+ },
+
+ setOffset: function( elem, options, i ) {
+ var position = jQuery.css( elem, "position" );
+
+ // set position first, in-case top/left are set even on static elem
+ if ( position === "static" ) {
+ elem.style.position = "relative";
+ }
+
+ var curElem = jQuery( elem ),
+ curOffset = curElem.offset(),
+ curCSSTop = jQuery.css( elem, "top" ),
+ curCSSLeft = jQuery.css( elem, "left" ),
+ calculatePosition = (position === "absolute" && jQuery.inArray('auto', [curCSSTop, curCSSLeft]) > -1),
+ props = {}, curPosition = {}, curTop, curLeft;
+
+ // need to be able to calculate position if either top or left is auto and position is absolute
+ if ( calculatePosition ) {
+ curPosition = curElem.position();
+ }
+
+ curTop = calculatePosition ? curPosition.top : parseInt( curCSSTop, 10 ) || 0;
+ curLeft = calculatePosition ? curPosition.left : parseInt( curCSSLeft, 10 ) || 0;
+
+ if ( jQuery.isFunction( options ) ) {
+ options = options.call( elem, i, curOffset );
+ }
+
+ if (options.top != null) {
+ props.top = (options.top - curOffset.top) + curTop;
+ }
+ if (options.left != null) {
+ props.left = (options.left - curOffset.left) + curLeft;
+ }
+
+ if ( "using" in options ) {
+ options.using.call( elem, props );
+ } else {
+ curElem.css( props );
+ }