ant-design/components/_util/throttleByAnimationFrame.tsx
陆离 3789e0cbbb Affix listener bug fix (#4756)
*  Affix listener bug fix

 + close #4755
 + close #4760
 + clearScrollEventListeners before setTargetEventListeners
 + add tests for throttle
 + append affix test case

*  genMockFn -> fn()
2017-02-08 14:44:43 +08:00

48 lines
1.2 KiB
TypeScript

import getRequestAnimationFrame, { cancelRequestAnimationFrame } from '../_util/getRequestAnimationFrame';
const reqAnimFrame = getRequestAnimationFrame();
export default function throttleByAnimationFrame(fn) {
let requestId;
const later = args => () => {
requestId = null;
fn(...args);
};
const throttled = (...args) => {
if (requestId == null) {
requestId = reqAnimFrame(later(args));
}
};
(throttled as any).cancel = () => cancelRequestAnimationFrame(requestId);
return throttled;
}
export function throttleByAnimationFrameDecorator() {
return function(target, key, descriptor) {
let fn = descriptor.value;
let definingProperty = false;
return {
configurable: true,
get() {
if (definingProperty || this === target.prototype || this.hasOwnProperty(key)) {
return fn;
}
let boundFn = throttleByAnimationFrame(fn.bind(this));
definingProperty = true;
Object.defineProperty(this, key, {
value: boundFn,
configurable: true,
writable: true,
});
definingProperty = false;
return boundFn;
},
};
};
}