framer-motion
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A simple and powerful JavaScript animation library
119 lines (116 loc) • 4.52 kB
JavaScript
import { time } from '../../frameloop/sync-time.mjs';
import { flushKeyframeResolvers } from '../../render/utils/KeyframesResolver.mjs';
import { instantAnimationState } from '../../utils/use-instant-transition-state.mjs';
import { canAnimate } from './utils/can-animate.mjs';
import { getFinalKeyframe } from './waapi/utils/get-final-keyframe.mjs';
/**
* Maximum time allowed between an animation being created and it being
* resolved for us to use the latter as the start time.
*
* This is to ensure that while we prefer to "start" an animation as soon
* as it's triggered, we also want to avoid a visual jump if there's a big delay
* between these two moments.
*/
const MAX_RESOLVE_DELAY = 40;
class BaseAnimation {
constructor({ autoplay = true, delay = 0, type = "keyframes", repeat = 0, repeatDelay = 0, repeatType = "loop", ...options }) {
// Track whether the animation has been stopped. Stopped animations won't restart.
this.isStopped = false;
this.hasAttemptedResolve = false;
this.createdAt = time.now();
this.options = {
autoplay,
delay,
type,
repeat,
repeatDelay,
repeatType,
...options,
};
this.updateFinishedPromise();
}
/**
* This method uses the createdAt and resolvedAt to calculate the
* animation startTime. *Ideally*, we would use the createdAt time as t=0
* as the following frame would then be the first frame of the animation in
* progress, which would feel snappier.
*
* However, if there's a delay (main thread work) between the creation of
* the animation and the first commited frame, we prefer to use resolvedAt
* to avoid a sudden jump into the animation.
*/
calcStartTime() {
if (!this.resolvedAt)
return this.createdAt;
return this.resolvedAt - this.createdAt > MAX_RESOLVE_DELAY
? this.resolvedAt
: this.createdAt;
}
/**
* A getter for resolved data. If keyframes are not yet resolved, accessing
* this.resolved will synchronously flush all pending keyframe resolvers.
* This is a deoptimisation, but at its worst still batches read/writes.
*/
get resolved() {
if (!this._resolved && !this.hasAttemptedResolve) {
flushKeyframeResolvers();
}
return this._resolved;
}
/**
* A method to be called when the keyframes resolver completes. This method
* will check if its possible to run the animation and, if not, skip it.
* Otherwise, it will call initPlayback on the implementing class.
*/
onKeyframesResolved(keyframes, finalKeyframe) {
this.resolvedAt = time.now();
this.hasAttemptedResolve = true;
const { name, type, velocity, delay, onComplete, onUpdate, isGenerator, } = this.options;
/**
* If we can't animate this value with the resolved keyframes
* then we should complete it immediately.
*/
if (!isGenerator && !canAnimate(keyframes, name, type, velocity)) {
// Finish immediately
if (instantAnimationState.current || !delay) {
onUpdate &&
onUpdate(getFinalKeyframe(keyframes, this.options, finalKeyframe));
onComplete && onComplete();
this.resolveFinishedPromise();
return;
}
// Finish after a delay
else {
this.options.duration = 0;
}
}
const resolvedAnimation = this.initPlayback(keyframes, finalKeyframe);
if (resolvedAnimation === false)
return;
this._resolved = {
keyframes,
finalKeyframe,
...resolvedAnimation,
};
this.onPostResolved();
}
onPostResolved() { }
/**
* Allows the returned animation to be awaited or promise-chained. Currently
* resolves when the animation finishes at all but in a future update could/should
* reject if its cancels.
*/
then(resolve, reject) {
return this.currentFinishedPromise.then(resolve, reject);
}
flatten() {
this.options.type = "keyframes";
this.options.ease = "linear";
}
updateFinishedPromise() {
this.currentFinishedPromise = new Promise((resolve) => {
this.resolveFinishedPromise = resolve;
});
}
}
export { BaseAnimation };