// 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 An event manager for both native browser event
* targets and custom JavaScript event targets
* ({@code goog.events.Listenable}). This provides an abstraction
* over browsers' event systems.
*
* It also provides a simulation of W3C event model's capture phase in
* Internet Explorer (IE 8 and below). Caveat: the simulation does not
* interact well with listeners registered directly on the elements
* (bypassing goog.events) or even with listeners registered via
* goog.events in a separate JS binary. In these cases, we provide
* no ordering guarantees.
*
* The listeners will receive a "patched" event object. Such event object
* contains normalized values for certain event properties that differs in
* different browsers.
*
* Example usage:
* <pre>
* goog.events.listen(myNode, 'click', function(e) { alert('woo') });
* goog.events.listen(myNode, 'mouseover', mouseHandler, true);
* goog.events.unlisten(myNode, 'mouseover', mouseHandler, true);
* goog.events.removeAll(myNode);
* </pre>
*
* in IE and event object patching]
* @author [email protected] (Erik Arvidsson)
*
* @see ../demos/events.html
* @see ../demos/event-propagation.html
* @see ../demos/stopevent.html
*/
// IMPLEMENTATION NOTES:
// goog.events stores an auxiliary data structure on each EventTarget
// source being listened on. This allows us to take advantage of GC,
// having the data structure GC'd when the EventTarget is GC'd. This
// GC behavior is equivalent to using W3C DOM Events directly.
goog.provide('goog.events');
goog.provide('goog.events.CaptureSimulationMode');
goog.provide('goog.events.Key');
goog.provide('goog.events.ListenableType');
goog.require('goog.asserts');
goog.require('goog.debug.entryPointRegistry');
goog.require('goog.events.BrowserEvent');
goog.require('goog.events.BrowserFeature');
goog.require('goog.events.Listenable');
goog.require('goog.events.ListenerMap');
goog.forwardDeclare('goog.debug.ErrorHandler');
goog.forwardDeclare('goog.events.EventWrapper');
/**
* @typedef {number|goog.events.ListenableKey}
*/
goog.events.Key;
/**
* @typedef {EventTarget|goog.events.Listenable}
*/
goog.events.ListenableType;
/**
* Property name on a native event target for the listener map
* associated with the event target.
* @private @const {string}
*/
goog.events.LISTENER_MAP_PROP_ = 'closure_lm_' + ((Math.random() * 1e6) | 0);
/**
* String used to prepend to IE event types.
* @const
* @private
*/
goog.events.onString_ = 'on';
/**
* Map of computed "on<eventname>" strings for IE event types. Caching
* this removes an extra object allocation in goog.events.listen which
* improves IE6 performance.
* @const
* @dict
* @private
*/
goog.events.onStringMap_ = {};
/**
* @enum {number} Different capture simulation mode for IE8-.
*/
goog.events.CaptureSimulationMode = {
/**
* Does not perform capture simulation. Will asserts in IE8- when you
* add capture listeners.
*/
OFF_AND_FAIL: 0,
/**
* Does not perform capture simulation, silently ignore capture
* listeners.
*/
OFF_AND_SILENT: 1,
/**
* Performs capture simulation.
*/
ON: 2
};
/**
* @define {number} The capture simulation mode for IE8-. By default,
* this is ON.
*/
goog.define('goog.events.CAPTURE_SIMULATION_MODE', 2);
/**
* Estimated count of total native listeners.
* @private {number}
*/
goog.events.listenerCountEstimate_ = 0;
/**
* Adds an event listener for a specific event on a native event
* target (such as a DOM element) or an object that has implemented
* {@link goog.events.Listenable}. A listener can only be added once
* to an object and if it is added again the key for the listener is
* returned. Note that if the existing listener is a one-off listener
* (registered via listenOnce), it will no longer be a one-off
* listener after a call to listen().
*
* @param {EventTarget|goog.events.Listenable} src The node to listen
* to events on.
* @param {string|Array<string>|
* !goog.events.EventId<EVENTOBJ>|!Array<!goog.events.EventId<EVENTOBJ>>}
* type Event type or array of event types.
* @param {function(this:T, EVENTOBJ):?|{handleEvent:function(?):?}|null}
* listener Callback method, or an object with a handleEvent function.
* WARNING: passing an Object is now softly deprecated.
* @param {boolean=} opt_capt Whether to fire in capture phase (defaults to
* false).
* @param {T=} opt_handler Element in whose scope to call the listener.
* @return {goog.events.Key} Unique key for the listener.
* @template T,EVENTOBJ
*/
goog.events.listen = function(src, type, listener, opt_capt, opt_handler) {
if (goog.isArray(type)) {
for (var i = 0; i < type.length; i++) {
goog.events.listen(src, type[i], listener, opt_capt, opt_handler);
}
return null;
}
listener = goog.events.wrapListener(listener);
if (goog.events.Listenable.isImplementedBy(src)) {
return src.listen(
/** @type {string|!goog.events.EventId} */ (type),
listener, opt_capt, opt_handler);
} else {
return goog.events.listen_(
/** @type {!EventTarget} */ (src),
/** @type {string|!goog.events.EventId} */ (type),
listener, /* callOnce */ false, opt_capt, opt_handler);
}
};
/**
* Adds an event listener for a specific event on a native event
* target. A listener can only be added once to an object and if it
* is added again the key for the listener is returned.
*
* Note that a one-off listener will not change an existing listener,
* if any. On the other hand a normal listener will change existing
* one-off listener to become a normal listener.
*
* @param {EventTarget} src The node to listen to events on.
* @param {string|!goog.events.EventId} type Event type.
* @param {!Function} listener Callback function.
* @param {boolean} callOnce Whether the listener is a one-off
* listener or otherwise.
* @param {boolean=} opt_capt Whether to fire in capture phase (defaults to
* false).
* @param {Object=} opt_handler Element in whose scope to call the listener.
* @return {goog.events.ListenableKey} Unique key for the listener.
* @private
*/
goog.events.listen_ = function(
src, type, listener, callOnce, opt_capt, opt_handler) {
if (!type) {
throw Error('Invalid event type');
}
var capture = !!opt_capt;
if (capture && !goog.events.BrowserFeature.HAS_W3C_EVENT_SUPPORT) {
if (goog.events.CAPTURE_SIMULATION_MODE ==
goog.events.CaptureSimulationMode.OFF_AND_FAIL) {
goog.asserts.fail('Can not register capture listener in IE8-.');
return null;
} else if (goog.events.CAPTURE_SIMULATION_MODE ==
goog.events.CaptureSimulationMode.OFF_AND_SILENT) {
return null;
}
}
var listenerMap = goog.events.getListenerMap_(src);
if (!listenerMap) {
src[goog.events.LISTENER_MAP_PROP_] = listenerMap =
new goog.events.ListenerMap(src);
}
var listenerObj = listenerMap.add(
type, listener, callOnce, opt_capt, opt_handler);
// If the listenerObj already has a proxy, it has been set up
// previously. We simply return.
if (listenerObj.proxy) {
return listenerObj;
}
var proxy = goog.events.getProxy();
listenerObj.proxy = proxy;
proxy.src = src;
proxy.listener = listenerObj;
// Attach the proxy through the browser's API
if (src.addEventListener) {
src.addEventListener(type.toString(), proxy, capture);
} else if (src.attachEvent) {
// The else if above used to be an unconditional else. It would call
// exception on IE11, spoiling the day of some callers. The previous
// incarnation of this code, from 2007, indicates that it replaced an
// earlier still version that caused excess allocations on IE6.
src.attachEvent(goog.events.getOnString_(type.toString()), proxy);
} else {
throw Error('addEventListener and attachEvent are unavailable.');
}
goog.events.listenerCountEstimate_++;
return listenerObj;
};
/**
* Helper function for returning a proxy function.
* @return {!Function} A new or reused function object.
*/
goog.events.getProxy = function() {
var proxyCallbackFunction = goog.events.handleBrowserEvent_;
// Use a local var f to prevent one allocation.
var f = goog.events.BrowserFeature.HAS_W3C_EVENT_SUPPORT ?
function(eventObject) {
return proxyCallbackFunction.call(f.src, f.listener, eventObject);
} :
function(eventObject) {
var v = proxyCallbackFunction.call(f.src, f.listener, eventObject);
// NOTE(chrishenry): In IE, we hack in a capture phase. However, if
// there is inline event handler which tries to prevent default (for
// example <a href="..." onclick="return false">...</a>) in a
// descendant element, the prevent default will be overridden
// by this listener if this listener were to return true. Hence, we
// return undefined.
if (!v) return v;
};
return f;
};
/**
* Adds an event listener for a specific event on a native event
* target (such as a DOM element) or an object that has implemented
* {@link goog.events.Listenable}. After the event has fired the event
* listener is removed from the target.
*
* If an existing listener already exists, listenOnce will do
* nothing. In particular, if the listener was previously registered
* via listen(), listenOnce() will not turn the listener into a
* one-off listener. Similarly, if there is already an existing
* one-off listener, listenOnce does not modify the listeners (it is
* still a once listener).
*
* @param {EventTarget|goog.events.Listenable} src The node to listen
* to events on.
* @param {string|Array<string>|
* !goog.events.EventId<EVENTOBJ>|!Array<!goog.events.EventId<EVENTOBJ>>}
* type Event type or array of event types.
* @param {function(this:T, EVENTOBJ):?|{handleEvent:function(?):?}|null}
* listener Callback method.
* @param {boolean=} opt_capt Fire in capture phase?.
* @param {T=} opt_handler Element in whose scope to call the listener.
* @return {goog.events.Key} Unique key for the listener.
* @template T,EVENTOBJ
*/
goog.events.listenOnce = function(src, type, listener, opt_capt, opt_handler) {
if (goog.isArray(type)) {
for (var i = 0; i < type.length; i++) {
goog.events.listenOnce(src, type[i], listener, opt_capt, opt_handler);
}
return null;
}
listener = goog.events.wrapListener(listener);
if (goog.events.Listenable.isImplementedBy(src)) {
return src.listenOnce(
/** @type {string|!goog.events.EventId} */ (type),
listener, opt_capt, opt_handler);
} else {
return goog.events.listen_(
/** @type {!EventTarget} */ (src),
/** @type {string|!goog.events.EventId} */ (type),
listener, /* callOnce */ true, opt_capt, opt_handler);
}
};
/**
* Adds an event listener with a specific event wrapper on a DOM Node or an
* object that has implemented {@link goog.events.Listenable}. A listener can
* only be added once to an object.
*
* @param {EventTarget|goog.events.Listenable} src The target to
* listen to events on.
* @param {goog.events.EventWrapper} wrapper Event wrapper to use.
* @param {function(this:T, ?):?|{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 {T=} opt_handler Element in whose scope to call the listener.
* @template T
*/
goog.events.listenWithWrapper = function(src, wrapper, listener, opt_capt,
opt_handler) {
wrapper.listen(src, listener, opt_capt, opt_handler);
};
/**
* Removes an event listener which was added with listen().
*
* @param {EventTarget|goog.events.Listenable} src The target to stop
* listening to events on.
* @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(?):?|{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_handler Element in whose scope to call the listener.
* @return {?boolean} indicating whether the listener was there to remove.
* @template EVENTOBJ
*/
goog.events.unlisten = function(src, type, listener, opt_capt, opt_handler) {
if (goog.isArray(type)) {
for (var i = 0; i < type.length; i++) {
goog.events.unlisten(src, type[i], listener, opt_capt, opt_handler);
}
return null;
}
listener = goog.events.wrapListener(listener);
if (goog.events.Listenable.isImplementedBy(src)) {
return src.unlisten(
/** @type {string|!goog.events.EventId} */ (type),
listener, opt_capt, opt_handler);
}
if (!src) {
// TODO(chrishenry): We should tighten the API to only accept
// non-null objects, or add an assertion here.
return false;
}
var capture = !!opt_capt;
var listenerMap = goog.events.getListenerMap_(
/** @type {!EventTarget} */ (src));
if (listenerMap) {
var listenerObj = listenerMap.getListener(
/** @type {string|!goog.events.EventId} */ (type),
listener, capture, opt_handler);
if (listenerObj) {
return goog.events.unlistenByKey(listenerObj);
}
}
return false;
};
/**
* Removes an event listener which was added with listen() by the key
* returned by listen().
*
* @param {goog.events.Key} key The key returned by listen() for this
* event listener.
* @return {boolean} indicating whether the listener was there to remove.
*/
goog.events.unlistenByKey = function(key) {
// TODO(chrishenry): Remove this check when tests that rely on this
// are fixed.
if (goog.isNumber(key)) {
return false;
}
var listener = key;
if (!listener || listener.removed) {
return false;
}
var src = listener.src;
if (goog.events.Listenable.isImplementedBy(src)) {
return src.unlistenByKey(listener);
}
var type = listener.type;
var proxy = listener.proxy;
if (src.removeEventListener) {
src.removeEventListener(type, proxy, listener.capture);
} else if (src.detachEvent) {
src.detachEvent(goog.events.getOnString_(type), proxy);
}
goog.events.listenerCountEstimate_--;
var listenerMap = goog.events.getListenerMap_(
/** @type {!EventTarget} */ (src));
// TODO(chrishenry): Try to remove this conditional and execute the
// first branch always. This should be safe.
if (listenerMap) {
listenerMap.removeByKey(listener);
if (listenerMap.getTypeCount() == 0) {
// Null the src, just because this is simple to do (and useful
// for IE <= 7).
listenerMap.src = null;
// We don't use delete here because IE does not allow delete
// on a window object.
src[goog.events.LISTENER_MAP_PROP_] = null;
}
} else {
listener.markAsRemoved();
}
return true;
};
/**
* Removes an event listener which was added with listenWithWrapper().
*
* @param {EventTarget|goog.events.Listenable} 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_handler Element in whose scope to call the listener.
*/
goog.events.unlistenWithWrapper = function(src, wrapper, listener, opt_capt,
opt_handler) {
wrapper.unlisten(src, listener, opt_capt, opt_handler);
};
/**
* Removes all listeners from an object. You can also optionally
* remove listeners of a particular type.
*
* @param {Object|undefined} obj Object to remove listeners from. Must be an
* EventTarget or a goog.events.Listenable.
* @param {string|!goog.events.EventId=} opt_type Type of event to remove.
* Default is all types.
* @return {number} Number of listeners removed.
*/
goog.events.removeAll = function(obj, opt_type) {
// TODO(chrishenry): Change the type of obj to
// (!EventTarget|!goog.events.Listenable).
if (!obj) {
return 0;
}
if (goog.events.Listenable.isImplementedBy(obj)) {
return obj.removeAllListeners(opt_type);
}
var listenerMap = goog.events.getListenerMap_(
/** @type {!EventTarget} */ (obj));
if (!listenerMap) {
return 0;
}
var count = 0;
var typeStr = opt_type && opt_type.toString();
for (var type in listenerMap.listeners) {
if (!typeStr || type == typeStr) {
// Clone so that we don't need to worry about unlistenByKey
// changing the content of the ListenerMap.
var listeners = listenerMap.listeners[type].concat();
for (var i = 0; i < listeners.length; ++i) {
if (goog.events.unlistenByKey(listeners[i])) {
++count;
}
}
}
}
return count;
};
/**
* Gets the listeners for a given object, type and capture phase.
*
* @param {Object} obj Object to get listeners for.
* @param {string|!goog.events.EventId} type Event type.
* @param {boolean} capture Capture phase?.
* @return {Array<goog.events.Listener>} Array of listener objects.
*/
goog.events.getListeners = function(obj, type, capture) {
if (goog.events.Listenable.isImplementedBy(obj)) {
return obj.getListeners(type, capture);
} else {
if (!obj) {
// TODO(chrishenry): We should tighten the API to accept
// !EventTarget|goog.events.Listenable, and add an assertion here.
return [];
}
var listenerMap = goog.events.getListenerMap_(
/** @type {!EventTarget} */ (obj));
return listenerMap ? listenerMap.getListeners(type, capture) : [];
}
};
/**
* Gets the goog.events.Listener for the event or null if no such listener is
* in use.
*
* @param {EventTarget|goog.events.Listenable} src The target from
* which to get listeners.
* @param {?string|!goog.events.EventId<EVENTOBJ>} type The type of the event.
* @param {function(EVENTOBJ):?|{handleEvent:function(?):?}|null} listener The
* listener function to get.
* @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_handler Element in whose scope to call the listener.
* @return {goog.events.ListenableKey} the found listener or null if not found.
* @template EVENTOBJ
*/
goog.events.getListener = function(src, type, listener, opt_capt, opt_handler) {
// TODO(chrishenry): Change type from ?string to string, or add assertion.
type = /** @type {string} */ (type);
listener = goog.events.wrapListener(listener);
var capture = !!opt_capt;
if (goog.events.Listenable.isImplementedBy(src)) {
return src.getListener(type, listener, capture, opt_handler);
}
if (!src) {
// TODO(chrishenry): We should tighten the API to only accept
// non-null objects, or add an assertion here.
return null;
}
var listenerMap = goog.events.getListenerMap_(
/** @type {!EventTarget} */ (src));
if (listenerMap) {
return listenerMap.getListener(type, listener, capture, opt_handler);
}
return null;
};
/**
* Returns whether an event target has any active listeners matching the
* specified signature. If either the type or capture parameters are
* unspecified, the function will match on the remaining criteria.
*
* @param {EventTarget|goog.events.Listenable} obj Target to get
* listeners for.
* @param {string|!goog.events.EventId=} opt_type Event type.
* @param {boolean=} opt_capture Whether to check for capture or bubble-phase
* listeners.
* @return {boolean} Whether an event target has one or more listeners matching
* the requested type and/or capture phase.
*/
goog.events.hasListener = function(obj, opt_type, opt_capture) {
if (goog.events.Listenable.isImplementedBy(obj)) {
return obj.hasListener(opt_type, opt_capture);
}
var listenerMap = goog.events.getListenerMap_(
/** @type {!EventTarget} */ (obj));
return !!listenerMap && listenerMap.hasListener(opt_type, opt_capture);
};
/**
* Provides a nice string showing the normalized event objects public members
* @param {Object} e Event Object.
* @return {string} String of the public members of the normalized event object.
*/
goog.events.expose = function(e) {
var str = [];
for (var key in e) {
if (e[key] && e[key].id) {
str.push(key + ' = ' + e[key] + ' (' + e[key].id + ')');
} else {
str.push(key + ' = ' + e[key]);
}
}
return str.join('\n');
};
/**
* Returns a string with on prepended to the specified type. This is used for IE
* which expects "on" to be prepended. This function caches the string in order
* to avoid extra allocations in steady state.
* @param {string} type Event type.
* @return {string} The type string with 'on' prepended.
* @private
*/
goog.events.getOnString_ = function(type) {
if (type in goog.events.onStringMap_) {
return goog.events.onStringMap_[type];
}
return goog.events.onStringMap_[type] = goog.events.onString_ + type;
};
/**
* Fires an object's listeners of a particular type and phase
*
* @param {Object} obj Object whose listeners to call.
* @param {string|!goog.events.EventId} type Event type.
* @param {boolean} capture Which event phase.
* @param {Object} eventObject Event object to be passed to listener.
* @return {boolean} True if all listeners returned true else false.
*/
goog.events.fireListeners = function(obj, type, capture, eventObject) {
if (goog.events.Listenable.isImplementedBy(obj)) {
return obj.fireListeners(type, capture, eventObject);
}
return goog.events.fireListeners_(obj, type, capture, eventObject);
};
/**
* Fires an object's listeners of a particular type and phase.
* @param {Object} obj Object whose listeners to call.
* @param {string|!goog.events.EventId} type Event type.
* @param {boolean} capture Which event phase.
* @param {Object} eventObject Event object to be passed to listener.
* @return {boolean} True if all listeners returned true else false.
* @private
*/
goog.events.fireListeners_ = function(obj, type, capture, eventObject) {
/** @type {boolean} */
var retval = true;
var listenerMap = goog.events.getListenerMap_(
/** @type {EventTarget} */ (obj));
if (listenerMap) {
// TODO(chrishenry): Original code avoids array creation when there
// is no listener, so we do the same. If this optimization turns
// out to be not required, we can replace this with
// listenerMap.getListeners(type, capture) instead, which is simpler.
var listenerArray = listenerMap.listeners[type.toString()];
if (listenerArray) {
listenerArray = listenerArray.concat();
for (var i = 0; i < listenerArray.length; i++) {
var listener = listenerArray[i];
// We might not have a listener if the listener was removed.
if (listener && listener.capture == capture && !listener.removed) {
var result = goog.events.fireListener(listener, eventObject);
retval = retval && (result !== false);
}
}
}
}
return retval;
};
/**
* Fires a listener with a set of arguments
*
* @param {goog.events.Listener} listener The listener object to call.
* @param {Object} eventObject The event object to pass to the listener.
* @return {boolean} Result of listener.
*/
goog.events.fireListener = function(listener, eventObject) {
var listenerFn = listener.listener;
var listenerHandler = listener.handler || listener.src;
if (listener.callOnce) {
goog.events.unlistenByKey(listener);
}
return listenerFn.call(listenerHandler, eventObject);
};
/**
* Gets the total number of listeners currently in the system.
* @return {number} Number of listeners.
* @deprecated This returns estimated count, now that Closure no longer
* stores a central listener registry. We still return an estimation
* to keep existing listener-related tests passing. In the near future,
* this function will be removed.
*/
goog.events.getTotalListenerCount = function() {
return goog.events.listenerCountEstimate_;
};
/**
* Dispatches an event (or event like object) and calls all listeners
* listening for events of this type. The type of the event is decided by the
* type property on the event object.
*
* If any of the listeners returns false OR calls preventDefault then this
* function will return false. If one of the capture listeners calls
* stopPropagation, then the bubble listeners won't fire.
*
* @param {goog.events.Listenable} src The event target.
* @param {goog.events.EventLike} e Event object.
* @return {boolean} If anyone called preventDefault on the event object (or
* if any of the handlers returns false) this will also return false.
* If there are no handlers, or if all handlers return true, this returns
* true.
*/
goog.events.dispatchEvent = function(src, e) {
goog.asserts.assert(
goog.events.Listenable.isImplementedBy(src),
'Can not use goog.events.dispatchEvent with ' +
'non-goog.events.Listenable instance.');
return src.dispatchEvent(e);
};
/**
* Installs exception protection for the browser event entry point using the
* given error handler.
*
* @param {goog.debug.ErrorHandler} errorHandler Error handler with which to
* protect the entry point.
*/
goog.events.protectBrowserEventEntryPoint = function(errorHandler) {
goog.events.handleBrowserEvent_ = errorHandler.protectEntryPoint(
goog.events.handleBrowserEvent_);
};
/**
* Handles an event and dispatches it to the correct listeners. This
* function is a proxy for the real listener the user specified.
*
* @param {goog.events.Listener} listener The listener object.
* @param {Event=} opt_evt Optional event object that gets passed in via the
* native event handlers.
* @return {boolean} Result of the event handler.
* @this {EventTarget} The object or Element that fired the event.
* @private
*/
goog.events.handleBrowserEvent_ = function(listener, opt_evt) {
if (listener.removed) {
return true;
}
// Synthesize event propagation if the browser does not support W3C
// event model.
if (!goog.events.BrowserFeature.HAS_W3C_EVENT_SUPPORT) {
var ieEvent = opt_evt ||
/** @type {Event} */ (goog.getObjectByName('window.event'));
var evt = new goog.events.BrowserEvent(ieEvent, this);
/** @type {boolean} */
var retval = true;
if (goog.events.CAPTURE_SIMULATION_MODE ==
goog.events.CaptureSimulationMode.ON) {
// If we have not marked this event yet, we should perform capture
// simulation.
if (!goog.events.isMarkedIeEvent_(ieEvent)) {
goog.events.markIeEvent_(ieEvent);
var ancestors = [];
for (var parent = evt.currentTarget; parent;
parent = parent.parentNode) {
ancestors.push(parent);
}
// Fire capture listeners.
var type = listener.type;
for (var i = ancestors.length - 1; !evt.propagationStopped_ && i >= 0;
i--) {
evt.currentTarget = ancestors[i];
var result = goog.events.fireListeners_(ancestors[i], type, true, evt);
retval = retval && result;
}
// Fire bubble listeners.
//
// We can technically rely on IE to perform bubble event
// propagation. However, it turns out that IE fires events in
// opposite order of attachEvent registration, which broke
// some code and tests that rely on the order. (While W3C DOM
// Level 2 Events TR leaves the event ordering unspecified,
// modern browsers and W3C DOM Level 3 Events Working Draft
// actually specify the order as the registration order.)
for (var i = 0; !evt.propagationStopped_ && i < ancestors.length; i++) {
evt.currentTarget = ancestors[i];
var result = goog.events.fireListeners_(ancestors[i], type, false, evt);
retval = retval && result;
}
}
} else {
retval = goog.events.fireListener(listener, evt);
}
return retval;
}
// Otherwise, simply fire the listener.
return goog.events.fireListener(
listener, new goog.events.BrowserEvent(opt_evt, this));
};
/**
* This is used to mark the IE event object so we do not do the Closure pass
* twice for a bubbling event.
* @param {Event} e The IE browser event.
* @private
*/
goog.events.markIeEvent_ = function(e) {
// Only the keyCode and the returnValue can be changed. We use keyCode for
// non keyboard events.
// event.returnValue is a bit more tricky. It is undefined by default. A
// boolean false prevents the default action. In a window.onbeforeunload and
// the returnValue is non undefined it will be alerted. However, we will only
// modify the returnValue for keyboard events. We can get a problem if non
// closure events sets the keyCode or the returnValue
var useReturnValue = false;
if (e.keyCode == 0) {
// We cannot change the keyCode in case that srcElement is input[type=file].
// We could test that that is the case but that would allocate 3 objects.
// If we use try/catch we will only allocate extra objects in the case of a
// failure.
/** @preserveTry */
try {
e.keyCode = -1;
return;
} catch (ex) {
useReturnValue = true;
}
}
if (useReturnValue ||
/** @type {boolean|undefined} */ (e.returnValue) == undefined) {
e.returnValue = true;
}
};
/**
* This is used to check if an IE event has already been handled by the Closure
* system so we do not do the Closure pass twice for a bubbling event.
* @param {Event} e The IE browser event.
* @return {boolean} True if the event object has been marked.
* @private
*/
goog.events.isMarkedIeEvent_ = function(e) {
return e.keyCode < 0 || e.returnValue != undefined;
};
/**
* Counter to create unique event ids.
* @private {number}
*/
goog.events.uniqueIdCounter_ = 0;
/**
* Creates a unique event id.
*
* @param {string} identifier The identifier.
* @return {string} A unique identifier.
* @idGenerator
*/
goog.events.getUniqueId = function(identifier) {
return identifier + '_' + goog.events.uniqueIdCounter_++;
};
/**
* @param {EventTarget} src The source object.
* @return {goog.events.ListenerMap} A listener map for the given
* source object, or null if none exists.
* @private
*/
goog.events.getListenerMap_ = function(src) {
var listenerMap = src[goog.events.LISTENER_MAP_PROP_];
// IE serializes the property as well (e.g. when serializing outer
// HTML). So we must check that the value is of the correct type.
return listenerMap instanceof goog.events.ListenerMap ? listenerMap : null;
};
/**
* Expando property for listener function wrapper for Object with
* handleEvent.
* @private @const {string}
*/
goog.events.LISTENER_WRAPPER_PROP_ = '__closure_events_fn_' +
((Math.random() * 1e9) >>> 0);
/**
* @param {Object|Function} listener The listener function or an
* object that contains handleEvent method.
* @return {!Function} Either the original function or a function that
* calls obj.handleEvent. If the same listener is passed to this
* function more than once, the same function is guaranteed to be
* returned.
*/
goog.events.wrapListener = function(listener) {
goog.asserts.assert(listener, 'Listener can not be null.');
if (goog.isFunction(listener)) {
return listener;
}
goog.asserts.assert(
listener.handleEvent, 'An object listener must have handleEvent method.');
if (!listener[goog.events.LISTENER_WRAPPER_PROP_]) {
listener[goog.events.LISTENER_WRAPPER_PROP_] =
function(e) { return listener.handleEvent(e); };
}
return listener[goog.events.LISTENER_WRAPPER_PROP_];
};
// Register the browser event handler as an entry point, so that
// it can be monitored for exception handling, etc.
goog.debug.entryPointRegistry.register(
/**
* @param {function(!Function): !Function} transformer The transforming
* function.
*/
function(transformer) {
goog.events.handleBrowserEvent_ = transformer(
goog.events.handleBrowserEvent_);
});
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