/*
Script: Element.Measure.js
	Extends the Element native object to include methods useful in measuring dimensions.

License:
	http://clientside.cnet.com/wiki/cnet-libraries#license
*/

Element.implement({

	expose: function(){
		if (this.getStyle('display') != 'none') return $empty;
		var before = {};
		//use this method instead of getStyles 
		['visibility', 'display', 'position'].each(function(style){
			before[style] = this.style[style]||'';
		}, this);
		//this.getStyles('visibility', 'display', 'position');
		this.setStyles({
			visibility: 'hidden',
			display: 'block',
			position:'absolute'
		});
		return (function(){
			this.setStyles(before);
		}).bind(this);
	},
	
	getDimensions: function(options) {
		options = $merge({computeSize: false},options);
		var dim = {};
		function getSize(el, options){
			if(options.computeSize) dim = el.getComputedSize(options);
			else {
				var sz = el.getSize();
				dim.width = sz.x;
				dim.height = sz.y;
			}
			return dim;
		}
		try { //safari sometimes crashes here, so catch it
			dim = getSize(this, options);
		}catch(e){}
		if(this.getStyle('display') == 'none'){
			var restore = this.expose();
			dim = getSize(this, options); //works now, because the display isn't none
			restore(); //put it back where it was
		}
		return $merge(dim, {x: dim.width, y: dim.height});
	},
	
	getComputedSize: function(options){
		options = $merge({
			styles: ['padding','border'],
			plains: {height: ['top','bottom'], width: ['left','right']},
			mode: 'both'
		}, options);
		var size = {width: 0,height: 0};
		switch (options.mode){
			case 'vertical':
				delete size.width;
				delete options.plains.width;
				break;
			case 'horizontal':
				delete size.height;
				delete options.plains.height;
				break;
		}
		var getStyles = [];
		//this function might be useful in other places; perhaps it should be outside this function?
		$each(options.plains, function(plain, key){
			plain.each(function(edge){
				options.styles.each(function(style){
					getStyles.push((style=="border")?style+'-'+edge+'-'+'width':style+'-'+edge);
				});
			});
		});
		var styles = this.getStyles.apply(this, getStyles);
		var subtracted = [];
		$each(options.plains, function(plain, key){ //keys: width, height, plains: ['left','right'], ['top','bottom']
			size['total'+key.capitalize()] = 0;
			size['computed'+key.capitalize()] = 0;
			plain.each(function(edge){ //top, left, right, bottom
				size['computed'+edge.capitalize()] = 0;
				getStyles.each(function(style,i){ //padding, border, etc.
					//'padding-left'.test('left') size['totalWidth'] = size['width']+[padding-left]
					if(style.test(edge)) {
						styles[style] = styles[style].toInt(); //styles['padding-left'] = 5;
						if(isNaN(styles[style]))styles[style]=0;
						size['total'+key.capitalize()] = size['total'+key.capitalize()]+styles[style];
						size['computed'+edge.capitalize()] = size['computed'+edge.capitalize()]+styles[style];
					}
					//if width != width (so, padding-left, for instance), then subtract that from the total
					if(style.test(edge) && key!=style && 
						(style.test('border') || style.test('padding')) && !subtracted.contains(style)) {
						subtracted.push(style);
						size['computed'+key.capitalize()] = size['computed'+key.capitalize()]-styles[style];
					}
				});
			});
		});
		if($chk(size.width)) {
			size.width = size.width+this.offsetWidth+size.computedWidth;
			size.totalWidth = size.width + size.totalWidth;
			delete size.computedWidth;
		}
		if($chk(size.height)) {
			size.height = size.height+this.offsetHeight+size.computedHeight;
			size.totalHeight = size.height + size.totalHeight;
			delete size.computedHeight;
		}
		return $merge(styles, size);
	}
});