/*
	By sean at 2010.07,  modified on 2010.09.10;
	
	Example:
	$(".productshow").xslider({//.productshow鏄绉诲姩瀵硅薄鐨勫妗咞
		unitdisplayed:3,//鍙鐨勫崟浣嶄釜鏁   蹇呴渶椤耕
		movelength:1,//瑕佺Щ鍔ㄧ殑鍗曚綅涓暟    蹇呴渶椤耕
		maxlength:null,//鍙瀹藉害鎴栭珮搴    榛樿鏌ユ壘瑕佺Щ鍔ㄥ璞″灞傜殑瀹芥垨楂樺害;
		scrollobj:null,//瑕佺Щ鍔ㄧ殑瀵硅薄     榛樿鏌ユ壘productshow涓嬬殑ul;
		unitlen:null,//绉诲姩鐨勫崟浣嶅鎴栭珮搴     榛樿鏌ユ壘li鐨勫昂瀵符
		nowlength:null,//绉诲姩鏈€闀垮鎴栭珮锛堣绉诲姩瀵硅薄鐨勫搴︽垨楂樺害锛   榛樿鐢眑i涓暟涔樹互unitlen鎵€寰楃殑绉?
		dir:"H",//姘村钩绉诲姩杩樻槸鍨傜洿绉诲姩锛岄粯璁涓烘按骞崇Щ鍔紝浼犲叆V鎴栧叾浠栧瓧绗﹀垯琛ㄧず鍨傜洿绉诲姩;
		autoscroll:1000//鑷姩绉诲姩闂撮殧鏃堕棿     榛樿null涓嶈嚜鍔ㄧЩ鍔?
	});
*/
jQuery.extend(jQuery.easing, {
	easeInSine: function (x, t, b, c, d) {
		return -c * Math.cos(t / d * (Math.PI / 2)) + c + b;
	}
});
(function ($) {
	$.fn.xslider = function (settings) {
		settings = $.extend({}, $.fn.xslider.defaults, settings);
		this.each(function () {
			var scrollobj = settings.scrollobj || $(this).find("ul");
			var maxlength = settings.maxlength || (settings.dir == "H" ? scrollobj.parent().width() : scrollobj.parent().height()); //length of the wrapper visible;
			var scrollunits = scrollobj.find("li"); //units to move;
			var unitlen = settings.unitlen || (settings.dir == "H" ? scrollunits.eq(0).outerWidth() : scrollunits.eq(0).outerHeight());
			var unitdisplayed = settings.unitdisplayed; //units num displayed;
			var nowlength = settings.nowlength || scrollunits.length * unitlen; //length of the scrollobj;
			var offset = 0;
			var sn = 0;
			var movelength = unitlen * settings.movelength;
			var moving = false; //moving now?;
			var btnright = $("a.aright");
			var btnleft = $("a.aleft");

			if (settings.dir == "H") {
				scrollobj.css("left", "0px");
			} else {
				scrollobj.css("top", "0px");
			}
			if (nowlength > maxlength) {
				btnleft.addClass("agrayleft");
				btnright.removeClass("agrayright");
				offset = nowlength - maxlength;
			} else {
				btnleft.addClass("agrayleft");
				btnright.addClass("agrayright");
			}

			btnleft.click(function () {
				if ($(this).is("[class*='agrayleft']")) {
					return false;
				}
				if (!moving) {
					moving = true;
					sn -= movelength;
					if (sn > unitlen * unitdisplayed - maxlength) {
						jQuery.fn.xslider.scroll(scrollobj, -sn, settings.dir, function () {
							moving = false;
						});
					} else {
						jQuery.fn.xslider.scroll(scrollobj, 0, settings.dir, function () {
							moving = false;
						});
						sn = 0;
						$(this).addClass("agrayleft");
					}
					btnright.removeClass("agrayright");
				}
				return false;
			});
			btnright.click(function () {
				if ($(this).is("[class*='agrayright']")) {
					return false;
				}
				if (!moving) {
					moving = true;
					sn += movelength;
					if (sn < offset - (unitlen * unitdisplayed - maxlength)) {
						jQuery.fn.xslider.scroll(scrollobj, -sn, settings.dir, function () {
							moving = false;
						});
					} else {
						jQuery.fn.xslider.scroll(scrollobj, -offset, settings.dir, function () {
							moving = false;
						}); //婊氬姩鍒版渶鍚庝竴涓綅缃?
						sn = offset;
						$(this).addClass("agrayright");
					}
					btnleft.removeClass("agrayleft");
				}
				return false;
			});

			if (settings.autoscroll) {
				jQuery.fn.xslider.autoscroll($(this), settings.autoscroll);
			}

		})
	}
})(jQuery);

jQuery.fn.xslider.defaults = {
	maxlength: 0,
	scrollobj: null,
	unitlen: 0,
	nowlength: 0,
	dir: "H",
	autoscroll: null
};
jQuery.fn.xslider.scroll = function (obj, w, dir, callback) {
	if (dir == "H") {
		obj.animate({
			left: w
		}, 500, "easeInSine", callback);
	} else {
		obj.animate({
			top: w
		}, 500, "easeInSine", callback);
	}
}
jQuery.fn.xslider.autoscroll = function (obj, time) {
	var vane = "right";

	function autoscrolling() {
		if (vane == "right") {
			if (!$("a.agrayright").length) {
				$("a.aright").trigger("click");
			} else {
				vane = "left";
			}
		}
		if (vane == "left") {
			if (!$("a.agrayleft").length) {
				$("a.aleft").trigger("click");
			} else {
				vane = "right";
			}
		}
	}
	var scrollTimmer = setInterval(autoscrolling, time);
	obj.hover(function () {
		clearInterval(scrollTimmer);
	}, function () {
		scrollTimmer = setInterval(autoscrolling, time);
	});
}