/**

* @author Alexander Farkas

* v. 1.21

*/

 

 

(function($) {

        if(!document.defaultView || !document.defaultView.getComputedStyle){ // IE6-IE8

               var oldCurCSS = jQuery.curCSS;

               jQuery.curCSS = function(elem, name, force){

                       if(name === 'background-position'){

                               name = 'backgroundPosition';

                       }

                       if(name !== 'backgroundPosition' || !elem.currentStyle || elem.currentStyle[ name ]){

                               return oldCurCSS.apply(this, arguments);

                       }

                       var style = elem.style;

                       if ( !force && style && style[ name ] ){

                               return style[ name ];

                       }

                       return oldCurCSS(elem, 'backgroundPositionX', force) +' '+ oldCurCSS(elem, 'backgroundPositionY', force);

               };

        }

       

        var oldAnim = $.fn.animate;

        $.fn.animate = function(prop){

               if('background-position' in prop){

                       prop.backgroundPosition = prop['background-position'];

                       delete prop['background-position'];

               }

               if('backgroundPosition' in prop){

                       prop.backgroundPosition = '('+ prop.backgroundPosition;

               }

               return oldAnim.apply(this, arguments);

        };

       

        function toArray(strg){

               strg = strg.replace(/left|top/g,'0px');

               strg = strg.replace(/right|bottom/g,'100%');

               strg = strg.replace(/([0-9\.]+)(\s|\)|$)/g,"$1px$2");

               var res = strg.match(/(-?[0-9\.]+)(px|\%|em|pt)\s(-?[0-9\.]+)(px|\%|em|pt)/);

               return [parseFloat(res[1],10),res[2],parseFloat(res[3],10),res[4]];

        }

       

        $.fx.step. backgroundPosition = function(fx) {

               if (!fx.bgPosReady) {

                       var start = $.curCSS(fx.elem,'backgroundPosition');

                      

                       if(!start){//FF2 no inline-style fallback

                               start = '0px 0px';

                       }

                      

                       start = toArray(start);

                      

                       fx.start = [start[0],start[2]];

                      

                       var end = toArray(fx.options.curAnim.backgroundPosition);

                       fx.end = [end[0],end[2]];

                      

                       fx.unit = [end[1],end[3]];

                       fx.bgPosReady = true;

               }

               //return;

               var nowPosX = [];

               nowPosX[0] = ((fx.end[0] - fx.start[0]) * fx.pos) + fx.start[0] + fx.unit[0];

               nowPosX[1] = ((fx.end[1] - fx.start[1]) * fx.pos) + fx.start[1] + fx.unit[1];          

               fx.elem.style.backgroundPosition = nowPosX[0]+' '+nowPosX[1];

 

        };

})(jQuery);