/* 
 * thanks to Lawrence Carvalho
 */
var TextResizeDetector = function() { 
    var el  = null;
	var iIntervalDelay  = 200;
	var iInterval = null;
	var iCurrSize = -1;
	var iBase = -1;
 	var aListeners = [];
 	var createControlElement = function() {
	 	el = document.createElement('span');
		el.id='textResizeControl';
		el.innerHTML=' ';
		el.style.position="absolute";
		el.style.left="-9999px";
		var elC = document.getElementById(TextResizeDetector.TARGET_ELEMENT_ID);
		if (elC)
			elC.insertBefore(el,elC.firstChild);
		iBase = iCurrSize = TextResizeDetector.getSize();
 	};
 	function _stopDetector() {
		window.clearInterval(iInterval);
		iInterval=null;
	};
	function _startDetector() {
		if (!iInterval) {
			iInterval = window.setInterval('TextResizeDetector.detect()',iIntervalDelay);
		}
	};
 	 function _detect() {
 		var iNewSize = TextResizeDetector.getSize();
 		if(iNewSize!== iCurrSize) {
			for (var 	i=0;i <aListeners.length;i++) {
				aListnr = aListeners[i];
				var oArgs = {  iBase: iBase,iDelta:((iCurrSize!=-1) ? iNewSize - iCurrSize + 'px' : "0px"),iSize:iCurrSize = iNewSize};
				if (!aListnr.obj) {
					aListnr.fn('textSizeChanged',[oArgs]);
				}
				else  {
					aListnr.fn.apply(aListnr.obj,['textSizeChanged',[oArgs]]);
				}
			}
		}
 		return iCurrSize;
 	};
	var onAvailable = function() {
		if (!TextResizeDetector.onAvailableCount_i ) {
			TextResizeDetector.onAvailableCount_i =0;
		}
		if (document.getElementById(TextResizeDetector.TARGET_ELEMENT_ID)) {
			TextResizeDetector.init();
			if (TextResizeDetector.USER_INIT_FUNC){
				TextResizeDetector.USER_INIT_FUNC();
			}
			TextResizeDetector.onAvailableCount_i = null;
		}
		else {
			if (TextResizeDetector.onAvailableCount_i<600) {
	  	 	    TextResizeDetector.onAvailableCount_i++;
				setTimeout(onAvailable,200)
			}
		}
	};
	setTimeout(onAvailable,500);
 	return {
		init: function() {
			createControlElement();		
			_startDetector();
		},
		addEventListener:function(fn,obj,bScope) {
			aListeners[aListeners.length] = {
				fn: fn,
				obj: obj
			}
			return iBase;
		},
		detect:function() {
			return _detect();
		},
		getSize:function() {
				var iSize;
				return el.offsetHeight;
		},
		stopDetector:function() {
			return _stopDetector();
		},
		startDetector:function() {
			return _startDetector();
		}
 	}
 }();
TextResizeDetector.TARGET_ELEMENT_ID = 'doc';
TextResizeDetector.USER_INIT_FUNC = null;