3 * Copyright 2012 Dan Vanderkam (danvdk@gmail.com)
4 * MIT-licensed (http://opensource.org/licenses/MIT)
6 /*global Dygraph:false */
9 Current bits of jankiness:
10 - Uses two private APIs:
11 1. Dygraph.optionsViewForAxis_
12 2. dygraph.plotter_.area
13 - Registers for a "predraw" event, which should be renamed.
14 - I call calculateEmWidthInDiv more often than needed.
17 /*global Dygraph:false */
20 import * as utils from
'../dygraph-utils';
24 * Creates the legend, which appears when the user hovers over the chart.
25 * The legend can be either a user-specified or generated div.
29 var Legend
= function() {
30 this.legend_div_
= null;
31 this.is_generated_div_
= false; // do we own this div, or was it user-specified?
34 Legend
.prototype.toString
= function() {
35 return "Legend Plugin";
39 var generateLegendDashHTML
;
42 * This is called during the dygraph constructor, after options have been set
43 * but before the data is available.
45 * Proper tasks to do here include:
46 * - Reading your own options
48 * - Registering event listeners
50 * @param {Dygraph} g Graph instance.
51 * @return {object.<string, function(ev)>} Mapping of event names to callbacks.
53 Legend
.prototype.activate
= function(g
) {
55 var divWidth
= g
.getOption('labelsDivWidth');
57 var userLabelsDiv
= g
.getOption('labelsDiv');
58 if (userLabelsDiv
&& null !== userLabelsDiv
) {
59 if (typeof(userLabelsDiv
) == "string" || userLabelsDiv
instanceof String
) {
60 div
= document
.getElementById(userLabelsDiv
);
65 // Default legend styles. These can be overridden in CSS by adding
66 // "!important" after your rule, e.g. "left: 30px !important;"
68 "position": "absolute",
71 "width": divWidth
+ "px",
73 "left": (g
.size().width
- divWidth
- 2) + "px",
74 "background": "white",
75 "lineHeight": "normal",
77 "overflow": "hidden"};
79 // TODO(danvk): get rid of labelsDivStyles? CSS is better.
80 utils
.update(messagestyle
, g
.getOption('labelsDivStyles'));
81 div
= document
.createElement("div");
82 div
.className
= "dygraph-legend";
83 for (var name
in messagestyle
) {
84 if (!messagestyle
.hasOwnProperty(name
)) continue;
87 div
.style
[name
] = messagestyle
[name
];
89 console
.warn("You are using unsupported css properties for your " +
90 "browser in labelsDivStyles");
94 // TODO(danvk): come up with a cleaner way to expose this.
95 g
.graphDiv
.appendChild(div
);
96 this.is_generated_div_
= true;
99 this.legend_div_
= div
;
100 this.one_em_width_
= 10; // just a guess, will be updated.
104 deselect
: this.deselect
,
105 // TODO(danvk): rethink the name "predraw" before we commit to it in any API.
106 predraw
: this.predraw
,
107 didDrawChart
: this.didDrawChart
111 // Needed for dashed lines.
112 var calculateEmWidthInDiv
= function(div
) {
113 var sizeSpan
= document
.createElement('span');
114 sizeSpan
.setAttribute('style', 'margin: 0; padding: 0 0 0 1em; border: 0;');
115 div
.appendChild(sizeSpan
);
116 var oneEmWidth
=sizeSpan
.offsetWidth
;
117 div
.removeChild(sizeSpan
);
121 var escapeHTML
= function(str
) {
122 return str
.replace(/&/g, "&").replace(/"/g, """).replace(/</g, "<").replace(/>/g, ">");
125 Legend
.prototype.select
= function(e
) {
126 var xValue
= e
.selectedX
;
127 var points
= e
.selectedPoints
;
128 var row
= e
.selectedRow
;
130 var legendMode
= e
.dygraph
.getOption('legend');
131 if (legendMode
=== 'never') {
132 this.legend_div_
.style
.display
= 'none';
136 if (legendMode
=== 'follow') {
137 // create floating legend div
138 var area
= e
.dygraph
.plotter_
.area
;
139 var labelsDivWidth
= e
.dygraph
.getOption('labelsDivWidth');
140 var yAxisLabelWidth
= e
.dygraph
.getOptionForAxis('axisLabelWidth', 'y');
141 // determine floating [left, top] coordinates of the legend div
142 // within the plotter_ area
143 // offset 50 px to the right and down from the first selection point
144 // 50 px is guess based on mouse cursor size
145 var leftLegend
= points
[0].x
* area
.w
+ 50;
146 var topLegend
= points
[0].y
* area
.h
- 50;
148 // if legend floats to end of the chart area, it flips to the other
149 // side of the selection point
150 if ((leftLegend
+ labelsDivWidth
+ 1) > area
.w
) {
151 leftLegend
= leftLegend
- 2 * 50 - labelsDivWidth
- (yAxisLabelWidth
- area
.x
);
154 e
.dygraph
.graphDiv
.appendChild(this.legend_div_
);
155 this.legend_div_
.style
.left
= yAxisLabelWidth
+ leftLegend
+ "px";
156 this.legend_div_
.style
.top
= topLegend
+ "px";
159 var html
= Legend
.generateLegendHTML(e
.dygraph
, xValue
, points
, this.one_em_width_
, row
);
160 this.legend_div_
.innerHTML
= html
;
161 this.legend_div_
.style
.display
= '';
164 Legend
.prototype.deselect
= function(e
) {
165 var legendMode
= e
.dygraph
.getOption('legend');
166 if (legendMode
!== 'always') {
167 this.legend_div_
.style
.display
= "none";
170 // Have to do this every time, since styles might have changed.
171 var oneEmWidth
= calculateEmWidthInDiv(this.legend_div_
);
172 this.one_em_width_
= oneEmWidth
;
174 var html
= Legend
.generateLegendHTML(e
.dygraph
, undefined
, undefined
, oneEmWidth
, null);
175 this.legend_div_
.innerHTML
= html
;
178 Legend
.prototype.didDrawChart
= function(e
) {
182 // Right edge should be flush with the right edge of the charting area (which
183 // may not be the same as the right edge of the div, if we have two y-axes.
184 // TODO(danvk): is any of this really necessary? Could just set "right" in "activate".
186 * Position the labels div so that:
187 * - its right edge is flush with the right edge of the charting area
188 * - its top edge is flush with the top edge of the charting area
191 Legend
.prototype.predraw
= function(e
) {
192 // Don't touch a user-specified labelsDiv.
193 if (!this.is_generated_div_
) return;
195 // TODO(danvk): only use real APIs for this.
196 e
.dygraph
.graphDiv
.appendChild(this.legend_div_
);
197 var area
= e
.dygraph
.getArea();
198 var labelsDivWidth
= e
.dygraph
.getOption("labelsDivWidth");
199 this.legend_div_
.style
.left
= area
.x
+ area
.w
- labelsDivWidth
- 1 + "px";
200 this.legend_div_
.style
.top
= area
.y
+ "px";
201 this.legend_div_
.style
.width
= labelsDivWidth
+ "px";
205 * Called when dygraph.destroy() is called.
206 * You should null out any references and detach any DOM elements.
208 Legend
.prototype.destroy
= function() {
209 this.legend_div_
= null;
213 * Generates HTML for the legend which is displayed when hovering over the
214 * chart. If no selected points are specified, a default legend is returned
215 * (this may just be the empty string).
216 * @param {number} x The x-value of the selected points.
217 * @param {Object} sel_points List of selected points for the given
218 * x-value. Should have properties like 'name', 'yval' and 'canvasy'.
219 * @param {number} oneEmWidth The pixel width for 1em in the legend. Only
220 * relevant when displaying a legend with no selection (i.e. {legend:
221 * 'always'}) and with dashed lines.
222 * @param {number} row The selected row index.
225 Legend
.generateLegendHTML
= function(g
, x
, sel_points
, oneEmWidth
, row
) {
226 // Data about the selection to pass to legendFormatter
233 var labelToSeries
= {};
234 var labels
= g
.getLabels();
236 for (var i
= 1; i
< labels
.length
; i
++) {
237 var series
= g
.getPropertiesForSeries(labels
[i
]);
238 var strokePattern
= g
.getOption('strokePattern', labels
[i
]);
240 dashHTML
: generateLegendDashHTML(strokePattern
, series
.color
, oneEmWidth
),
242 labelHTML
: escapeHTML(labels
[i
]),
243 isVisible
: series
.visible
,
247 data
.series
.push(seriesData
);
248 labelToSeries
[labels
[i
]] = seriesData
;
252 if (typeof(x
) !== 'undefined') {
253 var xOptView
= g
.optionsViewForAxis_('x');
254 var xvf
= xOptView('valueFormatter');
255 data
.xHTML
= xvf
.call(g
, x
, xOptView
, labels
[0], g
, row
, 0);
258 var num_axes
= g
.numAxes();
259 for (var i
= 0; i
< num_axes
; i
++) {
260 // TODO(danvk): remove this use of a private API
261 yOptViews
[i
] = g
.optionsViewForAxis_('y' + (i
? 1 + i
: ''));
264 var showZeros
= g
.getOption('labelsShowZeroValues');
265 var highlightSeries
= g
.getHighlightSeries();
266 for (i
= 0; i
< sel_points
.length
; i
++) {
267 var pt
= sel_points
[i
];
268 var seriesData
= labelToSeries
[pt
.name
];
269 seriesData
.y
= pt
.yval
;
271 if ((pt
.yval
=== 0 && !showZeros
) || isNaN(pt
.canvasy
)) {
272 seriesData
.isVisible
= false;
276 var series
= g
.getPropertiesForSeries(pt
.name
);
277 var yOptView
= yOptViews
[series
.axis
- 1];
278 var fmtFunc
= yOptView('valueFormatter');
279 var yHTML
= fmtFunc
.call(g
, pt
.yval
, yOptView
, pt
.name
, g
, row
, labels
.indexOf(pt
.name
));
281 utils
.update(seriesData
, {yHTML
});
283 if (pt
.name
== highlightSeries
) {
284 seriesData
.isHighlighted
= true;
289 var formatter
= (g
.getOption('legendFormatter') || Legend
.defaultFormatter
);
290 return formatter
.call(g
, data
);
293 Legend
.defaultFormatter
= function(data
) {
294 var g
= data
.dygraph
;
296 // TODO(danvk): deprecate this option in place of {legend: 'never'}
297 // XXX should this logic be in the formatter?
298 if (g
.getOption('showLabelsOnHighlight') !== true) return '';
300 var sepLines
= g
.getOption('labelsSeparateLines');
303 if (typeof(data
.x
) === 'undefined') {
304 // TODO: this check is duplicated in generateLegendHTML. Put it in one place.
305 if (g
.getOption('legend') != 'always') {
310 for (var i
= 0; i
< data
.series
.length
; i
++) {
311 var series
= data
.series
[i
];
312 if (!series
.isVisible
) continue;
314 if (html
!== '') html
+= (sepLines
? '<br/>' : ' ');
315 html
+= `<span style
='font-weight: bold; color: ${series.color};'>${series
.dashHTML
} ${series
.labelHTML
}</span
>`;
320 html
= data
.xHTML
+ ':';
321 for (var i
= 0; i
< data
.series
.length
; i
++) {
322 var series
= data
.series
[i
];
323 if (!series
.isVisible
) continue;
324 if (sepLines
) html
+= '<br>';
325 var cls
= series
.isHighlighted
? ' class="highlight"' : '';
326 html
+= `<span
${cls
}> <b
><span style
='color: ${series.color};'>${series
.labelHTML
}</span></b
>: ${series
.yHTML
}</span
>`;
333 * Generates html for the "dash" displayed on the legend when using "legend: always".
334 * In particular, this works for dashed lines with any stroke pattern. It will
335 * try to scale the pattern to fit in 1em width. Or if small enough repeat the
336 * pattern for 1em width.
338 * @param strokePattern The pattern
339 * @param color The color of the series.
340 * @param oneEmWidth The width in pixels of 1em in the legend.
343 // TODO(danvk): cache the results of this
344 generateLegendDashHTML
= function(strokePattern
, color
, oneEmWidth
) {
345 // Easy, common case: a solid line
346 if (!strokePattern
|| strokePattern
.length
<= 1) {
347 return "<div style=\"display: inline-block; position: relative; " +
348 "bottom: .5ex; padding-left: 1em; height: 1px; " +
349 "border-bottom: 2px solid " + color
+ ";\"></div>";
352 var i
, j
, paddingLeft
, marginRight
;
353 var strokePixelLength
= 0, segmentLoop
= 0;
354 var normalizedPattern
= [];
357 // Compute the length of the pixels including the first segment twice,
358 // since we repeat it.
359 for (i
= 0; i
<= strokePattern
.length
; i
++) {
360 strokePixelLength
+= strokePattern
[i
%strokePattern
.length
];
363 // See if we can loop the pattern by itself at least twice.
364 loop
= Math
.floor(oneEmWidth
/(strokePixelLength
-strokePattern
[0]));
366 // This pattern fits at least two times, no scaling just convert to em;
367 for (i
= 0; i
< strokePattern
.length
; i
++) {
368 normalizedPattern
[i
] = strokePattern
[i
]/oneEmWidth
;
370 // Since we are repeating the pattern, we don't worry about repeating the
371 // first segment in one draw.
372 segmentLoop
= normalizedPattern
.length
;
374 // If the pattern doesn't fit in the legend we scale it to fit.
376 for (i
= 0; i
< strokePattern
.length
; i
++) {
377 normalizedPattern
[i
] = strokePattern
[i
]/strokePixelLength
;
379 // For the scaled patterns we do redraw the first segment.
380 segmentLoop
= normalizedPattern
.length
+1;
383 // Now make the pattern.
385 for (j
= 0; j
< loop
; j
++) {
386 for (i
= 0; i
< segmentLoop
; i
+=2) {
387 // The padding is the drawn segment.
388 paddingLeft
= normalizedPattern
[i
%normalizedPattern
.length
];
389 if (i
< strokePattern
.length
) {
390 // The margin is the space segment.
391 marginRight
= normalizedPattern
[(i
+1)%normalizedPattern
.length
];
393 // The repeated first segment has no right margin.
396 dash
+= "<div style=\"display: inline-block; position: relative; " +
397 "bottom: .5ex; margin-right: " + marginRight
+ "em; padding-left: " +
398 paddingLeft
+ "em; height: 1px; border-bottom: 2px solid " + color
+
405 export default Legend
;