40 lines
1.1 KiB
TypeScript
40 lines
1.1 KiB
TypeScript
import { EventEmitter as NodeEventEmitter } from 'events'
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import { Event } from './event.js'
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// Similar to node's builtin EventEmitter, but is also aware of our `Event`
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// class, and so `emit` respects `stopImmediatePropagation()`.
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export class EventEmitter extends NodeEventEmitter {
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constructor() {
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super()
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// Disable the default maxListeners warning. In React, many components
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// can legitimately listen to the same event (e.g., useInput hooks).
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// The default limit of 10 causes spurious warnings.
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this.setMaxListeners(0)
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}
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override emit(type: string | symbol, ...args: unknown[]): boolean {
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// Delegate to node for `error`, since it's not treated like a normal event
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if (type === 'error') {
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return super.emit(type, ...args)
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}
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const listeners = this.rawListeners(type)
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if (listeners.length === 0) {
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return false
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}
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const ccEvent = args[0] instanceof Event ? args[0] : null
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for (const listener of listeners) {
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listener.apply(this, args)
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if (ccEvent?.didStopImmediatePropagation()) {
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break
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}
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}
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return true
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}
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}
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