/*
* DOM event listener abstraction layer
* @module event
* @submodule event-base
*/
(function() {
// Unlike most of the library, this code has to be executed as soon as it is
// introduced into the page -- and it should only be executed one time
// regardless of the number of instances that use it.
var stateChangeListener,
GLOBAL_ENV = YUI.Env,
config = YUI.config,
doc = config.doc,
docElement = doc.documentElement,
doScrollCap = docElement.doScroll,
add = YUI.Env.add,
remove = YUI.Env.remove,
targetEvent = (doScrollCap) ? 'onreadystatechange' : 'DOMContentLoaded',
pollInterval = config.pollInterval || 40,
_ready = function(e) {
GLOBAL_ENV._ready();
};
if (!GLOBAL_ENV._ready) {
GLOBAL_ENV._ready = function() {
if (!GLOBAL_ENV.DOMReady) {
GLOBAL_ENV.DOMReady = true;
remove(doc, targetEvent, _ready); // remove DOMContentLoaded listener
}
};
/*! DOMReady: based on work by: Dean Edwards/John Resig/Matthias Miller/Diego Perini */
// Internet Explorer: use the doScroll() method on the root element. This isolates what
// appears to be a safe moment to manipulate the DOM prior to when the document's readyState
// suggests it is safe to do so.
if (doScrollCap) {
if (self !== self.top) {
stateChangeListener = function() {
if (doc.readyState == 'complete') {
remove(doc, targetEvent, stateChangeListener); // remove onreadystatechange listener
_ready();
}
};
add(doc, targetEvent, stateChangeListener); // add onreadystatechange listener
} else {
GLOBAL_ENV._dri = setInterval(function() {
try {
docElement.doScroll('left');
clearInterval(GLOBAL_ENV._dri);
GLOBAL_ENV._dri = null;
_ready();
} catch (domNotReady) { }
}, pollInterval);
}
} else { // FireFox, Opera, Safari 3+ provide an event for this moment.
add(doc, targetEvent, _ready); // add DOMContentLoaded listener
}
}
})();