Update dygraph-externs to better reflect the public API (thanks mcantos)
[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 */
6
7/**
8 * @fileoverview Based on PlotKitLayout, but modified to meet the needs of
9 * dygraphs.
10 */
11
12/*jshint globalstrict: true */
13/*global Dygraph:false */
14"use strict";
15
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 */
32var DygraphLayout = function(dygraph) {
33 this.dygraph_ = dygraph;
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 = [];
46 this.setNames = [];
47 this.annotations = [];
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
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 */
62DygraphLayout.prototype.addDataset = function(setname, set_xy) {
63 this.points.push(set_xy);
64 this.setNames.push(setname);
65};
66
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 */
73DygraphLayout.prototype.getPlotArea = function() {
74 return this.area_;
75};
76
77// Compute the box which the chart should be drawn in. This is the canvas's
78// box, less space needed for axis, chart labels, and other plug-ins.
79// NOTE: This should only be called by Dygraph.predraw_().
80DygraphLayout.prototype.computePlotArea = function() {
81 var area = {
82 // TODO(danvk): per-axis setting.
83 x: 0,
84 y: 0
85 };
86
87 area.w = this.dygraph_.width_ - area.x - this.dygraph_.getOption('rightGap');
88 area.h = this.dygraph_.height_;
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 },
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 },
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 },
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 },
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
141 this.area_ = area;
142};
143
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 = [];
148 var parse = this.dygraph_.getOption('xValueParser') || function(x) { return x; };
149 for (var i = 0; i < ann.length; i++) {
150 var a = {};
151 if (!ann[i].xval && ann[i].x === undefined) {
152 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 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
177DygraphLayout.prototype.evaluate = function() {
178 this._evaluateLimits();
179 this._evaluateLineCharts();
180 this._evaluateLineTicks();
181 this._evaluateAnnotations();
182};
183
184DygraphLayout.prototype._evaluateLimits = function() {
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);
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;
196 axis.yscale = (axis.yrange !== 0 ? 1.0 / axis.yrange : 1.0);
197
198 if (axis.g.getOption("logscale")) {
199 axis.ylogrange = Dygraph.log10(axis.maxyval) - Dygraph.log10(axis.minyval);
200 axis.ylogscale = (axis.ylogrange !== 0 ? 1.0 / axis.ylogrange : 1.0);
201 if (!isFinite(axis.ylogrange) || isNaN(axis.ylogrange)) {
202 Dygraph.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
210/**
211 * @param {DygraphAxisType} axis
212 * @param {number} value
213 * @param {boolean} logscale
214 * @return {number}
215 */
216DygraphLayout.calcYNormal_ = function(axis, value, logscale) {
217 if (logscale) {
218 var x = 1.0 - ((Dygraph.log10(value) - Dygraph.log10(axis.minyval)) * axis.ylogscale);
219 return isFinite(x) ? x : NaN; // shim for v8 issue; see pull request 276
220 } else {
221 return 1.0 - ((value - axis.minyval) * axis.yscale);
222 }
223};
224
225DygraphLayout.prototype._evaluateLineCharts = function() {
226 var isStacked = this.dygraph_.getOption("stackedGraph");
227
228 for (var setIdx = 0; setIdx < this.points.length; setIdx++) {
229 var points = this.points[setIdx];
230 var setName = this.setNames[setIdx];
231 var connectSeparated = this.dygraph_.getOption('connectSeparatedPoints', setName);
232 var axis = this.dygraph_.axisPropertiesForSeries(setName);
233 // TODO (konigsberg): use optionsForAxis instead.
234 var logscale = this.dygraph_.attributes_.getForSeries("logscale", setName);
235
236 for (var j = 0; j < points.length; j++) {
237 var point = points[j];
238
239 // Range from 0-1 where 0 represents left and 1 represents right.
240 point.x = (point.xval - this.minxval) * this.xscale;
241 // Range from 0-1 where 0 represents top and 1 represents bottom
242 var yval = point.yval;
243 if (isStacked) {
244 point.y_stacked = DygraphLayout.calcYNormal_(
245 axis, point.yval_stacked, logscale);
246 if (yval !== null && !isNaN(yval)) {
247 yval = point.yval_stacked;
248 }
249 }
250 if (yval === null) {
251 yval = NaN;
252 if (!connectSeparated) {
253 point.yval = NaN;
254 }
255 }
256 point.y = DygraphLayout.calcYNormal_(axis, yval, logscale);
257 }
258
259 this.dygraph_.dataHandler_.onLineEvaluated(points, axis, logscale);
260 }
261};
262
263DygraphLayout.prototype._evaluateLineTicks = function() {
264 var i, tick, label, pos;
265 this.xticks = [];
266 for (i = 0; i < this.xTicks_.length; i++) {
267 tick = this.xTicks_[i];
268 label = tick.label;
269 pos = this.xscale * (tick.v - this.minxval);
270 if ((pos >= 0.0) && (pos < 1.0)) {
271 this.xticks.push([pos, label]);
272 }
273 }
274
275 this.yticks = [];
276 for (i = 0; i < this.yAxes_.length; i++ ) {
277 var axis = this.yAxes_[i];
278 for (var j = 0; j < axis.ticks.length; j++) {
279 tick = axis.ticks[j];
280 label = tick.label;
281 pos = this.dygraph_.toPercentYCoord(tick.v, i);
282 if ((pos > 0.0) && (pos <= 1.0)) {
283 this.yticks.push([i, pos, label]);
284 }
285 }
286 }
287};
288
289DygraphLayout.prototype._evaluateAnnotations = function() {
290 // Add the annotations to the point to which they belong.
291 // Make a map from (setName, xval) to annotation for quick lookups.
292 var i;
293 var annotations = {};
294 for (i = 0; i < this.annotations.length; i++) {
295 var a = this.annotations[i];
296 annotations[a.xval + "," + a.series] = a;
297 }
298
299 this.annotated_points = [];
300
301 // Exit the function early if there are no annotations.
302 if (!this.annotations || !this.annotations.length) {
303 return;
304 }
305
306 // TODO(antrob): loop through annotations not points.
307 for (var setIdx = 0; setIdx < this.points.length; setIdx++) {
308 var points = this.points[setIdx];
309 for (i = 0; i < points.length; i++) {
310 var p = points[i];
311 var k = p.xval + "," + p.name;
312 if (k in annotations) {
313 p.annotation = annotations[k];
314 this.annotated_points.push(p);
315 }
316 }
317 }
318};
319
320/**
321 * Convenience function to remove all the data sets from a graph
322 */
323DygraphLayout.prototype.removeAllDatasets = function() {
324 delete this.points;
325 delete this.setNames;
326 delete this.setPointsLengths;
327 delete this.setPointsOffsets;
328 this.points = [];
329 this.setNames = [];
330 this.setPointsLengths = [];
331 this.setPointsOffsets = [];
332};