Make connectSeparatedPoints a per-series option. Add automated test and visual test.
[dygraphs.git] / dygraph-layout.js
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 */
32 var 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 */
62 DygraphLayout.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 */
73 DygraphLayout.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_().
80 DygraphLayout.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_.attr_('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
144 DygraphLayout.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_.attr_('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 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
168 DygraphLayout.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.
173 DygraphLayout.prototype.setYAxes = function (yAxes) {
174 this.yAxes_ = yAxes;
175 };
176
177 DygraphLayout.prototype.evaluate = function() {
178 this._evaluateLimits();
179 this._evaluateLineCharts();
180 this._evaluateLineTicks();
181 this._evaluateAnnotations();
182 };
183
184 DygraphLayout.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.attr_("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 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
210 DygraphLayout._calcYNormal = function(axis, value, logscale) {
211 if (logscale) {
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
218 DygraphLayout.prototype._evaluateLineCharts = function() {
219 var isStacked = this.dygraph_.attr_("stackedGraph");
220
221 for (var setIdx = 0; setIdx < this.points.length; setIdx++) {
222 var points = this.points[setIdx];
223 var setName = this.setNames[setIdx];
224 var connectSeparated = this.dygraph_.attr_('connectSeparatedPoints', setName);
225 var axis = this.dygraph_.axisPropertiesForSeries(setName);
226 // TODO (konigsberg): use optionsForAxis instead.
227 var logscale = this.dygraph_.attributes_.getForSeries("logscale", setName);
228
229 for (var j = 0; j < points.length; j++) {
230 var point = points[j];
231
232 // Range from 0-1 where 0 represents left and 1 represents right.
233 point.x = (point.xval - this.minxval) * this.xscale;
234 // Range from 0-1 where 0 represents top and 1 represents bottom
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);
250 }
251
252 this.dygraph_.dataHandler_.onLineEvaluated(points, axis, logscale);
253 }
254 };
255
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 */
260 DygraphLayout.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;
268 };
269
270 DygraphLayout.prototype._evaluateLineTicks = function() {
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);
277 if ((pos >= 0.0) && (pos <= 1.0)) {
278 this.xticks.push([pos, label]);
279 }
280 }
281
282 this.yticks = [];
283 for (i = 0; i < this.yAxes_.length; i++ ) {
284 var axis = this.yAxes_[i];
285 for (var j = 0; j < axis.ticks.length; j++) {
286 tick = axis.ticks[j];
287 label = tick.label;
288 pos = this.dygraph_.toPercentYCoord(tick.v, i);
289 if ((pos >= 0.0) && (pos <= 1.0)) {
290 this.yticks.push([i, pos, label]);
291 }
292 }
293 }
294 };
295
296 DygraphLayout.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.
299 var i;
300 var annotations = {};
301 for (i = 0; i < this.annotations.length; i++) {
302 var a = this.annotations[i];
303 annotations[a.xval + "," + a.series] = a;
304 }
305
306 this.annotated_points = [];
307
308 // Exit the function early if there are no annotations.
309 if (!this.annotations || !this.annotations.length) {
310 return;
311 }
312
313 // TODO(antrob): loop through annotations not points.
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 }
323 }
324 }
325 };
326
327 /**
328 * Convenience function to remove all the data sets from a graph
329 */
330 DygraphLayout.prototype.removeAllDatasets = function() {
331 delete this.points;
332 delete this.setNames;
333 delete this.setPointsLengths;
334 delete this.setPointsOffsets;
335 this.points = [];
336 this.setNames = [];
337 this.setPointsLengths = [];
338 this.setPointsOffsets = [];
339 };