//banner婊氬姩鏁堟灉
$(function(){
	var $video_container = $('#video_container')  //瑙嗛瀹瑰櫒
	var $banner_list = $('#banner_list')
	var $points = $('#banner_list>video')
	var video_width = 770 // 涓€涓浘鐨勫搴
	var Time = 600       //  缈婚〉鐨勬寔缁椂闂
	var Item_Time = 30   //  鍗曞厓绉诲姩鐨勯棿闅
 	var imgCount = $points.length
	var $prev= $('#prev')
	var $next = $('#next')
	
	// 鐐瑰嚮鍚戝乏(鍙?鐨勫浘鏍?骞虫粦鍒囨崲鍒颁笂(涓?涓€椤

	$next.click(function(){nextpage(true)})
	$prev.click(function(){nextpage(false)})
	
	function nextpage(next){
		
		var offset = 0
		// 璁＄畻鎬荤殑鍋忕Щ閲弌ffset
		offset = next ? -video_width : video_width
		// 璁＄畻鍗曞厓绉诲姩鐨勫亸绉婚噺item_offsset
		var item_offsset = offset/(Time/Item_Time)
		// 寰楀埌褰撳墠left鍊
		var currLeft = $banner_list.position().left 
		// 璁＄畻鍑虹洰鏍囧鐨刲eft鍊
		var targetLeft = currLeft + offset 


		// 鍚姩寰幆瀹氭椂鍣?setInterval)涓嶆柇鏇存柊$list鐨刲eft,鍒拌揪鐩爣澶勫仠姝㈠畾鏃跺櫒
		var intervalId = setInterval(function(){
			if( (( currLeft <0)&&(next===false)) || ((currLeft > -(imgCount-1) * video_width)&&(next===true)) ){
				// 璁＄畻鍑烘渶鏂扮殑currLeft
				currLeft += item_offsset
				if(currLeft===targetLeft){// 鍒拌揪鐩爣浣嶇疆
					//娓呴櫎瀹氭椂鍣
					clearInterval(intervalId)	
				}
				// 璁剧疆left
				$banner_list.css('left', currLeft)
			}
		},Item_Time)
	}		
});