23 lines
588 B
JavaScript
23 lines
588 B
JavaScript
export default class Bus {
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constructor() {
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this.listeners = new Map();
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this.emitted = new Set();
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}
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on(evtName, listener) {
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if (this.emitted.has(evtName)) {
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listener();
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return;
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}
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const target = this.listeners.get(evtName) || [];
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target.push(listener);
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this.listeners.set(evtName, target);
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}
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emit(evtName) {
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const listeners = this.listeners.get(evtName);
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if (listeners) {
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listeners.forEach((func) => func());
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}
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this.emitted.add(evtName);
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}
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}
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