Michael Telatynski
39 lines
972 B
TypeScript
39 lines
972 B
TypeScript
/*
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Copyright 2025 New Vector Ltd.
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SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
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Please see LICENSE files in the repository root for full details.
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*/
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type WatchFn<T> = (value: T) => void;
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/**
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* Utility class to wrap a value and allow listeners to be notified when the value changes.
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*/
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export class Watchable<T> {
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private readonly listeners = new Set<WatchFn<T>>();
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public constructor(private currentValue: T) {}
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public get value(): T {
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return this.currentValue;
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}
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public set value(value: T) {
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if (this.currentValue !== value) {
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this.currentValue = value;
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for (const listener of this.listeners) {
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listener(this.currentValue);
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}
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}
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}
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public watch(listener: (value: T) => void): void {
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this.listeners.add(listener);
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}
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public unwatch(listener: (value: T) => void): void {
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this.listeners.delete(listener);
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}
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}
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