/*
 * Lazy Load - jQuery plugin for lazy loading images
 *
 * Copyright (c) 2007-2012 Mika Tuupola
 *
 * Licensed under the MIT license:
 *   http://www.opensource.org/licenses/mit-license.php
 *
 * Project home:
 *   http://www.appelsiini.net/projects/lazyload
 *
 * Version:  1.8.3
 *
 */
(function($, window, document, undefined) {
    var $window = $(window);
    
    var swf_template = '<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" id="" width="{$width}" height="{$height}"' +
	'codebase="http://fpdownload.macromedia.com/get/flashplayer/current/swflash.cab">' +
	'<param name="movie" value="{$url}" />' +
	'<param name="bgcolor" value="{$bgcolor}" />' +
	'<param name="quality" value="high" />' +
	'<param name="wmode" value="{$wmode}" />' +
	'<param name="loop" value="true" />' +
	'<param name="allowFullScreen" value="true" />' +
	'<param name="allowScriptAccess" value="sameDomain" />' +
	'<embed src="{$url}" quality="high"' +
	'	width="{$width}" height="{$height}" align="middle"' +
	'	bgcolor="{$bgcolor}"' +
	'	play="true"' +
	'	loop="true"' +
	'	quality="high"' +
	'	wmode="{$wmode}"' +
	'	allowFullScreen="true"' +
	'	allowScriptAccess="sameDomain"' +
	'	type="application/x-shockwave-flash"' +
	'	pluginspage="http://www.adobe.com/go/getflashplayer">' +
	'</embed>' +
	'</object>' ;

    $.fn.lazyload = function(options) {
        var elements = this;
        var $container;
        var settings = {
            threshold       : 0,
            failure_limit   : 0,
            event           : "scroll",
            effect          : "show",
            container       : window,
            data_attribute  : "original",
            skip_invisible  : true,
            appear          : null,
            load            : null
        };

        function update() {
            var counter = 0;
      
            elements.each(function() {
                var $this = $(this);
                if (settings.skip_invisible && !$this.is(":visible")) {
                    return;
                }
                if ($.abovethetop(this, settings) ||
                    $.leftofbegin(this, settings)) {
                        /* Nothing. */
                } else if (!$.belowthefold(this, settings) &&
                    !$.rightoffold(this, settings)) {
                        $this.trigger("appear");
                        /* if we found an image we'll load, reset the counter */
                        counter = 0;
                } else {
                    if (++counter > settings.failure_limit) {
                        return false;
                    }
                }
            });

        }

        if(options) {
            /* Maintain BC for a couple of versions. */
            if (undefined !== options.failurelimit) {
                options.failure_limit = options.failurelimit; 
                delete options.failurelimit;
            }
            if (undefined !== options.effectspeed) {
                options.effect_speed = options.effectspeed; 
                delete options.effectspeed;
            }

            $.extend(settings, options);
        }

        /* Cache container as jQuery as object. */
        $container = (settings.container === undefined ||
                      settings.container === window) ? $window : $(settings.container);

        /* Fire one scroll event per scroll. Not one scroll event per image. */
        if (0 === settings.event.indexOf("scroll")) {
            $container.bind(settings.event, function(event) {
                return update();
            });
        }

        this.each(function() {
            var self = this;
            var $self = $(self);

            self.loaded = false;

            /* When appear is triggered load original image. */
            $self.one("appear", function() {
                if (!this.loaded) {
                    if (settings.appear) {
                        var elements_left = elements.length;
                        settings.appear.call(self, elements_left, settings);
                    }
                    
                    if($self.attr("src")){
	                    $("<img />").bind("load", function() {
	                        $self.hide().attr("src", $self.data(settings.data_attribute))[settings.effect](settings.effect_speed);
	                        self.loaded = true;
	
	                        /* Remove image from array so it is not looped next time. */
	                        var temp = $.grep(elements, function(element) {
	                            return !element.loaded;
	                        });
	                        elements = $(temp);
	
	                        if (settings.load) {
	                            var elements_left = elements.length;
	                            settings.load.call(self, elements_left, settings);
	                        }
	                    }).attr("src", $self.data(settings.data_attribute));
	                    
                    }else if($self.children('object').attr('classid') || $self.children('embed').attr('src')){
    					var $object = null;
    					var wmode = '';
    					var bgcolor = '';
    					
    					if($self.children('embed').attr('src')){ //只有embed的情况
    						$object = $self.children('embed');
    						wmode = $object.attr('wmode');
    						bgcolor = $object.attr('bgcolor');
    					}else if($self.children('object').attr('classid')){//只能从object标签中获取，不能从embed中获取，ie某些版本不识别embed
    						$object = $self.children('object');
    					}
    					var swf_html = swf_template.replace(/\{\$url\}/g, $object.attr('data-'+settings.data_attribute));
            			swf_html = getNewSwf($object, swf_html, $object.attr('width'), $object.attr('height'), wmode, bgcolor);
    					$self.html(swf_html);
    				}else{ 
						$self.css({"background":""+$self.data(settings.data_attribute)+""});
					}
                    
                }
            });

            /* When wanted event is triggered load original image */
            /* by triggering appear.                              */
            if (0 !== settings.event.indexOf("scroll")) {
                $self.bind(settings.event, function(event) {
                    if (!self.loaded) {
                        $self.trigger("appear");
                    }
                });
            }
        });

        /* Check if something appears when window is resized. */
        $window.bind("resize", function(event) {
            update();
        });
              
        /* With IOS5 force loading images when navigating with back button. */
        /* Non optimal workaround. */
        if ((/iphone|ipod|ipad.*os 5/gi).test(navigator.appVersion)) {
            $window.bind("pageshow", function(event) {
                if (event.originalEvent.persisted) {
                    elements.each(function() {
                        $(this).trigger("appear");
                    });
                }
            });
        }

        /* Force initial check if images should appear. */
        $(window).load(function() {
            update();
        });
        
        return this;
    };

    /* Convenience methods in jQuery namespace.           */
    /* Use as  $.belowthefold(element, {threshold : 100, container : window}) */

    $.belowthefold = function(element, settings) {
        var fold;
        
        if (settings.container === undefined || settings.container === window) {
            fold = $window.height() + $window.scrollTop();
        } else {
            fold = $(settings.container).offset().top + $(settings.container).height();
        }

        return fold <= $(element).offset().top - settings.threshold;
    };
    
    $.rightoffold = function(element, settings) {
        var fold;

        if (settings.container === undefined || settings.container === window) {
            fold = $window.width() + $window.scrollLeft();
        } else {
            fold = $(settings.container).offset().left + $(settings.container).width();
        }

        return fold <= $(element).offset().left - settings.threshold;
    };
        
    $.abovethetop = function(element, settings) {
        var fold;
        
        if (settings.container === undefined || settings.container === window) {
            fold = $window.scrollTop();
        } else {
            fold = $(settings.container).offset().top;
        }

        return fold >= $(element).offset().top + settings.threshold  + $(element).height();
    };
    
    $.leftofbegin = function(element, settings) {
        var fold;
        
        if (settings.container === undefined || settings.container === window) {
            fold = $window.scrollLeft();
        } else {
            fold = $(settings.container).offset().left;
        }

        return fold >= $(element).offset().left + settings.threshold + $(element).width();
    };

    $.inviewport = function(element, settings) {
         return !$.rightoffold(element, settings) && !$.leftofbegin(element, settings) &&
                !$.belowthefold(element, settings) && !$.abovethetop(element, settings);
     };

    /* Custom selectors for your convenience.   */
    /* Use as $("img:below-the-fold").something() or */
    /* $("img").filter(":below-the-fold").something() which is faster */

    $.extend($.expr[':'], {
        "below-the-fold" : function(a) { return $.belowthefold(a, {threshold : 0}); },
        "above-the-top"  : function(a) { return !$.belowthefold(a, {threshold : 0}); },
        "right-of-screen": function(a) { return $.rightoffold(a, {threshold : 0}); },
        "left-of-screen" : function(a) { return !$.rightoffold(a, {threshold : 0}); },
        "in-viewport"    : function(a) { return $.inviewport(a, {threshold : 0}); },
        /* Maintain BC for couple of versions. */
        "above-the-fold" : function(a) { return !$.belowthefold(a, {threshold : 0}); },
        "right-of-fold"  : function(a) { return $.rightoffold(a, {threshold : 0}); },
        "left-of-fold"   : function(a) { return !$.rightoffold(a, {threshold : 0}); }
    });
    
    function getNewSwf(obj, swf_html, width, height, wmode, bgcolor){
    	var isIE6 = IE6();
    	swf_html = swf_html.replace(/\{\$width\}/g, width);
		swf_html = swf_html.replace(/\{\$height\}/g, height);
		if(typeof(wmode) == undefined || wmode == '' || typeof(bgcolor) == undefined || bgcolor == ''){ 
			obj.children('param').each(function(){
				if($(this).attr('name') && $(this).attr('name').toLowerCase() == 'wmode' && !isIE6){
					swf_html = swf_html.replace(/\{\$wmode\}/g, $(this).attr('value'));
				}
				if($(this).attr('name') && $(this).attr('name').toLowerCase() == 'bgcolor'){
					swf_html = swf_html.replace(/\{\$bgcolor\}/g, $(this).attr('value'));
				}
			});
		}else{
			swf_html = swf_html.replace(/\{\$wmode\}/g, wmode);//google firefox...
		}
		return swf_html;
    }
	
    function IE6(){
    	if($.browser.msie && $.browser.version == '6.0'){
    		return true;
    	}else{
    		return false;
    	}
    }
	 
    /* 
    function mask(){
    	if($(this).attr('mask-pic')){
			settings.maskType = 'image';
			settings.maskVar = $(this).attr('mask_pic');
		}else if($(this).attr('mask-text')){
			settings.maskType = 'text';
			settings.maskVar = $(this).attr('mask_text');
		}
    	 
    	if($(this).get(0).tagName == 'image'){
    		
    		if(settings.maskType == 'image'){
        		$(this).attr('src', settings.maskVar);
        	}else if(settings.maskType == 'text'){}
    		
    	} else if($(this).children('object').attr('classid') || $(this).children('embed').attr('src')){
    		
    		if(settings.maskType == 'image'){
    			
    			var swf_html = swf_template.replace(/\{\$url\}/g, settings.maskVar);
    			swf_html = getNewSwf($(this), swf_html, $(this).attr('width'), $(this).attr('height'));
				$(this).html(swf_html);
				
        	}else if(settings.maskType == 'text'){}
    	}
    	
    }
    */

})(jQuery, window, document);