/* Copyright (c) 2007 Paul Bakaus (paul.bakaus@googlemail.com) and Brandon Aaron (brandon.aaron@gmail.com || http://brandonaaron.net)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 *
 * $LastChangedDate: 2007-05-25 22:11:19 -0400 (Fri, 25 May 2007) $
 * $Rev: 1987 $
 *
 * Version: 1.0b
 */

(function($){

$.fn.extend({
	_height: $.fn.height,
	_width: $.fn.width,
	
	/**
	 * If used on document, returns the document's height (innerHeight)
	 * If used on window, returns the viewport's (window) height
	 * See core docs on height() to see what happens when used on an element.
	 *
	 * @example $("#testdiv").height()
	 * @result 200
	 *
	 * @example $(document).height()
	 * @result 800
	 *
	 * @example $(window).height()
	 * @result 400
	 *
	 * @name height
	 * @type Object
	 * @cat Plugins/Dimensions
	 */
	height: function(val) {
		if ( this[0] == window )
			return self.innerHeight ||
				$.boxModel && document.documentElement.clientHeight || 
				document.body.clientHeight;
		
		if ( this[0] == document )
			return Math.max( document.body.scrollHeight, document.body.offsetHeight );
		
		return this._height(val);
	},
	
	/**
	 * If used on document, returns the document's width (innerWidth)
	 * If used on window, returns the viewport's (window) width
	 * See core docs on height() to see what happens when used on an element.
	 *
	 * @example $("#testdiv").width()
	 * @result 200
	 *
	 * @example $(document).width()
	 * @result 800
	 *
	 * @example $(window).width()
	 * @result 400
	 *
	 * @name width
	 * @type Object
	 * @cat Plugins/Dimensions
	 */
	width: function(val) {
		if ( this[0] == window )
			return self.innerWidth ||
				$.boxModel && document.documentElement.clientWidth ||
				document.body.clientWidth;

		if ( this[0] == document )
			return Math.max( document.body.scrollWidth, document.body.offsetWidth );

		return this._width(val);
	},
	
	/**
	 * Returns the inner height value (without border) for the first matched element.
	 * If used on document, returns the document's height (innerHeight)
	 * If used on window, returns the viewport's (window) height
	 *
	 * @example $("#testdiv").innerHeight()
	 * @result 800
	 *
	 * @name innerHeight
	 * @type Number
	 * @cat Plugins/Dimensions
	 */
	innerHeight: function() {
		return this[0] == window || this[0] == document ?
			this.height() :
			this.is(':visible') ?
				this[0].offsetHeight - num(this, 'borderTopWidth') - num(this, 'borderBottomWidth') :
				this.height() + num(this, 'paddingTop') + num(this, 'paddingBottom');
	},
	
	/**
	 * Returns the inner width value (without border) for the first matched element.
	 * If used on document, returns the document's Width (innerWidth)
	 * If used on window, returns the viewport's (window) width
	 *
	 * @example $("#testdiv").innerWidth()
	 * @result 1000
	 *
	 * @name innerWidth
	 * @type Number
	 * @cat Plugins/Dimensions
	 */
	innerWidth: function() {
		return this[0] == window || this[0] == document ?
			this.width() :
			this.is(':visible') ?
				this[0].offsetWidth - num(this, 'borderLeftWidth') - num(this, 'borderRightWidth') :
				this.width() + num(this, 'paddingLeft') + num(this, 'paddingRight');
	},
	
	/**
	 * Returns the outer height value (including border) for the first matched element.
	 * Cannot be used on document or window.
	 *
	 * @example $("#testdiv").outerHeight()
	 * @result 1000
	 *
	 * @name outerHeight
	 * @type Number
	 * @cat Plugins/Dimensions
	 */
	outerHeight: function() {
		return this[0] == window || this[0] == document ?
			this.height() :
			this.is(':visible') ?
				this[0].offsetHeight :
				this.height() + num(this,'borderTopWidth') + num(this, 'borderBottomWidth') + num(this, 'paddingTop') + num(this, 'paddingBottom');
	},
	
	/**
	 * Returns the outer width value (including border) for the first matched element.
	 * Cannot be used on document or window.
	 *
	 * @example $("#testdiv").outerHeight()
	 * @result 1000
	 *
	 * @name outerHeight
	 * @type Number
	 * @cat Plugins/Dimensions
	 */
	outerWidth: function() {
		return this[0] == window || this[0] == document ?
			this.width() :
			this.is(':visible') ?
				this[0].offsetWidth :
				this.width() + num(this, 'borderLeftWidth') + num(this, 'borderRightWidth') + num(this, 'paddingLeft') + num(this, 'paddingRight');
	},
	
	/**
	 * Returns how many pixels the user has scrolled to the right (scrollLeft).
	 * Works on containers with overflow: auto and window/document.
	 *
	 * @example $("#testdiv").scrollLeft()
	 * @result 100
	 *
	 * @name scrollLeft
	 * @type Number
	 * @cat Plugins/Dimensions
	 */
	/**
	 * Sets the scrollLeft property and continues the chain.
	 * Works on containers with overflow: auto and window/document.
	 *
	 * @example $("#testdiv").scrollLeft(10).scrollLeft()
	 * @result 10
	 *
	 * @name scrollLeft
	 * @param Number value A positive number representing the desired scrollLeft.
	 * @type jQuery
	 * @cat Plugins/Dimensions
	 */
	scrollLeft: function(val) {
		if ( val != undefined )
			return this.each(function() {
				if (this == window || this == document)
					window.scrollTo( val, $(window).scrollTop() );
				else
					this.scrollLeft = val;
			});
		
		if ( this[0] == window || this[0] == document )
			return self.pageXOffset ||
				$.boxModel && document.documentElement.scrollLeft ||
				document.body.scrollLeft;
				
		return this[0].scrollLeft;
	},
	
	/**
	 * Returns how many pixels the user has scrolled to the bottom (scrollTop).
	 * Works on containers with overflow: auto and window/document.
	 *
	 * @example $("#testdiv").scrollTop()
	 * @result 100
	 *
	 * @name scrollTop
	 * @type Number
	 * @cat Plugins/Dimensions
	 */
	/**
	 * Sets the scrollTop property and continues the chain.
	 * Works on containers with overflow: auto and window/document.
	 *
	 * @example $("#testdiv").scrollTop(10).scrollTop()
	 * @result 10
	 *
	 * @name scrollTop
	 * @param Number value A positive number representing the desired scrollTop.
	 * @type jQuery
	 * @cat Plugins/Dimensions
	 */
	scrollTop: function(val) {
		if ( val != undefined )
			return this.each(function() {
				if (this == window || this == document)
					window.scrollTo( $(window).scrollLeft(), val );
				else
					this.scrollTop = val;
			});
		
		if ( this[0] == window || this[0] == document )
			return self.pageYOffset ||
				$.boxModel && document.documentElement.scrollTop ||
				document.body.scrollTop;

		return this[0].scrollTop;
	},
	
	/**
	 * Returns the location of the element in pixels from the top left corner of the viewport.
	 *
	 * For accurate readings make sure to use pixel values for margins, borders and padding.
	 * 
	 * Known issues:
	 *  - Issue: A div positioned relative or static without any content before it and its parent will report an offsetTop of 0 in Safari
	 *    Workaround: Place content before the realtive div ... and set height and width to 0 and overflow to hidden
	 *
	 * @example $("#testdiv").offset()
	 * @result { top: 100, left: 100, scrollTop: 10, scrollLeft: 10 }
	 *
	 * @example $("#testdiv").offset({ scroll: false })
	 * @result { top: 90, left: 90 }
	 *
	 * @example var offset = {}
	 * $("#testdiv").offset({ scroll: false }, offset)
	 * @result offset = { top: 90, left: 90 }
	 *
	 * @name offset
	 * @param Map options Optional settings to configure the way the offset is calculated.
	 * @option Boolean margin Should the margin of the element be included in the calculations? True by default.
	 * @option Boolean border Should the border of the element be included in the calculations? True by default.
	 * @option Boolean padding Should the padding of the element be included in the calculations? False by default.
	 * @option Boolean scroll Should the scroll offsets of the parent elements be included in the calculations? True by default.
	 *                        When true it adds the totla scroll offets of all parents to the total offset and also adds two properties
	 *                        to the returned object, scrollTop and scrollLeft. If scroll offsets are not needed, this can be a big
	 *                        performance boost if set to false.
	 * @options Boolean lite Will use offsetLite instead of offset when set to true. False by default.
	 * @param Object returnObject An object to store the return value in, so as not to break the chain. If passed in the
	 *                            chain will not be broken and the result will be assigned to this object.
	 * @type Object
	 * @cat Plugins/Dimensions
	 * @author Brandon Aaron (brandon.aaron@gmail.com || http://brandonaaron.net)
	 */
	offset: function(options, returnObject) {
		var x = 0, y = 0, sl = 0, st = 0,
		    elem = this[0], parent = this[0], op, parPos, elemPos = $.css(elem, 'position'),
		    mo = $.browser.mozilla, ie = $.browser.msie, sf = $.browser.safari, oa = $.browser.opera,
		    absparent = false, relparent = false, 
		    options = $.extend({ margin: true, border: true, padding: false, scroll: true, lite: false }, options || {});
		
		if (options.lite) return this.offsetLite(options, returnObject);
		
		if (elem.tagName.toLowerCase() == 'body') {
			// Safari is the only one to get offsetLeft and offsetTop properties of the body "correct"
			// Except they all mess up when the body is positioned absolute or relative
			x = elem.offsetLeft;
			y = elem.offsetTop;
			// Mozilla ignores margin and subtracts border from body element
			if (mo) {
				x += num(elem, 'marginLeft') + (num(elem, 'borderLeftWidth')*2);
				y += num(elem, 'marginTop')  + (num(elem, 'borderTopWidth') *2);
			} else
			// Opera ignores margin
			if (oa) {
				x += num(elem, 'marginLeft');
				y += num(elem, 'marginTop');
			} else
			// IE does not add the border in Standards Mode
			if (ie && jQuery.boxModel) {
				x += num(elem, 'borderLeftWidth');
				y += num(elem, 'borderTopWidth');
			}
		} else {
			do {
				parPos = $.css(parent, 'position');
			
				x += parent.offsetLeft;
				y += parent.offsetTop;

				// Mozilla and IE do not add the border
				if (mo || ie) {
					// add borders to offset
					x += num(parent, 'borderLeftWidth');
					y += num(parent, 'borderTopWidth');

					// Mozilla does not include the border on body if an element isn't positioned absolute and is without an absolute parent
					if (mo && parPos == 'absolute') absparent = true;
					// IE does not include the border on the body if an element is position static and without an absolute or relative parent
					if (ie && parPos == 'relative') relparent = true;
				}

				op = parent.offsetParent;
				do {
					if (options.scroll) {
						sl += parent.scrollLeft;
						st += parent.scrollTop;
					}
				
					if (mo && parent != elem && $.css(parent, 'overflow') != 'visible') {
						x += num(parent, 'borderLeftWidth');
						y += num(parent, 'borderTopWidth');
					}
				
					parent = parent.parentNode;
				} while (parent != op);
				parent = op;

				if (parent.tagName.toLowerCase() == 'body' || parent.tagName.toLowerCase() == 'html') {
					// Safari and IE Standards Mode doesn't add the body margin for elments positioned with static or relative
					if ((sf || (ie && $.boxModel)) && elemPos != 'absolute' && elemPos != 'fixed') {
						x += num(parent, 'marginLeft');
						y += num(parent, 'marginTop');
					}
					// Mozilla does not include the border on body if an element isn't positioned absolute and is without an absolute parent
					// IE does not include the border on the body if an element is positioned static and without an absolute or relative parent
					if ( (mo && !absparent && elemPos != 'fixed') || 
					     (ie && elemPos == 'static' && !relparent) ) {
						x += num(parent, 'borderLeftWidth');
						y += num(parent, 'borderTopWidth');
					}
					break; // Exit the loop
				}
			} while (parent);
		}

		var returnValue = handleOffsetReturn(elem, options, x, y, sl, st);

		if (returnObject) { $.extend(returnObject, returnValue); return this; }
		else              { return returnValue; }
	},
	
	offsetLite: function(options, returnObject) {
		var x = 0, y = 0, sl = 0, st = 0, parent = this[0], op, 
		    options = $.extend({ margin: true, border: true, padding: false, scroll: true }, options || {});
				
		do {
			x += parent.offsetLeft;
			y += parent.offsetTop;

			op = parent.offsetParent;
			if (options.scroll) {
				do {
					sl += parent.scrollLeft;
					st += parent.scrollTop;
					parent = parent.parentNode;
				} while(parent != op);
			}
			parent = op;
		} while (parent && parent.tagName.toLowerCase() != 'body' && parent.tagName.toLowerCase() != 'html');

		var returnValue = handleOffsetReturn(this[0], options, x, y, sl, st);

		if (returnObject) { $.extend(returnObject, returnValue); return this; }
		else              { return returnValue; }
	}
});

/**
 * Handles converting a CSS Style into an Integer.
 * @private
 */
var num = function(el, prop) {
	return parseInt($.css(el.jquery?el[0]:el,prop))||0;
};

/**
 * Handles the return value of the offset and offsetLite methods.
 * @private
 */
var handleOffsetReturn = function(elem, options, x, y, sl, st) {
	if ( !options.margin ) {
		x -= num(elem, 'marginLeft');
		y -= num(elem, 'marginTop');
	}

	// Safari and Opera do not add the border for the element
	if ( options.border && ($.browser.safari || $.browser.opera) ) {
		x += num(elem, 'borderLeftWidth');
		y += num(elem, 'borderTopWidth');
	} else if ( !options.border && !($.browser.safari || $.browser.opera) ) {
		x -= num(elem, 'borderLeftWidth');
		y -= num(elem, 'borderTopWidth');
	}

	if ( options.padding ) {
		x += num(elem, 'paddingLeft');
		y += num(elem, 'paddingTop');
	}
	
	// do not include scroll offset on the element
	if ( options.scroll ) {
		sl -= elem.scrollLeft;
		st -= elem.scrollTop;
	}

	return options.scroll ? { top: y - st, left: x - sl, scrollTop:  st, scrollLeft: sl }
	                      : { top: y, left: x };
};

})(jQuery);