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f8540c66 DV |
1 | /** |
2 | * @license | |
3 | * Copyright 2012 Dan Vanderkam (danvdk@gmail.com) | |
4 | * MIT-licensed (http://opensource.org/licenses/MIT) | |
5 | */ | |
6 | ||
7 | Dygraph.Plugins.Axes = (function() { | |
8 | ||
13f8b047 DV |
9 | "use strict"; |
10 | ||
f8540c66 DV |
11 | /* |
12 | ||
13 | Bits of jankiness: | |
14 | - Direct layout access | |
15 | - Direct area access | |
16 | - Should include calculation of ticks, not just the drawing. | |
17 | ||
18 | */ | |
19 | ||
20 | /** | |
21 | * Draws the axes. This includes the labels on the x- and y-axes, as well | |
22 | * as the tick marks on the axes. | |
23 | * It does _not_ draw the grid lines which span the entire chart. | |
24 | */ | |
25 | var axes = function() { | |
26 | this.xlabels_ = []; | |
27 | this.ylabels_ = []; | |
28 | }; | |
29 | ||
30 | axes.prototype.toString = function() { | |
31 | return "Axes Plugin"; | |
32 | }; | |
33 | ||
34 | axes.prototype.activate = function(g) { | |
35 | return { | |
36 | layout: this.layout, | |
37 | clearChart: this.clearChart, | |
98eb4713 | 38 | willDrawChart: this.willDrawChart |
f8540c66 DV |
39 | }; |
40 | }; | |
41 | ||
42 | axes.prototype.layout = function(e) { | |
43 | var g = e.dygraph; | |
44 | ||
45 | if (g.getOption('drawYAxis')) { | |
46 | var w = g.getOption('yAxisLabelWidth') + 2 * g.getOption('axisTickSize'); | |
47 | var y_axis_rect = e.reserveSpaceLeft(w); | |
48 | } | |
49 | ||
50 | if (g.getOption('drawXAxis')) { | |
51 | var h; | |
52 | if (g.getOption('xAxisHeight')) { | |
53 | h = g.getOption('xAxisHeight'); | |
54 | } else { | |
d43d407b | 55 | h = g.getOptionForAxis('axisLabelFontSize', 'x') + 2 * g.getOption('axisTickSize'); |
f8540c66 DV |
56 | } |
57 | var x_axis_rect = e.reserveSpaceBottom(h); | |
58 | } | |
59 | ||
60 | if (g.numAxes() == 2) { | |
61 | // TODO(danvk): per-axis setting. | |
62 | var w = g.getOption('yAxisLabelWidth') + 2 * g.getOption('axisTickSize'); | |
63 | var y2_axis_rect = e.reserveSpaceRight(w); | |
64 | } else if (g.numAxes() > 2) { | |
65 | g.error("Only two y-axes are supported at this time. (Trying " + | |
66 | "to use " + g.numAxes() + ")"); | |
67 | } | |
68 | }; | |
69 | ||
70 | axes.prototype.detachLabels = function() { | |
71 | function removeArray(ary) { | |
72 | for (var i = 0; i < ary.length; i++) { | |
73 | var el = ary[i]; | |
74 | if (el.parentNode) el.parentNode.removeChild(el); | |
75 | } | |
76 | } | |
77 | ||
78 | removeArray(this.xlabels_); | |
79 | removeArray(this.ylabels_); | |
80 | this.xlabels_ = []; | |
81 | this.ylabels_ = []; | |
82 | }; | |
83 | ||
84 | axes.prototype.clearChart = function(e) { | |
85 | var g = e.dygraph; | |
86 | this.detachLabels(); | |
42a9ebb8 | 87 | }; |
f8540c66 | 88 | |
98eb4713 | 89 | axes.prototype.willDrawChart = function(e) { |
f8540c66 DV |
90 | var g = e.dygraph; |
91 | if (!g.getOption('drawXAxis') && !g.getOption('drawYAxis')) return; | |
92 | ||
93 | // Round pixels to half-integer boundaries for crisper drawing. | |
94 | function halfUp(x) { return Math.round(x) + 0.5; } | |
95 | function halfDown(y){ return Math.round(y) - 0.5; } | |
96 | ||
97 | var context = e.drawingContext; | |
98 | var containerDiv = e.canvas.parentNode; | |
beeabac2 DV |
99 | var canvasWidth = e.canvas.width; |
100 | var canvasHeight = e.canvas.height; | |
f8540c66 DV |
101 | |
102 | var label, x, y, tick, i; | |
103 | ||
d43d407b RK |
104 | var makeLabelStyle = function(axis) { |
105 | return { | |
106 | position: "absolute", | |
107 | fontSize: g.getOptionForAxis('axisLabelFontSize', axis) + "px", | |
108 | zIndex: 10, | |
109 | color: g.getOption('axisLabelColor'), | |
110 | width: g.getOption('axisLabelWidth') + "px", | |
111 | // height: g.getOptionForAxis('axisLabelFontSize', 'x') + 2 + "px", | |
112 | lineHeight: "normal", // Something other than "normal" line-height screws up label positioning. | |
113 | overflow: "hidden" | |
114 | }; | |
115 | } | |
116 | ||
117 | var labelStyles = { | |
118 | x : makeLabelStyle('x'), | |
119 | y : makeLabelStyle('y'), | |
120 | y2 : makeLabelStyle('y2'), | |
f8540c66 | 121 | }; |
d43d407b | 122 | |
f8540c66 | 123 | var makeDiv = function(txt, axis, prec_axis) { |
d43d407b RK |
124 | /* |
125 | * This seems to be called with the following three sets of axis/perc_axis: | |
126 | * x: undefined | |
127 | * y: y1 | |
128 | * y: y2 | |
129 | */ | |
f8540c66 | 130 | var div = document.createElement("div"); |
d43d407b | 131 | var labelStyle = labelStyles[prec_axis == 'y2' ? 'y2' : axis]; |
f8540c66 DV |
132 | for (var name in labelStyle) { |
133 | if (labelStyle.hasOwnProperty(name)) { | |
134 | div.style[name] = labelStyle[name]; | |
135 | } | |
136 | } | |
137 | var inner_div = document.createElement("div"); | |
138 | inner_div.className = 'dygraph-axis-label' + | |
139 | ' dygraph-axis-label-' + axis + | |
140 | (prec_axis ? ' dygraph-axis-label-' + prec_axis : ''); | |
141 | inner_div.innerHTML = txt; | |
142 | div.appendChild(inner_div); | |
143 | return div; | |
144 | }; | |
145 | ||
146 | // axis lines | |
147 | context.save(); | |
148 | context.strokeStyle = g.getOption('axisLineColor'); | |
149 | context.lineWidth = g.getOption('axisLineWidth'); | |
150 | ||
151 | var layout = g.layout_; | |
152 | var area = e.dygraph.plotter_.area; | |
153 | ||
154 | if (g.getOption('drawYAxis')) { | |
155 | if (layout.yticks && layout.yticks.length > 0) { | |
156 | var num_axes = g.numAxes(); | |
157 | for (i = 0; i < layout.yticks.length; i++) { | |
158 | tick = layout.yticks[i]; | |
159 | if (typeof(tick) == "function") return; | |
160 | x = area.x; | |
161 | var sgn = 1; | |
162 | var prec_axis = 'y1'; | |
163 | if (tick[0] == 1) { // right-side y-axis | |
164 | x = area.x + area.w; | |
165 | sgn = -1; | |
166 | prec_axis = 'y2'; | |
167 | } | |
d43d407b | 168 | var fontSize = g.getOptionForAxis('axisLabelFontSize', prec_axis); |
f8540c66 DV |
169 | y = area.y + tick[1] * area.h; |
170 | ||
171 | /* Tick marks are currently clipped, so don't bother drawing them. | |
172 | context.beginPath(); | |
173 | context.moveTo(halfUp(x), halfDown(y)); | |
174 | context.lineTo(halfUp(x - sgn * this.attr_('axisTickSize')), halfDown(y)); | |
175 | context.closePath(); | |
176 | context.stroke(); | |
177 | */ | |
178 | ||
179 | label = makeDiv(tick[2], 'y', num_axes == 2 ? prec_axis : null); | |
d43d407b | 180 | var top = (y - fontSize / 2); |
f8540c66 DV |
181 | if (top < 0) top = 0; |
182 | ||
d43d407b | 183 | if (top + fontSize + 3 > canvasHeight) { |
f8540c66 DV |
184 | label.style.bottom = "0px"; |
185 | } else { | |
186 | label.style.top = top + "px"; | |
187 | } | |
188 | if (tick[0] === 0) { | |
189 | label.style.left = (area.x - g.getOption('yAxisLabelWidth') - g.getOption('axisTickSize')) + "px"; | |
190 | label.style.textAlign = "right"; | |
191 | } else if (tick[0] == 1) { | |
192 | label.style.left = (area.x + area.w + | |
193 | g.getOption('axisTickSize')) + "px"; | |
194 | label.style.textAlign = "left"; | |
195 | } | |
196 | label.style.width = g.getOption('yAxisLabelWidth') + "px"; | |
197 | containerDiv.appendChild(label); | |
198 | this.ylabels_.push(label); | |
199 | } | |
200 | ||
201 | // The lowest tick on the y-axis often overlaps with the leftmost | |
202 | // tick on the x-axis. Shift the bottom tick up a little bit to | |
203 | // compensate if necessary. | |
204 | var bottomTick = this.ylabels_[0]; | |
d43d407b RK |
205 | // Interested in the y2 axis also? |
206 | var fontSize = g.getOptionForAxis('axisLabelFontSize', "y"); | |
f8540c66 | 207 | var bottom = parseInt(bottomTick.style.top, 10) + fontSize; |
beeabac2 | 208 | if (bottom > canvasHeight - fontSize) { |
f8540c66 DV |
209 | bottomTick.style.top = (parseInt(bottomTick.style.top, 10) - |
210 | fontSize / 2) + "px"; | |
211 | } | |
212 | } | |
213 | ||
214 | // draw a vertical line on the left to separate the chart from the labels. | |
215 | var axisX; | |
216 | if (g.getOption('drawAxesAtZero')) { | |
beeabac2 | 217 | var r = g.toPercentXCoord(0); |
f8540c66 DV |
218 | if (r > 1 || r < 0) r = 0; |
219 | axisX = halfUp(area.x + r * area.w); | |
220 | } else { | |
221 | axisX = halfUp(area.x); | |
222 | } | |
223 | context.beginPath(); | |
224 | context.moveTo(axisX, halfDown(area.y)); | |
225 | context.lineTo(axisX, halfDown(area.y + area.h)); | |
226 | context.closePath(); | |
227 | context.stroke(); | |
228 | ||
229 | // if there's a secondary y-axis, draw a vertical line for that, too. | |
230 | if (g.numAxes() == 2) { | |
231 | context.beginPath(); | |
232 | context.moveTo(halfDown(area.x + area.w), halfDown(area.y)); | |
233 | context.lineTo(halfDown(area.x + area.w), halfDown(area.y + area.h)); | |
234 | context.closePath(); | |
235 | context.stroke(); | |
236 | } | |
237 | } | |
238 | ||
239 | if (g.getOption('drawXAxis')) { | |
240 | if (layout.xticks) { | |
241 | for (i = 0; i < layout.xticks.length; i++) { | |
242 | tick = layout.xticks[i]; | |
243 | x = area.x + tick[0] * area.w; | |
244 | y = area.y + area.h; | |
245 | ||
246 | /* Tick marks are currently clipped, so don't bother drawing them. | |
247 | context.beginPath(); | |
248 | context.moveTo(halfUp(x), halfDown(y)); | |
249 | context.lineTo(halfUp(x), halfDown(y + this.attr_('axisTickSize'))); | |
250 | context.closePath(); | |
251 | context.stroke(); | |
252 | */ | |
253 | ||
254 | label = makeDiv(tick[1], 'x'); | |
255 | label.style.textAlign = "center"; | |
256 | label.style.top = (y + g.getOption('axisTickSize')) + 'px'; | |
257 | ||
258 | var left = (x - g.getOption('axisLabelWidth')/2); | |
beeabac2 DV |
259 | if (left + g.getOption('axisLabelWidth') > canvasWidth) { |
260 | left = canvasWidth - g.getOption('xAxisLabelWidth'); | |
f8540c66 DV |
261 | label.style.textAlign = "right"; |
262 | } | |
263 | if (left < 0) { | |
264 | left = 0; | |
265 | label.style.textAlign = "left"; | |
266 | } | |
267 | ||
268 | label.style.left = left + "px"; | |
269 | label.style.width = g.getOption('xAxisLabelWidth') + "px"; | |
270 | containerDiv.appendChild(label); | |
271 | this.xlabels_.push(label); | |
272 | } | |
273 | } | |
274 | ||
275 | context.beginPath(); | |
276 | var axisY; | |
277 | if (g.getOption('drawAxesAtZero')) { | |
278 | var r = g.toPercentYCoord(0, 0); | |
279 | if (r > 1 || r < 0) r = 1; | |
280 | axisY = halfDown(area.y + r * area.h); | |
281 | } else { | |
282 | axisY = halfDown(area.y + area.h); | |
283 | } | |
284 | context.moveTo(halfUp(area.x), axisY); | |
285 | context.lineTo(halfUp(area.x + area.w), axisY); | |
286 | context.closePath(); | |
287 | context.stroke(); | |
288 | } | |
289 | ||
290 | context.restore(); | |
42a9ebb8 | 291 | }; |
f8540c66 DV |
292 | |
293 | return axes; | |
294 | })(); |