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