17 lines
702 B
TypeScript
17 lines
702 B
TypeScript
type StateUpdate<T> = T | ((current: T) => T);
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/** 编辑命令同步提交到 ref；React 只接收快照，不执行含副作用、可被重放的 updater。 */
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export function createCanvasStateWriter<T>(
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ref: { current: T },
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publish: (snapshot: T) => void,
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normalize: (before: T, after: T) => T = (_, after) => after,
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) {
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return (update: StateUpdate<T>) => {
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const before = ref.current;
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const after = normalize(before, typeof update === "function" ? (update as (current: T) => T)(before) : update);
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// 兼容先提交 ref 再发布快照的调用方；相同引用不代表 React 已收到它。
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ref.current = after;
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publish(after);
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};
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}
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