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6a1aa64f DV |
1 | // Copyright 2006 Dan Vanderkam (danvdk@gmail.com) |
2 | // All Rights Reserved. | |
3 | ||
4 | /** | |
5 | * @fileoverview Subclasses various parts of PlotKit to meet the additional | |
285a6bda | 6 | * needs of Dygraph: grid overlays and error bars |
6a1aa64f DV |
7 | */ |
8 | ||
9 | // Subclass PlotKit.Layout to add: | |
10 | // 1. Sigma/errorBars properties | |
11 | // 2. Copy error terms for PlotKit.CanvasRenderer._renderLineChart | |
12 | ||
13 | /** | |
285a6bda | 14 | * Creates a new DygraphLayout object. Options are the same as those allowed |
6a1aa64f DV |
15 | * by the PlotKit.Layout constructor. |
16 | * @param {Object} options Options for PlotKit.Layout | |
285a6bda | 17 | * @return {Object} The DygraphLayout object |
6a1aa64f | 18 | */ |
285a6bda | 19 | DygraphLayout = function(options) { |
6a1aa64f DV |
20 | PlotKit.Layout.call(this, "line", options); |
21 | }; | |
285a6bda | 22 | DygraphLayout.prototype = new PlotKit.Layout(); |
6a1aa64f DV |
23 | |
24 | /** | |
25 | * Behaves the same way as PlotKit.Layout, but also copies the errors | |
26 | * @private | |
27 | */ | |
285a6bda | 28 | DygraphLayout.prototype.evaluateWithError = function() { |
6a1aa64f DV |
29 | this.evaluate(); |
30 | if (!this.options.errorBars) return; | |
31 | ||
32 | // Copy over the error terms | |
33 | var i = 0; // index in this.points | |
34 | for (var setName in this.datasets) { | |
35 | var j = 0; | |
36 | var dataset = this.datasets[setName]; | |
37 | if (PlotKit.Base.isFuncLike(dataset)) continue; | |
38 | for (var j = 0; j < dataset.length; j++, i++) { | |
39 | var item = dataset[j]; | |
40 | var xv = parseFloat(item[0]); | |
41 | var yv = parseFloat(item[1]); | |
42 | ||
43 | if (xv == this.points[i].xval && | |
44 | yv == this.points[i].yval) { | |
45 | this.points[i].errorMinus = parseFloat(item[2]); | |
46 | this.points[i].errorPlus = parseFloat(item[3]); | |
47 | } | |
48 | } | |
49 | } | |
50 | }; | |
51 | ||
52 | /** | |
53 | * Convenience function to remove all the data sets from a graph | |
54 | */ | |
285a6bda | 55 | DygraphLayout.prototype.removeAllDatasets = function() { |
6a1aa64f DV |
56 | delete this.datasets; |
57 | this.datasets = new Array(); | |
58 | }; | |
59 | ||
60 | /** | |
61 | * Change the values of various layout options | |
62 | * @param {Object} new_options an associative array of new properties | |
63 | */ | |
285a6bda | 64 | DygraphLayout.prototype.updateOptions = function(new_options) { |
6a1aa64f DV |
65 | MochiKit.Base.update(this.options, new_options ? new_options : {}); |
66 | }; | |
67 | ||
68 | // Subclass PlotKit.CanvasRenderer to add: | |
69 | // 1. X/Y grid overlay | |
70 | // 2. Ability to draw error bars (if required) | |
71 | ||
72 | /** | |
73 | * Sets some PlotKit.CanvasRenderer options | |
74 | * @param {Object} element The canvas to attach to | |
285a6bda | 75 | * @param {Layout} layout The DygraphLayout object for this graph. |
6a1aa64f DV |
76 | * @param {Object} options Options to pass on to CanvasRenderer |
77 | */ | |
9317362d DV |
78 | DygraphCanvasRenderer = function(dygraph, element, layout, options) { |
79 | // TODO(danvk): remove options, just use dygraph.attr_. | |
6a1aa64f | 80 | PlotKit.CanvasRenderer.call(this, element, layout, options); |
9317362d | 81 | this.dygraph_ = dygraph; |
6a1aa64f DV |
82 | this.options.shouldFill = false; |
83 | this.options.shouldStroke = true; | |
84 | this.options.drawYGrid = true; | |
85 | this.options.drawXGrid = true; | |
86 | this.options.gridLineColor = MochiKit.Color.Color.grayColor(); | |
87 | MochiKit.Base.update(this.options, options); | |
88 | ||
89 | // TODO(danvk) This shouldn't be necessary: effects should be overlaid | |
90 | this.options.drawBackground = false; | |
91 | }; | |
285a6bda | 92 | DygraphCanvasRenderer.prototype = new PlotKit.CanvasRenderer(); |
6a1aa64f DV |
93 | |
94 | /** | |
95 | * Draw an X/Y grid on top of the existing plot | |
96 | */ | |
285a6bda | 97 | DygraphCanvasRenderer.prototype.render = function() { |
6a1aa64f DV |
98 | // Draw the new X/Y grid |
99 | var ctx = this.element.getContext("2d"); | |
100 | if (this.options.drawYGrid) { | |
101 | var ticks = this.layout.yticks; | |
102 | ctx.save(); | |
103 | ctx.strokeStyle = this.options.gridLineColor.toRGBString(); | |
104 | ctx.lineWidth = this.options.axisLineWidth; | |
105 | for (var i = 0; i < ticks.length; i++) { | |
106 | var x = this.area.x; | |
107 | var y = this.area.y + ticks[i][0] * this.area.h; | |
108 | ctx.beginPath(); | |
109 | ctx.moveTo(x, y); | |
110 | ctx.lineTo(x + this.area.w, y); | |
111 | ctx.closePath(); | |
112 | ctx.stroke(); | |
113 | } | |
114 | } | |
115 | ||
116 | if (this.options.drawXGrid) { | |
117 | var ticks = this.layout.xticks; | |
118 | ctx.save(); | |
119 | ctx.strokeStyle = this.options.gridLineColor.toRGBString(); | |
120 | ctx.lineWidth = this.options.axisLineWidth; | |
121 | for (var i=0; i<ticks.length; i++) { | |
122 | var x = this.area.x + ticks[i][0] * this.area.w; | |
123 | var y = this.area.y + this.area.h; | |
124 | ctx.beginPath(); | |
125 | ctx.moveTo(x, y); | |
126 | ctx.lineTo(x, this.area.y); | |
127 | ctx.closePath(); | |
128 | ctx.stroke(); | |
129 | } | |
130 | } | |
2ce09b19 DV |
131 | |
132 | // Do the ordinary rendering, as before | |
133 | // TODO(danvk) Call super.render() | |
134 | this._renderLineChart(); | |
135 | this._renderLineAxis(); | |
6a1aa64f DV |
136 | }; |
137 | ||
138 | /** | |
139 | * Overrides the CanvasRenderer method to draw error bars | |
140 | */ | |
285a6bda | 141 | DygraphCanvasRenderer.prototype._renderLineChart = function() { |
6a1aa64f DV |
142 | var context = this.element.getContext("2d"); |
143 | var colorCount = this.options.colorScheme.length; | |
144 | var colorScheme = this.options.colorScheme; | |
145 | var setNames = MochiKit.Base.keys(this.layout.datasets); | |
146 | var errorBars = this.layout.options.errorBars; | |
147 | var setCount = setNames.length; | |
148 | var bind = MochiKit.Base.bind; | |
149 | var partial = MochiKit.Base.partial; | |
150 | ||
151 | //Update Points | |
152 | var updatePoint = function(point) { | |
153 | point.canvasx = this.area.w * point.x + this.area.x; | |
154 | point.canvasy = this.area.h * point.y + this.area.y; | |
155 | } | |
156 | MochiKit.Iter.forEach(this.layout.points, updatePoint, this); | |
157 | ||
158 | // create paths | |
9317362d | 159 | var isOK = function(x) { return x && !isNaN(x); }; |
6a1aa64f DV |
160 | var makePath = function(ctx) { |
161 | for (var i = 0; i < setCount; i++) { | |
162 | var setName = setNames[i]; | |
163 | var color = colorScheme[i%colorCount]; | |
164 | var strokeX = this.options.strokeColorTransform; | |
165 | ||
166 | // setup graphics context | |
167 | context.save(); | |
168 | context.strokeStyle = color.toRGBString(); | |
169 | context.lineWidth = this.options.strokeWidth; | |
6a1aa64f | 170 | var point = this.layout.points[0]; |
9317362d DV |
171 | var pointSize = this.dygraph_.attr_("pointSize"); |
172 | var prevX = null, prevY = null; | |
173 | var drawPoints = this.dygraph_.attr_("drawPoints"); | |
174 | var points = this.layout.points; | |
175 | for (var j = 0; j < points.length; j++) { | |
176 | var point = points[j]; | |
6a1aa64f | 177 | if (point.name == setName) { |
9317362d | 178 | if (!isOK(point.canvasy)) { |
9a730910 | 179 | // this will make us move to the next point, not draw a line to it. |
9317362d | 180 | prevX = prevY = null; |
9a730910 | 181 | } else { |
9317362d DV |
182 | // A point is "isolated" if it is non-null but both the previous |
183 | // and next points are null. | |
184 | var isIsolated = (!prevX && (j == points.length - 1 || | |
185 | !isOK(points[j+1].canvasy))); | |
186 | ||
187 | if (!prevX) { | |
188 | prevX = point.canvasx; | |
189 | prevY = point.canvasy; | |
9a730910 | 190 | } else { |
9317362d DV |
191 | ctx.beginPath(); |
192 | ctx.moveTo(prevX, prevY); | |
193 | prevX = point.canvasx; | |
194 | prevY = point.canvasy; | |
195 | ctx.lineTo(prevX, prevY); | |
196 | ctx.stroke(); | |
197 | } | |
198 | ||
199 | if (drawPoints || isIsolated) { | |
200 | ctx.beginPath(); | |
201 | ctx.fillStyle = color.toRGBString(); | |
202 | ctx.arc(point.canvasx, point.canvasy, pointSize, 0, 360, false); | |
203 | ctx.fill(); | |
9a730910 DV |
204 | } |
205 | } | |
6a1aa64f | 206 | } |
9317362d | 207 | } |
6a1aa64f DV |
208 | } |
209 | }; | |
210 | ||
211 | var makeErrorBars = function(ctx) { | |
212 | for (var i = 0; i < setCount; i++) { | |
213 | var setName = setNames[i]; | |
214 | var color = colorScheme[i % colorCount]; | |
215 | var strokeX = this.options.strokeColorTransform; | |
216 | ||
217 | // setup graphics context | |
218 | context.save(); | |
219 | context.strokeStyle = color.toRGBString(); | |
220 | context.lineWidth = this.options.strokeWidth; | |
221 | var prevX = -1; | |
222 | var prevYs = [-1, -1]; | |
223 | var count = 0; | |
224 | var yscale = this.layout.yscale; | |
225 | var errorTrapezoid = function(ctx_,point) { | |
226 | count++; | |
227 | if (point.name == setName) { | |
5011e7a1 DV |
228 | if (!point.y || isNaN(point.y)) { |
229 | prevX = -1; | |
230 | return; | |
231 | } | |
6a1aa64f DV |
232 | var newYs = [ point.y - point.errorPlus * yscale, |
233 | point.y + point.errorMinus * yscale ]; | |
234 | newYs[0] = this.area.h * newYs[0] + this.area.y; | |
235 | newYs[1] = this.area.h * newYs[1] + this.area.y; | |
236 | if (prevX >= 0) { | |
237 | ctx_.moveTo(prevX, prevYs[0]); | |
238 | ctx_.lineTo(point.canvasx, newYs[0]); | |
239 | ctx_.lineTo(point.canvasx, newYs[1]); | |
240 | ctx_.lineTo(prevX, prevYs[1]); | |
241 | ctx_.closePath(); | |
242 | } | |
243 | prevYs[0] = newYs[0]; | |
244 | prevYs[1] = newYs[1]; | |
245 | prevX = point.canvasx; | |
246 | } | |
247 | }; | |
248 | // should be same color as the lines | |
249 | var err_color = color.colorWithAlpha(0.15); | |
250 | ctx.fillStyle = err_color.toRGBString(); | |
251 | ctx.beginPath(); | |
252 | MochiKit.Iter.forEach(this.layout.points, partial(errorTrapezoid, ctx), this); | |
253 | ctx.fill(); | |
254 | } | |
255 | }; | |
256 | ||
257 | if (errorBars) | |
258 | bind(makeErrorBars, this)(context); | |
259 | bind(makePath, this)(context); | |
260 | context.restore(); | |
261 | }; |