@qooxdoo/framework
Version:
The JS Framework for Coders
90 lines (75 loc) • 2.47 kB
JavaScript
/* ************************************************************************
qooxdoo - the new era of web development
http://qooxdoo.org
Copyright:
2012 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:
* Daniel Wagner (danielwagner)
************************************************************************ */
/**
* Orientation handler which is responsible for registering and unregistering a
* {@link qx.event.handler.OrientationCore} handler for each given element.
*
* @require(qx.module.Event)
*
* @group (Event_Normalization)
*/
qx.Bootstrap.define("qx.module.event.OrientationHandler", {
statics :
{
/**
* List of events that require an orientation handler
*/
TYPES : ["orientationchange"],
/**
* Creates an orientation handler for the given window when an
* orientationchange event listener is attached to it
*
* @param element {Window} DOM Window
*/
register : function(element)
{
if (!qx.dom.Node.isWindow(element)) {
throw new Error("The 'orientationchange' event is only available on window objects!");
}
if (!element.__orientationHandler) {
if (!element.$$emitter) {
element.$$emitter = new qx.event.Emitter();
}
element.__orientationHandler = new qx.event.handler.OrientationCore(element, element.$$emitter);
}
},
/**
* Removes the orientation event handler from the element if there are no more
* orientationchange event listeners attached to it
* @param element {Element} DOM element
*/
unregister : function(element)
{
if (element.__orientationHandler) {
if (!element.$$emitter) {
element.__orientationHandler = null;
}
else {
var hasListener = false;
var listeners = element.$$emitter.getListeners();
qx.module.event.OrientationHandler.TYPES.forEach(function(type) {
if (type in listeners && listeners[type].length > 0) {
hasListener = true;
}
});
if (!hasListener) {
element.__orientationHandler = null;
}
}
}
}
},
defer : function(statics)
{
qxWeb.$registerEventHook(statics.TYPES, statics.register, statics.unregister);
}
});