@qooxdoo/framework
Version:
The JS Framework for Coders
240 lines (173 loc) • 5.56 kB
JavaScript
/* ************************************************************************
qooxdoo - the new era of web development
http://qooxdoo.org
Copyright:
2007-2008 1&1 Internet AG, Germany, http://www.1und1.de
License:
MIT: https://opensource.org/licenses/MIT
See the LICENSE file in the project's top-level directory for details.
Authors:
* Sebastian Werner (wpbasti)
************************************************************************ */
/**
* This class supports <code>appear</code> and <code>disappear</code> events
* on DOM level.
*
* NOTE: Instances of this class must be disposed of after use
*
*/
qx.Class.define("qx.event.handler.Appear",
{
extend : qx.core.Object,
implement : [ qx.event.IEventHandler, qx.core.IDisposable ],
/*
*****************************************************************************
CONSTRUCTOR
*****************************************************************************
*/
/**
* Create a new instance
*
* @param manager {qx.event.Manager} Event manager for the window to use
*/
construct : function(manager)
{
this.base(arguments);
this.__manager = manager;
this.__targets = {};
// Register
qx.event.handler.Appear.__instances[this.$$hash] = this;
},
/*
*****************************************************************************
STATICS
*****************************************************************************
*/
statics :
{
/** @type {Integer} Priority of this handler */
PRIORITY : qx.event.Registration.PRIORITY_NORMAL,
/** @type {Map} Supported event types */
SUPPORTED_TYPES :
{
appear : true,
disappear : true
},
/** @type {Integer} Which target check to use */
TARGET_CHECK : qx.event.IEventHandler.TARGET_DOMNODE,
/** @type {Integer} Whether the method "canHandleEvent" must be called */
IGNORE_CAN_HANDLE : true,
/** @type {Map} Stores all appear manager instances */
__instances : {},
/**
* Refreshes all appear handlers. Useful after massive DOM manipulations e.g.
* through qx.html.Element.
*
*/
refresh : function()
{
var all = this.__instances;
for (var hash in all) {
all[hash].refresh();
}
}
},
/*
*****************************************************************************
MEMBERS
*****************************************************************************
*/
members :
{
__manager : null,
__targets : null,
/*
---------------------------------------------------------------------------
EVENT HANDLER INTERFACE
---------------------------------------------------------------------------
*/
// interface implementation
canHandleEvent : function(target, type) {},
// interface implementation
registerEvent : function(target, type, capture)
{
var hash = qx.core.ObjectRegistry.toHashCode(target) + type;
var targets = this.__targets;
if (targets && !targets[hash])
{
targets[hash] = target;
target.$$displayed = target.offsetWidth > 0;
}
},
// interface implementation
unregisterEvent : function(target, type, capture)
{
var hash = qx.core.ObjectRegistry.toHashCode(target) + type;
var targets = this.__targets;
if (!targets) {
return;
}
if (targets[hash]) {
delete targets[hash];
}
},
/*
---------------------------------------------------------------------------
USER ACCESS
---------------------------------------------------------------------------
*/
/**
* This method should be called by all DOM tree modifying routines
* to check the registered nodes for changes.
*
* @return {qx.Promise?} a promise, if one or more of the event handlers returned one
*/
refresh : function()
{
var targets = this.__targets;
var legacyIe = qx.core.Environment.get("engine.name") == "mshtml" &&
qx.core.Environment.get("browser.documentmode") < 9;
var tracker = {};
var self = this;
Object.keys(targets).forEach(function(hash) {
var elem = targets[hash];
if (elem === undefined) {
return;
}
qx.event.Utils.then(tracker, function() {
var displayed = elem.offsetWidth > 0;
if (!displayed && legacyIe) {
// force recalculation in IE 8. See bug #7872
displayed = elem.offsetWidth > 0;
}
if ((!!elem.$$displayed) !== displayed)
{
elem.$$displayed = displayed;
var evt = qx.event.Registration.createEvent(displayed ? "appear" : "disappear");
return self.__manager.dispatchEvent(elem, evt);
}
});
});
return tracker.promise;
}
},
/*
*****************************************************************************
DESTRUCTOR
*****************************************************************************
*/
destruct : function()
{
this.__manager = this.__targets = null;
// Deregister
delete qx.event.handler.Appear.__instances[this.$$hash];
},
/*
*****************************************************************************
DEFER
*****************************************************************************
*/
defer : function(statics) {
qx.event.Registration.addHandler(statics);
}
});