///
- This is an internal constructor and shouldn't be called by regular users.
*
- inspired by Joa Ebert AS3 SignalBinding and Robert Penner's Slot classes.
* @author Miller Medeiros
* @constructor
* @internal
* @name SignalBinding
* @param {Signal} signal Reference to Signal object that listener is currently bound to.
* @param {Function} listener Handler function bound to the signal.
* @param {boolean} isOnce If binding should be executed just once.
* @param {Object} [listenerContext] Context on which listener will be executed (object that should represent the `this` variable inside listener function).
* @param {Number} [priority] The priority level of the event listener. (default = 0).
*/
constructor(signal: Signal, listener, isOnce: boolean, listenerContext, priority: number = 0) {
this._listener = listener;
this._isOnce = isOnce;
this.context = listenerContext;
this._signal = signal;
this.priority = priority || 0;
}
/**
* Handler function bound to the signal.
* @type Function
* @private
*/
private _listener;
/**
* If binding should be executed just once.
* @type boolean
* @private
*/
private _isOnce: boolean;
/**
* Context on which listener will be executed (object that should represent the `this` variable inside listener function).
* @memberOf SignalBinding.prototype
* @name context
* @type Object|undefined|null
*/
public context;
/**
* Reference to Signal object that listener is currently bound to.
* @type Signal
* @private
*/
private _signal: Signal;
/**
* Listener priority
* @type Number
*/
public priority: number;
/**
* If binding is active and should be executed.
* @type boolean
*/
public active: boolean = true;
/**
* Default parameters passed to listener during `Signal.dispatch` and `SignalBinding.execute`. (curried parameters)
* @type Array|null
*/
public params = null;
/**
* Call listener passing arbitrary parameters.
*
If binding was added using `Signal.addOnce()` it will be automatically removed from signal dispatch queue, this method is used internally for the signal dispatch.
* @param {Array} [paramsArr] Array of parameters that should be passed to the listener * @return {*} Value returned by the listener. */ public execute(paramsArr: any[]) { var handlerReturn; var params; if (this.active && !!this._listener) { params = this.params ? this.params.concat(paramsArr) : paramsArr; handlerReturn = this._listener.apply(this.context, params); if (this._isOnce) { this.detach(); } } return handlerReturn; } /** * Detach binding from signal. * - alias to: mySignal.remove(myBinding.getListener()); * @return {Function|null} Handler function bound to the signal or `null` if binding was previously detached. */ public detach() { return this.isBound() ? this._signal.remove(this._listener, this.context) : null; } /** * @return {Boolean} `true` if binding is still bound to the signal and have a listener. */ public isBound(): boolean { return (!!this._signal && !!this._listener); } /** * @return {boolean} If SignalBinding will only be executed once. */ public isOnce(): boolean { return this._isOnce; } /** * @return {Function} Handler function bound to the signal. */ public getListener() { return this._listener; } /** * @return {Signal} Signal that listener is currently bound to. */ public getSignal() { return this._signal; } /** * Delete instance properties * @private */ public _destroy() { delete this._signal; delete this._listener; delete this.context; } /** * @return {string} String representation of the object. */ public toString(): string { return '[SignalBinding isOnce:' + this._isOnce + ', isBound:' + this.isBound() + ', active:' + this.active + ']'; } } }