(function($) {
	$.fn.easySlider = function(options){
		// default configuration properties
		var defaults = {			
			prevId: 		'prevBtn',
			prevText: 		'前一个',
			nextId: 		'nextBtn',	
			nextText: 		'后一个',
			controlsShow:	true,
			controlsBefore:	'',
			controlsAfter:	'',	
			controlsFade:	true,
			firstId: 		'firstBtn',
			firstText: 		'First',
			firstShow:		false,
			lastId: 		'lastBtn',	
			lastText: 		'Last',
			lastShow:		false,				
			vertical:		false,
			speed: 			400,
			auto:			false,
			pause:			6000,
			continuous:		false,
			step:			1
		}; 		
		var options = $.extend(defaults, options);  
		this.each(function() {  
			var obj = $(this); 				
			var s = $(">ul > li", obj).length;
			var w = $(">ul > li", obj).outerWidth(true); 
			var h = $(">ul > li", obj).outerHeight(true); 
			var boxW = $(obj).outerWidth(true);
			var boxH = $(obj).outerHeight(true);
			var contentH = $(">ul", obj).outerHeight(true);
			var contentW = $(">ul", obj).outerWidth(true);
			var cols=(contentW-boxW)/w;
			var rows=(contentH-boxH)/h;
			var step = options.step;
			var ts = s/step-1;
			var t = 0;
			$(obj).css('overflow', 'hidden');
			if (options.vertical) {
				ts = rows/step;
			} else {
				ts = cols/step;
				//$("> ul", obj).css('width',contentW);
			};
			if (ts == 0) return;
			if(options.controlsShow){
				var html = options.controlsBefore;
				if(options.firstShow) html += '<span id="'+ options.firstId +'"><a href=\"javascript:void(0);\">'+ options.firstText +'</a></span>';
				html += ' <span id="'+ options.prevId +'"><a href=\"javascript:void(0);\">'+ options.prevText +'</a></span>';
				html += ' <span id="'+ options.nextId +'"><a href=\"javascript:void(0);\">'+ options.nextText +'</a></span>';
				if(options.lastShow) html += ' <span id="'+ options.lastId +'"><a href=\"javascript:void(0);\">'+ options.lastText +'</a></span>';
				html += options.controlsAfter;						
				$(obj).after(html);										
			};	
			$("a","#"+options.nextId).click(function(){		
				animate("next",true);
			});
			$("a","#"+options.prevId).click(function(){		
				animate("prev",true);				
			});	
			$("a","#"+options.firstId).click(function(){		
				animate("first",true);
			});				
			$("a","#"+options.lastId).click(function(){		
				animate("last",true);				
			});					
			function animate(dir,clicked){
				var ot = t;
				var contentX = parseInt($("> ul",obj).css('marginLeft'));
				var contentY = parseInt($("> ul",obj).css('marginTop'));
				switch(dir){
					case "next":
						t = (ot>=ts) ? (options.continuous ? 0 : ts) : t+1;						
						break; 
					case "prev":
						t = (t<=0) ? (options.continuous ? ts : 0) : t-1;
						break; 
					case "first":
						t = 0;
						break; 
					case "last":
						t = ts;
						break; 
					default:
						break; 
				};	
				
				var diff = Math.abs(ot-t);
				var speed = diff*options.speed;		
				var j = options.jump;
				if(!options.vertical) {
					p = (t*w*step*-1);
					$("> ul",obj).animate(
						{ marginLeft: p }, 
						speed
					);
				} else {
					p = (t*h*step*-1);
					$("> ul",obj).animate(
						{ marginTop: p }, 
						speed
					);
				};
				
				if(!options.continuous && options.controlsFade){
					if(t==ts){
						$("a","#"+options.nextId).hide();
						$("a","#"+options.lastId).hide();
					} else {
						$("a","#"+options.nextId).show();
						$("a","#"+options.lastId).show();					
					};
					if(t==0){
						$("a","#"+options.prevId).hide();
						$("a","#"+options.firstId).hide();
					} else {
						$("a","#"+options.prevId).show();
						$("a","#"+options.firstId).show();
					};
				};				
				
				if(clicked) clearTimeout(timeout);
				if(options.auto && dir=="next" && !clicked){;
					timeout = setTimeout(function(){
						animate("next",false);
					},diff*options.speed+options.pause);
				};
				
			};
			// init
			var timeout;
			if(options.auto){;
				timeout = setTimeout(function(){
					animate("next",false);
				},options.pause);
			};
			if(!options.continuous && options.controlsFade){					
				$("a","#"+options.prevId).hide();
				$("a","#"+options.firstId).hide();				
			};				
			
		});
	  
	};
})(jQuery);

$(document).ready(function(){
  $(".ngg-galleryoverview").easySlider({
    controlsBefore: '<div id="scrollBar">',
    controlsAfter: '</div>',
	prevText: '&and;',
	nextText: '&or;',
	speed:500,
	pause: 10000,
    auto: false,
	vertical: true,
    continuous: false,
	step: 1
  });
});