| 1 | /** |
| 2 | * @license |
| 3 | * Copyright 2006 Dan Vanderkam (danvdk@gmail.com) |
| 4 | * MIT-licensed (http://opensource.org/licenses/MIT) |
| 5 | */ |
| 6 | |
| 7 | /** |
| 8 | * @fileoverview Based on PlotKit.CanvasRenderer, but modified to meet the |
| 9 | * needs of dygraphs. |
| 10 | * |
| 11 | * In particular, support for: |
| 12 | * - grid overlays |
| 13 | * - error bars |
| 14 | * - dygraphs attribute system |
| 15 | */ |
| 16 | |
| 17 | /** |
| 18 | * The DygraphCanvasRenderer class does the actual rendering of the chart onto |
| 19 | * a canvas. It's based on PlotKit.CanvasRenderer. |
| 20 | * @param {Object} element The canvas to attach to |
| 21 | * @param {Object} elementContext The 2d context of the canvas (injected so it |
| 22 | * can be mocked for testing.) |
| 23 | * @param {Layout} layout The DygraphLayout object for this graph. |
| 24 | * @constructor |
| 25 | */ |
| 26 | |
| 27 | /*jshint globalstrict: true */ |
| 28 | /*global Dygraph:false,RGBColor:false */ |
| 29 | "use strict"; |
| 30 | |
| 31 | |
| 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 | */ |
| 49 | var DygraphCanvasRenderer = function(dygraph, element, elementContext, layout) { |
| 50 | this.dygraph_ = dygraph; |
| 51 | |
| 52 | this.layout = layout; |
| 53 | this.element = element; |
| 54 | this.elementContext = elementContext; |
| 55 | this.container = this.element.parentNode; |
| 56 | |
| 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 |
| 65 | this.xlabels = []; |
| 66 | this.ylabels = []; |
| 67 | |
| 68 | this.area = layout.getPlotArea(); |
| 69 | this.container.style.position = "relative"; |
| 70 | this.container.style.width = this.width + "px"; |
| 71 | |
| 72 | // Set up a clipping area for the canvas (and the interaction canvas). |
| 73 | // This ensures that we don't overdraw. |
| 74 | if (this.dygraph_.isUsingExcanvas_) { |
| 75 | this._createIEClipArea(); |
| 76 | } else { |
| 77 | // on Android 3 and 4, setting a clipping area on a canvas prevents it from |
| 78 | // displaying anything. |
| 79 | if (!Dygraph.isAndroid()) { |
| 80 | var ctx = this.dygraph_.canvas_ctx_; |
| 81 | ctx.beginPath(); |
| 82 | ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h); |
| 83 | ctx.clip(); |
| 84 | |
| 85 | ctx = this.dygraph_.hidden_ctx_; |
| 86 | ctx.beginPath(); |
| 87 | ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h); |
| 88 | ctx.clip(); |
| 89 | } |
| 90 | } |
| 91 | }; |
| 92 | |
| 93 | DygraphCanvasRenderer.prototype.attr_ = function(x) { |
| 94 | return this.dygraph_.attr_(x); |
| 95 | }; |
| 96 | |
| 97 | /** |
| 98 | * Clears out all chart content and DOM elements. |
| 99 | * This is called immediately before render() on every frame, including |
| 100 | * during zooms and pans. |
| 101 | * @private |
| 102 | */ |
| 103 | DygraphCanvasRenderer.prototype.clear = function() { |
| 104 | var context; |
| 105 | if (this.isIE) { |
| 106 | // VML takes a while to start up, so we just poll every this.IEDelay |
| 107 | try { |
| 108 | if (this.clearDelay) { |
| 109 | this.clearDelay.cancel(); |
| 110 | this.clearDelay = null; |
| 111 | } |
| 112 | context = this.elementContext; |
| 113 | } |
| 114 | catch (e) { |
| 115 | // TODO(danvk): this is broken, since MochiKit.Async is gone. |
| 116 | // this.clearDelay = MochiKit.Async.wait(this.IEDelay); |
| 117 | // this.clearDelay.addCallback(bind(this.clear, this)); |
| 118 | return; |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | context = this.elementContext; |
| 123 | context.clearRect(0, 0, this.width, this.height); |
| 124 | |
| 125 | function removeArray(ary) { |
| 126 | for (var i = 0; i < ary.length; i++) { |
| 127 | var el = ary[i]; |
| 128 | if (el.parentNode) el.parentNode.removeChild(el); |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | removeArray(this.xlabels); |
| 133 | removeArray(this.ylabels); |
| 134 | |
| 135 | this.xlabels = []; |
| 136 | this.ylabels = []; |
| 137 | }; |
| 138 | |
| 139 | /** |
| 140 | * Checks whether the browser supports the <canvas> tag. |
| 141 | * @private |
| 142 | */ |
| 143 | DygraphCanvasRenderer.isSupported = function(canvasName) { |
| 144 | var canvas = null; |
| 145 | try { |
| 146 | if (typeof(canvasName) == 'undefined' || canvasName === null) { |
| 147 | canvas = document.createElement("canvas"); |
| 148 | } else { |
| 149 | canvas = canvasName; |
| 150 | } |
| 151 | canvas.getContext("2d"); |
| 152 | } |
| 153 | catch (e) { |
| 154 | var ie = navigator.appVersion.match(/MSIE (\d\.\d)/); |
| 155 | var opera = (navigator.userAgent.toLowerCase().indexOf("opera") != -1); |
| 156 | if ((!ie) || (ie[1] < 6) || (opera)) |
| 157 | return false; |
| 158 | return true; |
| 159 | } |
| 160 | return true; |
| 161 | }; |
| 162 | |
| 163 | /** |
| 164 | * @param { [String] } colors Array of color strings. Should have one entry for |
| 165 | * each series to be rendered. |
| 166 | */ |
| 167 | DygraphCanvasRenderer.prototype.setColors = function(colors) { |
| 168 | this.colorScheme_ = colors; |
| 169 | }; |
| 170 | |
| 171 | /** |
| 172 | * This method is responsible for drawing everything on the chart, including |
| 173 | * lines, error bars, fills and axes. |
| 174 | * It is called immediately after clear() on every frame, including during pans |
| 175 | * and zooms. |
| 176 | * @private |
| 177 | */ |
| 178 | DygraphCanvasRenderer.prototype.render = function() { |
| 179 | // Draw the new X/Y grid. Lines appear crisper when pixels are rounded to |
| 180 | // half-integers. This prevents them from drawing in two rows/cols. |
| 181 | var ctx = this.elementContext; |
| 182 | function halfUp(x) { return Math.round(x) + 0.5; } |
| 183 | function halfDown(y){ return Math.round(y) - 0.5; } |
| 184 | |
| 185 | if (this.attr_('underlayCallback')) { |
| 186 | // NOTE: we pass the dygraph object to this callback twice to avoid breaking |
| 187 | // users who expect a deprecated form of this callback. |
| 188 | this.attr_('underlayCallback')(ctx, this.area, this.dygraph_, this.dygraph_); |
| 189 | } |
| 190 | |
| 191 | var x, y, i, ticks; |
| 192 | if (this.attr_('drawYGrid')) { |
| 193 | ticks = this.layout.yticks; |
| 194 | // TODO(konigsberg): I don't think these calls to save() have a corresponding restore(). |
| 195 | ctx.save(); |
| 196 | ctx.strokeStyle = this.attr_('gridLineColor'); |
| 197 | ctx.lineWidth = this.attr_('gridLineWidth'); |
| 198 | for (i = 0; i < ticks.length; i++) { |
| 199 | // TODO(danvk): allow secondary axes to draw a grid, too. |
| 200 | if (ticks[i][0] !== 0) continue; |
| 201 | x = halfUp(this.area.x); |
| 202 | y = halfDown(this.area.y + ticks[i][1] * this.area.h); |
| 203 | ctx.beginPath(); |
| 204 | ctx.moveTo(x, y); |
| 205 | ctx.lineTo(x + this.area.w, y); |
| 206 | ctx.closePath(); |
| 207 | ctx.stroke(); |
| 208 | } |
| 209 | ctx.restore(); |
| 210 | } |
| 211 | |
| 212 | if (this.attr_('drawXGrid')) { |
| 213 | ticks = this.layout.xticks; |
| 214 | ctx.save(); |
| 215 | ctx.strokeStyle = this.attr_('gridLineColor'); |
| 216 | ctx.lineWidth = this.attr_('gridLineWidth'); |
| 217 | for (i=0; i<ticks.length; i++) { |
| 218 | x = halfUp(this.area.x + ticks[i][0] * this.area.w); |
| 219 | y = halfDown(this.area.y + this.area.h); |
| 220 | ctx.beginPath(); |
| 221 | ctx.moveTo(x, y); |
| 222 | ctx.lineTo(x, this.area.y); |
| 223 | ctx.closePath(); |
| 224 | ctx.stroke(); |
| 225 | } |
| 226 | ctx.restore(); |
| 227 | } |
| 228 | |
| 229 | // Do the ordinary rendering, as before |
| 230 | this._renderLineChart(); |
| 231 | this._renderAxis(); |
| 232 | }; |
| 233 | |
| 234 | DygraphCanvasRenderer.prototype._createIEClipArea = function() { |
| 235 | var className = 'dygraph-clip-div'; |
| 236 | var graphDiv = this.dygraph_.graphDiv; |
| 237 | |
| 238 | // Remove old clip divs. |
| 239 | for (var i = graphDiv.childNodes.length-1; i >= 0; i--) { |
| 240 | if (graphDiv.childNodes[i].className == className) { |
| 241 | graphDiv.removeChild(graphDiv.childNodes[i]); |
| 242 | } |
| 243 | } |
| 244 | |
| 245 | // Determine background color to give clip divs. |
| 246 | var backgroundColor = document.bgColor; |
| 247 | var element = this.dygraph_.graphDiv; |
| 248 | while (element != document) { |
| 249 | var bgcolor = element.currentStyle.backgroundColor; |
| 250 | if (bgcolor && bgcolor != 'transparent') { |
| 251 | backgroundColor = bgcolor; |
| 252 | break; |
| 253 | } |
| 254 | element = element.parentNode; |
| 255 | } |
| 256 | |
| 257 | function createClipDiv(area) { |
| 258 | if (area.w === 0 || area.h === 0) { |
| 259 | return; |
| 260 | } |
| 261 | var elem = document.createElement('div'); |
| 262 | elem.className = className; |
| 263 | elem.style.backgroundColor = backgroundColor; |
| 264 | elem.style.position = 'absolute'; |
| 265 | elem.style.left = area.x + 'px'; |
| 266 | elem.style.top = area.y + 'px'; |
| 267 | elem.style.width = area.w + 'px'; |
| 268 | elem.style.height = area.h + 'px'; |
| 269 | graphDiv.appendChild(elem); |
| 270 | } |
| 271 | |
| 272 | var plotArea = this.area; |
| 273 | // Left side |
| 274 | createClipDiv({ |
| 275 | x:0, y:0, |
| 276 | w:plotArea.x, |
| 277 | h:this.height |
| 278 | }); |
| 279 | |
| 280 | // Top |
| 281 | createClipDiv({ |
| 282 | x: plotArea.x, y: 0, |
| 283 | w: this.width - plotArea.x, |
| 284 | h: plotArea.y |
| 285 | }); |
| 286 | |
| 287 | // Right side |
| 288 | createClipDiv({ |
| 289 | x: plotArea.x + plotArea.w, y: 0, |
| 290 | w: this.width-plotArea.x - plotArea.w, |
| 291 | h: this.height |
| 292 | }); |
| 293 | |
| 294 | // Bottom |
| 295 | createClipDiv({ |
| 296 | x: plotArea.x, |
| 297 | y: plotArea.y + plotArea.h, |
| 298 | w: this.width - plotArea.x, |
| 299 | h: this.height - plotArea.h - plotArea.y |
| 300 | }); |
| 301 | }; |
| 302 | |
| 303 | DygraphCanvasRenderer.prototype._renderAxis = function() { |
| 304 | if (!this.attr_('drawXAxis') && !this.attr_('drawYAxis')) return; |
| 305 | |
| 306 | // Round pixels to half-integer boundaries for crisper drawing. |
| 307 | function halfUp(x) { return Math.round(x) + 0.5; } |
| 308 | function halfDown(y){ return Math.round(y) - 0.5; } |
| 309 | |
| 310 | var context = this.elementContext; |
| 311 | |
| 312 | var label, x, y, tick, i; |
| 313 | |
| 314 | var labelStyle = { |
| 315 | position: "absolute", |
| 316 | fontSize: this.attr_('axisLabelFontSize') + "px", |
| 317 | zIndex: 10, |
| 318 | color: this.attr_('axisLabelColor'), |
| 319 | width: this.attr_('axisLabelWidth') + "px", |
| 320 | // height: this.attr_('axisLabelFontSize') + 2 + "px", |
| 321 | lineHeight: "normal", // Something other than "normal" line-height screws up label positioning. |
| 322 | overflow: "hidden" |
| 323 | }; |
| 324 | var makeDiv = function(txt, axis, prec_axis) { |
| 325 | var div = document.createElement("div"); |
| 326 | for (var name in labelStyle) { |
| 327 | if (labelStyle.hasOwnProperty(name)) { |
| 328 | div.style[name] = labelStyle[name]; |
| 329 | } |
| 330 | } |
| 331 | var inner_div = document.createElement("div"); |
| 332 | inner_div.className = 'dygraph-axis-label' + |
| 333 | ' dygraph-axis-label-' + axis + |
| 334 | (prec_axis ? ' dygraph-axis-label-' + prec_axis : ''); |
| 335 | inner_div.innerHTML=txt; |
| 336 | div.appendChild(inner_div); |
| 337 | return div; |
| 338 | }; |
| 339 | |
| 340 | // axis lines |
| 341 | context.save(); |
| 342 | context.strokeStyle = this.attr_('axisLineColor'); |
| 343 | context.lineWidth = this.attr_('axisLineWidth'); |
| 344 | |
| 345 | if (this.attr_('drawYAxis')) { |
| 346 | if (this.layout.yticks && this.layout.yticks.length > 0) { |
| 347 | var num_axes = this.dygraph_.numAxes(); |
| 348 | for (i = 0; i < this.layout.yticks.length; i++) { |
| 349 | tick = this.layout.yticks[i]; |
| 350 | if (typeof(tick) == "function") return; |
| 351 | x = this.area.x; |
| 352 | var sgn = 1; |
| 353 | var prec_axis = 'y1'; |
| 354 | if (tick[0] == 1) { // right-side y-axis |
| 355 | x = this.area.x + this.area.w; |
| 356 | sgn = -1; |
| 357 | prec_axis = 'y2'; |
| 358 | } |
| 359 | y = this.area.y + tick[1] * this.area.h; |
| 360 | |
| 361 | /* Tick marks are currently clipped, so don't bother drawing them. |
| 362 | context.beginPath(); |
| 363 | context.moveTo(halfUp(x), halfDown(y)); |
| 364 | context.lineTo(halfUp(x - sgn * this.attr_('axisTickSize')), halfDown(y)); |
| 365 | context.closePath(); |
| 366 | context.stroke(); |
| 367 | */ |
| 368 | |
| 369 | label = makeDiv(tick[2], 'y', num_axes == 2 ? prec_axis : null); |
| 370 | var top = (y - this.attr_('axisLabelFontSize') / 2); |
| 371 | if (top < 0) top = 0; |
| 372 | |
| 373 | if (top + this.attr_('axisLabelFontSize') + 3 > this.height) { |
| 374 | label.style.bottom = "0px"; |
| 375 | } else { |
| 376 | label.style.top = top + "px"; |
| 377 | } |
| 378 | if (tick[0] === 0) { |
| 379 | label.style.left = (this.area.x - this.attr_('yAxisLabelWidth') - this.attr_('axisTickSize')) + "px"; |
| 380 | label.style.textAlign = "right"; |
| 381 | } else if (tick[0] == 1) { |
| 382 | label.style.left = (this.area.x + this.area.w + |
| 383 | this.attr_('axisTickSize')) + "px"; |
| 384 | label.style.textAlign = "left"; |
| 385 | } |
| 386 | label.style.width = this.attr_('yAxisLabelWidth') + "px"; |
| 387 | this.container.appendChild(label); |
| 388 | this.ylabels.push(label); |
| 389 | } |
| 390 | |
| 391 | // The lowest tick on the y-axis often overlaps with the leftmost |
| 392 | // tick on the x-axis. Shift the bottom tick up a little bit to |
| 393 | // compensate if necessary. |
| 394 | var bottomTick = this.ylabels[0]; |
| 395 | var fontSize = this.attr_('axisLabelFontSize'); |
| 396 | var bottom = parseInt(bottomTick.style.top, 10) + fontSize; |
| 397 | if (bottom > this.height - fontSize) { |
| 398 | bottomTick.style.top = (parseInt(bottomTick.style.top, 10) - |
| 399 | fontSize / 2) + "px"; |
| 400 | } |
| 401 | } |
| 402 | |
| 403 | // draw a vertical line on the left to separate the chart from the labels. |
| 404 | var axisX; |
| 405 | if (this.attr_('drawAxesAtZero')) { |
| 406 | var r = this.dygraph_.toPercentXCoord(0); |
| 407 | if (r > 1 || r < 0) r = 0; |
| 408 | axisX = halfUp(this.area.x + r * this.area.w); |
| 409 | } else { |
| 410 | axisX = halfUp(this.area.x); |
| 411 | } |
| 412 | context.beginPath(); |
| 413 | context.moveTo(axisX, halfDown(this.area.y)); |
| 414 | context.lineTo(axisX, halfDown(this.area.y + this.area.h)); |
| 415 | context.closePath(); |
| 416 | context.stroke(); |
| 417 | |
| 418 | // if there's a secondary y-axis, draw a vertical line for that, too. |
| 419 | if (this.dygraph_.numAxes() == 2) { |
| 420 | context.beginPath(); |
| 421 | context.moveTo(halfDown(this.area.x + this.area.w), halfDown(this.area.y)); |
| 422 | context.lineTo(halfDown(this.area.x + this.area.w), halfDown(this.area.y + this.area.h)); |
| 423 | context.closePath(); |
| 424 | context.stroke(); |
| 425 | } |
| 426 | } |
| 427 | |
| 428 | if (this.attr_('drawXAxis')) { |
| 429 | if (this.layout.xticks) { |
| 430 | for (i = 0; i < this.layout.xticks.length; i++) { |
| 431 | tick = this.layout.xticks[i]; |
| 432 | x = this.area.x + tick[0] * this.area.w; |
| 433 | y = this.area.y + this.area.h; |
| 434 | |
| 435 | /* Tick marks are currently clipped, so don't bother drawing them. |
| 436 | context.beginPath(); |
| 437 | context.moveTo(halfUp(x), halfDown(y)); |
| 438 | context.lineTo(halfUp(x), halfDown(y + this.attr_('axisTickSize'))); |
| 439 | context.closePath(); |
| 440 | context.stroke(); |
| 441 | */ |
| 442 | |
| 443 | label = makeDiv(tick[1], 'x'); |
| 444 | label.style.textAlign = "center"; |
| 445 | label.style.top = (y + this.attr_('axisTickSize')) + 'px'; |
| 446 | |
| 447 | var left = (x - this.attr_('axisLabelWidth')/2); |
| 448 | if (left + this.attr_('axisLabelWidth') > this.width) { |
| 449 | left = this.width - this.attr_('xAxisLabelWidth'); |
| 450 | label.style.textAlign = "right"; |
| 451 | } |
| 452 | if (left < 0) { |
| 453 | left = 0; |
| 454 | label.style.textAlign = "left"; |
| 455 | } |
| 456 | |
| 457 | label.style.left = left + "px"; |
| 458 | label.style.width = this.attr_('xAxisLabelWidth') + "px"; |
| 459 | this.container.appendChild(label); |
| 460 | this.xlabels.push(label); |
| 461 | } |
| 462 | } |
| 463 | |
| 464 | context.beginPath(); |
| 465 | var axisY; |
| 466 | if (this.attr_('drawAxesAtZero')) { |
| 467 | var r = this.dygraph_.toPercentYCoord(0, 0); |
| 468 | if (r > 1 || r < 0) r = 1; |
| 469 | axisY = halfDown(this.area.y + r * this.area.h); |
| 470 | } else { |
| 471 | axisY = halfDown(this.area.y + this.area.h); |
| 472 | } |
| 473 | context.moveTo(halfUp(this.area.x), axisY); |
| 474 | context.lineTo(halfUp(this.area.x + this.area.w), axisY); |
| 475 | context.closePath(); |
| 476 | context.stroke(); |
| 477 | } |
| 478 | |
| 479 | context.restore(); |
| 480 | }; |
| 481 | |
| 482 | |
| 483 | /** |
| 484 | * Returns a predicate to be used with an iterator, which will |
| 485 | * iterate over points appropriately, depending on whether |
| 486 | * connectSeparatedPoints is true. When it's false, the predicate will |
| 487 | * skip over points with missing yVals. |
| 488 | */ |
| 489 | DygraphCanvasRenderer._getIteratorPredicate = function(connectSeparatedPoints) { |
| 490 | return connectSeparatedPoints ? DygraphCanvasRenderer._predicateThatSkipsEmptyPoints : null; |
| 491 | } |
| 492 | |
| 493 | DygraphCanvasRenderer._predicateThatSkipsEmptyPoints = |
| 494 | function(array, idx) { return array[idx].yval !== null; } |
| 495 | |
| 496 | DygraphCanvasRenderer.prototype._drawStyledLine = function( |
| 497 | ctx, i, setName, color, strokeWidth, strokePattern, drawPoints, |
| 498 | drawPointCallback, pointSize) { |
| 499 | // TODO(konigsberg): Compute attributes outside this method call. |
| 500 | var stepPlot = this.attr_("stepPlot"); |
| 501 | var firstIndexInSet = this.layout.setPointsOffsets[i]; |
| 502 | var setLength = this.layout.setPointsLengths[i]; |
| 503 | var points = this.layout.points; |
| 504 | if (!Dygraph.isArrayLike(strokePattern)) { |
| 505 | strokePattern = null; |
| 506 | } |
| 507 | var drawGapPoints = this.dygraph_.attr_('drawGapEdgePoints', setName); |
| 508 | |
| 509 | ctx.save(); |
| 510 | |
| 511 | var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, |
| 512 | DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints"))); |
| 513 | |
| 514 | var pointsOnLine; |
| 515 | var strategy; |
| 516 | if (!strokePattern || strokePattern.length <= 1) { |
| 517 | strategy = trivialStrategy(ctx, color, strokeWidth); |
| 518 | } else { |
| 519 | strategy = nonTrivialStrategy(this, ctx, color, strokeWidth, strokePattern); |
| 520 | } |
| 521 | pointsOnLine = this._drawSeries(ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, stepPlot, strategy); |
| 522 | this._drawPointsOnLine(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize); |
| 523 | |
| 524 | ctx.restore(); |
| 525 | }; |
| 526 | |
| 527 | var nonTrivialStrategy = function(renderer, ctx, color, strokeWidth, strokePattern) { |
| 528 | return new function() { |
| 529 | this.init = function() { }; |
| 530 | this.finish = function() { }; |
| 531 | this.startSegment = function() { |
| 532 | ctx.beginPath(); |
| 533 | ctx.strokeStyle = color; |
| 534 | ctx.lineWidth = strokeWidth; |
| 535 | }; |
| 536 | this.endSegment = function() { |
| 537 | ctx.stroke(); // should this include closePath? |
| 538 | }; |
| 539 | this.drawLine = function(x1, y1, x2, y2) { |
| 540 | renderer._dashedLine(ctx, x1, y1, x2, y2, strokePattern); |
| 541 | }; |
| 542 | this.skipPixel = function(prevX, prevY, curX, curY) { |
| 543 | // TODO(konigsberg): optimize with http://jsperf.com/math-round-vs-hack/6 ? |
| 544 | return (Math.round(prevX) == Math.round(curX) && |
| 545 | Math.round(prevY) == Math.round(curY)); |
| 546 | }; |
| 547 | }; |
| 548 | }; |
| 549 | |
| 550 | var trivialStrategy = function(ctx, color, strokeWidth) { |
| 551 | return new function() { |
| 552 | this.init = function() { |
| 553 | ctx.beginPath(); |
| 554 | ctx.strokeStyle = color; |
| 555 | ctx.lineWidth = strokeWidth; |
| 556 | }; |
| 557 | this.finish = function() { |
| 558 | ctx.stroke(); // should this include closePath? |
| 559 | }; |
| 560 | this.startSegment = function() { }; |
| 561 | this.endSegment = function() { }; |
| 562 | this.drawLine = function(x1, y1, x2, y2) { |
| 563 | ctx.moveTo(x1, y1); |
| 564 | ctx.lineTo(x2, y2); |
| 565 | }; |
| 566 | // don't skip pixels. |
| 567 | this.skipPixel = function() { |
| 568 | return false; |
| 569 | }; |
| 570 | }; |
| 571 | }; |
| 572 | |
| 573 | DygraphCanvasRenderer.prototype._drawPointsOnLine = function(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize) { |
| 574 | for (var idx = 0; idx < pointsOnLine.length; idx++) { |
| 575 | var cb = pointsOnLine[idx]; |
| 576 | ctx.save(); |
| 577 | drawPointCallback( |
| 578 | this.dygraph_, setName, ctx, cb[0], cb[1], color, pointSize); |
| 579 | ctx.restore(); |
| 580 | } |
| 581 | } |
| 582 | |
| 583 | DygraphCanvasRenderer.prototype._drawSeries = function( |
| 584 | ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, |
| 585 | stepPlot, strategy) { |
| 586 | |
| 587 | var prevCanvasX = null; |
| 588 | var prevCanvasY = null; |
| 589 | var nextCanvasY = null; |
| 590 | var isIsolated; // true if this point is isolated (no line segments) |
| 591 | var point; // the point being processed in the while loop |
| 592 | var pointsOnLine = []; // Array of [canvasx, canvasy] pairs. |
| 593 | var first = true; // the first cycle through the while loop |
| 594 | |
| 595 | strategy.init(); |
| 596 | |
| 597 | while(iter.hasNext()) { |
| 598 | point = iter.next(); |
| 599 | if (point.canvasy === null || point.canvasy != point.canvasy) { |
| 600 | if (stepPlot && prevCanvasX !== null) { |
| 601 | // Draw a horizontal line to the start of the missing data |
| 602 | strategy.startSegment(); |
| 603 | strategy.drawLine(prevX, prevY, point.canvasx, prevY); |
| 604 | strategy.endSegment(); |
| 605 | } |
| 606 | prevCanvasX = prevCanvasY = null; |
| 607 | } else { |
| 608 | nextCanvasY = iter.hasNext() ? iter.peek().canvasy : null; |
| 609 | // TODO: we calculate isNullOrNaN for this point, and the next, and then, when |
| 610 | // we iterate, test for isNullOrNaN again. Why bother? |
| 611 | var isNextCanvasYNullOrNaN = nextCanvasY === null || nextCanvasY != nextCanvasY; |
| 612 | isIsolated = (!prevCanvasX && isNextCanvasYNullOrNaN); |
| 613 | if (drawGapPoints) { |
| 614 | // Also consider a point to be "isolated" if it's adjacent to a |
| 615 | // null point, excluding the graph edges. |
| 616 | if ((!first && !prevCanvasX) || |
| 617 | (iter.hasNext() && isNextCanvasYNullOrNaN)) { |
| 618 | isIsolated = true; |
| 619 | } |
| 620 | } |
| 621 | if (prevCanvasX !== null) { |
| 622 | if (strategy.skipPixel(prevCanvasX, prevCanvasY, point.canvasx, point.canvasy)) { |
| 623 | continue; |
| 624 | } |
| 625 | if (strokeWidth) { |
| 626 | strategy.startSegment(); |
| 627 | if (stepPlot) { |
| 628 | strategy.drawLine(prevCanvasX, prevCanvasY, point.canvasx, prevCanvasY); |
| 629 | prevCanvasX = point.canvasx; |
| 630 | } |
| 631 | strategy.drawLine(prevCanvasX, prevCanvasY, point.canvasx, point.canvasy); |
| 632 | strategy.endSegment(); |
| 633 | } |
| 634 | } |
| 635 | if (drawPoints || isIsolated) { |
| 636 | pointsOnLine.push([point.canvasx, point.canvasy]); |
| 637 | } |
| 638 | prevCanvasX = point.canvasx; |
| 639 | prevCanvasY = point.canvasy; |
| 640 | } |
| 641 | first = false; |
| 642 | } |
| 643 | strategy.finish(); |
| 644 | return pointsOnLine; |
| 645 | }; |
| 646 | |
| 647 | DygraphCanvasRenderer.prototype._drawLine = function(ctx, i) { |
| 648 | var setNames = this.layout.setNames; |
| 649 | var setName = setNames[i]; |
| 650 | |
| 651 | var strokeWidth = this.dygraph_.attr_("strokeWidth", setName); |
| 652 | var borderWidth = this.dygraph_.attr_("strokeBorderWidth", setName); |
| 653 | var drawPointCallback = this.dygraph_.attr_("drawPointCallback", setName) || |
| 654 | Dygraph.Circles.DEFAULT; |
| 655 | |
| 656 | if (borderWidth && strokeWidth) { |
| 657 | this._drawStyledLine(ctx, i, setName, |
| 658 | this.dygraph_.attr_("strokeBorderColor", setName), |
| 659 | strokeWidth + 2 * borderWidth, |
| 660 | this.dygraph_.attr_("strokePattern", setName), |
| 661 | this.dygraph_.attr_("drawPoints", setName), |
| 662 | drawPointCallback, |
| 663 | this.dygraph_.attr_("pointSize", setName)); |
| 664 | } |
| 665 | |
| 666 | this._drawStyledLine(ctx, i, setName, |
| 667 | this.colors[setName], |
| 668 | strokeWidth, |
| 669 | this.dygraph_.attr_("strokePattern", setName), |
| 670 | this.dygraph_.attr_("drawPoints", setName), |
| 671 | drawPointCallback, |
| 672 | this.dygraph_.attr_("pointSize", setName)); |
| 673 | }; |
| 674 | |
| 675 | /** |
| 676 | * Actually draw the lines chart, including error bars. |
| 677 | * TODO(danvk): split this into several smaller functions. |
| 678 | * @private |
| 679 | */ |
| 680 | DygraphCanvasRenderer.prototype._renderLineChart = function() { |
| 681 | // TODO(danvk): use this.attr_ for many of these. |
| 682 | var ctx = this.elementContext; |
| 683 | var fillAlpha = this.attr_('fillAlpha'); |
| 684 | var errorBars = this.attr_("errorBars") || this.attr_("customBars"); |
| 685 | var fillGraph = this.attr_("fillGraph"); |
| 686 | var stackedGraph = this.attr_("stackedGraph"); |
| 687 | var stepPlot = this.attr_("stepPlot"); |
| 688 | var points = this.layout.points; |
| 689 | var pointsLength = points.length; |
| 690 | var point, i, prevX, prevY, prevYs, color, setName, newYs, err_color, rgb, yscale, axis; |
| 691 | |
| 692 | var setNames = this.layout.setNames; |
| 693 | var setCount = setNames.length; |
| 694 | |
| 695 | this.colors = this.dygraph_.colorsMap_; |
| 696 | |
| 697 | // Update Points |
| 698 | // TODO(danvk): here |
| 699 | // |
| 700 | // TODO(bhs): this loop is a hot-spot for high-point-count charts. These |
| 701 | // transformations can be pushed into the canvas via linear transformation |
| 702 | // matrices. |
| 703 | for (i = pointsLength; i--;) { |
| 704 | point = points[i]; |
| 705 | point.canvasx = this.area.w * point.x + this.area.x; |
| 706 | point.canvasy = this.area.h * point.y + this.area.y; |
| 707 | } |
| 708 | |
| 709 | // create paths |
| 710 | if (errorBars) { |
| 711 | ctx.save(); |
| 712 | if (fillGraph) { |
| 713 | this.dygraph_.warn("Can't use fillGraph option with error bars"); |
| 714 | } |
| 715 | |
| 716 | for (i = 0; i < setCount; i++) { |
| 717 | setName = setNames[i]; |
| 718 | axis = this.dygraph_.axisPropertiesForSeries(setName); |
| 719 | color = this.colors[setName]; |
| 720 | |
| 721 | var firstIndexInSet = this.layout.setPointsOffsets[i]; |
| 722 | var setLength = this.layout.setPointsLengths[i]; |
| 723 | |
| 724 | var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, |
| 725 | DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints"))); |
| 726 | |
| 727 | // setup graphics context |
| 728 | prevX = NaN; |
| 729 | prevY = NaN; |
| 730 | prevYs = [-1, -1]; |
| 731 | yscale = axis.yscale; |
| 732 | // should be same color as the lines but only 15% opaque. |
| 733 | rgb = new RGBColor(color); |
| 734 | err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + |
| 735 | fillAlpha + ')'; |
| 736 | ctx.fillStyle = err_color; |
| 737 | ctx.beginPath(); |
| 738 | while (iter.hasNext()) { |
| 739 | point = iter.next(); |
| 740 | if (point.name == setName) { // TODO(klausw): this is always true |
| 741 | if (!Dygraph.isOK(point.y)) { |
| 742 | prevX = NaN; |
| 743 | continue; |
| 744 | } |
| 745 | |
| 746 | // TODO(danvk): here |
| 747 | if (stepPlot) { |
| 748 | newYs = [ point.y_bottom, point.y_top ]; |
| 749 | prevY = point.y; |
| 750 | } else { |
| 751 | newYs = [ point.y_bottom, point.y_top ]; |
| 752 | } |
| 753 | newYs[0] = this.area.h * newYs[0] + this.area.y; |
| 754 | newYs[1] = this.area.h * newYs[1] + this.area.y; |
| 755 | if (!isNaN(prevX)) { |
| 756 | if (stepPlot) { |
| 757 | ctx.moveTo(prevX, newYs[0]); |
| 758 | } else { |
| 759 | ctx.moveTo(prevX, prevYs[0]); |
| 760 | } |
| 761 | ctx.lineTo(point.canvasx, newYs[0]); |
| 762 | ctx.lineTo(point.canvasx, newYs[1]); |
| 763 | if (stepPlot) { |
| 764 | ctx.lineTo(prevX, newYs[1]); |
| 765 | } else { |
| 766 | ctx.lineTo(prevX, prevYs[1]); |
| 767 | } |
| 768 | ctx.closePath(); |
| 769 | } |
| 770 | prevYs = newYs; |
| 771 | prevX = point.canvasx; |
| 772 | } |
| 773 | } |
| 774 | ctx.fill(); |
| 775 | } |
| 776 | ctx.restore(); |
| 777 | } else if (fillGraph) { |
| 778 | ctx.save(); |
| 779 | var baseline = {}; // for stacked graphs: baseline for filling |
| 780 | var currBaseline; |
| 781 | |
| 782 | // process sets in reverse order (needed for stacked graphs) |
| 783 | for (i = setCount - 1; i >= 0; i--) { |
| 784 | setName = setNames[i]; |
| 785 | color = this.colors[setName]; |
| 786 | axis = this.dygraph_.axisPropertiesForSeries(setName); |
| 787 | var axisY = 1.0 + axis.minyval * axis.yscale; |
| 788 | if (axisY < 0.0) axisY = 0.0; |
| 789 | else if (axisY > 1.0) axisY = 1.0; |
| 790 | axisY = this.area.h * axisY + this.area.y; |
| 791 | var firstIndexInSet = this.layout.setPointsOffsets[i]; |
| 792 | var setLength = this.layout.setPointsLengths[i]; |
| 793 | |
| 794 | var iter = Dygraph.createIterator(points, firstIndexInSet, setLength, |
| 795 | DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints"))); |
| 796 | |
| 797 | // setup graphics context |
| 798 | prevX = NaN; |
| 799 | prevYs = [-1, -1]; |
| 800 | yscale = axis.yscale; |
| 801 | // should be same color as the lines but only 15% opaque. |
| 802 | rgb = new RGBColor(color); |
| 803 | err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + |
| 804 | fillAlpha + ')'; |
| 805 | ctx.fillStyle = err_color; |
| 806 | ctx.beginPath(); |
| 807 | while(iter.hasNext()) { |
| 808 | point = iter.next(); |
| 809 | if (point.name == setName) { // TODO(klausw): this is always true |
| 810 | if (!Dygraph.isOK(point.y)) { |
| 811 | prevX = NaN; |
| 812 | continue; |
| 813 | } |
| 814 | if (stackedGraph) { |
| 815 | currBaseline = baseline[point.canvasx]; |
| 816 | var lastY; |
| 817 | if (currBaseline === undefined) { |
| 818 | lastY = axisY; |
| 819 | } else { |
| 820 | if(stepPlot) { |
| 821 | lastY = currBaseline[0]; |
| 822 | } else { |
| 823 | lastY = currBaseline; |
| 824 | } |
| 825 | } |
| 826 | newYs = [ point.canvasy, lastY ]; |
| 827 | |
| 828 | if(stepPlot) { |
| 829 | // Step plots must keep track of the top and bottom of |
| 830 | // the baseline at each point. |
| 831 | if(prevYs[0] === -1) { |
| 832 | baseline[point.canvasx] = [ point.canvasy, axisY ]; |
| 833 | } else { |
| 834 | baseline[point.canvasx] = [ point.canvasy, prevYs[0] ]; |
| 835 | } |
| 836 | } else { |
| 837 | baseline[point.canvasx] = point.canvasy; |
| 838 | } |
| 839 | |
| 840 | } else { |
| 841 | newYs = [ point.canvasy, axisY ]; |
| 842 | } |
| 843 | if (!isNaN(prevX)) { |
| 844 | ctx.moveTo(prevX, prevYs[0]); |
| 845 | |
| 846 | if (stepPlot) { |
| 847 | ctx.lineTo(point.canvasx, prevYs[0]); |
| 848 | if(currBaseline) { |
| 849 | // Draw to the bottom of the baseline |
| 850 | ctx.lineTo(point.canvasx, currBaseline[1]); |
| 851 | } else { |
| 852 | ctx.lineTo(point.canvasx, newYs[1]); |
| 853 | } |
| 854 | } else { |
| 855 | ctx.lineTo(point.canvasx, newYs[0]); |
| 856 | ctx.lineTo(point.canvasx, newYs[1]); |
| 857 | } |
| 858 | |
| 859 | ctx.lineTo(prevX, prevYs[1]); |
| 860 | ctx.closePath(); |
| 861 | } |
| 862 | prevYs = newYs; |
| 863 | prevX = point.canvasx; |
| 864 | } |
| 865 | } |
| 866 | ctx.fill(); |
| 867 | } |
| 868 | ctx.restore(); |
| 869 | } |
| 870 | |
| 871 | // Drawing the lines. |
| 872 | for (i = 0; i < setCount; i += 1) { |
| 873 | this._drawLine(ctx, i); |
| 874 | } |
| 875 | }; |
| 876 | |
| 877 | /** |
| 878 | * This does dashed lines onto a canvas for a given pattern. You must call |
| 879 | * ctx.stroke() after to actually draw it, much line ctx.lineTo(). It remembers |
| 880 | * the state of the line in regards to where we left off on drawing the pattern. |
| 881 | * You can draw a dashed line in several function calls and the pattern will be |
| 882 | * continous as long as you didn't call this function with a different pattern |
| 883 | * in between. |
| 884 | * @param ctx The canvas 2d context to draw on. |
| 885 | * @param x The start of the line's x coordinate. |
| 886 | * @param y The start of the line's y coordinate. |
| 887 | * @param x2 The end of the line's x coordinate. |
| 888 | * @param y2 The end of the line's y coordinate. |
| 889 | * @param pattern The dash pattern to draw, an array of integers where even |
| 890 | * index is drawn and odd index is not drawn (Ex. [10, 2, 5, 2], 10 is drawn 5 |
| 891 | * is drawn, 2 is the space between.). A null pattern, array of length one, or |
| 892 | * empty array will do just a solid line. |
| 893 | * @private |
| 894 | */ |
| 895 | DygraphCanvasRenderer.prototype._dashedLine = function(ctx, x, y, x2, y2, pattern) { |
| 896 | // Original version http://stackoverflow.com/questions/4576724/dotted-stroke-in-canvas |
| 897 | // Modified by Russell Valentine to keep line history and continue the pattern |
| 898 | // where it left off. |
| 899 | var dx, dy, len, rot, patternIndex, segment; |
| 900 | |
| 901 | // If we don't have a pattern or it is an empty array or of size one just |
| 902 | // do a solid line. |
| 903 | if (!pattern || pattern.length <= 1) { |
| 904 | ctx.moveTo(x, y); |
| 905 | ctx.lineTo(x2, y2); |
| 906 | return; |
| 907 | } |
| 908 | |
| 909 | // If we have a different dash pattern than the last time this was called we |
| 910 | // reset our dash history and start the pattern from the begging |
| 911 | // regardless of state of the last pattern. |
| 912 | if (!Dygraph.compareArrays(pattern, this._dashedLineToHistoryPattern)) { |
| 913 | this._dashedLineToHistoryPattern = pattern; |
| 914 | this._dashedLineToHistory = [0, 0]; |
| 915 | } |
| 916 | ctx.save(); |
| 917 | |
| 918 | // Calculate transformation parameters |
| 919 | dx = (x2-x); |
| 920 | dy = (y2-y); |
| 921 | len = Math.sqrt(dx*dx + dy*dy); |
| 922 | rot = Math.atan2(dy, dx); |
| 923 | |
| 924 | // Set transformation |
| 925 | ctx.translate(x, y); |
| 926 | ctx.moveTo(0, 0); |
| 927 | ctx.rotate(rot); |
| 928 | |
| 929 | // Set last pattern index we used for this pattern. |
| 930 | patternIndex = this._dashedLineToHistory[0]; |
| 931 | x = 0; |
| 932 | while (len > x) { |
| 933 | // Get the length of the pattern segment we are dealing with. |
| 934 | segment = pattern[patternIndex]; |
| 935 | // If our last draw didn't complete the pattern segment all the way we |
| 936 | // will try to finish it. Otherwise we will try to do the whole segment. |
| 937 | if (this._dashedLineToHistory[1]) { |
| 938 | x += this._dashedLineToHistory[1]; |
| 939 | } else { |
| 940 | x += segment; |
| 941 | } |
| 942 | if (x > len) { |
| 943 | // We were unable to complete this pattern index all the way, keep |
| 944 | // where we are the history so our next draw continues where we left off |
| 945 | // in the pattern. |
| 946 | this._dashedLineToHistory = [patternIndex, x-len]; |
| 947 | x = len; |
| 948 | } else { |
| 949 | // We completed this patternIndex, we put in the history that we are on |
| 950 | // the beginning of the next segment. |
| 951 | this._dashedLineToHistory = [(patternIndex+1)%pattern.length, 0]; |
| 952 | } |
| 953 | |
| 954 | // We do a line on a even pattern index and just move on a odd pattern index. |
| 955 | // The move is the empty space in the dash. |
| 956 | if(patternIndex % 2 === 0) { |
| 957 | ctx.lineTo(x, 0); |
| 958 | } else { |
| 959 | ctx.moveTo(x, 0); |
| 960 | } |
| 961 | // If we are not done, next loop process the next pattern segment, or the |
| 962 | // first segment again if we are at the end of the pattern. |
| 963 | patternIndex = (patternIndex+1) % pattern.length; |
| 964 | } |
| 965 | ctx.restore(); |
| 966 | }; |