Commit | Line | Data |
---|---|---|
88e95c46 DV |
1 | /** |
2 | * @license | |
3 | * Copyright 2006 Dan Vanderkam (danvdk@gmail.com) | |
4 | * MIT-licensed (http://opensource.org/licenses/MIT) | |
5 | */ | |
6a1aa64f DV |
6 | |
7 | /** | |
74a5af31 DV |
8 | * @fileoverview Based on PlotKit.CanvasRenderer, but modified to meet the |
9 | * needs of dygraphs. | |
10 | * | |
3df0ccf0 | 11 | * In particular, support for: |
0abfbd7e | 12 | * - grid overlays |
3df0ccf0 DV |
13 | * - error bars |
14 | * - dygraphs attribute system | |
6a1aa64f DV |
15 | */ |
16 | ||
6a1aa64f | 17 | /** |
423f5ed3 DV |
18 | * The DygraphCanvasRenderer class does the actual rendering of the chart onto |
19 | * a canvas. It's based on PlotKit.CanvasRenderer. | |
6a1aa64f | 20 | * @param {Object} element The canvas to attach to |
2cf95fff RK |
21 | * @param {Object} elementContext The 2d context of the canvas (injected so it |
22 | * can be mocked for testing.) | |
285a6bda | 23 | * @param {Layout} layout The DygraphLayout object for this graph. |
74a5af31 | 24 | * @constructor |
6a1aa64f | 25 | */ |
c0f54d4f | 26 | |
758a629f DV |
27 | /*jshint globalstrict: true */ |
28 | /*global Dygraph:false,RGBColor:false */ | |
c0f54d4f DV |
29 | "use strict"; |
30 | ||
79253bd0 | 31 | |
8cfe592f DV |
32 | /** |
33 | * @constructor | |
34 | * | |
35 | * This gets called when there are "new points" to chart. This is generally the | |
36 | * case when the underlying data being charted has changed. It is _not_ called | |
37 | * in the common case that the user has zoomed or is panning the view. | |
38 | * | |
39 | * The chart canvas has already been created by the Dygraph object. The | |
40 | * renderer simply gets a drawing context. | |
41 | * | |
42 | * @param {Dyraph} dygraph The chart to which this renderer belongs. | |
43 | * @param {Canvas} element The <canvas> DOM element on which to draw. | |
44 | * @param {CanvasRenderingContext2D} elementContext The drawing context. | |
45 | * @param {DygraphLayout} layout The chart's DygraphLayout object. | |
46 | * | |
47 | * TODO(danvk): remove the elementContext property. | |
48 | */ | |
c0f54d4f | 49 | var DygraphCanvasRenderer = function(dygraph, element, elementContext, layout) { |
9317362d | 50 | this.dygraph_ = dygraph; |
fbe31dc8 | 51 | |
fbe31dc8 | 52 | this.layout = layout; |
b0c3b730 | 53 | this.element = element; |
2cf95fff | 54 | this.elementContext = elementContext; |
fbe31dc8 DV |
55 | this.container = this.element.parentNode; |
56 | ||
fbe31dc8 DV |
57 | this.height = this.element.height; |
58 | this.width = this.element.width; | |
59 | ||
60 | // --- check whether everything is ok before we return | |
61 | if (!this.isIE && !(DygraphCanvasRenderer.isSupported(this.element))) | |
62 | throw "Canvas is not supported."; | |
63 | ||
64 | // internal state | |
70be5ed1 | 65 | this.area = layout.getPlotArea(); |
423f5ed3 DV |
66 | this.container.style.position = "relative"; |
67 | this.container.style.width = this.width + "px"; | |
68 | ||
69 | // Set up a clipping area for the canvas (and the interaction canvas). | |
70 | // This ensures that we don't overdraw. | |
920208fb PF |
71 | if (this.dygraph_.isUsingExcanvas_) { |
72 | this._createIEClipArea(); | |
73 | } else { | |
971870e5 DV |
74 | // on Android 3 and 4, setting a clipping area on a canvas prevents it from |
75 | // displaying anything. | |
76 | if (!Dygraph.isAndroid()) { | |
77 | var ctx = this.dygraph_.canvas_ctx_; | |
78 | ctx.beginPath(); | |
79 | ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h); | |
80 | ctx.clip(); | |
920208fb | 81 | |
971870e5 DV |
82 | ctx = this.dygraph_.hidden_ctx_; |
83 | ctx.beginPath(); | |
84 | ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h); | |
85 | ctx.clip(); | |
86 | } | |
920208fb | 87 | } |
423f5ed3 DV |
88 | }; |
89 | ||
90 | DygraphCanvasRenderer.prototype.attr_ = function(x) { | |
91 | return this.dygraph_.attr_(x); | |
92 | }; | |
93 | ||
8cfe592f DV |
94 | /** |
95 | * Clears out all chart content and DOM elements. | |
96 | * This is called immediately before render() on every frame, including | |
97 | * during zooms and pans. | |
98 | * @private | |
99 | */ | |
fbe31dc8 | 100 | DygraphCanvasRenderer.prototype.clear = function() { |
758a629f | 101 | var context; |
fbe31dc8 DV |
102 | if (this.isIE) { |
103 | // VML takes a while to start up, so we just poll every this.IEDelay | |
104 | try { | |
105 | if (this.clearDelay) { | |
106 | this.clearDelay.cancel(); | |
107 | this.clearDelay = null; | |
108 | } | |
758a629f | 109 | context = this.elementContext; |
fbe31dc8 DV |
110 | } |
111 | catch (e) { | |
76171648 | 112 | // TODO(danvk): this is broken, since MochiKit.Async is gone. |
758a629f DV |
113 | // this.clearDelay = MochiKit.Async.wait(this.IEDelay); |
114 | // this.clearDelay.addCallback(bind(this.clear, this)); | |
fbe31dc8 DV |
115 | return; |
116 | } | |
117 | } | |
118 | ||
758a629f | 119 | context = this.elementContext; |
fbe31dc8 | 120 | context.clearRect(0, 0, this.width, this.height); |
fbe31dc8 DV |
121 | }; |
122 | ||
8cfe592f DV |
123 | /** |
124 | * Checks whether the browser supports the <canvas> tag. | |
125 | * @private | |
126 | */ | |
fbe31dc8 DV |
127 | DygraphCanvasRenderer.isSupported = function(canvasName) { |
128 | var canvas = null; | |
129 | try { | |
758a629f | 130 | if (typeof(canvasName) == 'undefined' || canvasName === null) { |
b0c3b730 | 131 | canvas = document.createElement("canvas"); |
758a629f | 132 | } else { |
b0c3b730 | 133 | canvas = canvasName; |
758a629f DV |
134 | } |
135 | canvas.getContext("2d"); | |
fbe31dc8 DV |
136 | } |
137 | catch (e) { | |
138 | var ie = navigator.appVersion.match(/MSIE (\d\.\d)/); | |
139 | var opera = (navigator.userAgent.toLowerCase().indexOf("opera") != -1); | |
140 | if ((!ie) || (ie[1] < 6) || (opera)) | |
141 | return false; | |
142 | return true; | |
143 | } | |
144 | return true; | |
6a1aa64f | 145 | }; |
6a1aa64f DV |
146 | |
147 | /** | |
600d841a DV |
148 | * @param { [String] } colors Array of color strings. Should have one entry for |
149 | * each series to be rendered. | |
150 | */ | |
151 | DygraphCanvasRenderer.prototype.setColors = function(colors) { | |
152 | this.colorScheme_ = colors; | |
153 | }; | |
154 | ||
155 | /** | |
8cfe592f DV |
156 | * This method is responsible for drawing everything on the chart, including |
157 | * lines, error bars, fills and axes. | |
158 | * It is called immediately after clear() on every frame, including during pans | |
159 | * and zooms. | |
160 | * @private | |
6a1aa64f | 161 | */ |
285a6bda | 162 | DygraphCanvasRenderer.prototype.render = function() { |
528ce7e5 DV |
163 | // Draw the new X/Y grid. Lines appear crisper when pixels are rounded to |
164 | // half-integers. This prevents them from drawing in two rows/cols. | |
2cf95fff | 165 | var ctx = this.elementContext; |
758a629f DV |
166 | function halfUp(x) { return Math.round(x) + 0.5; } |
167 | function halfDown(y){ return Math.round(y) - 0.5; } | |
e7746234 | 168 | |
423f5ed3 | 169 | if (this.attr_('underlayCallback')) { |
1e41bd2d DV |
170 | // NOTE: we pass the dygraph object to this callback twice to avoid breaking |
171 | // users who expect a deprecated form of this callback. | |
423f5ed3 | 172 | this.attr_('underlayCallback')(ctx, this.area, this.dygraph_, this.dygraph_); |
e7746234 EC |
173 | } |
174 | ||
758a629f | 175 | var x, y, i, ticks; |
423f5ed3 | 176 | if (this.attr_('drawYGrid')) { |
758a629f | 177 | ticks = this.layout.yticks; |
bbba718a | 178 | // TODO(konigsberg): I don't think these calls to save() have a corresponding restore(). |
6a1aa64f | 179 | ctx.save(); |
423f5ed3 | 180 | ctx.strokeStyle = this.attr_('gridLineColor'); |
990d6a35 | 181 | ctx.lineWidth = this.attr_('gridLineWidth'); |
758a629f | 182 | for (i = 0; i < ticks.length; i++) { |
880a574f | 183 | // TODO(danvk): allow secondary axes to draw a grid, too. |
758a629f DV |
184 | if (ticks[i][0] !== 0) continue; |
185 | x = halfUp(this.area.x); | |
186 | y = halfDown(this.area.y + ticks[i][1] * this.area.h); | |
6a1aa64f DV |
187 | ctx.beginPath(); |
188 | ctx.moveTo(x, y); | |
189 | ctx.lineTo(x + this.area.w, y); | |
190 | ctx.closePath(); | |
191 | ctx.stroke(); | |
192 | } | |
6bf4df7f | 193 | ctx.restore(); |
6a1aa64f DV |
194 | } |
195 | ||
423f5ed3 | 196 | if (this.attr_('drawXGrid')) { |
758a629f | 197 | ticks = this.layout.xticks; |
6a1aa64f | 198 | ctx.save(); |
423f5ed3 | 199 | ctx.strokeStyle = this.attr_('gridLineColor'); |
990d6a35 | 200 | ctx.lineWidth = this.attr_('gridLineWidth'); |
758a629f DV |
201 | for (i=0; i<ticks.length; i++) { |
202 | x = halfUp(this.area.x + ticks[i][0] * this.area.w); | |
203 | y = halfDown(this.area.y + this.area.h); | |
6a1aa64f | 204 | ctx.beginPath(); |
880a574f | 205 | ctx.moveTo(x, y); |
6a1aa64f DV |
206 | ctx.lineTo(x, this.area.y); |
207 | ctx.closePath(); | |
208 | ctx.stroke(); | |
209 | } | |
6bf4df7f | 210 | ctx.restore(); |
6a1aa64f | 211 | } |
2ce09b19 DV |
212 | |
213 | // Do the ordinary rendering, as before | |
2ce09b19 | 214 | this._renderLineChart(); |
fbe31dc8 DV |
215 | }; |
216 | ||
920208fb PF |
217 | DygraphCanvasRenderer.prototype._createIEClipArea = function() { |
218 | var className = 'dygraph-clip-div'; | |
219 | var graphDiv = this.dygraph_.graphDiv; | |
220 | ||
221 | // Remove old clip divs. | |
222 | for (var i = graphDiv.childNodes.length-1; i >= 0; i--) { | |
223 | if (graphDiv.childNodes[i].className == className) { | |
224 | graphDiv.removeChild(graphDiv.childNodes[i]); | |
225 | } | |
226 | } | |
227 | ||
228 | // Determine background color to give clip divs. | |
229 | var backgroundColor = document.bgColor; | |
230 | var element = this.dygraph_.graphDiv; | |
231 | while (element != document) { | |
232 | var bgcolor = element.currentStyle.backgroundColor; | |
233 | if (bgcolor && bgcolor != 'transparent') { | |
234 | backgroundColor = bgcolor; | |
235 | break; | |
236 | } | |
237 | element = element.parentNode; | |
238 | } | |
239 | ||
240 | function createClipDiv(area) { | |
758a629f | 241 | if (area.w === 0 || area.h === 0) { |
920208fb PF |
242 | return; |
243 | } | |
244 | var elem = document.createElement('div'); | |
245 | elem.className = className; | |
246 | elem.style.backgroundColor = backgroundColor; | |
247 | elem.style.position = 'absolute'; | |
248 | elem.style.left = area.x + 'px'; | |
249 | elem.style.top = area.y + 'px'; | |
250 | elem.style.width = area.w + 'px'; | |
251 | elem.style.height = area.h + 'px'; | |
252 | graphDiv.appendChild(elem); | |
253 | } | |
254 | ||
255 | var plotArea = this.area; | |
256 | // Left side | |
758a629f DV |
257 | createClipDiv({ |
258 | x:0, y:0, | |
259 | w:plotArea.x, | |
260 | h:this.height | |
261 | }); | |
262 | ||
920208fb | 263 | // Top |
758a629f DV |
264 | createClipDiv({ |
265 | x: plotArea.x, y: 0, | |
266 | w: this.width - plotArea.x, | |
267 | h: plotArea.y | |
268 | }); | |
269 | ||
920208fb | 270 | // Right side |
758a629f DV |
271 | createClipDiv({ |
272 | x: plotArea.x + plotArea.w, y: 0, | |
273 | w: this.width-plotArea.x - plotArea.w, | |
274 | h: this.height | |
275 | }); | |
276 | ||
920208fb | 277 | // Bottom |
758a629f DV |
278 | createClipDiv({ |
279 | x: plotArea.x, | |
280 | y: plotArea.y + plotArea.h, | |
281 | w: this.width - plotArea.x, | |
282 | h: this.height - plotArea.h - plotArea.y | |
283 | }); | |
284 | }; | |
fbe31dc8 | 285 | |
fbe31dc8 | 286 | |
ccb0001c | 287 | /** |
8722284b RK |
288 | * Returns a predicate to be used with an iterator, which will |
289 | * iterate over points appropriately, depending on whether | |
290 | * connectSeparatedPoints is true. When it's false, the predicate will | |
291 | * skip over points with missing yVals. | |
ccb0001c | 292 | */ |
8722284b RK |
293 | DygraphCanvasRenderer._getIteratorPredicate = function(connectSeparatedPoints) { |
294 | return connectSeparatedPoints ? DygraphCanvasRenderer._predicateThatSkipsEmptyPoints : null; | |
295 | } | |
296 | ||
297 | DygraphCanvasRenderer._predicateThatSkipsEmptyPoints = | |
298 | function(array, idx) { return array[idx].yval !== null; } | |
04c104d7 | 299 | |
857a6931 | 300 | DygraphCanvasRenderer.prototype._drawStyledLine = function( |
5469113b KW |
301 | ctx, i, setName, color, strokeWidth, strokePattern, drawPoints, |
302 | drawPointCallback, pointSize) { | |
99a77a04 | 303 | // TODO(konigsberg): Compute attributes outside this method call. |
857a6931 KW |
304 | var stepPlot = this.attr_("stepPlot"); |
305 | var firstIndexInSet = this.layout.setPointsOffsets[i]; | |
306 | var setLength = this.layout.setPointsLengths[i]; | |
857a6931 | 307 | var points = this.layout.points; |
857a6931 KW |
308 | if (!Dygraph.isArrayLike(strokePattern)) { |
309 | strokePattern = null; | |
310 | } | |
a5a50727 | 311 | var drawGapPoints = this.dygraph_.attr_('drawGapEdgePoints', setName); |
857a6931 | 312 | |
b843b52c | 313 | ctx.save(); |
7d1afbb9 | 314 | |
7d1afbb9 | 315 | var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, |
8722284b | 316 | DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints"))); |
7d1afbb9 | 317 | |
31f8e58b RK |
318 | var pointsOnLine; |
319 | var strategy; | |
320 | if (!strokePattern || strokePattern.length <= 1) { | |
321 | strategy = trivialStrategy(ctx, color, strokeWidth); | |
b843b52c | 322 | } else { |
31f8e58b | 323 | strategy = nonTrivialStrategy(this, ctx, color, strokeWidth, strokePattern); |
b843b52c | 324 | } |
31f8e58b RK |
325 | pointsOnLine = this._drawSeries(ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, stepPlot, strategy); |
326 | this._drawPointsOnLine(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize); | |
327 | ||
b843b52c RK |
328 | ctx.restore(); |
329 | }; | |
330 | ||
31f8e58b RK |
331 | var nonTrivialStrategy = function(renderer, ctx, color, strokeWidth, strokePattern) { |
332 | return new function() { | |
333 | this.init = function() { }; | |
334 | this.finish = function() { }; | |
335 | this.startSegment = function() { | |
336 | ctx.beginPath(); | |
337 | ctx.strokeStyle = color; | |
338 | ctx.lineWidth = strokeWidth; | |
339 | }; | |
340 | this.endSegment = function() { | |
341 | ctx.stroke(); // should this include closePath? | |
342 | }; | |
343 | this.drawLine = function(x1, y1, x2, y2) { | |
344 | renderer._dashedLine(ctx, x1, y1, x2, y2, strokePattern); | |
345 | }; | |
346 | this.skipPixel = function(prevX, prevY, curX, curY) { | |
347 | // TODO(konigsberg): optimize with http://jsperf.com/math-round-vs-hack/6 ? | |
348 | return (Math.round(prevX) == Math.round(curX) && | |
349 | Math.round(prevY) == Math.round(curY)); | |
350 | }; | |
351 | }; | |
352 | }; | |
353 | ||
354 | var trivialStrategy = function(ctx, color, strokeWidth) { | |
355 | return new function() { | |
356 | this.init = function() { | |
357 | ctx.beginPath(); | |
358 | ctx.strokeStyle = color; | |
359 | ctx.lineWidth = strokeWidth; | |
360 | }; | |
361 | this.finish = function() { | |
362 | ctx.stroke(); // should this include closePath? | |
363 | }; | |
364 | this.startSegment = function() { }; | |
365 | this.endSegment = function() { }; | |
366 | this.drawLine = function(x1, y1, x2, y2) { | |
367 | ctx.moveTo(x1, y1); | |
368 | ctx.lineTo(x2, y2); | |
369 | }; | |
370 | // don't skip pixels. | |
371 | this.skipPixel = function() { | |
372 | return false; | |
373 | }; | |
374 | }; | |
375 | }; | |
376 | ||
a401ca8a RK |
377 | DygraphCanvasRenderer.prototype._drawPointsOnLine = function(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize) { |
378 | for (var idx = 0; idx < pointsOnLine.length; idx++) { | |
379 | var cb = pointsOnLine[idx]; | |
380 | ctx.save(); | |
381 | drawPointCallback( | |
382 | this.dygraph_, setName, ctx, cb[0], cb[1], color, pointSize); | |
383 | ctx.restore(); | |
384 | } | |
385 | } | |
386 | ||
31f8e58b RK |
387 | DygraphCanvasRenderer.prototype._drawSeries = function( |
388 | ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, | |
389 | stepPlot, strategy) { | |
390 | ||
31f8e58b RK |
391 | var prevCanvasX = null; |
392 | var prevCanvasY = null; | |
393 | var nextCanvasY = null; | |
394 | var isIsolated; // true if this point is isolated (no line segments) | |
395 | var point; // the point being processed in the while loop | |
b843b52c | 396 | var pointsOnLine = []; // Array of [canvasx, canvasy] pairs. |
31f8e58b RK |
397 | var first = true; // the first cycle through the while loop |
398 | ||
399 | strategy.init(); | |
400 | ||
7d1afbb9 RK |
401 | while(iter.hasNext()) { |
402 | point = iter.next(); | |
a02978e2 | 403 | if (point.canvasy === null || point.canvasy != point.canvasy) { |
31f8e58b | 404 | if (stepPlot && prevCanvasX !== null) { |
857a6931 | 405 | // Draw a horizontal line to the start of the missing data |
31f8e58b RK |
406 | strategy.startSegment(); |
407 | strategy.drawLine(prevX, prevY, point.canvasx, prevY); | |
408 | strategy.endSegment(); | |
857a6931 | 409 | } |
31f8e58b | 410 | prevCanvasX = prevCanvasY = null; |
857a6931 | 411 | } else { |
31f8e58b | 412 | nextCanvasY = iter.hasNext() ? iter.peek().canvasy : null; |
a02978e2 RK |
413 | // TODO: we calculate isNullOrNaN for this point, and the next, and then, when |
414 | // we iterate, test for isNullOrNaN again. Why bother? | |
415 | var isNextCanvasYNullOrNaN = nextCanvasY === null || nextCanvasY != nextCanvasY; | |
416 | isIsolated = (!prevCanvasX && isNextCanvasYNullOrNaN); | |
19b84fe7 | 417 | if (drawGapPoints) { |
31f8e58b | 418 | // Also consider a point to be "isolated" if it's adjacent to a |
19b84fe7 | 419 | // null point, excluding the graph edges. |
31f8e58b | 420 | if ((!first && !prevCanvasX) || |
a02978e2 | 421 | (iter.hasNext() && isNextCanvasYNullOrNaN)) { |
19b84fe7 KW |
422 | isIsolated = true; |
423 | } | |
424 | } | |
31f8e58b RK |
425 | if (prevCanvasX !== null) { |
426 | if (strategy.skipPixel(prevCanvasX, prevCanvasY, point.canvasx, point.canvasy)) { | |
857a6931 KW |
427 | continue; |
428 | } | |
857a6931 | 429 | if (strokeWidth) { |
31f8e58b | 430 | strategy.startSegment(); |
857a6931 | 431 | if (stepPlot) { |
31f8e58b RK |
432 | strategy.drawLine(prevCanvasX, prevCanvasY, point.canvasx, prevCanvasY); |
433 | prevCanvasX = point.canvasx; | |
857a6931 | 434 | } |
31f8e58b RK |
435 | strategy.drawLine(prevCanvasX, prevCanvasY, point.canvasx, point.canvasy); |
436 | strategy.endSegment(); | |
b843b52c RK |
437 | } |
438 | } | |
b843b52c RK |
439 | if (drawPoints || isIsolated) { |
440 | pointsOnLine.push([point.canvasx, point.canvasy]); | |
441 | } | |
31f8e58b RK |
442 | prevCanvasX = point.canvasx; |
443 | prevCanvasY = point.canvasy; | |
b843b52c | 444 | } |
7d1afbb9 | 445 | first = false; |
b843b52c | 446 | } |
31f8e58b RK |
447 | strategy.finish(); |
448 | return pointsOnLine; | |
857a6931 KW |
449 | }; |
450 | ||
451 | DygraphCanvasRenderer.prototype._drawLine = function(ctx, i) { | |
452 | var setNames = this.layout.setNames; | |
453 | var setName = setNames[i]; | |
454 | ||
455 | var strokeWidth = this.dygraph_.attr_("strokeWidth", setName); | |
456 | var borderWidth = this.dygraph_.attr_("strokeBorderWidth", setName); | |
5469113b KW |
457 | var drawPointCallback = this.dygraph_.attr_("drawPointCallback", setName) || |
458 | Dygraph.Circles.DEFAULT; | |
99a77a04 | 459 | |
857a6931 | 460 | if (borderWidth && strokeWidth) { |
5469113b | 461 | this._drawStyledLine(ctx, i, setName, |
857a6931 KW |
462 | this.dygraph_.attr_("strokeBorderColor", setName), |
463 | strokeWidth + 2 * borderWidth, | |
464 | this.dygraph_.attr_("strokePattern", setName), | |
465 | this.dygraph_.attr_("drawPoints", setName), | |
5469113b | 466 | drawPointCallback, |
857a6931 KW |
467 | this.dygraph_.attr_("pointSize", setName)); |
468 | } | |
469 | ||
5469113b | 470 | this._drawStyledLine(ctx, i, setName, |
857a6931 KW |
471 | this.colors[setName], |
472 | strokeWidth, | |
473 | this.dygraph_.attr_("strokePattern", setName), | |
474 | this.dygraph_.attr_("drawPoints", setName), | |
5469113b | 475 | drawPointCallback, |
857a6931 KW |
476 | this.dygraph_.attr_("pointSize", setName)); |
477 | }; | |
ce49c2fa | 478 | |
6a1aa64f | 479 | /** |
758a629f DV |
480 | * Actually draw the lines chart, including error bars. |
481 | * TODO(danvk): split this into several smaller functions. | |
482 | * @private | |
6a1aa64f | 483 | */ |
285a6bda | 484 | DygraphCanvasRenderer.prototype._renderLineChart = function() { |
44c6bc29 | 485 | // TODO(danvk): use this.attr_ for many of these. |
857a6931 | 486 | var ctx = this.elementContext; |
423f5ed3 | 487 | var fillAlpha = this.attr_('fillAlpha'); |
e4182459 | 488 | var errorBars = this.attr_("errorBars") || this.attr_("customBars"); |
44c6bc29 | 489 | var fillGraph = this.attr_("fillGraph"); |
b2c9222a DV |
490 | var stackedGraph = this.attr_("stackedGraph"); |
491 | var stepPlot = this.attr_("stepPlot"); | |
c3e1495b AR |
492 | var points = this.layout.points; |
493 | var pointsLength = points.length; | |
8722284b | 494 | var point, i, prevX, prevY, prevYs, color, setName, newYs, err_color, rgb, yscale, axis; |
21d3323f | 495 | |
82c6fe4d | 496 | var setNames = this.layout.setNames; |
21d3323f | 497 | var setCount = setNames.length; |
6a1aa64f | 498 | |
ee53deb9 | 499 | this.colors = this.dygraph_.colorsMap_; |
f032c51d | 500 | |
ff00d3e2 DV |
501 | // Update Points |
502 | // TODO(danvk): here | |
b843b52c RK |
503 | // |
504 | // TODO(bhs): this loop is a hot-spot for high-point-count charts. These | |
505 | // transformations can be pushed into the canvas via linear transformation | |
506 | // matrices. | |
758a629f DV |
507 | for (i = pointsLength; i--;) { |
508 | point = points[i]; | |
6a1aa64f DV |
509 | point.canvasx = this.area.w * point.x + this.area.x; |
510 | point.canvasy = this.area.h * point.y + this.area.y; | |
511 | } | |
6a1aa64f DV |
512 | |
513 | // create paths | |
80aaae18 | 514 | if (errorBars) { |
857a6931 | 515 | ctx.save(); |
6a834bbb DV |
516 | if (fillGraph) { |
517 | this.dygraph_.warn("Can't use fillGraph option with error bars"); | |
518 | } | |
519 | ||
758a629f DV |
520 | for (i = 0; i < setCount; i++) { |
521 | setName = setNames[i]; | |
522 | axis = this.dygraph_.axisPropertiesForSeries(setName); | |
523 | color = this.colors[setName]; | |
6a1aa64f | 524 | |
04c104d7 KW |
525 | var firstIndexInSet = this.layout.setPointsOffsets[i]; |
526 | var setLength = this.layout.setPointsLengths[i]; | |
04c104d7 | 527 | |
8722284b RK |
528 | var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, |
529 | DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints"))); | |
04c104d7 | 530 | |
6a1aa64f | 531 | // setup graphics context |
758a629f DV |
532 | prevX = NaN; |
533 | prevY = NaN; | |
534 | prevYs = [-1, -1]; | |
535 | yscale = axis.yscale; | |
f474c2a3 | 536 | // should be same color as the lines but only 15% opaque. |
758a629f DV |
537 | rgb = new RGBColor(color); |
538 | err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + | |
43af96e7 | 539 | fillAlpha + ')'; |
f474c2a3 | 540 | ctx.fillStyle = err_color; |
05c9d0c4 | 541 | ctx.beginPath(); |
8722284b RK |
542 | while (iter.hasNext()) { |
543 | point = iter.next(); | |
04c104d7 | 544 | if (point.name == setName) { // TODO(klausw): this is always true |
e9fe4a2f | 545 | if (!Dygraph.isOK(point.y)) { |
56623f3b | 546 | prevX = NaN; |
ae85914a | 547 | continue; |
5011e7a1 | 548 | } |
ce49c2fa | 549 | |
3637724f | 550 | // TODO(danvk): here |
afdc483f | 551 | if (stepPlot) { |
758a629f | 552 | newYs = [ point.y_bottom, point.y_top ]; |
afdc483f NN |
553 | prevY = point.y; |
554 | } else { | |
758a629f | 555 | newYs = [ point.y_bottom, point.y_top ]; |
afdc483f | 556 | } |
6a1aa64f DV |
557 | newYs[0] = this.area.h * newYs[0] + this.area.y; |
558 | newYs[1] = this.area.h * newYs[1] + this.area.y; | |
56623f3b | 559 | if (!isNaN(prevX)) { |
afdc483f | 560 | if (stepPlot) { |
47600757 | 561 | ctx.moveTo(prevX, newYs[0]); |
afdc483f | 562 | } else { |
47600757 | 563 | ctx.moveTo(prevX, prevYs[0]); |
afdc483f | 564 | } |
5954ef32 DV |
565 | ctx.lineTo(point.canvasx, newYs[0]); |
566 | ctx.lineTo(point.canvasx, newYs[1]); | |
afdc483f | 567 | if (stepPlot) { |
47600757 | 568 | ctx.lineTo(prevX, newYs[1]); |
afdc483f | 569 | } else { |
47600757 | 570 | ctx.lineTo(prevX, prevYs[1]); |
afdc483f | 571 | } |
5954ef32 DV |
572 | ctx.closePath(); |
573 | } | |
354e15ab | 574 | prevYs = newYs; |
5954ef32 DV |
575 | prevX = point.canvasx; |
576 | } | |
577 | } | |
578 | ctx.fill(); | |
579 | } | |
857a6931 | 580 | ctx.restore(); |
5954ef32 | 581 | } else if (fillGraph) { |
857a6931 | 582 | ctx.save(); |
349dd9ba DW |
583 | var baseline = {}; // for stacked graphs: baseline for filling |
584 | var currBaseline; | |
354e15ab DE |
585 | |
586 | // process sets in reverse order (needed for stacked graphs) | |
758a629f DV |
587 | for (i = setCount - 1; i >= 0; i--) { |
588 | setName = setNames[i]; | |
589 | color = this.colors[setName]; | |
590 | axis = this.dygraph_.axisPropertiesForSeries(setName); | |
ea4942ed DV |
591 | var axisY = 1.0 + axis.minyval * axis.yscale; |
592 | if (axisY < 0.0) axisY = 0.0; | |
593 | else if (axisY > 1.0) axisY = 1.0; | |
594 | axisY = this.area.h * axisY + this.area.y; | |
04c104d7 KW |
595 | var firstIndexInSet = this.layout.setPointsOffsets[i]; |
596 | var setLength = this.layout.setPointsLengths[i]; | |
04c104d7 | 597 | |
8722284b RK |
598 | var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, |
599 | DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints"))); | |
5954ef32 DV |
600 | |
601 | // setup graphics context | |
758a629f DV |
602 | prevX = NaN; |
603 | prevYs = [-1, -1]; | |
604 | yscale = axis.yscale; | |
5954ef32 | 605 | // should be same color as the lines but only 15% opaque. |
758a629f DV |
606 | rgb = new RGBColor(color); |
607 | err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + | |
43af96e7 | 608 | fillAlpha + ')'; |
5954ef32 DV |
609 | ctx.fillStyle = err_color; |
610 | ctx.beginPath(); | |
8722284b RK |
611 | while(iter.hasNext()) { |
612 | point = iter.next(); | |
04c104d7 | 613 | if (point.name == setName) { // TODO(klausw): this is always true |
e9fe4a2f | 614 | if (!Dygraph.isOK(point.y)) { |
56623f3b | 615 | prevX = NaN; |
5954ef32 DV |
616 | continue; |
617 | } | |
354e15ab | 618 | if (stackedGraph) { |
349dd9ba DW |
619 | currBaseline = baseline[point.canvasx]; |
620 | var lastY; | |
621 | if (currBaseline === undefined) { | |
622 | lastY = axisY; | |
623 | } else { | |
624 | if(stepPlot) { | |
625 | lastY = currBaseline[0]; | |
626 | } else { | |
627 | lastY = currBaseline; | |
628 | } | |
629 | } | |
354e15ab | 630 | newYs = [ point.canvasy, lastY ]; |
b843b52c | 631 | |
349dd9ba DW |
632 | if(stepPlot) { |
633 | // Step plots must keep track of the top and bottom of | |
634 | // the baseline at each point. | |
635 | if(prevYs[0] === -1) { | |
636 | baseline[point.canvasx] = [ point.canvasy, axisY ]; | |
637 | } else { | |
638 | baseline[point.canvasx] = [ point.canvasy, prevYs[0] ]; | |
639 | } | |
640 | } else { | |
641 | baseline[point.canvasx] = point.canvasy; | |
642 | } | |
b843b52c | 643 | |
354e15ab DE |
644 | } else { |
645 | newYs = [ point.canvasy, axisY ]; | |
646 | } | |
56623f3b | 647 | if (!isNaN(prevX)) { |
05c9d0c4 | 648 | ctx.moveTo(prevX, prevYs[0]); |
b843b52c | 649 | |
afdc483f | 650 | if (stepPlot) { |
47600757 | 651 | ctx.lineTo(point.canvasx, prevYs[0]); |
349dd9ba DW |
652 | if(currBaseline) { |
653 | // Draw to the bottom of the baseline | |
654 | ctx.lineTo(point.canvasx, currBaseline[1]); | |
655 | } else { | |
656 | ctx.lineTo(point.canvasx, newYs[1]); | |
657 | } | |
afdc483f | 658 | } else { |
47600757 | 659 | ctx.lineTo(point.canvasx, newYs[0]); |
349dd9ba | 660 | ctx.lineTo(point.canvasx, newYs[1]); |
afdc483f | 661 | } |
b843b52c | 662 | |
05c9d0c4 DV |
663 | ctx.lineTo(prevX, prevYs[1]); |
664 | ctx.closePath(); | |
6a1aa64f | 665 | } |
354e15ab | 666 | prevYs = newYs; |
6a1aa64f DV |
667 | prevX = point.canvasx; |
668 | } | |
05c9d0c4 | 669 | } |
6a1aa64f DV |
670 | ctx.fill(); |
671 | } | |
857a6931 | 672 | ctx.restore(); |
80aaae18 DV |
673 | } |
674 | ||
f9414b11 | 675 | // Drawing the lines. |
758a629f | 676 | for (i = 0; i < setCount; i += 1) { |
857a6931 | 677 | this._drawLine(ctx, i); |
80aaae18 | 678 | } |
6a1aa64f | 679 | }; |
79253bd0 | 680 | |
681 | /** | |
682 | * This does dashed lines onto a canvas for a given pattern. You must call | |
683 | * ctx.stroke() after to actually draw it, much line ctx.lineTo(). It remembers | |
684 | * the state of the line in regards to where we left off on drawing the pattern. | |
685 | * You can draw a dashed line in several function calls and the pattern will be | |
686 | * continous as long as you didn't call this function with a different pattern | |
687 | * in between. | |
688 | * @param ctx The canvas 2d context to draw on. | |
689 | * @param x The start of the line's x coordinate. | |
690 | * @param y The start of the line's y coordinate. | |
691 | * @param x2 The end of the line's x coordinate. | |
692 | * @param y2 The end of the line's y coordinate. | |
693 | * @param pattern The dash pattern to draw, an array of integers where even | |
694 | * index is drawn and odd index is not drawn (Ex. [10, 2, 5, 2], 10 is drawn 5 | |
695 | * is drawn, 2 is the space between.). A null pattern, array of length one, or | |
696 | * empty array will do just a solid line. | |
697 | * @private | |
698 | */ | |
699 | DygraphCanvasRenderer.prototype._dashedLine = function(ctx, x, y, x2, y2, pattern) { | |
700 | // Original version http://stackoverflow.com/questions/4576724/dotted-stroke-in-canvas | |
701 | // Modified by Russell Valentine to keep line history and continue the pattern | |
702 | // where it left off. | |
703 | var dx, dy, len, rot, patternIndex, segment; | |
704 | ||
705 | // If we don't have a pattern or it is an empty array or of size one just | |
706 | // do a solid line. | |
707 | if (!pattern || pattern.length <= 1) { | |
708 | ctx.moveTo(x, y); | |
709 | ctx.lineTo(x2, y2); | |
710 | return; | |
711 | } | |
712 | ||
713 | // If we have a different dash pattern than the last time this was called we | |
714 | // reset our dash history and start the pattern from the begging | |
715 | // regardless of state of the last pattern. | |
716 | if (!Dygraph.compareArrays(pattern, this._dashedLineToHistoryPattern)) { | |
717 | this._dashedLineToHistoryPattern = pattern; | |
718 | this._dashedLineToHistory = [0, 0]; | |
719 | } | |
720 | ctx.save(); | |
721 | ||
722 | // Calculate transformation parameters | |
723 | dx = (x2-x); | |
724 | dy = (y2-y); | |
725 | len = Math.sqrt(dx*dx + dy*dy); | |
726 | rot = Math.atan2(dy, dx); | |
727 | ||
728 | // Set transformation | |
729 | ctx.translate(x, y); | |
730 | ctx.moveTo(0, 0); | |
731 | ctx.rotate(rot); | |
732 | ||
733 | // Set last pattern index we used for this pattern. | |
734 | patternIndex = this._dashedLineToHistory[0]; | |
735 | x = 0; | |
736 | while (len > x) { | |
737 | // Get the length of the pattern segment we are dealing with. | |
738 | segment = pattern[patternIndex]; | |
739 | // If our last draw didn't complete the pattern segment all the way we | |
740 | // will try to finish it. Otherwise we will try to do the whole segment. | |
741 | if (this._dashedLineToHistory[1]) { | |
742 | x += this._dashedLineToHistory[1]; | |
743 | } else { | |
744 | x += segment; | |
745 | } | |
746 | if (x > len) { | |
747 | // We were unable to complete this pattern index all the way, keep | |
748 | // where we are the history so our next draw continues where we left off | |
749 | // in the pattern. | |
750 | this._dashedLineToHistory = [patternIndex, x-len]; | |
751 | x = len; | |
752 | } else { | |
753 | // We completed this patternIndex, we put in the history that we are on | |
754 | // the beginning of the next segment. | |
755 | this._dashedLineToHistory = [(patternIndex+1)%pattern.length, 0]; | |
756 | } | |
757 | ||
758 | // We do a line on a even pattern index and just move on a odd pattern index. | |
759 | // The move is the empty space in the dash. | |
760 | if(patternIndex % 2 === 0) { | |
761 | ctx.lineTo(x, 0); | |
762 | } else { | |
763 | ctx.moveTo(x, 0); | |
764 | } | |
765 | // If we are not done, next loop process the next pattern segment, or the | |
766 | // first segment again if we are at the end of the pattern. | |
767 | patternIndex = (patternIndex+1) % pattern.length; | |
768 | } | |
769 | ctx.restore(); | |
770 | }; |