import * as THREE from "three" ; /**
 * JavaScript events for custom objects. Stores all listeners to allow removing all listeners for
 * housekeeping.
 *
 * Will be replaced by `THREE.EventDispatcher` once https://github.com/mrdoob/three.js/pull/19844
 * is released.
 */ export class EventDispatcher { private readonly m_listeners : Map < string , Array < ( event : THREE . Event ) => void > > = new Map ( ) ; /**
     * Destroy this `EventDispatcher` instance.
     *
     * Unregister all event handlers used. This is method should be called when you stop
     * using `EventDispatcher`.
     */ dispose ( ) { this . removeAllEventListeners ( ) ; } param type param listener hasEventListener ( type , listener ? ) { const listeners = this . m_listeners . get ( type ) ; if ( listeners === undefined ) { return false ; } return listener !== undefined ? listeners . includes ( listener ) : true ; } param type param listener addEventListener ( type , listener ) { let listeners = this . m_listeners . get ( type ) ; if ( listeners === undefined ) { listeners = [ ] ; this . m_listeners . set ( type , listeners ) ; } if ( ! listeners . includes ( listener ) ) { listeners . push ( listener ) ; } } param type param listener removeEventListener ( type , listener ? ) { const listeners = this . m_listeners . get ( type ) ; if ( listeners === undefined ) { return ; } if ( listener === undefined ) { this . m_listeners . delete ( type ) ; } else { const index = listeners . indexOf ( listener ) ; if ( index !== - 1 ) { listeners . splice ( index , 1 ) ; if ( listeners . length === 0 ) { this . m_listeners . delete ( type ) ; } } } } /**
     * Remove all event listeners for housekeeping.
     */ removeAllEventListeners ( ) { const events = Array . from ( this . m_listeners . keys ( ) ) ; for ( const event of events ) { this . removeEventListener ( event ) ; } } returns get eventTypes ( ) : string [ ] { return Array . from ( this . m_listeners . keys ( ) ) ; } param type returns listeners ( type ) { return this . m_listeners . get ( type ) ; } param event dispatchEvent ( event ) { const listeners = this . m_listeners . get ( event . type ) ; if ( listeners !== undefined ) { event . target = this ; const array = listeners . slice ( 0 ) ; for ( let i = 0 , l = array . length ; i < l ; i ++ ) { array [ i ] . call ( this , event ) ; } } } }