X-Git-Url: https://adrianiainlam.tk/git/?a=blobdiff_plain;f=dygraph-canvas.js;h=4a29848c61708d121162c8c21f5fc24bdecb663e;hb=a02978e25e2155e5e6fda12d1a3184fa3bd7987c;hp=764bac1b001a25fb55c7568aefe1b6dcd5e23360;hpb=95398db102a88ce4165d2a407957a044d3577fea;p=dygraphs.git diff --git a/dygraph-canvas.js b/dygraph-canvas.js index 764bac1..4a29848 100644 --- a/dygraph-canvas.js +++ b/dygraph-canvas.js @@ -1,282 +1,18 @@ -// 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 * - error bars * - dygraphs attribute system - * - * High level overview of classes: - * - * - DygraphLayout - * This contains all the data to be charted. - * It uses data coordinates, but also records the chart range (in data - * coordinates) and hence is able to calculate percentage positions ('In - * this view, Point A lies 25% down the x-axis.') - * Two things that it does not do are: - * 1. Record pixel coordinates for anything. - * 2. (oddly) determine anything about the layout of chart elements. - * The naming is a vestige of Dygraph's original PlotKit roots. - * - * - DygraphCanvasRenderer - * This class determines the charting area (in pixel coordinates), maps the - * percentage coordinates in the DygraphLayout to pixels and draws them. - * It's also responsible for creating chart DOM elements, i.e. annotations, - * tick mark labels, the title and the x/y-axis labels. - */ - -/** - * Creates a new DygraphLayout object. - * @return {Object} The DygraphLayout object */ -DygraphLayout = function(dygraph) { - this.dygraph_ = dygraph; - this.datasets = new Array(); - this.annotations = new Array(); - this.yAxes_ = null; - - // TODO(danvk): it's odd that xTicks_ and yTicks_ are inputs, but xticks and - // yticks are outputs. Clean this up. - this.xTicks_ = null; - this.yTicks_ = null; -}; - -DygraphLayout.prototype.attr_ = function(name) { - return this.dygraph_.attr_(name); -}; - -DygraphLayout.prototype.addDataset = function(setname, set_xy) { - this.datasets[setname] = set_xy; -}; - -DygraphLayout.prototype.setAnnotations = function(ann) { - // The Dygraph object's annotations aren't parsed. We parse them here and - // save a copy. If there is no parser, then the user must be using raw format. - this.annotations = []; - var parse = this.attr_('xValueParser') || function(x) { return x; }; - for (var i = 0; i < ann.length; i++) { - var a = {}; - if (!ann[i].xval && !ann[i].x) { - this.dygraph_.error("Annotations must have an 'x' property"); - return; - } - if (ann[i].icon && - !(ann[i].hasOwnProperty('width') && - ann[i].hasOwnProperty('height'))) { - this.dygraph_.error("Must set width and height when setting " + - "annotation.icon property"); - return; - } - Dygraph.update(a, ann[i]); - if (!a.xval) a.xval = parse(a.x); - this.annotations.push(a); - } -}; - -DygraphLayout.prototype.setXTicks = function(xTicks) { - this.xTicks_ = xTicks; -}; - -// TODO(danvk): add this to the Dygraph object's API or move it into Layout. -DygraphLayout.prototype.setYAxes = function (yAxes) { - this.yAxes_ = yAxes; -}; - -DygraphLayout.prototype.setDateWindow = function(dateWindow) { - this.dateWindow_ = dateWindow; -}; - -DygraphLayout.prototype.evaluate = function() { - this._evaluateLimits(); - this._evaluateLineCharts(); - this._evaluateLineTicks(); - this._evaluateAnnotations(); -}; - -DygraphLayout.prototype._evaluateLimits = function() { - this.minxval = this.maxxval = null; - if (this.dateWindow_) { - this.minxval = this.dateWindow_[0]; - this.maxxval = this.dateWindow_[1]; - } else { - for (var name in this.datasets) { - if (!this.datasets.hasOwnProperty(name)) continue; - var series = this.datasets[name]; - if (series.length > 1) { - 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); - - for (var i = 0; i < this.yAxes_.length; i++) { - var axis = this.yAxes_[i]; - axis.minyval = axis.computedValueRange[0]; - axis.maxyval = axis.computedValueRange[1]; - axis.yrange = axis.maxyval - axis.minyval; - axis.yscale = (axis.yrange != 0 ? 1.0 / axis.yrange : 1.0); - - if (axis.g.attr_("logscale")) { - axis.ylogrange = Dygraph.log10(axis.maxyval) - Dygraph.log10(axis.minyval); - axis.ylogscale = (axis.ylogrange != 0 ? 1.0 / axis.ylogrange : 1.0); - if (!isFinite(axis.ylogrange) || isNaN(axis.ylogrange)) { - axis.g.error('axis ' + i + ' of graph at ' + axis.g + - ' can\'t be displayed in log scale for range [' + - axis.minyval + ' - ' + axis.maxyval + ']'); - } - } - } -}; - -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]; - var axis = this.dygraph_.axisPropertiesForSeries(setName); - - for (var j = 0; j < dataset.length; j++) { - var item = dataset[j]; - - var yval; - if (axis.logscale) { - yval = 1.0 - ((Dygraph.log10(parseFloat(item[1])) - Dygraph.log10(axis.minyval)) * axis.ylogscale); // really should just be yscale. - } else { - yval = 1.0 - ((parseFloat(item[1]) - axis.minyval) * axis.yscale); - } - var point = { - // TODO(danvk): here - x: ((parseFloat(item[0]) - this.minxval) * this.xscale), - y: yval, - xval: parseFloat(item[0]), - yval: parseFloat(item[1]), - name: setName - }; - - this.points.push(point); - } - } -}; - -DygraphLayout.prototype._evaluateLineTicks = function() { - this.xticks = new Array(); - for (var i = 0; i < this.xTicks_.length; i++) { - var tick = this.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.yAxes_.length; i++ ) { - var axis = this.yAxes_[i]; - for (var j = 0; j < axis.ticks.length; j++) { - var tick = axis.ticks[j]; - var label = tick.label; - var pos = this.dygraph_.toPercentYCoord(tick.v, i); - if ((pos >= 0.0) && (pos <= 1.0)) { - this.yticks.push([i, pos, label]); - } - } - } -}; - - -/** - * Behaves the same way as PlotKit.Layout, but also copies the errors - * @private - */ -DygraphLayout.prototype.evaluateWithError = function() { - this.evaluate(); - if (!(this.attr_('errorBars') || this.attr_('customBars'))) 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 - */ -DygraphLayout.prototype.removeAllDatasets = function() { - delete this.datasets; - this.datasets = new Array(); -}; - -/** - * Return a copy of the point at the indicated index, with its yval unstacked. - * @param int index of point in layout_.points - */ -DygraphLayout.prototype.unstackPointAtIndex = function(idx) { - var point = this.points[idx]; - - // Clone the point since we modify it - var unstackedPoint = {}; - for (var i in point) { - unstackedPoint[i] = point[i]; - } - - if (!this.attr_("stackedGraph")) { - return unstackedPoint; - } - - // The unstacked yval is equal to the current yval minus the yval of the - // next point at the same xval. - for (var i = idx+1; i < this.points.length; i++) { - if (this.points[i].xval == point.xval) { - unstackedPoint.yval -= this.points[i].yval; - break; - } - } - - return unstackedPoint; -} /** * The DygraphCanvasRenderer class does the actual rendering of the chart onto @@ -285,8 +21,15 @@ DygraphLayout.prototype.unstackPointAtIndex = function(idx) { * @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 */ -DygraphCanvasRenderer = function(dygraph, element, elementContext, layout) { + +/*jshint globalstrict: true */ +/*global Dygraph:false,RGBColor:false */ +"use strict"; + + +var DygraphCanvasRenderer = function(dygraph, element, elementContext, layout) { this.dygraph_ = dygraph; this.layout = layout; @@ -302,79 +45,42 @@ DygraphCanvasRenderer = function(dygraph, element, elementContext, layout) { throw "Canvas is not supported."; // internal state - this.xlabels = new Array(); - this.ylabels = new Array(); - this.annotations = new Array(); + this.xlabels = []; + this.ylabels = []; + this.annotations = []; this.chartLabels = {}; - this.area = this.computeArea_(); + 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. - 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(); + 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); }; -// Compute the box which the chart should be drawn in. This is the canvas's -// box, less space needed for axis and chart labels. -// TODO(danvk): this belongs in DygraphLayout. -DygraphCanvasRenderer.prototype.computeArea_ = function() { - var area = { - // TODO(danvk): per-axis setting. - x: 0, - y: 0 - }; - if (this.attr_('drawYAxis')) { - area.x = this.attr_('yAxisLabelWidth') + 2 * this.attr_('axisTickSize'); - } - - area.w = this.width - area.x - this.attr_('rightGap'); - area.h = this.height; - if (this.attr_('drawXAxis')) { - area.h -= this.attr_('axisLabelFontSize') + 2 * this.attr_('axisTickSize'); - } - - // Shrink the drawing area to accomodate additional y-axes. - if (this.dygraph_.numAxes() == 2) { - // TODO(danvk): per-axis setting. - area.w -= (this.attr_('yAxisLabelWidth') + 2 * this.attr_('axisTickSize')); - } else if (this.dygraph_.numAxes() > 2) { - this.dygraph_.error("Only two y-axes are supported at this time. (Trying " + - "to use " + this.dygraph_.numAxes() + ")"); - } - - // Add space for chart labels: title, xlabel and ylabel. - if (this.attr_('title')) { - area.h -= this.attr_('titleHeight'); - area.y += this.attr_('titleHeight'); - } - if (this.attr_('xlabel')) { - area.h -= this.attr_('xLabelHeight'); - } - if (this.attr_('ylabel')) { - // It would make sense to shift the chart here to make room for the y-axis - // label, but the default yAxisLabelWidth is large enough that this results - // in overly-padded charts. The y-axis label should fit fine. If it - // doesn't, the yAxisLabelWidth option can be increased. - } - - return area; -}; - DygraphCanvasRenderer.prototype.clear = function() { + var context; if (this.isIE) { // VML takes a while to start up, so we just poll every this.IEDelay try { @@ -382,39 +88,38 @@ DygraphCanvasRenderer.prototype.clear = function() { this.clearDelay.cancel(); this.clearDelay = null; } - var context = this.elementContext; + 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.elementContext; + 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]; - if (el.parentNode) el.parentNode.removeChild(el); - } - for (var i = 0; i < this.ylabels.length; i++) { - var el = this.ylabels[i]; - if (el.parentNode) el.parentNode.removeChild(el); - } - for (var i = 0; i < this.annotations.length; i++) { - var el = this.annotations[i]; - if (el.parentNode) el.parentNode.removeChild(el); + function removeArray(ary) { + for (var i = 0; i < ary.length; i++) { + var el = ary[i]; + if (el.parentNode) el.parentNode.removeChild(el); + } } + + removeArray(this.xlabels); + removeArray(this.ylabels); + removeArray(this.annotations); + for (var k in this.chartLabels) { if (!this.chartLabels.hasOwnProperty(k)) continue; var el = this.chartLabels[k]; if (el.parentNode) el.parentNode.removeChild(el); } - this.xlabels = new Array(); - this.ylabels = new Array(); - this.annotations = new Array(); + this.xlabels = []; + this.ylabels = []; + this.annotations = []; this.chartLabels = {}; }; @@ -422,11 +127,12 @@ DygraphCanvasRenderer.prototype.clear = function() { 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)/); @@ -453,8 +159,8 @@ 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}; + 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 @@ -462,66 +168,142 @@ DygraphCanvasRenderer.prototype.render = function() { this.attr_('underlayCallback')(ctx, this.area, this.dygraph_, this.dygraph_); } + var x, y, i, ticks; if (this.attr_('drawYGrid')) { - var ticks = this.layout.yticks; + ticks = this.layout.yticks; + // TODO(konigsberg): I don't think these calls to save() have a corresponding restore(). ctx.save(); ctx.strokeStyle = this.attr_('gridLineColor'); ctx.lineWidth = this.attr_('gridLineWidth'); - for (var i = 0; i < ticks.length; i++) { + for (i = 0; i < ticks.length; i++) { // TODO(danvk): allow secondary axes to draw a grid, too. - if (ticks[i][0] != 0) continue; - var x = halfUp(this.area.x); - var y = halfDown(this.area.y + ticks[i][1] * this.area.h); + 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.attr_('drawXGrid')) { - var ticks = this.layout.xticks; + ticks = this.layout.xticks; ctx.save(); ctx.strokeStyle = this.attr_('gridLineColor'); ctx.lineWidth = this.attr_('gridLineWidth'); - for (var i=0; i= 0; i--) { + if (graphDiv.childNodes[i].className == className) { + graphDiv.removeChild(graphDiv.childNodes[i]); + } + } + + // 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; + } + + function createClipDiv(area) { + if (area.w === 0 || area.h === 0) { + return; + } + 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); + } + + 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 + }); +}; DygraphCanvasRenderer.prototype._renderAxis = function() { if (!this.attr_('drawXAxis') && !this.attr_('drawYAxis')) return; // Round pixels to half-integer boundaries for crisper drawing. - function halfUp(x){return Math.round(x)+0.5}; - function halfDown(y){return Math.round(y)-0.5}; + function halfUp(x) { return Math.round(x) + 0.5; } + function halfDown(y){ return Math.round(y) - 0.5; } var context = this.elementContext; + var label, x, y, tick, i; + var labelStyle = { position: "absolute", fontSize: this.attr_('axisLabelFontSize') + "px", zIndex: 10, color: this.attr_('axisLabelColor'), width: this.attr_('axisLabelWidth') + "px", + // height: this.attr_('axisLabelFontSize') + 2 + "px", + lineHeight: "normal", // Something other than "normal" line-height screws up label positioning. overflow: "hidden" }; - var makeDiv = function(txt, axis) { + var makeDiv = function(txt, axis, prec_axis) { var div = document.createElement("div"); for (var name in labelStyle) { if (labelStyle.hasOwnProperty(name)) { @@ -529,9 +311,10 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { } } var inner_div = document.createElement("div"); - // TODO(danvk): separate class for secondary y-axis - inner_div.className = 'dygraph-axis-label dygraph-axis-label-' + axis; - inner_div.appendChild(document.createTextNode(txt)); + inner_div.className = 'dygraph-axis-label' + + ' dygraph-axis-label-' + axis + + (prec_axis ? ' dygraph-axis-label-' + prec_axis : ''); + inner_div.innerHTML=txt; div.appendChild(inner_div); return div; }; @@ -543,23 +326,29 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { if (this.attr_('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]; + var num_axes = this.dygraph_.numAxes(); + for (i = 0; i < this.layout.yticks.length; i++) { + tick = this.layout.yticks[i]; if (typeof(tick) == "function") return; - var x = this.area.x; + x = this.area.x; var sgn = 1; + var prec_axis = 'y1'; if (tick[0] == 1) { // right-side y-axis x = this.area.x + this.area.w; sgn = -1; + prec_axis = 'y2'; } - var y = this.area.y + tick[1] * this.area.h; + y = this.area.y + tick[1] * this.area.h; + + /* Tick marks are currently clipped, so don't bother drawing them. context.beginPath(); context.moveTo(halfUp(x), halfDown(y)); context.lineTo(halfUp(x - sgn * this.attr_('axisTickSize')), halfDown(y)); context.closePath(); context.stroke(); + */ - var label = makeDiv(tick[2], 'y'); + label = makeDiv(tick[2], 'y', num_axes == 2 ? prec_axis : null); var top = (y - this.attr_('axisLabelFontSize') / 2); if (top < 0) top = 0; @@ -568,7 +357,7 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { } else { label.style.top = top + "px"; } - if (tick[0] == 0) { + if (tick[0] === 0) { label.style.left = (this.area.x - this.attr_('yAxisLabelWidth') - this.attr_('axisTickSize')) + "px"; label.style.textAlign = "right"; } else if (tick[0] == 1) { @@ -586,17 +375,25 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { // compensate if necessary. var bottomTick = this.ylabels[0]; var fontSize = this.attr_('axisLabelFontSize'); - var bottom = parseInt(bottomTick.style.top) + fontSize; + var bottom = parseInt(bottomTick.style.top, 10) + fontSize; if (bottom > this.height - fontSize) { - bottomTick.style.top = (parseInt(bottomTick.style.top) - + bottomTick.style.top = (parseInt(bottomTick.style.top, 10) - fontSize / 2) + "px"; } } // draw a vertical line on the left to separate the chart from the labels. + var axisX; + if (this.attr_('drawAxesAtZero')) { + var r = this.dygraph_.toPercentXCoord(0); + if (r > 1 || r < 0) r = 0; + axisX = halfUp(this.area.x + r * this.area.w); + } else { + axisX = halfUp(this.area.x); + } context.beginPath(); - context.moveTo(halfUp(this.area.x), halfDown(this.area.y)); - context.lineTo(halfUp(this.area.x), halfDown(this.area.y + this.area.h)); + context.moveTo(axisX, halfDown(this.area.y)); + context.lineTo(axisX, halfDown(this.area.y + this.area.h)); context.closePath(); context.stroke(); @@ -612,19 +409,20 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { if (this.attr_('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; + for (i = 0; i < this.layout.xticks.length; i++) { + tick = this.layout.xticks[i]; + x = this.area.x + tick[0] * this.area.w; + y = this.area.y + this.area.h; - var x = this.area.x + tick[0] * this.area.w; - var y = this.area.y + this.area.h; + /* Tick marks are currently clipped, so don't bother drawing them. context.beginPath(); context.moveTo(halfUp(x), halfDown(y)); context.lineTo(halfUp(x), halfDown(y + this.attr_('axisTickSize'))); context.closePath(); context.stroke(); + */ - var label = makeDiv(tick[1], 'x'); + label = makeDiv(tick[1], 'x'); label.style.textAlign = "center"; label.style.top = (y + this.attr_('axisTickSize')) + 'px'; @@ -646,8 +444,16 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { } context.beginPath(); - context.moveTo(halfUp(this.area.x), halfDown(this.area.y + this.area.h)); - context.lineTo(halfUp(this.area.x + this.area.w), halfDown(this.area.y + this.area.h)); + var axisY; + if (this.attr_('drawAxesAtZero')) { + var r = this.dygraph_.toPercentYCoord(0, 0); + if (r > 1 || r < 0) r = 1; + axisY = halfDown(this.area.y + r * this.area.h); + } else { + axisY = halfDown(this.area.y + this.area.h); + } + context.moveTo(halfUp(this.area.x), axisY); + context.lineTo(halfUp(this.area.x + this.area.w), axisY); context.closePath(); context.stroke(); } @@ -657,11 +463,13 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { DygraphCanvasRenderer.prototype._renderChartLabels = function() { + var div, class_div; + // Generate divs for the chart title, xlabel and ylabel. // Space for these divs has already been taken away from the charting area in // the DygraphCanvasRenderer constructor. if (this.attr_('title')) { - var div = document.createElement("div"); + div = document.createElement("div"); div.style.position = 'absolute'; div.style.top = '0px'; div.style.left = this.area.x + 'px'; @@ -670,7 +478,7 @@ DygraphCanvasRenderer.prototype._renderChartLabels = function() { div.style.textAlign = 'center'; div.style.fontSize = (this.attr_('titleHeight') - 8) + 'px'; div.style.fontWeight = 'bold'; - var class_div = document.createElement("div"); + class_div = document.createElement("div"); class_div.className = 'dygraph-label dygraph-title'; class_div.innerHTML = this.attr_('title'); div.appendChild(class_div); @@ -679,7 +487,7 @@ DygraphCanvasRenderer.prototype._renderChartLabels = function() { } if (this.attr_('xlabel')) { - var div = document.createElement("div"); + div = document.createElement("div"); div.style.position = 'absolute'; div.style.bottom = 0; // TODO(danvk): this is lazy. Calculate style.top. div.style.left = this.area.x + 'px'; @@ -688,7 +496,7 @@ DygraphCanvasRenderer.prototype._renderChartLabels = function() { div.style.textAlign = 'center'; div.style.fontSize = (this.attr_('xLabelHeight') - 2) + 'px'; - var class_div = document.createElement("div"); + class_div = document.createElement("div"); class_div.className = 'dygraph-label dygraph-xlabel'; class_div.innerHTML = this.attr_('xlabel'); div.appendChild(class_div); @@ -696,21 +504,26 @@ DygraphCanvasRenderer.prototype._renderChartLabels = function() { this.chartLabels.xlabel = div; } - if (this.attr_('ylabel')) { + var that = this; + function createRotatedDiv(axis, classes, html) { var box = { left: 0, - top: this.area.y, - width: this.attr_('yLabelWidth'), - height: this.area.h + top: that.area.y, + width: that.attr_('yLabelWidth'), + height: that.area.h }; // TODO(danvk): is this outer div actually necessary? - var div = document.createElement("div"); + div = document.createElement("div"); div.style.position = 'absolute'; - div.style.left = box.left; + if (axis == 1) { + div.style.left = box.left; + } else { + div.style.right = box.left; + } div.style.top = box.top + 'px'; div.style.width = box.width + 'px'; div.style.height = box.height + 'px'; - div.style.fontSize = (this.attr_('yLabelWidth') - 2) + 'px'; + div.style.fontSize = (that.attr_('yLabelWidth') - 2) + 'px'; var inner_div = document.createElement("div"); inner_div.style.position = 'absolute'; @@ -722,11 +535,12 @@ DygraphCanvasRenderer.prototype._renderChartLabels = function() { // CSS rotation is an HTML5 feature which is not standardized. Hence every // browser has its own name for the CSS style. - inner_div.style.transform = 'rotate(-90deg)'; // HTML5 - inner_div.style.WebkitTransform = 'rotate(-90deg)'; // Safari/Chrome - inner_div.style.MozTransform = 'rotate(-90deg)'; // Firefox - inner_div.style.OTransform = 'rotate(-90deg)'; // Opera - inner_div.style.msTransform = 'rotate(-90deg)'; // IE9 + var val = 'rotate(' + (axis == 1 ? '-' : '') + '90deg)'; + inner_div.style.transform = val; // HTML5 + inner_div.style.WebkitTransform = val; // Safari/Chrome + inner_div.style.MozTransform = val; // Firefox + inner_div.style.OTransform = val; // Opera + inner_div.style.msTransform = val; // IE9 if (typeof(document.documentMode) !== 'undefined' && document.documentMode < 9) { @@ -734,20 +548,34 @@ DygraphCanvasRenderer.prototype._renderChartLabels = function() { // using a BasicImage transform. This uses a different origin of rotation // than HTML5 rotation (top left of div vs. its center). inner_div.style.filter = - 'progid:DXImageTransform.Microsoft.BasicImage(rotation=3)'; + 'progid:DXImageTransform.Microsoft.BasicImage(rotation=' + + (axis == 1 ? '3' : '1') + ')'; inner_div.style.left = '0px'; inner_div.style.top = '0px'; } - var class_div = document.createElement("div"); - class_div.className = 'dygraph-label dygraph-ylabel'; - class_div.innerHTML = this.attr_('ylabel'); + class_div = document.createElement("div"); + class_div.className = classes; + class_div.innerHTML = html; inner_div.appendChild(class_div); div.appendChild(inner_div); + return div; + } + + var div; + if (this.attr_('ylabel')) { + div = createRotatedDiv(1, 'dygraph-label dygraph-ylabel', + this.attr_('ylabel')); this.container.appendChild(div); this.chartLabels.ylabel = div; } + if (this.attr_('y2label') && this.dygraph_.numAxes() == 2) { + div = createRotatedDiv(2, 'dygraph-label dygraph-y2label', + this.attr_('y2label')); + this.container.appendChild(div); + this.chartLabels.y2label = div; + } }; @@ -768,13 +596,14 @@ DygraphCanvasRenderer.prototype._renderAnnotations = function() { self.dygraph_.attr_(classEventName)(a, p, self.dygraph_,e ); } }; - } + }; // 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]; - if (p.canvasx < this.area.x || p.canvasx > this.area.x + this.area.w) { + if (p.canvasx < this.area.x || p.canvasx > this.area.x + this.area.w || + p.canvasy < this.area.y || p.canvasy > this.area.y + this.area.h) { continue; } @@ -821,13 +650,13 @@ DygraphCanvasRenderer.prototype._renderAnnotations = function() { div.style.borderColor = this.colors[p.name]; a.div = div; - Dygraph.addEvent(div, 'click', + this.dygraph_.addEvent(div, 'click', bindEvt('clickHandler', 'annotationClickHandler', p, this)); - Dygraph.addEvent(div, 'mouseover', + this.dygraph_.addEvent(div, 'mouseover', bindEvt('mouseOverHandler', 'annotationMouseOverHandler', p, this)); - Dygraph.addEvent(div, 'mouseout', + this.dygraph_.addEvent(div, 'mouseout', bindEvt('mouseOutHandler', 'annotationMouseOutHandler', p, this)); - Dygraph.addEvent(div, 'dblclick', + this.dygraph_.addEvent(div, 'dblclick', bindEvt('dblClickHandler', 'annotationDblClickHandler', p, this)); this.container.appendChild(div); @@ -848,68 +677,268 @@ DygraphCanvasRenderer.prototype._renderAnnotations = function() { } }; +/** + * 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); + + ctx.save(); + + var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, + DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints"))); + + 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); + + 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)); + }; + }; +}; + +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; + }; + }; +}; + +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; + } + 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() { // TODO(danvk): use this.attr_ for many of these. - var context = this.elementContext; + 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 = []; - for (var name in this.layout.datasets) { - if (this.layout.datasets.hasOwnProperty(name)) { - setNames.push(name); - } - } + var setNames = this.layout.setNames; var setCount = setNames.length; // TODO(danvk): Move this mapping into Dygraph and get it out of here. - this.colors = {} - for (var i = 0; i < setCount; i++) { + this.colors = {}; + for (i = 0; i < setCount; i++) { this.colors[setNames[i]] = this.colorScheme_[i % this.colorScheme_.length]; } // 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 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 axis = this.dygraph_.axisPropertiesForSeries(setName); - 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 = axis.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) { + while (iter.hasNext()) { + point = iter.next(); + if (point.name == setName) { // TODO(klausw): this is always true if (!Dygraph.isOK(point.y)) { prevX = NaN; continue; @@ -917,12 +946,10 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { // 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; @@ -947,54 +974,89 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { } ctx.fill(); } + ctx.restore(); } else if (fillGraph) { - 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]; - var axis = this.dygraph_.axisPropertiesForSeries(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 = axis.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) { + 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(); } @@ -1004,72 +1066,102 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { } ctx.fill(); } + ctx.restore(); } - for (var i = 0; i < setCount; i++) { - var setName = setNames[i]; - var color = this.colors[setName]; - var strokeWidth = this.dygraph_.attr_("strokeWidth", setName); - - // setup graphics context - context.save(); - var point = this.layout.points[0]; - var pointSize = this.dygraph_.attr_("pointSize", setName); - var prevX = null, prevY = null; - var drawPoints = this.dygraph_.attr_("drawPoints", setName); - var points = this.layout.points; - for (var j = 0; j < points.length; j++) { - var point = points[j]; - if (point.name == setName) { - if (!Dygraph.isOK(point.canvasy)) { - if (stepPlot && prevX != null) { - // Draw a horizontal line to the start of the missing data - ctx.beginPath(); - ctx.strokeStyle = color; - ctx.lineWidth = this.attr_('strokeWidth'); - ctx.moveTo(prevX, prevY); - ctx.lineTo(point.canvasx, prevY); - ctx.stroke(); - } - // 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 || - !Dygraph.isOK(points[j+1].canvasy))); - - if (prevX === null) { - prevX = point.canvasx; - prevY = point.canvasy; - } else { - // TODO(danvk): figure out why this conditional is necessary. - if (strokeWidth) { - ctx.beginPath(); - ctx.strokeStyle = color; - ctx.lineWidth = 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; } - context.restore(); + // 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]; + } + + // 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(); };