X-Git-Url: https://adrianiainlam.tk/git/?a=blobdiff_plain;f=dygraph-canvas.js;h=9ac88be7d8d7fdcf66b5f3b1f98903a57ed9c600;hb=beeabac2f71ae45c510b0355d0e76972083a6ca6;hp=13c8061ae864f35f5e78df6bb14aa641cdcde51e;hpb=ce49c2faeceae3e5cbc964b2de9df86da067578b;p=dygraphs.git diff --git a/dygraph-canvas.js b/dygraph-canvas.js index 13c8061..5326673 100644 --- a/dygraph-canvas.js +++ b/dygraph-canvas.js @@ -1,239 +1,57 @@ -// Copyright 2006 Dan Vanderkam (danvdk@gmail.com) -// All Rights Reserved. +/** + * @license + * Copyright 2006 Dan Vanderkam (danvdk@gmail.com) + * MIT-licensed (http://opensource.org/licenses/MIT) + */ /** - * @fileoverview Based on PlotKit, but modified to meet the needs of dygraphs. + * @fileoverview Based on PlotKit.CanvasRenderer, but modified to meet the + * needs of dygraphs. + * * In particular, support for: - * - grid overlays + * - grid overlays * - error bars * - dygraphs attribute system */ /** - * Creates a new DygraphLayout object. - * @param {Object} options Options for PlotKit.Layout - * @return {Object} The DygraphLayout object - */ -DygraphLayout = function(dygraph, options) { - this.dygraph_ = dygraph; - this.options = {}; // TODO(danvk): remove, use attr_ instead. - Dygraph.update(this.options, options ? options : {}); - this.datasets = new Array(); -}; - -DygraphLayout.prototype.attr_ = function(name) { - return this.dygraph_.attr_(name); -}; - -DygraphLayout.prototype.addDataset = function(setname, set_xy) { - this.datasets[setname] = set_xy; -}; - -// TODO(danvk): CONTRACT remove -DygraphLayout.prototype.addAnnotation = function() { - // Add an annotation to one series. - this.annotations = []; - for (var x = 10; x < 30; x += 2) { - this.annotations.push( { - series: 'sine wave', - xval: this.attr_('xValueParser')("200610" + x), - shortText: x, - text: 'Stock Market Crash ' + x - } ); - } - this.annotations.push( { - series: 'another line', - xval: this.attr_('xValueParser')("20061013"), - shortText: 'X', - text: 'Another one' - } ); -}; - -DygraphLayout.prototype.evaluate = function() { - this._evaluateLimits(); - this._evaluateLineCharts(); - this._evaluateLineTicks(); - this._evaluateAnnotations(); -}; - -DygraphLayout.prototype._evaluateLimits = function() { - this.minxval = this.maxxval = null; - if (this.options.dateWindow) { - this.minxval = this.options.dateWindow[0]; - this.maxxval = this.options.dateWindow[1]; - } else { - for (var name in this.datasets) { - if (!this.datasets.hasOwnProperty(name)) continue; - var series = this.datasets[name]; - var x1 = series[0][0]; - if (!this.minxval || x1 < this.minxval) this.minxval = x1; - - var x2 = series[series.length - 1][0]; - if (!this.maxxval || x2 > this.maxxval) this.maxxval = x2; - } - } - this.xrange = this.maxxval - this.minxval; - this.xscale = (this.xrange != 0 ? 1/this.xrange : 1.0); - - this.minyval = this.options.yAxis[0]; - this.maxyval = this.options.yAxis[1]; - this.yrange = this.maxyval - this.minyval; - this.yscale = (this.yrange != 0 ? 1/this.yrange : 1.0); -}; - -DygraphLayout.prototype._evaluateLineCharts = function() { - // add all the rects - this.points = new Array(); - for (var setName in this.datasets) { - if (!this.datasets.hasOwnProperty(setName)) continue; - - var dataset = this.datasets[setName]; - for (var j = 0; j < dataset.length; j++) { - var item = dataset[j]; - var point = { - // TODO(danvk): here - x: ((parseFloat(item[0]) - this.minxval) * this.xscale), - y: 1.0 - ((parseFloat(item[1]) - this.minyval) * this.yscale), - xval: parseFloat(item[0]), - yval: parseFloat(item[1]), - name: setName - }; - - // limit the x, y values so they do not overdraw - if (point.y <= 0.0) { - point.y = 0.0; - } - if (point.y >= 1.0) { - point.y = 1.0; - } - this.points.push(point); - } - } -}; - -DygraphLayout.prototype._evaluateLineTicks = function() { - this.xticks = new Array(); - for (var i = 0; i < this.options.xTicks.length; i++) { - var tick = this.options.xTicks[i]; - var label = tick.label; - var pos = this.xscale * (tick.v - this.minxval); - if ((pos >= 0.0) && (pos <= 1.0)) { - this.xticks.push([pos, label]); - } - } - - this.yticks = new Array(); - for (var i = 0; i < this.options.yTicks.length; i++) { - var tick = this.options.yTicks[i]; - var label = tick.label; - var pos = 1.0 - (this.yscale * (tick.v - this.minyval)); - if ((pos >= 0.0) && (pos <= 1.0)) { - this.yticks.push([pos, label]); - } - } -}; - - -/** - * Behaves the same way as PlotKit.Layout, but also copies the errors - * @private - */ -DygraphLayout.prototype.evaluateWithError = function() { - this.evaluate(); - if (!this.options.errorBars) return; - - // Copy over the error terms - var i = 0; // index in this.points - for (var setName in this.datasets) { - if (!this.datasets.hasOwnProperty(setName)) continue; - var j = 0; - var dataset = this.datasets[setName]; - for (var j = 0; j < dataset.length; j++, i++) { - var item = dataset[j]; - var xv = parseFloat(item[0]); - var yv = parseFloat(item[1]); - - if (xv == this.points[i].xval && - yv == this.points[i].yval) { - this.points[i].errorMinus = parseFloat(item[2]); - this.points[i].errorPlus = parseFloat(item[3]); - } - } - } -}; - -DygraphLayout.prototype._evaluateAnnotations = function() { - // Add the annotations to the point to which they belong. - // Make a map from (setName, xval) to annotation for quick lookups. - var annotations = {}; - for (var i = 0; i < this.annotations.length; i++) { - var a = this.annotations[i]; - annotations[a.xval + "," + a.series] = a; - } - - this.annotated_points = []; - for (var i = 0; i < this.points.length; i++) { - var p = this.points[i]; - var k = p.xval + "," + p.name; - if (k in annotations) { - p.annotation = annotations[k]; - this.annotated_points.push(p); - } - } -}; - -/** - * Convenience function to remove all the data sets from a graph + * The DygraphCanvasRenderer class does the actual rendering of the chart onto + * a canvas. It's based on PlotKit.CanvasRenderer. + * @param {Object} element The canvas to attach to + * @param {Object} elementContext The 2d context of the canvas (injected so it + * can be mocked for testing.) + * @param {Layout} layout The DygraphLayout object for this graph. + * @constructor */ -DygraphLayout.prototype.removeAllDatasets = function() { - delete this.datasets; - this.datasets = new Array(); -}; -/** - * Change the values of various layout options - * @param {Object} new_options an associative array of new properties - */ -DygraphLayout.prototype.updateOptions = function(new_options) { - Dygraph.update(this.options, new_options ? new_options : {}); -}; +/*jshint globalstrict: true */ +/*global Dygraph:false,RGBColor:false */ +"use strict"; -// Subclass PlotKit.CanvasRenderer to add: -// 1. X/Y grid overlay -// 2. Ability to draw error bars (if required) /** - * Sets some PlotKit.CanvasRenderer options - * @param {Object} element The canvas to attach to - * @param {Layout} layout The DygraphLayout object for this graph. - * @param {Object} options Options to pass on to CanvasRenderer + * @constructor + * + * This gets called when there are "new points" to chart. This is generally the + * case when the underlying data being charted has changed. It is _not_ called + * in the common case that the user has zoomed or is panning the view. + * + * The chart canvas has already been created by the Dygraph object. The + * renderer simply gets a drawing context. + * + * @param {Dyraph} dygraph The chart to which this renderer belongs. + * @param {Canvas} element The <canvas> DOM element on which to draw. + * @param {CanvasRenderingContext2D} elementContext The drawing context. + * @param {DygraphLayout} layout The chart's DygraphLayout object. + * + * TODO(danvk): remove the elementContext property. */ -DygraphCanvasRenderer = function(dygraph, element, layout, options) { - // TODO(danvk): remove options, just use dygraph.attr_. +var DygraphCanvasRenderer = function(dygraph, element, elementContext, layout) { this.dygraph_ = dygraph; - // default options - this.options = { - "strokeWidth": 0.5, - "drawXAxis": true, - "drawYAxis": true, - "axisLineColor": "black", - "axisLineWidth": 0.5, - "axisTickSize": 3, - "axisLabelColor": "black", - "axisLabelFont": "Arial", - "axisLabelFontSize": 9, - "axisLabelWidth": 50, - "drawYGrid": true, - "drawXGrid": true, - "gridLineColor": "rgb(128,128,128)", - "fillAlpha": 0.15, - "underlayCallback": null - }; - Dygraph.update(this.options, options); - this.layout = layout; this.element = element; + this.elementContext = elementContext; this.container = this.element.parentNode; this.height = this.element.height; @@ -244,23 +62,43 @@ DygraphCanvasRenderer = function(dygraph, element, layout, options) { throw "Canvas is not supported."; // internal state - this.xlabels = new Array(); - this.ylabels = new Array(); - this.annotations = new Array(); - - this.area = { - x: this.options.yAxisLabelWidth + 2 * this.options.axisTickSize, - y: 0 - }; - this.area.w = this.width - this.area.x - this.options.rightGap; - this.area.h = this.height - this.options.axisLabelFontSize - - 2 * this.options.axisTickSize; - + this.area = layout.getPlotArea(); this.container.style.position = "relative"; this.container.style.width = this.width + "px"; + + // Set up a clipping area for the canvas (and the interaction canvas). + // This ensures that we don't overdraw. + if (this.dygraph_.isUsingExcanvas_) { + this._createIEClipArea(); + } else { + // on Android 3 and 4, setting a clipping area on a canvas prevents it from + // displaying anything. + if (!Dygraph.isAndroid()) { + var ctx = this.dygraph_.canvas_ctx_; + ctx.beginPath(); + ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h); + ctx.clip(); + + ctx = this.dygraph_.hidden_ctx_; + ctx.beginPath(); + ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h); + ctx.clip(); + } + } }; +DygraphCanvasRenderer.prototype.attr_ = function(x) { + return this.dygraph_.attr_(x); +}; + +/** + * Clears out all chart content and DOM elements. + * This is called immediately before render() on every frame, including + * during zooms and pans. + * @private + */ DygraphCanvasRenderer.prototype.clear = function() { + var context; if (this.isIE) { // VML takes a while to start up, so we just poll every this.IEDelay try { @@ -268,45 +106,33 @@ DygraphCanvasRenderer.prototype.clear = function() { this.clearDelay.cancel(); this.clearDelay = null; } - var context = this.element.getContext("2d"); + context = this.elementContext; } catch (e) { // TODO(danvk): this is broken, since MochiKit.Async is gone. - this.clearDelay = MochiKit.Async.wait(this.IEDelay); - this.clearDelay.addCallback(bind(this.clear, this)); + // this.clearDelay = MochiKit.Async.wait(this.IEDelay); + // this.clearDelay.addCallback(bind(this.clear, this)); return; } } - var context = this.element.getContext("2d"); + context = this.elementContext; context.clearRect(0, 0, this.width, this.height); - - for (var i = 0; i < this.xlabels.length; i++) { - var el = this.xlabels[i]; - el.parentNode.removeChild(el); - } - for (var i = 0; i < this.ylabels.length; i++) { - var el = this.ylabels[i]; - el.parentNode.removeChild(el); - } - for (var i = 0; i < this.annotations.length; i++) { - var el = this.annotations[i]; - el.parentNode.removeChild(el); - } - this.xlabels = new Array(); - this.ylabels = new Array(); - this.annotations = new Array(); }; - +/** + * Checks whether the browser supports the <canvas> tag. + * @private + */ DygraphCanvasRenderer.isSupported = function(canvasName) { var canvas = null; try { - if (typeof(canvasName) == 'undefined' || canvasName == null) + if (typeof(canvasName) == 'undefined' || canvasName === null) { canvas = document.createElement("canvas"); - else + } else { canvas = canvasName; - var context = canvas.getContext("2d"); + } + canvas.getContext("2d"); } catch (e) { var ie = navigator.appVersion.match(/MSIE (\d\.\d)/); @@ -319,288 +145,414 @@ DygraphCanvasRenderer.isSupported = function(canvasName) { }; /** - * Draw an X/Y grid on top of the existing plot + * @param { [String] } colors Array of color strings. Should have one entry for + * each series to be rendered. */ -DygraphCanvasRenderer.prototype.render = function() { - // Draw the new X/Y grid - var ctx = this.element.getContext("2d"); +DygraphCanvasRenderer.prototype.setColors = function(colors) { + this.colorScheme_ = colors; +}; - if (this.options.underlayCallback) { - this.options.underlayCallback(ctx, this.area, this.layout, this.dygraph_); +/** + * This method is responsible for drawing everything on the chart, including + * lines, error bars, fills and axes. + * It is called immediately after clear() on every frame, including during pans + * and zooms. + * @private + */ +DygraphCanvasRenderer.prototype.render = function() { + // Draw the new X/Y grid. Lines appear crisper when pixels are rounded to + // half-integers. This prevents them from drawing in two rows/cols. + var ctx = this.elementContext; + function halfUp(x) { return Math.round(x) + 0.5; } + function halfDown(y){ return Math.round(y) - 0.5; } + + if (this.attr_('underlayCallback')) { + // NOTE: we pass the dygraph object to this callback twice to avoid breaking + // users who expect a deprecated form of this callback. + this.attr_('underlayCallback')(ctx, this.area, this.dygraph_, this.dygraph_); } - if (this.options.drawYGrid) { - var ticks = this.layout.yticks; + var x, y, i, ticks; + if (this.attr_('drawYGrid')) { + ticks = this.layout.yticks; + // TODO(konigsberg): I don't think these calls to save() have a corresponding restore(). ctx.save(); - ctx.strokeStyle = this.options.gridLineColor; - ctx.lineWidth = this.options.axisLineWidth; - for (var i = 0; i < ticks.length; i++) { - var x = this.area.x; - var y = this.area.y + ticks[i][0] * this.area.h; + ctx.strokeStyle = this.attr_('gridLineColor'); + ctx.lineWidth = this.attr_('gridLineWidth'); + for (i = 0; i < ticks.length; i++) { + // TODO(danvk): allow secondary axes to draw a grid, too. + if (ticks[i][0] !== 0) continue; + x = halfUp(this.area.x); + y = halfDown(this.area.y + ticks[i][1] * this.area.h); ctx.beginPath(); ctx.moveTo(x, y); ctx.lineTo(x + this.area.w, y); ctx.closePath(); ctx.stroke(); } + ctx.restore(); } - if (this.options.drawXGrid) { - var ticks = this.layout.xticks; + if (this.attr_('drawXGrid')) { + ticks = this.layout.xticks; ctx.save(); - ctx.strokeStyle = this.options.gridLineColor; - ctx.lineWidth = this.options.axisLineWidth; - for (var i=0; i= 0; i--) { + if (graphDiv.childNodes[i].className == className) { + graphDiv.removeChild(graphDiv.childNodes[i]); + } + } - var context = this.element.getContext("2d"); + // Determine background color to give clip divs. + var backgroundColor = document.bgColor; + var element = this.dygraph_.graphDiv; + while (element != document) { + var bgcolor = element.currentStyle.backgroundColor; + if (bgcolor && bgcolor != 'transparent') { + backgroundColor = bgcolor; + break; + } + element = element.parentNode; + } - var labelStyle = { - "position": "absolute", - "fontSize": this.options.axisLabelFontSize + "px", - "zIndex": 10, - "color": this.options.axisLabelColor, - "width": this.options.axisLabelWidth + "px", - "overflow": "hidden" - }; - var makeDiv = function(txt) { - var div = document.createElement("div"); - for (var name in labelStyle) { - if (labelStyle.hasOwnProperty(name)) { - div.style[name] = labelStyle[name]; - } + function createClipDiv(area) { + if (area.w === 0 || area.h === 0) { + return; } - div.appendChild(document.createTextNode(txt)); - return div; - }; + var elem = document.createElement('div'); + elem.className = className; + elem.style.backgroundColor = backgroundColor; + elem.style.position = 'absolute'; + elem.style.left = area.x + 'px'; + elem.style.top = area.y + 'px'; + elem.style.width = area.w + 'px'; + elem.style.height = area.h + 'px'; + graphDiv.appendChild(elem); + } - // axis lines - context.save(); - context.strokeStyle = this.options.axisLineColor; - context.lineWidth = this.options.axisLineWidth; - - if (this.options.drawYAxis) { - if (this.layout.yticks && this.layout.yticks.length > 0) { - for (var i = 0; i < this.layout.yticks.length; i++) { - var tick = this.layout.yticks[i]; - if (typeof(tick) == "function") return; - var x = this.area.x; - var y = this.area.y + tick[0] * this.area.h; - context.beginPath(); - context.moveTo(x, y); - context.lineTo(x - this.options.axisTickSize, y); - context.closePath(); - context.stroke(); - - var label = makeDiv(tick[1]); - var top = (y - this.options.axisLabelFontSize / 2); - if (top < 0) top = 0; - - if (top + this.options.axisLabelFontSize + 3 > this.height) { - label.style.bottom = "0px"; - } else { - label.style.top = top + "px"; - } - label.style.left = "0px"; - label.style.textAlign = "right"; - label.style.width = this.options.yAxisLabelWidth + "px"; - this.container.appendChild(label); - this.ylabels.push(label); - } + var plotArea = this.area; + // Left side + createClipDiv({ + x:0, y:0, + w:plotArea.x, + h:this.height + }); + + // Top + createClipDiv({ + x: plotArea.x, y: 0, + w: this.width - plotArea.x, + h: plotArea.y + }); + + // Right side + createClipDiv({ + x: plotArea.x + plotArea.w, y: 0, + w: this.width-plotArea.x - plotArea.w, + h: this.height + }); + + // Bottom + createClipDiv({ + x: plotArea.x, + y: plotArea.y + plotArea.h, + w: this.width - plotArea.x, + h: this.height - plotArea.h - plotArea.y + }); +}; - // The lowest tick on the y-axis often overlaps with the leftmost - // tick on the x-axis. Shift the bottom tick up a little bit to - // compensate if necessary. - var bottomTick = this.ylabels[0]; - var fontSize = this.options.axisLabelFontSize; - var bottom = parseInt(bottomTick.style.top) + fontSize; - if (bottom > this.height - fontSize) { - bottomTick.style.top = (parseInt(bottomTick.style.top) - - fontSize / 2) + "px"; - } - } - context.beginPath(); - context.moveTo(this.area.x, this.area.y); - context.lineTo(this.area.x, this.area.y + this.area.h); - context.closePath(); - context.stroke(); +/** + * Returns a predicate to be used with an iterator, which will + * iterate over points appropriately, depending on whether + * connectSeparatedPoints is true. When it's false, the predicate will + * skip over points with missing yVals. + */ +DygraphCanvasRenderer._getIteratorPredicate = function(connectSeparatedPoints) { + return connectSeparatedPoints ? DygraphCanvasRenderer._predicateThatSkipsEmptyPoints : null; +} + +DygraphCanvasRenderer._predicateThatSkipsEmptyPoints = + function(array, idx) { return array[idx].yval !== null; } + +DygraphCanvasRenderer.prototype._drawStyledLine = function( + ctx, i, setName, color, strokeWidth, strokePattern, drawPoints, + drawPointCallback, pointSize) { + // TODO(konigsberg): Compute attributes outside this method call. + var stepPlot = this.attr_("stepPlot"); + var firstIndexInSet = this.layout.setPointsOffsets[i]; + var setLength = this.layout.setPointsLengths[i]; + var points = this.layout.points; + if (!Dygraph.isArrayLike(strokePattern)) { + strokePattern = null; } + var drawGapPoints = this.dygraph_.attr_('drawGapEdgePoints', setName); - if (this.options.drawXAxis) { - if (this.layout.xticks) { - for (var i = 0; i < this.layout.xticks.length; i++) { - var tick = this.layout.xticks[i]; - if (typeof(dataset) == "function") return; - - var x = this.area.x + tick[0] * this.area.w; - var y = this.area.y + this.area.h; - context.beginPath(); - context.moveTo(x, y); - context.lineTo(x, y + this.options.axisTickSize); - context.closePath(); - context.stroke(); - - var label = makeDiv(tick[1]); - label.style.textAlign = "center"; - label.style.bottom = "0px"; - - var left = (x - this.options.axisLabelWidth/2); - if (left + this.options.axisLabelWidth > this.width) { - left = this.width - this.options.xAxisLabelWidth; - label.style.textAlign = "right"; - } - if (left < 0) { - left = 0; - label.style.textAlign = "left"; - } + ctx.save(); - label.style.left = left + "px"; - label.style.width = this.options.xAxisLabelWidth + "px"; - this.container.appendChild(label); - this.xlabels.push(label); - } - } + var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, + DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints"))); - context.beginPath(); - context.moveTo(this.area.x, this.area.y + this.area.h); - context.lineTo(this.area.x + this.area.w, this.area.y + this.area.h); - context.closePath(); - context.stroke(); + var pointsOnLine; + var strategy; + if (!strokePattern || strokePattern.length <= 1) { + strategy = trivialStrategy(ctx, color, strokeWidth); + } else { + strategy = nonTrivialStrategy(this, ctx, color, strokeWidth, strokePattern); } + pointsOnLine = this._drawSeries(ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, stepPlot, strategy); + this._drawPointsOnLine(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize); - context.restore(); + ctx.restore(); }; +var nonTrivialStrategy = function(renderer, ctx, color, strokeWidth, strokePattern) { + return new function() { + this.init = function() { }; + this.finish = function() { }; + this.startSegment = function() { + ctx.beginPath(); + ctx.strokeStyle = color; + ctx.lineWidth = strokeWidth; + }; + this.endSegment = function() { + ctx.stroke(); // should this include closePath? + }; + this.drawLine = function(x1, y1, x2, y2) { + renderer._dashedLine(ctx, x1, y1, x2, y2, strokePattern); + }; + this.skipPixel = function(prevX, prevY, curX, curY) { + // TODO(konigsberg): optimize with http://jsperf.com/math-round-vs-hack/6 ? + return (Math.round(prevX) == Math.round(curX) && + Math.round(prevY) == Math.round(curY)); + }; + }; +}; -DygraphCanvasRenderer.prototype._renderAnnotations = function() { - var annotationStyle = { - "position": "absolute", - "fontSize": this.options.axisLabelFontSize + "px", - "zIndex": 10, - "width": "20px", - "overflow": "hidden", - "border": "1px solid black", - "background-color": "white", - "text-align": "center" +var trivialStrategy = function(ctx, color, strokeWidth) { + return new function() { + this.init = function() { + ctx.beginPath(); + ctx.strokeStyle = color; + ctx.lineWidth = strokeWidth; + }; + this.finish = function() { + ctx.stroke(); // should this include closePath? + }; + this.startSegment = function() { }; + this.endSegment = function() { }; + this.drawLine = function(x1, y1, x2, y2) { + ctx.moveTo(x1, y1); + ctx.lineTo(x2, y2); + }; + // don't skip pixels. + this.skipPixel = function() { + return false; + }; }; +}; - // Get a list of point with annotations. - var points = this.layout.annotated_points; - for (var i = 0; i < points.length; i++) { - var p = points[i]; - var div = document.createElement("div"); - for (var name in annotationStyle) { - if (annotationStyle.hasOwnProperty(name)) { - div.style[name] = annotationStyle[name]; +DygraphCanvasRenderer.prototype._drawPointsOnLine = function(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize) { + for (var idx = 0; idx < pointsOnLine.length; idx++) { + var cb = pointsOnLine[idx]; + ctx.save(); + drawPointCallback( + this.dygraph_, setName, ctx, cb[0], cb[1], color, pointSize); + ctx.restore(); + } +} + +DygraphCanvasRenderer.prototype._drawSeries = function( + ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, + stepPlot, strategy) { + + var prevCanvasX = null; + var prevCanvasY = null; + var nextCanvasY = null; + var isIsolated; // true if this point is isolated (no line segments) + var point; // the point being processed in the while loop + var pointsOnLine = []; // Array of [canvasx, canvasy] pairs. + var first = true; // the first cycle through the while loop + + strategy.init(); + + while(iter.hasNext()) { + point = iter.next(); + if (point.canvasy === null || point.canvasy != point.canvasy) { + if (stepPlot && prevCanvasX !== null) { + // Draw a horizontal line to the start of the missing data + strategy.startSegment(); + strategy.drawLine(prevX, prevY, point.canvasx, prevY); + strategy.endSegment(); + } + prevCanvasX = prevCanvasY = null; + } else { + nextCanvasY = iter.hasNext() ? iter.peek().canvasy : null; + // TODO: we calculate isNullOrNaN for this point, and the next, and then, when + // we iterate, test for isNullOrNaN again. Why bother? + var isNextCanvasYNullOrNaN = nextCanvasY === null || nextCanvasY != nextCanvasY; + isIsolated = (!prevCanvasX && isNextCanvasYNullOrNaN); + if (drawGapPoints) { + // Also consider a point to be "isolated" if it's adjacent to a + // null point, excluding the graph edges. + if ((!first && !prevCanvasX) || + (iter.hasNext() && isNextCanvasYNullOrNaN)) { + isIsolated = true; + } + } + if (prevCanvasX !== null) { + if (strategy.skipPixel(prevCanvasX, prevCanvasY, point.canvasx, point.canvasy)) { + continue; + } + if (strokeWidth) { + strategy.startSegment(); + if (stepPlot) { + strategy.drawLine(prevCanvasX, prevCanvasY, point.canvasx, prevCanvasY); + prevCanvasX = point.canvasx; + } + strategy.drawLine(prevCanvasX, prevCanvasY, point.canvasx, point.canvasy); + strategy.endSegment(); + } + } + if (drawPoints || isIsolated) { + pointsOnLine.push([point.canvasx, point.canvasy]); } + prevCanvasX = point.canvasx; + prevCanvasY = point.canvasy; } - div.appendChild(document.createTextNode(p.annotation.shortText)); - div.style.left = (p.canvasx - 10) + "px"; - div.style.top = p.canvasy + "px"; - div.title = p.annotation.text; - div.style.color = this.colors[p.name]; - div.style.borderColor = this.colors[p.name]; - this.container.appendChild(div); - this.annotations.push(div); + first = false; } + strategy.finish(); + return pointsOnLine; }; +DygraphCanvasRenderer.prototype._drawLine = function(ctx, i) { + var setNames = this.layout.setNames; + var setName = setNames[i]; + + var strokeWidth = this.dygraph_.attr_("strokeWidth", setName); + var borderWidth = this.dygraph_.attr_("strokeBorderWidth", setName); + var drawPointCallback = this.dygraph_.attr_("drawPointCallback", setName) || + Dygraph.Circles.DEFAULT; + + if (borderWidth && strokeWidth) { + this._drawStyledLine(ctx, i, setName, + this.dygraph_.attr_("strokeBorderColor", setName), + strokeWidth + 2 * borderWidth, + this.dygraph_.attr_("strokePattern", setName), + this.dygraph_.attr_("drawPoints", setName), + drawPointCallback, + this.dygraph_.attr_("pointSize", setName)); + } + + this._drawStyledLine(ctx, i, setName, + this.colors[setName], + strokeWidth, + this.dygraph_.attr_("strokePattern", setName), + this.dygraph_.attr_("drawPoints", setName), + drawPointCallback, + this.dygraph_.attr_("pointSize", setName)); +}; /** - * Overrides the CanvasRenderer method to draw error bars + * Actually draw the lines chart, including error bars. + * TODO(danvk): split this into several smaller functions. + * @private */ DygraphCanvasRenderer.prototype._renderLineChart = function() { - var context = this.element.getContext("2d"); - var colorCount = this.options.colorScheme.length; - var colorScheme = this.options.colorScheme; - var fillAlpha = this.options.fillAlpha; - var errorBars = this.layout.options.errorBars; - var fillGraph = this.layout.options.fillGraph; - var stackedGraph = this.layout.options.stackedGraph; - var stepPlot = this.layout.options.stepPlot; - - var setNames = []; - for (var name in this.layout.datasets) { - if (this.layout.datasets.hasOwnProperty(name)) { - setNames.push(name); - } - } + // TODO(danvk): use this.attr_ for many of these. + var ctx = this.elementContext; + var fillAlpha = this.attr_('fillAlpha'); + var errorBars = this.attr_("errorBars") || this.attr_("customBars"); + var fillGraph = this.attr_("fillGraph"); + var stackedGraph = this.attr_("stackedGraph"); + var stepPlot = this.attr_("stepPlot"); + var points = this.layout.points; + var pointsLength = points.length; + var point, i, prevX, prevY, prevYs, color, setName, newYs, err_color, rgb, yscale, axis; + + var setNames = this.layout.setNames; var setCount = setNames.length; - this.colors = {} - for (var i = 0; i < setCount; i++) { - this.colors[setNames[i]] = colorScheme[i % colorCount]; - } + this.colors = this.dygraph_.colorsMap_; // Update Points // TODO(danvk): here - for (var i = 0; i < this.layout.points.length; i++) { - var point = this.layout.points[i]; + // + // TODO(bhs): this loop is a hot-spot for high-point-count charts. These + // transformations can be pushed into the canvas via linear transformation + // matrices. + for (i = pointsLength; i--;) { + point = points[i]; point.canvasx = this.area.w * point.x + this.area.x; point.canvasy = this.area.h * point.y + this.area.y; } // create paths - var isOK = function(x) { return x && !isNaN(x); }; - - var ctx = context; if (errorBars) { + ctx.save(); if (fillGraph) { this.dygraph_.warn("Can't use fillGraph option with error bars"); } - for (var i = 0; i < setCount; i++) { - var setName = setNames[i]; - var color = this.colors[setName]; + for (i = 0; i < setCount; i++) { + setName = setNames[i]; + axis = this.dygraph_.axisPropertiesForSeries(setName); + color = this.colors[setName]; + + var firstIndexInSet = this.layout.setPointsOffsets[i]; + var setLength = this.layout.setPointsLengths[i]; + + var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, + DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints"))); // setup graphics context - ctx.save(); - var prevX = NaN; - var prevY = NaN; - var prevYs = [-1, -1]; - var yscale = this.layout.yscale; + prevX = NaN; + prevY = NaN; + prevYs = [-1, -1]; + yscale = axis.yscale; // should be same color as the lines but only 15% opaque. - var rgb = new RGBColor(color); - var err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + + rgb = new RGBColor(color); + err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + fillAlpha + ')'; ctx.fillStyle = err_color; ctx.beginPath(); - for (var j = 0; j < this.layout.points.length; j++) { - var point = this.layout.points[j]; - if (point.name == setName) { - if (!isOK(point.y)) { + while (iter.hasNext()) { + point = iter.next(); + if (point.name == setName) { // TODO(klausw): this is always true + if (!Dygraph.isOK(point.y)) { prevX = NaN; continue; } // TODO(danvk): here if (stepPlot) { - var newYs = [ prevY - point.errorPlus * yscale, - prevY + point.errorMinus * yscale ]; + newYs = [ point.y_bottom, point.y_top ]; prevY = point.y; } else { - var newYs = [ point.y - point.errorPlus * yscale, - point.y + point.errorMinus * yscale ]; + newYs = [ point.y_bottom, point.y_top ]; } newYs[0] = this.area.h * newYs[0] + this.area.y; newYs[1] = this.area.h * newYs[1] + this.area.y; @@ -625,54 +577,89 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { } ctx.fill(); } + ctx.restore(); } else if (fillGraph) { - var axisY = 1.0 + this.layout.minyval * this.layout.yscale; - if (axisY < 0.0) axisY = 0.0; - else if (axisY > 1.0) axisY = 1.0; - axisY = this.area.h * axisY + this.area.y; - - var baseline = [] // for stacked graphs: baseline for filling + ctx.save(); + var baseline = {}; // for stacked graphs: baseline for filling + var currBaseline; // process sets in reverse order (needed for stacked graphs) - for (var i = setCount - 1; i >= 0; i--) { - var setName = setNames[i]; - var color = this.colors[setName]; + for (i = setCount - 1; i >= 0; i--) { + setName = setNames[i]; + color = this.colors[setName]; + axis = this.dygraph_.axisPropertiesForSeries(setName); + var axisY = 1.0 + axis.minyval * axis.yscale; + if (axisY < 0.0) axisY = 0.0; + else if (axisY > 1.0) axisY = 1.0; + axisY = this.area.h * axisY + this.area.y; + var firstIndexInSet = this.layout.setPointsOffsets[i]; + var setLength = this.layout.setPointsLengths[i]; + + var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, + DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints"))); // setup graphics context - ctx.save(); - var prevX = NaN; - var prevYs = [-1, -1]; - var yscale = this.layout.yscale; + prevX = NaN; + prevYs = [-1, -1]; + yscale = axis.yscale; // should be same color as the lines but only 15% opaque. - var rgb = new RGBColor(color); - var err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + + rgb = new RGBColor(color); + err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + fillAlpha + ')'; ctx.fillStyle = err_color; ctx.beginPath(); - for (var j = 0; j < this.layout.points.length; j++) { - var point = this.layout.points[j]; - if (point.name == setName) { - if (!isOK(point.y)) { + while(iter.hasNext()) { + point = iter.next(); + if (point.name == setName) { // TODO(klausw): this is always true + if (!Dygraph.isOK(point.y)) { prevX = NaN; continue; } - var newYs; if (stackedGraph) { - lastY = baseline[point.canvasx]; - if (lastY === undefined) lastY = axisY; - baseline[point.canvasx] = point.canvasy; + currBaseline = baseline[point.canvasx]; + var lastY; + if (currBaseline === undefined) { + lastY = axisY; + } else { + if(stepPlot) { + lastY = currBaseline[0]; + } else { + lastY = currBaseline; + } + } newYs = [ point.canvasy, lastY ]; + + if(stepPlot) { + // Step plots must keep track of the top and bottom of + // the baseline at each point. + if(prevYs[0] === -1) { + baseline[point.canvasx] = [ point.canvasy, axisY ]; + } else { + baseline[point.canvasx] = [ point.canvasy, prevYs[0] ]; + } + } else { + baseline[point.canvasx] = point.canvasy; + } + } else { newYs = [ point.canvasy, axisY ]; } if (!isNaN(prevX)) { ctx.moveTo(prevX, prevYs[0]); + if (stepPlot) { ctx.lineTo(point.canvasx, prevYs[0]); + if(currBaseline) { + // Draw to the bottom of the baseline + ctx.lineTo(point.canvasx, currBaseline[1]); + } else { + ctx.lineTo(point.canvasx, newYs[1]); + } } else { ctx.lineTo(point.canvasx, newYs[0]); + ctx.lineTo(point.canvasx, newYs[1]); } - ctx.lineTo(point.canvasx, newYs[1]); + ctx.lineTo(prevX, prevYs[1]); ctx.closePath(); } @@ -682,59 +669,102 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { } ctx.fill(); } + ctx.restore(); } - for (var i = 0; i < setCount; i++) { - var setName = setNames[i]; - var color = this.colors[setName]; - - // setup graphics context - context.save(); - var point = this.layout.points[0]; - var pointSize = this.dygraph_.attr_("pointSize"); - var prevX = null, prevY = null; - var drawPoints = this.dygraph_.attr_("drawPoints"); - var points = this.layout.points; - for (var j = 0; j < points.length; j++) { - var point = points[j]; - if (point.name == setName) { - if (!isOK(point.canvasy)) { - // this will make us move to the next point, not draw a line to it. - prevX = prevY = null; - } else { - // A point is "isolated" if it is non-null but both the previous - // and next points are null. - var isIsolated = (!prevX && (j == points.length - 1 || - !isOK(points[j+1].canvasy))); - - if (!prevX) { - prevX = point.canvasx; - prevY = point.canvasy; - } else { - ctx.beginPath(); - ctx.strokeStyle = color; - ctx.lineWidth = this.options.strokeWidth; - ctx.moveTo(prevX, prevY); - if (stepPlot) { - ctx.lineTo(point.canvasx, prevY); - } - prevX = point.canvasx; - prevY = point.canvasy; - ctx.lineTo(prevX, prevY); - ctx.stroke(); - } + // Drawing the lines. + for (i = 0; i < setCount; i += 1) { + this._drawLine(ctx, i); + } +}; - if (drawPoints || isIsolated) { - ctx.beginPath(); - ctx.fillStyle = color; - ctx.arc(point.canvasx, point.canvasy, pointSize, - 0, 2 * Math.PI, false); - ctx.fill(); - } - } - } - } +/** + * This does dashed lines onto a canvas for a given pattern. You must call + * ctx.stroke() after to actually draw it, much line ctx.lineTo(). It remembers + * the state of the line in regards to where we left off on drawing the pattern. + * You can draw a dashed line in several function calls and the pattern will be + * continous as long as you didn't call this function with a different pattern + * in between. + * @param ctx The canvas 2d context to draw on. + * @param x The start of the line's x coordinate. + * @param y The start of the line's y coordinate. + * @param x2 The end of the line's x coordinate. + * @param y2 The end of the line's y coordinate. + * @param pattern The dash pattern to draw, an array of integers where even + * index is drawn and odd index is not drawn (Ex. [10, 2, 5, 2], 10 is drawn 5 + * is drawn, 2 is the space between.). A null pattern, array of length one, or + * empty array will do just a solid line. + * @private + */ +DygraphCanvasRenderer.prototype._dashedLine = function(ctx, x, y, x2, y2, pattern) { + // Original version http://stackoverflow.com/questions/4576724/dotted-stroke-in-canvas + // Modified by Russell Valentine to keep line history and continue the pattern + // where it left off. + var dx, dy, len, rot, patternIndex, segment; + + // If we don't have a pattern or it is an empty array or of size one just + // do a solid line. + if (!pattern || pattern.length <= 1) { + ctx.moveTo(x, y); + ctx.lineTo(x2, y2); + return; + } + + // If we have a different dash pattern than the last time this was called we + // reset our dash history and start the pattern from the begging + // regardless of state of the last pattern. + if (!Dygraph.compareArrays(pattern, this._dashedLineToHistoryPattern)) { + this._dashedLineToHistoryPattern = pattern; + this._dashedLineToHistory = [0, 0]; } + ctx.save(); + + // Calculate transformation parameters + dx = (x2-x); + dy = (y2-y); + len = Math.sqrt(dx*dx + dy*dy); + rot = Math.atan2(dy, dx); + + // Set transformation + ctx.translate(x, y); + ctx.moveTo(0, 0); + ctx.rotate(rot); + + // Set last pattern index we used for this pattern. + patternIndex = this._dashedLineToHistory[0]; + x = 0; + while (len > x) { + // Get the length of the pattern segment we are dealing with. + segment = pattern[patternIndex]; + // If our last draw didn't complete the pattern segment all the way we + // will try to finish it. Otherwise we will try to do the whole segment. + if (this._dashedLineToHistory[1]) { + x += this._dashedLineToHistory[1]; + } else { + x += segment; + } + if (x > len) { + // We were unable to complete this pattern index all the way, keep + // where we are the history so our next draw continues where we left off + // in the pattern. + this._dashedLineToHistory = [patternIndex, x-len]; + x = len; + } else { + // We completed this patternIndex, we put in the history that we are on + // the beginning of the next segment. + this._dashedLineToHistory = [(patternIndex+1)%pattern.length, 0]; + } - context.restore(); + // We do a line on a even pattern index and just move on a odd pattern index. + // The move is the empty space in the dash. + if(patternIndex % 2 === 0) { + ctx.lineTo(x, 0); + } else { + ctx.moveTo(x, 0); + } + // If we are not done, next loop process the next pattern segment, or the + // first segment again if we are at the end of the pattern. + patternIndex = (patternIndex+1) % pattern.length; + } + ctx.restore(); };