Code comments and indentation fixes.
[dygraphs.git] / dygraph-layout.js
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1/**
2 * @license
3 * Copyright 2011 Dan Vanderkam (danvdk@gmail.com)
4 * MIT-licensed (http://opensource.org/licenses/MIT)
5 */
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6
7/**
8 * @fileoverview Based on PlotKitLayout, but modified to meet the needs of
9 * dygraphs.
10 */
11
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12/*jshint globalstrict: true */
13/*global Dygraph:false */
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14"use strict";
15
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16/**
17 * Creates a new DygraphLayout object.
18 *
19 * This class contains all the data to be charted.
20 * It uses data coordinates, but also records the chart range (in data
21 * coordinates) and hence is able to calculate percentage positions ('In this
22 * view, Point A lies 25% down the x-axis.')
23 *
24 * Two things that it does not do are:
25 * 1. Record pixel coordinates for anything.
26 * 2. (oddly) determine anything about the layout of chart elements.
27 *
28 * The naming is a vestige of Dygraph's original PlotKit roots.
29 *
30 * @constructor
31 */
c0f54d4f 32var DygraphLayout = function(dygraph) {
74a5af31 33 this.dygraph_ = dygraph;
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34 /**
35 * Array of points for each series.
36 *
37 * [series index][row index in series] = |Point| structure,
38 * where series index refers to visible series only, and the
39 * point index is for the reduced set of points for the current
40 * zoom region (including one point just outside the window).
41 * All points in the same row index share the same X value.
42 *
43 * @type {Array.<Array.<Dygraph.PointType>>}
44 */
45 this.points = [];
82c6fe4d 46 this.setNames = [];
758a629f 47 this.annotations = [];
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48 this.yAxes_ = null;
49
50 // TODO(danvk): it's odd that xTicks_ and yTicks_ are inputs, but xticks and
51 // yticks are outputs. Clean this up.
52 this.xTicks_ = null;
53 this.yTicks_ = null;
54};
55
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56/**
57 * Add points for a single series.
58 *
59 * @param {string} setname Name of the series.
60 * @param {Array.<Dygraph.PointType>} set_xy Points for the series.
61 */
74a5af31 62DygraphLayout.prototype.addDataset = function(setname, set_xy) {
30a5cfc6 63 this.points.push(set_xy);
82c6fe4d 64 this.setNames.push(setname);
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65};
66
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67/**
68 * Returns the box which the chart should be drawn in. This is the canvas's
69 * box, less space needed for the axis and chart labels.
70 *
71 * @return {{x: number, y: number, w: number, h: number}}
72 */
70be5ed1 73DygraphLayout.prototype.getPlotArea = function() {
0d216a60 74 return this.area_;
758a629f 75};
70be5ed1 76
ccd9d7c2 77// Compute the box which the chart should be drawn in. This is the canvas's
ad617f17 78// box, less space needed for axis, chart labels, and other plug-ins.
ec475f44 79// NOTE: This should only be called by Dygraph.predraw_().
0d216a60 80DygraphLayout.prototype.computePlotArea = function() {
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81 var area = {
82 // TODO(danvk): per-axis setting.
83 x: 0,
84 y: 0
85 };
f8540c66 86
7e64db42 87 area.w = this.dygraph_.width_ - area.x - this.dygraph_.getOption('rightGap');
ccd9d7c2 88 area.h = this.dygraph_.height_;
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89
90 // Let plugins reserve space.
91 var e = {
92 chart_div: this.dygraph_.graphDiv,
93 reserveSpaceLeft: function(px) {
94 var r = {
95 x: area.x,
96 y: area.y,
97 w: px,
98 h: area.h
99 };
100 area.x += px;
101 area.w -= px;
102 return r;
103 },
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104 reserveSpaceRight: function(px) {
105 var r = {
106 x: area.x + area.w - px,
107 y: area.y,
108 w: px,
109 h: area.h
110 };
111 area.w -= px;
112 return r;
113 },
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114 reserveSpaceTop: function(px) {
115 var r = {
116 x: area.x,
117 y: area.y,
118 w: area.w,
119 h: px
120 };
121 area.y += px;
122 area.h -= px;
123 return r;
124 },
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125 reserveSpaceBottom: function(px) {
126 var r = {
127 x: area.x,
128 y: area.y + area.h - px,
129 w: area.w,
130 h: px
131 };
132 area.h -= px;
133 return r;
134 },
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135 chartRect: function() {
136 return {x:area.x, y:area.y, w:area.w, h:area.h};
137 }
138 };
139 this.dygraph_.cascadeEvents_('layout', e);
140
0d216a60 141 this.area_ = area;
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142};
143
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144DygraphLayout.prototype.setAnnotations = function(ann) {
145 // The Dygraph object's annotations aren't parsed. We parse them here and
146 // save a copy. If there is no parser, then the user must be using raw format.
147 this.annotations = [];
7e64db42 148 var parse = this.dygraph_.getOption('xValueParser') || function(x) { return x; };
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149 for (var i = 0; i < ann.length; i++) {
150 var a = {};
b5481aea 151 if (!ann[i].xval && ann[i].x === undefined) {
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152 this.dygraph_.error("Annotations must have an 'x' property");
153 return;
154 }
155 if (ann[i].icon &&
156 !(ann[i].hasOwnProperty('width') &&
157 ann[i].hasOwnProperty('height'))) {
158 this.dygraph_.error("Must set width and height when setting " +
159 "annotation.icon property");
160 return;
161 }
162 Dygraph.update(a, ann[i]);
163 if (!a.xval) a.xval = parse(a.x);
164 this.annotations.push(a);
165 }
166};
167
168DygraphLayout.prototype.setXTicks = function(xTicks) {
169 this.xTicks_ = xTicks;
170};
171
172// TODO(danvk): add this to the Dygraph object's API or move it into Layout.
173DygraphLayout.prototype.setYAxes = function (yAxes) {
174 this.yAxes_ = yAxes;
175};
176
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177DygraphLayout.prototype.evaluate = function() {
178 this._evaluateLimits();
179 this._evaluateLineCharts();
180 this._evaluateLineTicks();
181 this._evaluateAnnotations();
182};
183
184DygraphLayout.prototype._evaluateLimits = function() {
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185 var xlimits = this.dygraph_.xAxisRange();
186 this.minxval = xlimits[0];
187 this.maxxval = xlimits[1];
188 var xrange = xlimits[1] - xlimits[0];
189 this.xscale = (xrange !== 0 ? 1 / xrange : 1.0);
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190
191 for (var i = 0; i < this.yAxes_.length; i++) {
192 var axis = this.yAxes_[i];
193 axis.minyval = axis.computedValueRange[0];
194 axis.maxyval = axis.computedValueRange[1];
195 axis.yrange = axis.maxyval - axis.minyval;
758a629f 196 axis.yscale = (axis.yrange !== 0 ? 1.0 / axis.yrange : 1.0);
74a5af31 197
7e64db42 198 if (axis.g.getOption("logscale")) {
74a5af31 199 axis.ylogrange = Dygraph.log10(axis.maxyval) - Dygraph.log10(axis.minyval);
758a629f 200 axis.ylogscale = (axis.ylogrange !== 0 ? 1.0 / axis.ylogrange : 1.0);
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201 if (!isFinite(axis.ylogrange) || isNaN(axis.ylogrange)) {
202 axis.g.error('axis ' + i + ' of graph at ' + axis.g +
203 ' can\'t be displayed in log scale for range [' +
204 axis.minyval + ' - ' + axis.maxyval + ']');
205 }
206 }
207 }
208};
209
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210DygraphLayout._calcYNormal = function(axis, value, logscale) {
211 if (logscale) {
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212 return 1.0 - ((Dygraph.log10(value) - Dygraph.log10(axis.minyval)) * axis.ylogscale);
213 } else {
214 return 1.0 - ((value - axis.minyval) * axis.yscale);
215 }
216};
217
74a5af31 218DygraphLayout.prototype._evaluateLineCharts = function() {
7e64db42 219 var isStacked = this.dygraph_.getOption("stackedGraph");
a12a78ae 220
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221 for (var setIdx = 0; setIdx < this.points.length; setIdx++) {
222 var points = this.points[setIdx];
82c6fe4d 223 var setName = this.setNames[setIdx];
7e64db42 224 var connectSeparated = this.dygraph_.getOption('connectSeparatedPoints', setName);
74a5af31 225 var axis = this.dygraph_.axisPropertiesForSeries(setName);
23db4e07 226 // TODO (konigsberg): use optionsForAxis instead.
8e19509a 227 var logscale = this.dygraph_.attributes_.getForSeries("logscale", setName);
74a5af31 228
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229 for (var j = 0; j < points.length; j++) {
230 var point = points[j];
ecf9b464 231
4ab8db0c 232 // Range from 0-1 where 0 represents left and 1 represents right.
30a5cfc6 233 point.x = (point.xval - this.minxval) * this.xscale;
7f028980 234 // Range from 0-1 where 0 represents top and 1 represents bottom
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235 var yval = point.yval;
236 if (isStacked) {
237 point.y_stacked = DygraphLayout._calcYNormal(
238 axis, point.yval_stacked, logscale);
239 if (yval !== null && !isNaN(yval)) {
240 yval = point.yval_stacked;
241 }
242 }
243 if (yval === null) {
244 yval = NaN;
245 if (!connectSeparated) {
246 point.yval = NaN;
247 }
248 }
249 point.y = DygraphLayout._calcYNormal(axis, yval, logscale);
74a5af31 250 }
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251
252 this.dygraph_.dataHandler_.onLineEvaluated(points, axis, logscale);
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253 }
254};
255
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256/**
257 * Optimized replacement for parseFloat, which was way too slow when almost
258 * all values were type number, with few edge cases, none of which were strings.
259 */
260DygraphLayout.parseFloat_ = function(val) {
261 // parseFloat(null) is NaN
262 if (val === null) {
263 return NaN;
264 }
265
266 // Assume it's a number or NaN. If it's something else, I'll be shocked.
267 return val;
42a9ebb8 268};
57915b7a 269
74a5af31 270DygraphLayout.prototype._evaluateLineTicks = function() {
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271 var i, tick, label, pos;
272 this.xticks = [];
273 for (i = 0; i < this.xTicks_.length; i++) {
274 tick = this.xTicks_[i];
275 label = tick.label;
276 pos = this.xscale * (tick.v - this.minxval);
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277 if ((pos >= 0.0) && (pos <= 1.0)) {
278 this.xticks.push([pos, label]);
279 }
280 }
281
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282 this.yticks = [];
283 for (i = 0; i < this.yAxes_.length; i++ ) {
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284 var axis = this.yAxes_[i];
285 for (var j = 0; j < axis.ticks.length; j++) {
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286 tick = axis.ticks[j];
287 label = tick.label;
288 pos = this.dygraph_.toPercentYCoord(tick.v, i);
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289 if ((pos >= 0.0) && (pos <= 1.0)) {
290 this.yticks.push([i, pos, label]);
291 }
292 }
293 }
294};
295
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296DygraphLayout.prototype._evaluateAnnotations = function() {
297 // Add the annotations to the point to which they belong.
298 // Make a map from (setName, xval) to annotation for quick lookups.
758a629f 299 var i;
74a5af31 300 var annotations = {};
758a629f 301 for (i = 0; i < this.annotations.length; i++) {
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302 var a = this.annotations[i];
303 annotations[a.xval + "," + a.series] = a;
304 }
305
306 this.annotated_points = [];
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307
308 // Exit the function early if there are no annotations.
309 if (!this.annotations || !this.annotations.length) {
310 return;
311 }
ccd9d7c2 312
d570a072 313 // TODO(antrob): loop through annotations not points.
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314 for (var setIdx = 0; setIdx < this.points.length; setIdx++) {
315 var points = this.points[setIdx];
316 for (i = 0; i < points.length; i++) {
317 var p = points[i];
318 var k = p.xval + "," + p.name;
319 if (k in annotations) {
320 p.annotation = annotations[k];
321 this.annotated_points.push(p);
322 }
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323 }
324 }
325};
326
327/**
328 * Convenience function to remove all the data sets from a graph
329 */
330DygraphLayout.prototype.removeAllDatasets = function() {
30a5cfc6 331 delete this.points;
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332 delete this.setNames;
333 delete this.setPointsLengths;
334 delete this.setPointsOffsets;
30a5cfc6 335 this.points = [];
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336 this.setNames = [];
337 this.setPointsLengths = [];
338 this.setPointsOffsets = [];
74a5af31 339};