// 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 Class to create objects which want to handle multiple events
* and have their listeners easily cleaned up via a dispose method.
*
* Example:
* <pre>
* function Something() {
* Something.base(this);
*
* ... set up object ...
*
* // Add event listeners
* this.listen(this.starEl, goog.events.EventType.CLICK, this.handleStar);
* this.listen(this.headerEl, goog.events.EventType.CLICK, this.expand);
* this.listen(this.collapseEl, goog.events.EventType.CLICK, this.collapse);
* this.listen(this.infoEl, goog.events.EventType.MOUSEOVER, this.showHover);
* this.listen(this.infoEl, goog.events.EventType.MOUSEOUT, this.hideHover);
* }
* goog.inherits(Something, goog.events.EventHandler);
*
* Something.prototype.disposeInternal = function() {
* Something.base(this, 'disposeInternal');
* goog.dom.removeNode(this.container);
* };
*
*
* // Then elsewhere:
*
* var activeSomething = null;
* function openSomething() {
* activeSomething = new Something();
* }
*
* function closeSomething() {
* if (activeSomething) {
* activeSomething.dispose(); // Remove event listeners
* activeSomething = null;
* }
* }
* </pre>
*
*/
goog.provide('goog.events.EventHandler');
goog.require('goog.Disposable');
goog.require('goog.events');
goog.require('goog.object');
goog.forwardDeclare('goog.events.EventWrapper');
/**
* Super class for objects that want to easily manage a number of event
* listeners. It allows a short cut to listen and also provides a quick way
* to remove all events listeners belonging to this object.
* @param {SCOPE=} opt_scope Object in whose scope to call the listeners.
* @constructor
* @extends {goog.Disposable}
* @template SCOPE
*/
goog.events.EventHandler = function(opt_scope) {
goog.Disposable.call(this);
// TODO(mknichel): Rename this to this.scope_ and fix the classes in google3
// that access this private variable. :(
this.handler_ = opt_scope;
/**
* Keys for events that are being listened to.
* @type {!Object<!goog.events.Key>}
* @private
*/
this.keys_ = {};
};
goog.inherits(goog.events.EventHandler, goog.Disposable);
/**
* Utility array used to unify the cases of listening for an array of types
* and listening for a single event, without using recursion or allocating
* an array each time.
* @type {!Array<string>}
* @const
* @private
*/
goog.events.EventHandler.typeArray_ = [];
/**
* Listen to an event on a Listenable. If the function is omitted then the
* EventHandler's handleEvent method will be used.
* @param {goog.events.ListenableType} src Event source.
* @param {string|Array<string>|
* !goog.events.EventId<EVENTOBJ>|!Array<!goog.events.EventId<EVENTOBJ>>}
* type Event type to listen for or array of event types.
* @param {function(this:SCOPE, EVENTOBJ):?|{handleEvent:function(?):?}|null=}
* opt_fn Optional callback function to be used as the listener or an object
* with handleEvent function.
* @param {boolean=} opt_capture Optional whether to use capture phase.
* @return {!goog.events.EventHandler<SCOPE>} This object, allowing for
* chaining of calls.
* @template EVENTOBJ
*/
goog.events.EventHandler.prototype.listen = function(
src, type, opt_fn, opt_capture) {
return this.listen_(src, type, opt_fn, opt_capture);
};
/**
* Listen to an event on a Listenable. If the function is omitted then the
* EventHandler's handleEvent method will be used.
* @param {goog.events.ListenableType} src Event source.
* @param {string|Array<string>|
* !goog.events.EventId<EVENTOBJ>|!Array<!goog.events.EventId<EVENTOBJ>>}
* type Event type to listen for or array of event types.
* @param {function(this:T, EVENTOBJ):?|{handleEvent:function(this:T, ?):?}|
* null|undefined} fn Optional callback function to be used as the
* listener or an object with handleEvent function.
* @param {boolean|undefined} capture Optional whether to use capture phase.
* @param {T} scope Object in whose scope to call the listener.
* @return {!goog.events.EventHandler<SCOPE>} This object, allowing for
* chaining of calls.
* @template T,EVENTOBJ
*/
goog.events.EventHandler.prototype.listenWithScope = function(
src, type, fn, capture, scope) {
// TODO(mknichel): Deprecate this function.
return this.listen_(src, type, fn, capture, scope);
};
/**
* Listen to an event on a Listenable. If the function is omitted then the
* EventHandler's handleEvent method will be used.
* @param {goog.events.ListenableType} src Event source.
* @param {string|Array<string>|
* !goog.events.EventId<EVENTOBJ>|!Array<!goog.events.EventId<EVENTOBJ>>}
* type Event type to listen for or array of event types.
* @param {function(EVENTOBJ):?|{handleEvent:function(?):?}|null=} opt_fn
* Optional callback function to be used as the listener or an object with
* handleEvent function.
* @param {boolean=} opt_capture Optional whether to use capture phase.
* @param {Object=} opt_scope Object in whose scope to call the listener.
* @return {!goog.events.EventHandler<SCOPE>} This object, allowing for
* chaining of calls.
* @template EVENTOBJ
* @private
*/
goog.events.EventHandler.prototype.listen_ = function(src, type, opt_fn,
opt_capture,
opt_scope) {
if (!goog.isArray(type)) {
if (type) {
goog.events.EventHandler.typeArray_[0] = type.toString();
}
type = goog.events.EventHandler.typeArray_;
}
for (var i = 0; i < type.length; i++) {
var listenerObj = goog.events.listen(
src, type[i], opt_fn || this.handleEvent,
opt_capture || false,
opt_scope || this.handler_ || this);
if (!listenerObj) {
// When goog.events.listen run on OFF_AND_FAIL or OFF_AND_SILENT
// (goog.events.CaptureSimulationMode) in IE8-, it will return null
// value.
return this;
}
var key = listenerObj.key;
this.keys_[key] = listenerObj;
}
return this;
};
/**
* Listen to an event on a Listenable. If the function is omitted, then the
* EventHandler's handleEvent method will be used. After the event has fired the
* event listener is removed from the target. If an array of event types is
* provided, each event type will be listened to once.
* @param {goog.events.ListenableType} src Event source.
* @param {string|Array<string>|
* !goog.events.EventId<EVENTOBJ>|!Array<!goog.events.EventId<EVENTOBJ>>}
* type Event type to listen for or array of event types.
* @param {function(this:SCOPE, EVENTOBJ):?|{handleEvent:function(?):?}|null=} opt_fn
* Optional callback function to be used as the listener or an object with
* handleEvent function.
* @param {boolean=} opt_capture Optional whether to use capture phase.
* @return {!goog.events.EventHandler<SCOPE>} This object, allowing for
* chaining of calls.
* @template EVENTOBJ
*/
goog.events.EventHandler.prototype.listenOnce = function(
src, type, opt_fn, opt_capture) {
return this.listenOnce_(src, type, opt_fn, opt_capture);
};
/**
* Listen to an event on a Listenable. If the function is omitted, then the
* EventHandler's handleEvent method will be used. After the event has fired the
* event listener is removed from the target. If an array of event types is
* provided, each event type will be listened to once.
* @param {goog.events.ListenableType} src Event source.
* @param {string|Array<string>|
* !goog.events.EventId<EVENTOBJ>|!Array<!goog.events.EventId<EVENTOBJ>>}
* type Event type to listen for or array of event types.
* @param {function(this:T, EVENTOBJ):?|{handleEvent:function(this:T, ?):?}|
* null|undefined} fn Optional callback function to be used as the
* listener or an object with handleEvent function.
* @param {boolean|undefined} capture Optional whether to use capture phase.
* @param {T} scope Object in whose scope to call the listener.
* @return {!goog.events.EventHandler<SCOPE>} This object, allowing for
* chaining of calls.
* @template T,EVENTOBJ
*/
goog.events.EventHandler.prototype.listenOnceWithScope = function(
src, type, fn, capture, scope) {
// TODO(mknichel): Deprecate this function.
return this.listenOnce_(src, type, fn, capture, scope);
};
/**
* Listen to an event on a Listenable. If the function is omitted, then the
* EventHandler's handleEvent method will be used. After the event has fired
* the event listener is removed from the target. If an array of event types is
* provided, each event type will be listened to once.
* @param {goog.events.ListenableType} src Event source.
* @param {string|Array<string>|
* !goog.events.EventId<EVENTOBJ>|!Array<!goog.events.EventId<EVENTOBJ>>}
* type Event type to listen for or array of event types.
* @param {function(EVENTOBJ):?|{handleEvent:function(?):?}|null=} opt_fn
* Optional callback function to be used as the listener or an object with
* handleEvent function.
* @param {boolean=} opt_capture Optional whether to use capture phase.
* @param {Object=} opt_scope Object in whose scope to call the listener.
* @return {!goog.events.EventHandler<SCOPE>} This object, allowing for
* chaining of calls.
* @template EVENTOBJ
* @private
*/
goog.events.EventHandler.prototype.listenOnce_ = function(
src, type, opt_fn, opt_capture, opt_scope) {
if (goog.isArray(type)) {
for (var i = 0; i < type.length; i++) {
this.listenOnce_(src, type[i], opt_fn, opt_capture, opt_scope);
}
} else {
var listenerObj = goog.events.listenOnce(
src, type, opt_fn || this.handleEvent, opt_capture,
opt_scope || this.handler_ || this);
if (!listenerObj) {
// When goog.events.listen run on OFF_AND_FAIL or OFF_AND_SILENT
// (goog.events.CaptureSimulationMode) in IE8-, it will return null
// value.
return this;
}
var key = listenerObj.key;
this.keys_[key] = listenerObj;
}
return this;
};
/**
* Adds an event listener with a specific event wrapper on a DOM Node or an
* object that has implemented {@link goog.events.EventTarget}. A listener can
* only be added once to an object.
*
* @param {EventTarget|goog.events.EventTarget} src The node to listen to
* events on.
* @param {goog.events.EventWrapper} wrapper Event wrapper to use.
* @param {function(this:SCOPE, ?):?|{handleEvent:function(?):?}|null} listener
* Callback method, or an object with a handleEvent function.
* @param {boolean=} opt_capt Whether to fire in capture phase (defaults to
* false).
* @return {!goog.events.EventHandler<SCOPE>} This object, allowing for
* chaining of calls.
*/
goog.events.EventHandler.prototype.listenWithWrapper = function(
src, wrapper, listener, opt_capt) {
// TODO(mknichel): Remove the opt_scope from this function and then
// templatize it.
return this.listenWithWrapper_(src, wrapper, listener, opt_capt);
};
/**
* Adds an event listener with a specific event wrapper on a DOM Node or an
* object that has implemented {@link goog.events.EventTarget}. A listener can
* only be added once to an object.
*
* @param {EventTarget|goog.events.EventTarget} src The node to listen to
* events on.
* @param {goog.events.EventWrapper} wrapper Event wrapper to use.
* @param {function(this:T, ?):?|{handleEvent:function(this:T, ?):?}|null}
* listener Optional callback function to be used as the
* listener or an object with handleEvent function.
* @param {boolean|undefined} capture Optional whether to use capture phase.
* @param {T} scope Object in whose scope to call the listener.
* @return {!goog.events.EventHandler<SCOPE>} This object, allowing for
* chaining of calls.
* @template T
*/
goog.events.EventHandler.prototype.listenWithWrapperAndScope = function(
src, wrapper, listener, capture, scope) {
// TODO(mknichel): Deprecate this function.
return this.listenWithWrapper_(src, wrapper, listener, capture, scope);
};
/**
* Adds an event listener with a specific event wrapper on a DOM Node or an
* object that has implemented {@link goog.events.EventTarget}. A listener can
* only be added once to an object.
*
* @param {EventTarget|goog.events.EventTarget} src The node to listen to
* events on.
* @param {goog.events.EventWrapper} wrapper Event wrapper to use.
* @param {function(?):?|{handleEvent:function(?):?}|null} listener Callback
* method, or an object with a handleEvent function.
* @param {boolean=} opt_capt Whether to fire in capture phase (defaults to
* false).
* @param {Object=} opt_scope Element in whose scope to call the listener.
* @return {!goog.events.EventHandler<SCOPE>} This object, allowing for
* chaining of calls.
* @private
*/
goog.events.EventHandler.prototype.listenWithWrapper_ = function(
src, wrapper, listener, opt_capt, opt_scope) {
wrapper.listen(src, listener, opt_capt, opt_scope || this.handler_ || this,
this);
return this;
};
/**
* @return {number} Number of listeners registered by this handler.
*/
goog.events.EventHandler.prototype.getListenerCount = function() {
var count = 0;
for (var key in this.keys_) {
if (Object.prototype.hasOwnProperty.call(this.keys_, key)) {
count++;
}
}
return count;
};
/**
* Unlistens on an event.
* @param {goog.events.ListenableType} src Event source.
* @param {string|Array<string>|
* !goog.events.EventId<EVENTOBJ>|!Array<!goog.events.EventId<EVENTOBJ>>}
* type Event type or array of event types to unlisten to.
* @param {function(EVENTOBJ):?|{handleEvent:function(?):?}|null=} opt_fn
* Optional callback function to be used as the listener or an object with
* handleEvent function.
* @param {boolean=} opt_capture Optional whether to use capture phase.
* @param {Object=} opt_scope Object in whose scope to call the listener.
* @return {!goog.events.EventHandler} This object, allowing for chaining of
* calls.
* @template EVENTOBJ
*/
goog.events.EventHandler.prototype.unlisten = function(src, type, opt_fn,
opt_capture,
opt_scope) {
if (goog.isArray(type)) {
for (var i = 0; i < type.length; i++) {
this.unlisten(src, type[i], opt_fn, opt_capture, opt_scope);
}
} else {
var listener = goog.events.getListener(src, type,
opt_fn || this.handleEvent,
opt_capture, opt_scope || this.handler_ || this);
if (listener) {
goog.events.unlistenByKey(listener);
delete this.keys_[listener.key];
}
}
return this;
};
/**
* Removes an event listener which was added with listenWithWrapper().
*
* @param {EventTarget|goog.events.EventTarget} src The target to stop
* listening to events on.
* @param {goog.events.EventWrapper} wrapper Event wrapper to use.
* @param {function(?):?|{handleEvent:function(?):?}|null} listener The
* listener function to remove.
* @param {boolean=} opt_capt In DOM-compliant browsers, this determines
* whether the listener is fired during the capture or bubble phase of the
* event.
* @param {Object=} opt_scope Element in whose scope to call the listener.
* @return {!goog.events.EventHandler} This object, allowing for chaining of
* calls.
*/
goog.events.EventHandler.prototype.unlistenWithWrapper = function(src, wrapper,
listener, opt_capt, opt_scope) {
wrapper.unlisten(src, listener, opt_capt,
opt_scope || this.handler_ || this, this);
return this;
};
/**
* Unlistens to all events.
*/
goog.events.EventHandler.prototype.removeAll = function() {
goog.object.forEach(this.keys_, function(listenerObj, key) {
if (this.keys_.hasOwnProperty(key)) {
goog.events.unlistenByKey(listenerObj);
}
}, this);
this.keys_ = {};
};
/**
* Disposes of this EventHandler and removes all listeners that it registered.
* @override
* @protected
*/
goog.events.EventHandler.prototype.disposeInternal = function() {
goog.events.EventHandler.superClass_.disposeInternal.call(this);
this.removeAll();
};
/**
* Default event handler
* @param {goog.events.Event} e Event object.
*/
goog.events.EventHandler.prototype.handleEvent = function(e) {
throw Error('EventHandler.handleEvent not implemented');
};
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