forked from chartjs/Chart.js
/
core.interaction.js
340 lines (296 loc) · 10.3 KB
/
core.interaction.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
'use strict';
var helpers = require('../helpers/index');
/**
* Helper function to get relative position for an event
* @param {Event|IEvent} event - The event to get the position for
* @param {Chart} chart - The chart
* @returns {Point} the event position
*/
function getRelativePosition(e, chart) {
if (e.native) {
return {
x: e.x,
y: e.y
};
}
return helpers.getRelativePosition(e, chart);
}
/**
* Helper function to traverse all of the visible elements in the chart
* @param chart {chart} the chart
* @param handler {Function} the callback to execute for each visible item
*/
function parseVisibleItems(chart, handler) {
var datasets = chart.data.datasets;
var meta, i, j, ilen, jlen;
for (i = 0, ilen = datasets.length; i < ilen; ++i) {
if (!chart.isDatasetVisible(i)) {
continue;
}
meta = chart.getDatasetMeta(i);
for (j = 0, jlen = meta.data.length; j < jlen; ++j) {
var element = meta.data[j];
if (!element._view.skip) {
element.datasetlength = meta.data.length;
handler(element);
}
}
}
}
/**
* Helper function to get the items that intersect the event position
* @param items {ChartElement[]} elements to filter
* @param position {Point} the point to be nearest to
* @return {ChartElement[]} the nearest items
*/
function getIntersectItems(chart, position) {
var elements = [];
parseVisibleItems(chart, function(element) {
if (element.inRange(position.x, position.y)) {
elements.push(element);
}
});
return elements;
}
/**
* Helper function to get the items nearest to the event position considering all visible items in teh chart
* @param chart {Chart} the chart to look at elements from
* @param position {Point} the point to be nearest to
* @param intersect {Boolean} if true, only consider items that intersect the position
* @param distanceMetric {Function} function to provide the distance between points
* @return {ChartElement[]} the nearest items
*/
function getNearestItems(chart, position, intersect, distanceMetric) {
var minDistance = Number.POSITIVE_INFINITY;
var nearestItems = [];
parseVisibleItems(chart, function(element) {
if (intersect && !element.inRange(position.x, position.y)) {
return;
}
var center = element.getCenterPoint();
var distance = distanceMetric(position, center);
if (distance < minDistance) {
nearestItems = [element];
minDistance = distance;
} else if (distance === minDistance) {
// Can have multiple items at the same distance in which case we sort by size
nearestItems.push(element);
}
});
return nearestItems;
}
/**
* Get a distance metric function for two points based on the
* axis mode setting
* @param {String} axis the axis mode. x|y|xy
*/
function getDistanceMetricForAxis(axis) {
var useX = axis.indexOf('x') !== -1;
var useY = axis.indexOf('y') !== -1;
return function(pt1, pt2) {
var deltaX = useX ? Math.abs(pt1.x - pt2.x) : 0;
var deltaY = useY ? Math.abs(pt1.y - pt2.y) : 0;
return Math.sqrt(Math.pow(deltaX, 2) + Math.pow(deltaY, 2));
};
}
function indexMode(chart, e, options) {
var position = getRelativePosition(e, chart);
// Default axis for index mode is 'x' to match old behaviour
options.axis = options.axis || 'x';
var distanceMetric = getDistanceMetricForAxis(options.axis);
var items = options.intersect ? getIntersectItems(chart, position) : getNearestItems(chart, position, false, distanceMetric);
var elements = [];
if (!items.length) {
return [];
}
chart.data.datasets.forEach(function(dataset, datasetIndex) {
if (chart.isDatasetVisible(datasetIndex)) {
var meta = chart.getDatasetMeta(datasetIndex);
var element = meta.data[items[0]._index];
// don't count items that are skipped (null data)
if (element && !element._view.skip) {
elements.push(element);
}
}
});
return elements;
}
/**
* @interface IInteractionOptions
*/
/**
* If true, only consider items that intersect the point
* @name IInterfaceOptions#boolean
* @type Boolean
*/
/**
* Contains interaction related functions
* @namespace Chart.Interaction
*/
module.exports = {
// Helper function for different modes
modes: {
single: function(chart, e) {
var position = getRelativePosition(e, chart);
var elements = [];
parseVisibleItems(chart, function(element) {
if (element.inRange(position.x, position.y)) {
elements.push(element);
return elements;
}
});
return elements.slice(0, 1);
},
/**
* @function Chart.Interaction.modes.label
* @deprecated since version 2.4.0
* @todo remove at version 3
* @private
*/
label: indexMode,
/**
* Returns items at the same index. If the options.intersect parameter is true, we only return items if we intersect something
* If the options.intersect mode is false, we find the nearest item and return the items at the same index as that item
* @function Chart.Interaction.modes.index
* @since v2.4.0
* @param chart {chart} the chart we are returning items from
* @param e {Event} the event we are find things at
* @param options {IInteractionOptions} options to use during interaction
* @return {Chart.Element[]} Array of elements that are under the point. If none are found, an empty array is returned
*/
index: indexMode,
/**
* Returns items in the same dataset. If the options.intersect parameter is true, we only return items if we intersect something
* If the options.intersect is false, we find the nearest item and return the items in that dataset
* @function Chart.Interaction.modes.dataset
* @param chart {chart} the chart we are returning items from
* @param e {Event} the event we are find things at
* @param options {IInteractionOptions} options to use during interaction
* @return {Chart.Element[]} Array of elements that are under the point. If none are found, an empty array is returned
*/
dataset: function(chart, e, options) {
var position = getRelativePosition(e, chart);
options.axis = options.axis || 'xy';
var distanceMetric = getDistanceMetricForAxis(options.axis);
var items = options.intersect ? getIntersectItems(chart, position) : getNearestItems(chart, position, false, distanceMetric);
if (items.length > 0) {
items = chart.getDatasetMeta(items[0]._datasetIndex).data;
}
return items;
},
/**
* @function Chart.Interaction.modes.x-axis
* @deprecated since version 2.4.0. Use index mode and intersect == true
* @todo remove at version 3
* @private
*/
'x-axis': function(chart, e) {
return indexMode(chart, e, {intersect: false});
},
/**
* Point mode returns all elements that hit test based on the event position
* of the event
* @function Chart.Interaction.modes.intersect
* @param chart {chart} the chart we are returning items from
* @param e {Event} the event we are find things at
* @return {Chart.Element[]} Array of elements that are under the point. If none are found, an empty array is returned
*/
point: function(chart, e) {
var position = getRelativePosition(e, chart);
return getIntersectItems(chart, position);
},
/**
* nearest mode returns the element closest to the point
* @function Chart.Interaction.modes.intersect
* @param chart {chart} the chart we are returning items from
* @param e {Event} the event we are find things at
* @param options {IInteractionOptions} options to use
* @return {Chart.Element[]} Array of elements that are under the point. If none are found, an empty array is returned
*/
nearest: function(chart, e, options) {
var position = getRelativePosition(e, chart);
options.axis = options.axis || 'xy';
var distanceMetric = getDistanceMetricForAxis(options.axis);
var nearestItems = getNearestItems(chart, position, options.intersect, distanceMetric);
// We have multiple items at the same distance from the event. Now sort by smallest
if (nearestItems.length > 1) {
nearestItems.sort(function(a, b) {
var sizeA = a.getArea();
var sizeB = b.getArea();
var ret = sizeA - sizeB;
if (ret === 0) {
// if equal sort by dataset index
ret = a._datasetIndex - b._datasetIndex;
}
return ret;
});
}
// Return only 1 item
return nearestItems.slice(0, 1);
},
/**
* x mode returns the elements that hit-test at the current x coordinate
* @function Chart.Interaction.modes.x
* @param chart {chart} the chart we are returning items from
* @param e {Event} the event we are find things at
* @param options {IInteractionOptions} options to use
* @return {Chart.Element[]} Array of elements that are under the point. If none are found, an empty array is returned
*/
x: function(chart, e, options) {
var position = getRelativePosition(e, chart);
var items = [];
var intersectsItem = false;
parseVisibleItems(chart, function(element) {
if (element.datasetlength < 40) {
if (element.inXRange(position.x)) {
items.push(element);
}
} else if (element.datasetlength >= 40) {
if (element.inXRangeSmall(position.x)) {
items.push(element);
// Cleanup extra elements
if (items.length > 1) {
items.splice(1, items.length);
}
}
}
if (element.inRange(position.x, position.y)) {
intersectsItem = true;
}
});
// If we want to trigger on an intersect and we don't have any items
// that intersect the position, return nothing
if (options.intersect && !intersectsItem) {
items = [];
}
return items;
},
/**
* y mode returns the elements that hit-test at the current y coordinate
* @function Chart.Interaction.modes.y
* @param chart {chart} the chart we are returning items from
* @param e {Event} the event we are find things at
* @param options {IInteractionOptions} options to use
* @return {Chart.Element[]} Array of elements that are under the point. If none are found, an empty array is returned
*/
y: function(chart, e, options) {
var position = getRelativePosition(e, chart);
var items = [];
var intersectsItem = false;
parseVisibleItems(chart, function(element) {
if (element.inYRange(position.y)) {
items.push(element);
}
if (element.inRange(position.x, position.y)) {
intersectsItem = true;
}
});
// If we want to trigger on an intersect and we don't have any items
// that intersect the position, return nothing
if (options.intersect && !intersectsItem) {
items = [];
}
return items;
}
}
};