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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 | /** | |
8cfe592f DV |
148 | * This method is responsible for drawing everything on the chart, including |
149 | * lines, error bars, fills and axes. | |
150 | * It is called immediately after clear() on every frame, including during pans | |
151 | * and zooms. | |
152 | * @private | |
6a1aa64f | 153 | */ |
285a6bda | 154 | DygraphCanvasRenderer.prototype.render = function() { |
2ce09b19 | 155 | this._renderLineChart(); |
fbe31dc8 DV |
156 | }; |
157 | ||
920208fb PF |
158 | DygraphCanvasRenderer.prototype._createIEClipArea = function() { |
159 | var className = 'dygraph-clip-div'; | |
160 | var graphDiv = this.dygraph_.graphDiv; | |
161 | ||
162 | // Remove old clip divs. | |
163 | for (var i = graphDiv.childNodes.length-1; i >= 0; i--) { | |
164 | if (graphDiv.childNodes[i].className == className) { | |
165 | graphDiv.removeChild(graphDiv.childNodes[i]); | |
166 | } | |
167 | } | |
168 | ||
169 | // Determine background color to give clip divs. | |
170 | var backgroundColor = document.bgColor; | |
171 | var element = this.dygraph_.graphDiv; | |
172 | while (element != document) { | |
173 | var bgcolor = element.currentStyle.backgroundColor; | |
174 | if (bgcolor && bgcolor != 'transparent') { | |
175 | backgroundColor = bgcolor; | |
176 | break; | |
177 | } | |
178 | element = element.parentNode; | |
179 | } | |
180 | ||
181 | function createClipDiv(area) { | |
758a629f | 182 | if (area.w === 0 || area.h === 0) { |
920208fb PF |
183 | return; |
184 | } | |
185 | var elem = document.createElement('div'); | |
186 | elem.className = className; | |
187 | elem.style.backgroundColor = backgroundColor; | |
188 | elem.style.position = 'absolute'; | |
189 | elem.style.left = area.x + 'px'; | |
190 | elem.style.top = area.y + 'px'; | |
191 | elem.style.width = area.w + 'px'; | |
192 | elem.style.height = area.h + 'px'; | |
193 | graphDiv.appendChild(elem); | |
194 | } | |
195 | ||
196 | var plotArea = this.area; | |
197 | // Left side | |
758a629f DV |
198 | createClipDiv({ |
199 | x:0, y:0, | |
200 | w:plotArea.x, | |
201 | h:this.height | |
202 | }); | |
203 | ||
920208fb | 204 | // Top |
758a629f DV |
205 | createClipDiv({ |
206 | x: plotArea.x, y: 0, | |
207 | w: this.width - plotArea.x, | |
208 | h: plotArea.y | |
209 | }); | |
210 | ||
920208fb | 211 | // Right side |
758a629f DV |
212 | createClipDiv({ |
213 | x: plotArea.x + plotArea.w, y: 0, | |
214 | w: this.width-plotArea.x - plotArea.w, | |
215 | h: this.height | |
216 | }); | |
217 | ||
920208fb | 218 | // Bottom |
758a629f DV |
219 | createClipDiv({ |
220 | x: plotArea.x, | |
221 | y: plotArea.y + plotArea.h, | |
222 | w: this.width - plotArea.x, | |
223 | h: this.height - plotArea.h - plotArea.y | |
224 | }); | |
225 | }; | |
fbe31dc8 | 226 | |
fbe31dc8 | 227 | |
ccb0001c | 228 | /** |
8722284b RK |
229 | * Returns a predicate to be used with an iterator, which will |
230 | * iterate over points appropriately, depending on whether | |
231 | * connectSeparatedPoints is true. When it's false, the predicate will | |
232 | * skip over points with missing yVals. | |
ccb0001c | 233 | */ |
8722284b | 234 | DygraphCanvasRenderer._getIteratorPredicate = function(connectSeparatedPoints) { |
9f6db80e DV |
235 | return connectSeparatedPoints |
236 | ? DygraphCanvasRenderer._predicateThatSkipsEmptyPoints | |
237 | : null; | |
0f20de1c | 238 | }; |
8722284b RK |
239 | |
240 | DygraphCanvasRenderer._predicateThatSkipsEmptyPoints = | |
0f20de1c DV |
241 | function(array, idx) { |
242 | return array[idx].yval !== null; | |
243 | }; | |
04c104d7 | 244 | |
9f6db80e DV |
245 | /** |
246 | * | |
247 | * @private | |
248 | */ | |
857a6931 | 249 | DygraphCanvasRenderer.prototype._drawStyledLine = function( |
5469113b KW |
250 | ctx, i, setName, color, strokeWidth, strokePattern, drawPoints, |
251 | drawPointCallback, pointSize) { | |
99a77a04 | 252 | // TODO(konigsberg): Compute attributes outside this method call. |
857a6931 KW |
253 | var stepPlot = this.attr_("stepPlot"); |
254 | var firstIndexInSet = this.layout.setPointsOffsets[i]; | |
255 | var setLength = this.layout.setPointsLengths[i]; | |
857a6931 | 256 | var points = this.layout.points; |
857a6931 KW |
257 | if (!Dygraph.isArrayLike(strokePattern)) { |
258 | strokePattern = null; | |
259 | } | |
a5a50727 | 260 | var drawGapPoints = this.dygraph_.attr_('drawGapEdgePoints', setName); |
857a6931 | 261 | |
7d1afbb9 | 262 | var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, |
9f6db80e DV |
263 | DygraphCanvasRenderer._getIteratorPredicate( |
264 | this.attr_("connectSeparatedPoints"))); | |
7d1afbb9 | 265 | |
fb63bf1b DV |
266 | var stroking = strokePattern && (strokePattern.length >= 2); |
267 | ||
0140347d | 268 | ctx.save(); |
fb63bf1b DV |
269 | if (stroking) { |
270 | ctx.installPattern(strokePattern); | |
b843b52c | 271 | } |
fb63bf1b | 272 | |
0140347d | 273 | var pointsOnLine = this._drawSeries(ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, stepPlot, color); |
31f8e58b RK |
274 | this._drawPointsOnLine(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize); |
275 | ||
fb63bf1b DV |
276 | if (stroking) { |
277 | ctx.uninstallPattern(); | |
278 | } | |
b843b52c | 279 | |
fb63bf1b | 280 | ctx.restore(); |
31f8e58b RK |
281 | }; |
282 | ||
a401ca8a RK |
283 | DygraphCanvasRenderer.prototype._drawPointsOnLine = function(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize) { |
284 | for (var idx = 0; idx < pointsOnLine.length; idx++) { | |
285 | var cb = pointsOnLine[idx]; | |
286 | ctx.save(); | |
287 | drawPointCallback( | |
288 | this.dygraph_, setName, ctx, cb[0], cb[1], color, pointSize); | |
289 | ctx.restore(); | |
290 | } | |
291 | } | |
292 | ||
31f8e58b RK |
293 | DygraphCanvasRenderer.prototype._drawSeries = function( |
294 | ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, | |
0140347d | 295 | stepPlot, color) { |
31f8e58b | 296 | |
31f8e58b RK |
297 | var prevCanvasX = null; |
298 | var prevCanvasY = null; | |
299 | var nextCanvasY = null; | |
300 | var isIsolated; // true if this point is isolated (no line segments) | |
301 | var point; // the point being processed in the while loop | |
b843b52c | 302 | var pointsOnLine = []; // Array of [canvasx, canvasy] pairs. |
31f8e58b RK |
303 | var first = true; // the first cycle through the while loop |
304 | ||
0140347d DV |
305 | ctx.beginPath(); |
306 | ctx.strokeStyle = color; | |
307 | ctx.lineWidth = strokeWidth; | |
31f8e58b | 308 | |
c560c848 DV |
309 | var arr = iter.array_; |
310 | var limit = iter.end_; | |
311 | var predicate = iter.predicate_; | |
312 | ||
313 | for (var i = iter.start_; i < limit; i++) { | |
314 | point = arr[i]; | |
315 | if (predicate) { | |
316 | while (i < limit && !predicate(arr, i)) { | |
0f20de1c DV |
317 | i++; |
318 | } | |
c560c848 DV |
319 | if (i == limit) break; |
320 | point = arr[i]; | |
0f20de1c DV |
321 | } |
322 | ||
a02978e2 | 323 | if (point.canvasy === null || point.canvasy != point.canvasy) { |
31f8e58b | 324 | if (stepPlot && prevCanvasX !== null) { |
857a6931 | 325 | // Draw a horizontal line to the start of the missing data |
0140347d DV |
326 | ctx.moveTo(prevX, prevY); |
327 | ctx.lineTo(point.canvasx, prevY); | |
857a6931 | 328 | } |
31f8e58b | 329 | prevCanvasX = prevCanvasY = null; |
857a6931 | 330 | } else { |
0f20de1c DV |
331 | isIsolated = false; |
332 | if (drawGapPoints || !prevCanvasX) { | |
0f20de1c DV |
333 | iter.nextIdx_ = i; |
334 | var peek = iter.next(); | |
82f9b10f | 335 | nextCanvasY = iter.hasNext ? iter.peek.canvasy : null; |
0f20de1c | 336 | |
0f20de1c DV |
337 | var isNextCanvasYNullOrNaN = nextCanvasY === null || |
338 | nextCanvasY != nextCanvasY; | |
339 | isIsolated = (!prevCanvasX && isNextCanvasYNullOrNaN); | |
340 | if (drawGapPoints) { | |
341 | // Also consider a point to be "isolated" if it's adjacent to a | |
342 | // null point, excluding the graph edges. | |
343 | if ((!first && !prevCanvasX) || | |
344 | (iter.hasNext && isNextCanvasYNullOrNaN)) { | |
345 | isIsolated = true; | |
346 | } | |
19b84fe7 KW |
347 | } |
348 | } | |
0f20de1c | 349 | |
31f8e58b | 350 | if (prevCanvasX !== null) { |
857a6931 | 351 | if (strokeWidth) { |
857a6931 | 352 | if (stepPlot) { |
0140347d DV |
353 | ctx.moveTo(prevCanvasX, prevCanvasY); |
354 | ctx.lineTo(point.canvasx, prevCanvasY); | |
31f8e58b | 355 | prevCanvasX = point.canvasx; |
857a6931 | 356 | } |
0140347d DV |
357 | ctx.moveTo(prevCanvasX, prevCanvasY); |
358 | ctx.lineTo(point.canvasx, point.canvasy); | |
b843b52c RK |
359 | } |
360 | } | |
b843b52c RK |
361 | if (drawPoints || isIsolated) { |
362 | pointsOnLine.push([point.canvasx, point.canvasy]); | |
363 | } | |
31f8e58b RK |
364 | prevCanvasX = point.canvasx; |
365 | prevCanvasY = point.canvasy; | |
b843b52c | 366 | } |
7d1afbb9 | 367 | first = false; |
b843b52c | 368 | } |
0140347d | 369 | ctx.stroke(); |
31f8e58b | 370 | return pointsOnLine; |
857a6931 KW |
371 | }; |
372 | ||
373 | DygraphCanvasRenderer.prototype._drawLine = function(ctx, i) { | |
374 | var setNames = this.layout.setNames; | |
375 | var setName = setNames[i]; | |
376 | ||
377 | var strokeWidth = this.dygraph_.attr_("strokeWidth", setName); | |
378 | var borderWidth = this.dygraph_.attr_("strokeBorderWidth", setName); | |
5469113b KW |
379 | var drawPointCallback = this.dygraph_.attr_("drawPointCallback", setName) || |
380 | Dygraph.Circles.DEFAULT; | |
99a77a04 | 381 | |
857a6931 | 382 | if (borderWidth && strokeWidth) { |
5469113b | 383 | this._drawStyledLine(ctx, i, setName, |
857a6931 KW |
384 | this.dygraph_.attr_("strokeBorderColor", setName), |
385 | strokeWidth + 2 * borderWidth, | |
386 | this.dygraph_.attr_("strokePattern", setName), | |
387 | this.dygraph_.attr_("drawPoints", setName), | |
5469113b | 388 | drawPointCallback, |
857a6931 KW |
389 | this.dygraph_.attr_("pointSize", setName)); |
390 | } | |
391 | ||
5469113b | 392 | this._drawStyledLine(ctx, i, setName, |
857a6931 KW |
393 | this.colors[setName], |
394 | strokeWidth, | |
395 | this.dygraph_.attr_("strokePattern", setName), | |
396 | this.dygraph_.attr_("drawPoints", setName), | |
5469113b | 397 | drawPointCallback, |
857a6931 KW |
398 | this.dygraph_.attr_("pointSize", setName)); |
399 | }; | |
ce49c2fa | 400 | |
6a1aa64f | 401 | /** |
758a629f | 402 | * Actually draw the lines chart, including error bars. |
758a629f | 403 | * @private |
6a1aa64f | 404 | */ |
285a6bda | 405 | DygraphCanvasRenderer.prototype._renderLineChart = function() { |
857a6931 | 406 | var ctx = this.elementContext; |
e4182459 | 407 | var errorBars = this.attr_("errorBars") || this.attr_("customBars"); |
44c6bc29 | 408 | var fillGraph = this.attr_("fillGraph"); |
01a14b85 | 409 | var i; |
21d3323f | 410 | |
82c6fe4d | 411 | var setNames = this.layout.setNames; |
21d3323f | 412 | var setCount = setNames.length; |
6a1aa64f | 413 | |
ee53deb9 | 414 | this.colors = this.dygraph_.colorsMap_; |
f032c51d | 415 | |
ff00d3e2 DV |
416 | // Update Points |
417 | // TODO(danvk): here | |
b843b52c RK |
418 | // |
419 | // TODO(bhs): this loop is a hot-spot for high-point-count charts. These | |
420 | // transformations can be pushed into the canvas via linear transformation | |
421 | // matrices. | |
01a14b85 DV |
422 | var points = this.layout.points; |
423 | for (i = points.length; i--;) { | |
424 | var point = points[i]; | |
6a1aa64f DV |
425 | point.canvasx = this.area.w * point.x + this.area.x; |
426 | point.canvasy = this.area.h * point.y + this.area.y; | |
427 | } | |
6a1aa64f | 428 | |
01a14b85 DV |
429 | // Draw any "fills", i.e. error bars or the filled area under a series. |
430 | // These must all be drawn before any lines, so that the main lines of a | |
431 | // series are drawn on top. | |
80aaae18 | 432 | if (errorBars) { |
6a834bbb DV |
433 | if (fillGraph) { |
434 | this.dygraph_.warn("Can't use fillGraph option with error bars"); | |
435 | } | |
436 | ||
01a14b85 | 437 | ctx.save(); |
6a6439da | 438 | this.drawErrorBars_(points); |
857a6931 | 439 | ctx.restore(); |
5954ef32 | 440 | } else if (fillGraph) { |
857a6931 | 441 | ctx.save(); |
01a14b85 | 442 | this.drawFillBars_(points); |
857a6931 | 443 | ctx.restore(); |
80aaae18 DV |
444 | } |
445 | ||
f9414b11 | 446 | // Drawing the lines. |
758a629f | 447 | for (i = 0; i < setCount; i += 1) { |
857a6931 | 448 | this._drawLine(ctx, i); |
80aaae18 | 449 | } |
6a1aa64f | 450 | }; |
79253bd0 | 451 | |
01a14b85 DV |
452 | /** |
453 | * Draws the shaded error bars/confidence intervals for each series. | |
454 | * This happens before the center lines are drawn, since the center lines | |
455 | * need to be drawn on top of the error bars for all series. | |
456 | * | |
457 | * @private | |
458 | */ | |
6a6439da DV |
459 | DygraphCanvasRenderer.prototype.drawErrorBars_ = function(points) { |
460 | var ctx = this.elementContext; | |
461 | var setNames = this.layout.setNames; | |
462 | var setCount = setNames.length; | |
463 | var fillAlpha = this.attr_('fillAlpha'); | |
01a14b85 | 464 | var stepPlot = this.attr_('stepPlot'); |
6a6439da DV |
465 | |
466 | var newYs; | |
467 | ||
468 | for (var i = 0; i < setCount; i++) { | |
469 | var setName = setNames[i]; | |
470 | var axis = this.dygraph_.axisPropertiesForSeries(setName); | |
471 | var color = this.colors[setName]; | |
472 | ||
473 | var firstIndexInSet = this.layout.setPointsOffsets[i]; | |
474 | var setLength = this.layout.setPointsLengths[i]; | |
475 | ||
476 | var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, | |
01a14b85 DV |
477 | DygraphCanvasRenderer._getIteratorPredicate( |
478 | this.attr_("connectSeparatedPoints"))); | |
6a6439da DV |
479 | |
480 | // setup graphics context | |
481 | var prevX = NaN; | |
482 | var prevY = NaN; | |
483 | var prevYs = [-1, -1]; | |
484 | var yscale = axis.yscale; | |
485 | // should be same color as the lines but only 15% opaque. | |
486 | var rgb = new RGBColor(color); | |
487 | var err_color = | |
488 | 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + fillAlpha + ')'; | |
489 | ctx.fillStyle = err_color; | |
490 | ctx.beginPath(); | |
491 | while (iter.hasNext) { | |
492 | var point = iter.next(); | |
a5701188 DV |
493 | if (!Dygraph.isOK(point.y)) { |
494 | prevX = NaN; | |
495 | continue; | |
496 | } | |
6a6439da | 497 | |
a5701188 DV |
498 | // TODO(danvk): here |
499 | if (stepPlot) { | |
500 | newYs = [ point.y_bottom, point.y_top ]; | |
501 | prevY = point.y; | |
502 | } else { | |
503 | newYs = [ point.y_bottom, point.y_top ]; | |
504 | } | |
505 | newYs[0] = this.area.h * newYs[0] + this.area.y; | |
506 | newYs[1] = this.area.h * newYs[1] + this.area.y; | |
507 | if (!isNaN(prevX)) { | |
6a6439da | 508 | if (stepPlot) { |
a5701188 | 509 | ctx.moveTo(prevX, newYs[0]); |
6a6439da | 510 | } else { |
a5701188 | 511 | ctx.moveTo(prevX, prevYs[0]); |
6a6439da | 512 | } |
a5701188 DV |
513 | ctx.lineTo(point.canvasx, newYs[0]); |
514 | ctx.lineTo(point.canvasx, newYs[1]); | |
515 | if (stepPlot) { | |
516 | ctx.lineTo(prevX, newYs[1]); | |
517 | } else { | |
518 | ctx.lineTo(prevX, prevYs[1]); | |
6a6439da | 519 | } |
a5701188 | 520 | ctx.closePath(); |
6a6439da | 521 | } |
a5701188 DV |
522 | prevYs = newYs; |
523 | prevX = point.canvasx; | |
6a6439da DV |
524 | } |
525 | ctx.fill(); | |
526 | } | |
527 | }; | |
528 | ||
79253bd0 | 529 | /** |
01a14b85 DV |
530 | * Draws the shaded regions when "fillGraph" is set. Not to be confused with |
531 | * error bars. | |
532 | * | |
533 | * @private | |
534 | */ | |
535 | DygraphCanvasRenderer.prototype.drawFillBars_ = function(points) { | |
536 | var ctx = this.elementContext; | |
537 | var setNames = this.layout.setNames; | |
538 | var setCount = setNames.length; | |
539 | var fillAlpha = this.attr_('fillAlpha'); | |
540 | var stepPlot = this.attr_('stepPlot'); | |
541 | var stackedGraph = this.attr_("stackedGraph"); | |
542 | ||
543 | var baseline = {}; // for stacked graphs: baseline for filling | |
544 | var currBaseline; | |
545 | ||
546 | // process sets in reverse order (needed for stacked graphs) | |
547 | for (var i = setCount - 1; i >= 0; i--) { | |
548 | var setName = setNames[i]; | |
549 | var color = this.colors[setName]; | |
550 | var axis = this.dygraph_.axisPropertiesForSeries(setName); | |
551 | var axisY = 1.0 + axis.minyval * axis.yscale; | |
552 | if (axisY < 0.0) axisY = 0.0; | |
553 | else if (axisY > 1.0) axisY = 1.0; | |
554 | axisY = this.area.h * axisY + this.area.y; | |
555 | var firstIndexInSet = this.layout.setPointsOffsets[i]; | |
556 | var setLength = this.layout.setPointsLengths[i]; | |
557 | ||
558 | var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, | |
559 | DygraphCanvasRenderer._getIteratorPredicate( | |
560 | this.attr_("connectSeparatedPoints"))); | |
561 | ||
562 | // setup graphics context | |
563 | var prevX = NaN; | |
564 | var prevYs = [-1, -1]; | |
565 | var newYs; | |
566 | var yscale = axis.yscale; | |
567 | // should be same color as the lines but only 15% opaque. | |
568 | var rgb = new RGBColor(color); | |
569 | var err_color = | |
570 | 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + fillAlpha + ')'; | |
571 | ctx.fillStyle = err_color; | |
572 | ctx.beginPath(); | |
573 | while(iter.hasNext) { | |
574 | var point = iter.next(); | |
16febe6b DV |
575 | if (!Dygraph.isOK(point.y)) { |
576 | prevX = NaN; | |
577 | continue; | |
578 | } | |
579 | if (stackedGraph) { | |
580 | currBaseline = baseline[point.canvasx]; | |
581 | var lastY; | |
582 | if (currBaseline === undefined) { | |
583 | lastY = axisY; | |
584 | } else { | |
585 | if(stepPlot) { | |
586 | lastY = currBaseline[0]; | |
01a14b85 | 587 | } else { |
16febe6b | 588 | lastY = currBaseline; |
01a14b85 | 589 | } |
16febe6b DV |
590 | } |
591 | newYs = [ point.canvasy, lastY ]; | |
01a14b85 | 592 | |
16febe6b DV |
593 | if(stepPlot) { |
594 | // Step plots must keep track of the top and bottom of | |
595 | // the baseline at each point. | |
596 | if(prevYs[0] === -1) { | |
597 | baseline[point.canvasx] = [ point.canvasy, axisY ]; | |
01a14b85 | 598 | } else { |
16febe6b | 599 | baseline[point.canvasx] = [ point.canvasy, prevYs[0] ]; |
01a14b85 | 600 | } |
01a14b85 | 601 | } else { |
16febe6b | 602 | baseline[point.canvasx] = point.canvasy; |
01a14b85 | 603 | } |
01a14b85 | 604 | |
16febe6b DV |
605 | } else { |
606 | newYs = [ point.canvasy, axisY ]; | |
607 | } | |
608 | if (!isNaN(prevX)) { | |
609 | ctx.moveTo(prevX, prevYs[0]); | |
610 | ||
611 | if (stepPlot) { | |
612 | ctx.lineTo(point.canvasx, prevYs[0]); | |
613 | if(currBaseline) { | |
614 | // Draw to the bottom of the baseline | |
615 | ctx.lineTo(point.canvasx, currBaseline[1]); | |
01a14b85 | 616 | } else { |
01a14b85 DV |
617 | ctx.lineTo(point.canvasx, newYs[1]); |
618 | } | |
16febe6b DV |
619 | } else { |
620 | ctx.lineTo(point.canvasx, newYs[0]); | |
621 | ctx.lineTo(point.canvasx, newYs[1]); | |
01a14b85 | 622 | } |
16febe6b DV |
623 | |
624 | ctx.lineTo(prevX, prevYs[1]); | |
625 | ctx.closePath(); | |
01a14b85 | 626 | } |
16febe6b DV |
627 | prevYs = newYs; |
628 | prevX = point.canvasx; | |
01a14b85 DV |
629 | } |
630 | ctx.fill(); | |
631 | } | |
632 | }; |