve low and high for range series
|
|
if (isRange) {
|
|
if (useRaw) {
|
|
y = d.slice(1, 3);
|
|
}
|
|
low = y[0];
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y = y[1];
|
|
} else if (isStacked) {
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x = d.x;
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y = d.stackY;
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low = y - d.y;
|
|
}
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isNull = y === null;
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|
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// Optimize for scatter zooming
|
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if (!requireSorting) {
|
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isYInside = y >= yMin && y <= yMax;
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}
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if (!isNull && x >= xMin && x <= xMax && isYInside) {
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clientX = Math.round(xAxis.toPixels(x, true));
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|
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if (sampling) {
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|
if (minI === undefined || clientX === lastClientX) {
|
|
if (!isRange) {
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low = y;
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|
}
|
|
if (maxI === undefined || y > maxVal) {
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|
maxVal = y;
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maxI = i;
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|
}
|
|
if (minI === undefined || low < minVal) {
|
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minVal = low;
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minI = i;
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|
}
|
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}
|
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if (clientX !== lastClientX) { // Add points and reset
|
|
if (minI !== undefined) { // then maxI is also a number
|
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plotY = yAxis.toPixels(maxVal, true);
|
|
yBottom = yAxis.toPixels(minVal, true);
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drawPoint(
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clientX,
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hasThreshold ? Math.min(plotY, translatedThreshold) : plotY,
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hasThreshold ? Math.max(yBottom, translatedThreshold) : yBottom
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);
|
|
addKDPoint(clientX, plotY, maxI);
|
|
if (yBottom !== plotY) {
|
|
addKDPoint(clientX, yBottom, minI);
|
|
}
|
|
}
|
|
|
|
|
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minI = maxI = undefined;
|
|
lastClientX = clientX;
|
|
}
|
|
} else {
|
|
plotY = Math.round(yAxis.toPixels(y, true));
|
|
drawPoint(clientX, plotY, yBottom);
|
|
addKDPoint(clientX, plotY, i);
|
|
}
|
|
}
|
|
wasNull = isNull && !connectNulls;
|
|
|
|
i = i + 1;
|
|
|
|
if (i % CHUNK_SIZE === 0) {
|
|
series.canvasToSVG();
|
|
}
|
|
|
|
}, function () {
|
|
|
|
var loadingDiv = chart.loadingDiv,
|
|
loadingShown = +chart.loadingShown;
|
|
|
|
stroke();
|
|
series.canvasToSVG();
|
|
|
|
fireEvent(series, 'renderedCanvas');
|
|
|
|
// Do not use chart.hideLoading, as it runs JS animation and will be blocked by buildKDTree.
|
|
// CSS animation looks good, but then it must be deleted in timeout. If we add the module to core,
|
|
// change hideLoading so we can skip this block.
|
|
if (loadingShown === 1) {
|
|
extend(loadingDiv.style, {
|
|
transition: 'opacity 250ms',
|
|
opacity: 0
|
|
});
|
|
|
|
chart.loadingShown = false;
|
|
setTimeout(function () {
|
|
if (loadingDiv.parentNode) { // In exporting it is falsy
|
|
loadingDiv.parentNode.removeChild(loadingDiv);
|
|
}
|
|
chart.loadingDiv = chart.loadingSpan = null;
|
|
}, 250);
|
|
}
|
|
if (loadingShown) {
|
|
chart.loadingShown = loadingShown - 1;
|
|
}
|
|
|
|
// Pass tests in Pointer.
|
|
// TODO: Replace this with a single property, and replace when zooming in
|
|
// below boostThreshold.
|
|
series.directTouch = false;
|
|
series.options.stickyTracking = true;
|
|
|
|
delete series.buildKDTree; // Go back to prototype, ready to build
|
|
series.buildKDTree();
|
|
|
|
// Don't do async on export, the exportChart, getSVGForExport and getSVG methods are not chained for it.
|
|
}, chart.renderer.forExport ? Number.MAX_VALUE : undefined);
|
|
}
|
|
});
|
|
|
|
seriesTypes.scatter.prototype.cvsMarkerCircle = function (ctx, clientX, plotY, r) {
|
|
ctx.moveTo(clientX, plotY);
|
|
ctx.arc(clientX, plotY, r, 0, 2 * Math.PI, false);
|
|
};
|
|
|
|
// Rect is twice as fast as arc, should be used for small markers
|
|
seriesTypes.scatter.prototype.cvsMarkerSquare = function (ctx, clientX, plotY, r) {
|
|
ctx.moveTo(clientX, plotY);
|
|
ctx.rect(clientX - r, plotY - r, r * 2, r * 2);
|
|
};
|
|
seriesTypes.scatter.prototype.fill = true;
|
|
|
|
extend(seriesTypes.area.prototype, {
|
|
cvsDrawPoint: function (ctx, clientX, plotY, yBottom, lastPoint) {
|
|
if (lastPoint && clientX !== lastPoint.clientX) {
|
|
ctx.moveTo(lastPoint.clientX, lastPoint.yBottom);
|
|
ctx.lineTo(lastPoint.clientX, lastPoint.plotY);
|
|
ctx.lineTo(clientX, plotY);
|
|
ctx.lineTo(clientX, yBottom);
|
|
}
|
|
},
|
|
fill: true,
|
|
fillOpacity: true,
|
|
sampling: true
|
|
});
|
|
|
|
extend(seriesTypes.column.prototype, {
|
|
cvsDrawPoint: function (ctx, clientX, plotY, yBottom) {
|
|
ctx.rect(clientX - 1, plotY, 1, yBottom - plotY);
|
|
},
|
|
fill: true,
|
|
sampling: true
|
|
});
|
|
|
|
/**
|
|
* Return a point instance from the k-d-tree
|
|
*/
|
|
wrap(Series.prototype, 'searchPoint', function (proceed, e) {
|
|
var point = proceed.call(this, e),
|
|
ret = point;
|
|
|
|
if (point && !(point instanceof this.pointClass)) {
|
|
ret = (new this.pointClass()).init(this, this.options.data[point.i]);
|
|
ret.dist = point.dist;
|
|
ret.category = ret.x;
|
|
ret.plotX = point.plotX;
|
|
ret.plotY = point.plotY;
|
|
}
|
|
return ret;
|
|
});
|
|
}(Highcharts, HighchartsAdapter));
|