index.mjs
9.66 KB
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
import { warnOnce, SubscriptionManager, velocityPerSecond } from 'motion-utils';
import { time } from '../frameloop/sync-time.mjs';
import { frame } from '../frameloop/frame.mjs';
/**
* Maximum time between the value of two frames, beyond which we
* assume the velocity has since been 0.
*/
const MAX_VELOCITY_DELTA = 30;
const isFloat = (value) => {
return !isNaN(parseFloat(value));
};
const collectMotionValues = {
current: undefined,
};
/**
* `MotionValue` is used to track the state and velocity of motion values.
*
* @public
*/
class MotionValue {
/**
* @param init - The initiating value
* @param config - Optional configuration options
*
* - `transformer`: A function to transform incoming values with.
*/
constructor(init, options = {}) {
/**
* Tracks whether this value can output a velocity. Currently this is only true
* if the value is numerical, but we might be able to widen the scope here and support
* other value types.
*
* @internal
*/
this.canTrackVelocity = null;
/**
* An object containing a SubscriptionManager for each active event.
*/
this.events = {};
this.updateAndNotify = (v) => {
const currentTime = time.now();
/**
* If we're updating the value during another frame or eventloop
* than the previous frame, then the we set the previous frame value
* to current.
*/
if (this.updatedAt !== currentTime) {
this.setPrevFrameValue();
}
this.prev = this.current;
this.setCurrent(v);
// Update update subscribers
if (this.current !== this.prev) {
this.events.change?.notify(this.current);
if (this.dependents) {
for (const dependent of this.dependents) {
dependent.dirty();
}
}
}
};
this.hasAnimated = false;
this.setCurrent(init);
this.owner = options.owner;
}
setCurrent(current) {
this.current = current;
this.updatedAt = time.now();
if (this.canTrackVelocity === null && current !== undefined) {
this.canTrackVelocity = isFloat(this.current);
}
}
setPrevFrameValue(prevFrameValue = this.current) {
this.prevFrameValue = prevFrameValue;
this.prevUpdatedAt = this.updatedAt;
}
/**
* Adds a function that will be notified when the `MotionValue` is updated.
*
* It returns a function that, when called, will cancel the subscription.
*
* When calling `onChange` inside a React component, it should be wrapped with the
* `useEffect` hook. As it returns an unsubscribe function, this should be returned
* from the `useEffect` function to ensure you don't add duplicate subscribers..
*
* ```jsx
* export const MyComponent = () => {
* const x = useMotionValue(0)
* const y = useMotionValue(0)
* const opacity = useMotionValue(1)
*
* useEffect(() => {
* function updateOpacity() {
* const maxXY = Math.max(x.get(), y.get())
* const newOpacity = transform(maxXY, [0, 100], [1, 0])
* opacity.set(newOpacity)
* }
*
* const unsubscribeX = x.on("change", updateOpacity)
* const unsubscribeY = y.on("change", updateOpacity)
*
* return () => {
* unsubscribeX()
* unsubscribeY()
* }
* }, [])
*
* return <motion.div style={{ x }} />
* }
* ```
*
* @param subscriber - A function that receives the latest value.
* @returns A function that, when called, will cancel this subscription.
*
* @deprecated
*/
onChange(subscription) {
if (process.env.NODE_ENV !== "production") {
warnOnce(false, `value.onChange(callback) is deprecated. Switch to value.on("change", callback).`);
}
return this.on("change", subscription);
}
on(eventName, callback) {
if (!this.events[eventName]) {
this.events[eventName] = new SubscriptionManager();
}
const unsubscribe = this.events[eventName].add(callback);
if (eventName === "change") {
return () => {
unsubscribe();
/**
* If we have no more change listeners by the start
* of the next frame, stop active animations.
*/
frame.read(() => {
if (!this.events.change.getSize()) {
this.stop();
}
});
};
}
return unsubscribe;
}
clearListeners() {
for (const eventManagers in this.events) {
this.events[eventManagers].clear();
}
}
/**
* Attaches a passive effect to the `MotionValue`.
*/
attach(passiveEffect, stopPassiveEffect) {
this.passiveEffect = passiveEffect;
this.stopPassiveEffect = stopPassiveEffect;
}
/**
* Sets the state of the `MotionValue`.
*
* @remarks
*
* ```jsx
* const x = useMotionValue(0)
* x.set(10)
* ```
*
* @param latest - Latest value to set.
* @param render - Whether to notify render subscribers. Defaults to `true`
*
* @public
*/
set(v) {
if (!this.passiveEffect) {
this.updateAndNotify(v);
}
else {
this.passiveEffect(v, this.updateAndNotify);
}
}
setWithVelocity(prev, current, delta) {
this.set(current);
this.prev = undefined;
this.prevFrameValue = prev;
this.prevUpdatedAt = this.updatedAt - delta;
}
/**
* Set the state of the `MotionValue`, stopping any active animations,
* effects, and resets velocity to `0`.
*/
jump(v, endAnimation = true) {
this.updateAndNotify(v);
this.prev = v;
this.prevUpdatedAt = this.prevFrameValue = undefined;
endAnimation && this.stop();
if (this.stopPassiveEffect)
this.stopPassiveEffect();
}
dirty() {
this.events.change?.notify(this.current);
}
addDependent(dependent) {
if (!this.dependents) {
this.dependents = new Set();
}
this.dependents.add(dependent);
}
removeDependent(dependent) {
if (this.dependents) {
this.dependents.delete(dependent);
}
}
/**
* Returns the latest state of `MotionValue`
*
* @returns - The latest state of `MotionValue`
*
* @public
*/
get() {
if (collectMotionValues.current) {
collectMotionValues.current.push(this);
}
return this.current;
}
/**
* @public
*/
getPrevious() {
return this.prev;
}
/**
* Returns the latest velocity of `MotionValue`
*
* @returns - The latest velocity of `MotionValue`. Returns `0` if the state is non-numerical.
*
* @public
*/
getVelocity() {
const currentTime = time.now();
if (!this.canTrackVelocity ||
this.prevFrameValue === undefined ||
currentTime - this.updatedAt > MAX_VELOCITY_DELTA) {
return 0;
}
const delta = Math.min(this.updatedAt - this.prevUpdatedAt, MAX_VELOCITY_DELTA);
// Casts because of parseFloat's poor typing
return velocityPerSecond(parseFloat(this.current) -
parseFloat(this.prevFrameValue), delta);
}
/**
* Registers a new animation to control this `MotionValue`. Only one
* animation can drive a `MotionValue` at one time.
*
* ```jsx
* value.start()
* ```
*
* @param animation - A function that starts the provided animation
*/
start(startAnimation) {
this.stop();
return new Promise((resolve) => {
this.hasAnimated = true;
this.animation = startAnimation(resolve);
if (this.events.animationStart) {
this.events.animationStart.notify();
}
}).then(() => {
if (this.events.animationComplete) {
this.events.animationComplete.notify();
}
this.clearAnimation();
});
}
/**
* Stop the currently active animation.
*
* @public
*/
stop() {
if (this.animation) {
this.animation.stop();
if (this.events.animationCancel) {
this.events.animationCancel.notify();
}
}
this.clearAnimation();
}
/**
* Returns `true` if this value is currently animating.
*
* @public
*/
isAnimating() {
return !!this.animation;
}
clearAnimation() {
delete this.animation;
}
/**
* Destroy and clean up subscribers to this `MotionValue`.
*
* The `MotionValue` hooks like `useMotionValue` and `useTransform` automatically
* handle the lifecycle of the returned `MotionValue`, so this method is only necessary if you've manually
* created a `MotionValue` via the `motionValue` function.
*
* @public
*/
destroy() {
this.dependents?.clear();
this.events.destroy?.notify();
this.clearListeners();
this.stop();
if (this.stopPassiveEffect) {
this.stopPassiveEffect();
}
}
}
function motionValue(init, options) {
return new MotionValue(init, options);
}
export { MotionValue, collectMotionValues, motionValue };
//# sourceMappingURL=index.mjs.map