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// Copyright 2005 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview Listener object.
* @see ../demos/events.html
*/
goog.provide('goog.events.Listener');
goog.require('goog.events.ListenableKey');
/**
* Simple class that stores information about a listener
* @param {!Function} listener Callback function.
* @param {Function} proxy Wrapper for the listener that patches the event.
* @param {EventTarget|goog.events.Listenable} src Source object for
* the event.
* @param {string} type Event type.
* @param {boolean} capture Whether in capture or bubble phase.
* @param {Object=} opt_handler Object in whose context to execute the callback.
* @implements {goog.events.ListenableKey}
* @constructor
*/
goog.events.Listener = function(
listener, proxy, src, type, capture, opt_handler) {
if (goog.events.Listener.ENABLE_MONITORING) {
this.creationStack = new Error().stack;
}
/**
* Callback function.
* @type {Function}
*/
this.listener = listener;
/**
* A wrapper over the original listener. This is used solely to
* handle native browser events (it is used to simulate the capture
* phase and to patch the event object).
* @type {Function}
*/
this.proxy = proxy;
/**
* Object or node that callback is listening to
* @type {EventTarget|goog.events.Listenable}
*/
this.src = src;
/**
* The event type.
* @const {string}
*/
this.type = type;
/**
* Whether the listener is being called in the capture or bubble phase
* @const {boolean}
*/
this.capture = !!capture;
/**
* Optional object whose context to execute the listener in
* @type {Object|undefined}
*/
this.handler = opt_handler;
/**
* The key of the listener.
* @const {number}
* @override
*/
this.key = goog.events.ListenableKey.reserveKey();
/**
* Whether to remove the listener after it has been called.
* @type {boolean}
*/
this.callOnce = false;
/**
* Whether the listener has been removed.
* @type {boolean}
*/
this.removed = false;
};
/**
* @define {boolean} Whether to enable the monitoring of the
* goog.events.Listener instances. Switching on the monitoring is only
* recommended for debugging because it has a significant impact on
* performance and memory usage. If switched off, the monitoring code
* compiles down to 0 bytes.
*/
goog.define('goog.events.Listener.ENABLE_MONITORING', false);
/**
* If monitoring the goog.events.Listener instances is enabled, stores the
* creation stack trace of the Disposable instance.
* @type {string}
*/
goog.events.Listener.prototype.creationStack;
/**
* Marks this listener as removed. This also remove references held by
* this listener object (such as listener and event source).
*/
goog.events.Listener.prototype.markAsRemoved = function() {
this.removed = true;
this.listener = null;
this.proxy = null;
this.src = null;
this.handler = null;
};
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