30 lines
557 B
TypeScript
Executable file
30 lines
557 B
TypeScript
Executable file
export class Subscribable<TListener extends Function> {
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protected listeners = new Set<TListener>()
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constructor() {
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this.subscribe = this.subscribe.bind(this)
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}
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subscribe(listener: TListener): () => void {
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this.listeners.add(listener)
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this.onSubscribe()
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return () => {
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this.listeners.delete(listener)
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this.onUnsubscribe()
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}
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}
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hasListeners(): boolean {
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return this.listeners.size > 0
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}
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protected onSubscribe(): void {
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// Do nothing
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}
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protected onUnsubscribe(): void {
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// Do nothing
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}
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}
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