/*
 * jQuery ifixpng plugin
 * Version 2.1  (23/04/2008)
 */
 
 /**
  *
  * @example
  *
  * optional if location of pixel.gif if different to default which is images/pixel.gif
  * $.ifixpng('media/pixel.gif');
  *
  * $('img[@src$=.png], #panel').ifixpng();
  *
  * @apply hack to all png images and #panel which icluded png img in its css
  *
  * @name ifixpng
  * @type jQuery
  * @cat Plugins/Image
  * @return jQuery
  * @author jQuery Community
  */
 
(function($) {

  /**
   * helper variables and function
   */
  $.ifixpng = function(customPixel) {
    $.ifixpng.pixel = customPixel;
  };
  
  $.ifixpng.getPixel = function() {
    return $.ifixpng.pixel || $imageIfixpng || '../images/pixel.gif';
  };
  
  var hack = {
    ltie7  : $.browser.msie && $.browser.version < 7,
    filter : function(src) {
      return "progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true,sizingMethod=crop,src='"+src+"')";
    }
  };
  
  /**
   * Applies ie png hack to selected dom elements
   *
   * $('img[@src$=.png]').ifixpng();
   * @desc apply hack to all images with png extensions
   *
   * $('#panel, img[@src$=.png]').ifixpng();
   * @desc apply hack to element #panel and all images with png extensions
   *
   * @name ifixpng
   */
   
  $.fn.ifixpng = hack.ltie7 ? function() {
      return this.each(function() {
      var $$ = $(this);
      // in case rewriting urls
      var base = $('base').attr('href');
      if (base) {
        // remove anything after the last '/'
        base = base.replace(/\/[^\/]+$/,'/');
      }
      if ($$.is('img') || $$.is('input')) { // hack image tags present in dom
        if ($$.attr('src')) {
          if ($$.attr('src').match(/.*\.png([?].*)?$/i)) { // make sure it is png image
            // use source tag value if set 
            var source = (base && $$.attr('src').search(/^(\/|http:)/i)) ? base + $$.attr('src') : $$.attr('src');
            // apply filter
            $$.css({filter:hack.filter(source), width:$$.width(), height:$$.height()})
              .attr({src:$.ifixpng.getPixel()})
              .positionFix();
          }
        }
      } else { // hack png css properties present inside css
        var image = $$.css('backgroundImage');
        if (image.match(/^url\(["']?(.*\.png([?].*)?)["']?\)$/i)) {
          image = RegExp.$1;
          image = (base && image.substring(0,1)!='/') ? base + image : image;
          $$.css({backgroundImage:'none', filter:hack.filter(image)})
            .children().children().positionFix();
        }
      }
    });
  } : function() { return this; };
  
  /**
   * Removes any png hack that may have been applied previously
   *
   * $('img[@src$=.png]').iunfixpng();
   * @desc revert hack on all images with png extensions
   *
   * $('#panel, img[@src$=.png]').iunfixpng();
   * @desc revert hack on element #panel and all images with png extensions
   *
   * @name iunfixpng
   */
   
  $.fn.iunfixpng = hack.ltie7 ? function() {
      return this.each(function() {
      var $$ = $(this);
      var src = $$.css('filter');
      if (src.match(/src=["']?(.*\.png([?].*)?)["']?/i)) { // get img source from filter
        src = RegExp.$1;
        if ($$.is('img') || $$.is('input')) {
          $$.attr({src:src}).css({filter:''});
        } else {
          $$.css({filter:'', background:'url('+src+')'});
        }
      }
    });
  } : function() { return this; };
  
  /**
   * positions selected item relatively
   */
   
  $.fn.positionFix = function() {
    return this.each(function() {
      var $$ = $(this);
      var position = $$.css('position');
      if (position != 'absolute' && position != 'relative') {
        $$.css({position:'relative'});
      }
    });
  };

})(jQuery);