/*
 * jQuery ifixpng plugin
 * (previously known as pngfix)
 * Version 2.1  (23/04/2008)
 * @requires jQuery v1.1.3 or above
 *
 * Examples at: http://jquery.khurshid.com
 * Copyright (c) 2007 Kush M.
 * Dual licensed under the MIT and GPL licenses:
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.gnu.org/licenses/gpl.html
 */
 
 /**
  *
  * @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 || '/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+"')";
		}
	};
	
	$.fn.backgroundfix = hack.ltie7 ? function() {
    	return this.each(function() {
		    
		    // Find out the current background positioning and url
		    var posX = $(this).css('backgroundPositionX');
		    var posY = $(this).css('backgroundPositionY');
		    var src = $(this).css('backgroundImage');
		    
		    // Create a dummy image so we can calculate it's width and height
		    var imageUrl = src.replace('url(', '').replace(')', '').replace(/"/g, '').replace(/'/g, "");
		    var img = document.createElement('img');
		    img.src = imageUrl;
		    $(img).css('display', 'none');
		    $('body')[0].appendChild(img);
		    var imgWidth = $(img).width();
		    var imgHeight = $(img).height();
		    
		    // Create the new image container, positioned according to the original styling, i.e. right top
		    var newDiv = document.createElement('div');
		    $(newDiv).css('backgroundImage', src);
		    $(newDiv).css('width', imgWidth + 'px');
		    $(newDiv).css('height', imgHeight + 'px');
		    $(newDiv).css('position', 'absolute');
		    $(newDiv).css('zIndex', '-1');
		    $(newDiv).css(posX, '0px');
		    $(newDiv).css(posY, '0px');
		    
		    // Erase the old background image
		    $(this).css('backgroundImage', 'none');
		    $(this).css('position', 'relative');
		    
		    // Insert the shiny new div
		    this.appendChild(newDiv);
		    
		    // Apply the exist png fix on the positioned div
		    $(newDiv).ifixpng();
		    
		});
	} : function() { return this; };
	
	/**
	 * 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);