jquery/src/dimensions.js

(function( jQuery ) {

// Create width, height, innerHeight, innerWidth, outerHeight and outerWidth methods
jQuery.each( { Height: "height", Width: "width" }, function( name, type ) {
	var clientProp = "client" + name,
		scrollProp = "scroll" + name,
		offsetProp = "offset" + name;

	// innerHeight and innerWidth
	jQuery.fn[ "inner" + name ] = function() {
		var elem = this[0];
		return elem ?
			elem.style ?
			parseFloat( jQuery.css( elem, type, "padding" ) ) :
			this[ type ]() :
			null;
	};

	// outerHeight and outerWidth
	jQuery.fn[ "outer" + name ] = function( margin ) {
		var elem = this[0];
		return elem ?
			elem.style ?
			parseFloat( jQuery.css( elem, type, margin ? "margin" : "border" ) ) :
			this[ type ]() :
			null;
	};

	jQuery.fn[ type ] = function( value ) {
		return jQuery.access( this, function( elem, type, value ) {
			var doc, docElemProp, orig, ret;

			if ( jQuery.isWindow( elem ) ) {
				// 3rd condition allows Nokia support, as it supports the docElem prop but not CSS1Compat
				doc = elem.document;
				docElemProp = doc.documentElement[ clientProp ];
				return jQuery.support.boxModel && docElemProp ||
					doc.body && doc.body[ clientProp ] || docElemProp;
			}

			// Get document width or height
			if ( elem.nodeType === 9 ) {
				// Either scroll[Width/Height] or offset[Width/Height], whichever is greater
				doc = elem.documentElement;

				// when a window > document, IE6 reports a offset[Width/Height] > client[Width/Height]
				// so we can't use max, as it'll choose the incorrect offset[Width/Height]
				// instead we use the correct client[Width/Height]
				// support:IE6
				if ( doc[ clientProp ] >= doc[ scrollProp ] ) {
					return doc[ clientProp ];
				}

				return Math.max(
					elem.body[ scrollProp ], doc[ scrollProp ],
					elem.body[ offsetProp ], doc[ offsetProp ]
				);
			}

			// Get width or height on the element
			if ( value === undefined ) {
				orig = jQuery.css( elem, type, "content" );
				ret = parseFloat( orig );
				return jQuery.isNumeric( ret ) ? ret : orig;
			}

			// Set the width or height on the element
			jQuery.style( elem, type, value );
		}, type, value, arguments.length, null );
	};
});

})( jQuery );