adlayer-library/src/utils/contentloaded.js

Adlayer javascript core library

/**
* @module utils
* @class Utils
* @static
*/

/*!
* contentloaded.js
*
* Author: Diego Perini (diego.perini at gmail.com)
* Summary: cross-browser wrapper for DOMContentLoaded
* Updated: 20101020
* License: MIT
* Version: 1.2
*
* URL:
* http://javascript.nwbox.com/ContentLoaded/
* http://javascript.nwbox.com/ContentLoaded/MIT-LICENSE
* 
* @method contentLoaded
* @param {Object} win Reference for window object
* @param {Function} fn Callback for when content is loaded
* @async
*/

// @win window reference
// @fn function reference
function contentLoaded(win, fn) {

	var done = false, top = true,

	doc = win.document, root = doc.documentElement,

	add = doc.addEventListener ? 'addEventListener' : 'attachEvent',
	rem = doc.addEventListener ? 'removeEventListener' : 'detachEvent',
	pre = doc.addEventListener ? '' : 'on',

	init = function(e) {
		if (e.type === 'readystatechange' && doc.readyState !== 'complete') {
			return;
		}
		(e.type === 'load' ? win : doc)[rem](pre + e.type, init, false);
		if (!done && (done = true)) {
			fn.call(win, e.type || e);
		}
	},

	poll = function() {
		try { root.doScroll('left'); } catch(e) { setTimeout(poll, 50); return; }
		init('poll');
	};

	if (doc.readyState === 'complete') {
		fn.call(win, 'lazy');
	}
	else {
		if (doc.createEventObject && root.doScroll) {
			try { top = !win.frameElement; } catch(e) { }
			if (top) {
				poll();
			}
		}
		doc[add](pre + 'DOMContentLoaded', init, false);
		doc[add](pre + 'readystatechange', init, false);
		win[add](pre + 'load', init, false);
	}
}
exports.contentloaded = contentLoaded;