react-native-reanimated
Version:
More powerful alternative to Animated library for React Native.
77 lines (76 loc) • 3.1 kB
JavaScript
import { runOnUI } from '../core';
export const prepareUIRegistry = runOnUI(() => {
'worklet';
const frameCallbackRegistry = {
frameCallbackRegistry: new Map(),
activeFrameCallbacks: new Set(),
previousFrameTimestamp: null,
runCallbacks() {
const loop = (timestamp) => {
if (this.previousFrameTimestamp === null) {
this.previousFrameTimestamp = timestamp;
}
const delta = timestamp - this.previousFrameTimestamp;
this.activeFrameCallbacks.forEach((callbackId) => {
const callbackDetails = this.frameCallbackRegistry.get(callbackId);
const { startTime } = callbackDetails;
if (startTime === null) {
// First frame
callbackDetails.startTime = timestamp;
callbackDetails.callback({
timestamp,
timeSincePreviousFrame: null,
timeSinceFirstFrame: 0,
});
}
else {
// Next frame
callbackDetails.callback({
timestamp,
timeSincePreviousFrame: delta,
timeSinceFirstFrame: timestamp - startTime,
});
}
});
if (this.activeFrameCallbacks.size > 0) {
this.previousFrameTimestamp = timestamp;
requestAnimationFrame(loop);
}
else {
this.previousFrameTimestamp = null;
}
};
// runCallback() should only be called after registering a callback,
// so if there is only one active callback, then it means that there were
// zero previously and the loop isn't running yet.
if (this.activeFrameCallbacks.size === 1) {
requestAnimationFrame(loop);
}
},
registerFrameCallback(callback, callbackId) {
this.frameCallbackRegistry.set(callbackId, {
callback: callback,
startTime: null,
});
},
unregisterFrameCallback(callbackId) {
this.manageStateFrameCallback(callbackId, false);
this.frameCallbackRegistry.delete(callbackId);
},
manageStateFrameCallback(callbackId, state) {
if (callbackId === -1) {
return;
}
if (state) {
this.activeFrameCallbacks.add(callbackId);
this.runCallbacks();
}
else {
const callback = this.frameCallbackRegistry.get(callbackId);
callback.startTime = null;
this.activeFrameCallbacks.delete(callbackId);
}
},
};
global._frameCallbackRegistry = frameCallbackRegistry;
});