站在巨人肩膀：修改jCarousel Lite图片滚动插件

插件Home：http://www.gmarwaha.com/jquery/jcarousellite/index.php

 

很棒的图片滚动插件，加入国人常用的习惯:鼠标悬停的效果。

 

html结构要求：

 

 

<div id="handler">
    <ul>
        <li><img /></li>
         ……
    </ul>
</div>

 

div,ul都会自动加入合适的css，而且是相对定位。基本不需要额外css控制，当然在js生效前，会乱，如果网速慢的话。

 

有必要对div加额外的margin等，控制其居中或怎样。div的left属性为0，是插件自动设置的，所以不要通过这个去控制位置了。

 

 

(function($) {                                          // Compliant with jquery.noConflict()
$.fn.jCarouselLite = function(o) {
    o = $.extend({
        btnPrev: null,
        btnNext: null,
        btnGo: null,
        mouseWheel: false,
        auto: null,

        speed: 200,
        easing: null,

        vertical: false,
        circular: true,
        visible: 3,
        start: 0,
        scroll: 1,

        beforeStart: null,
        afterEnd: null
    }, o || {});

    return this.each(function() {                           // Returns the element collection. Chainable.

        var running = false, animCss=o.vertical?"top":"left", sizeCss=o.vertical?"height":"width";
        var div = $(this), ul = $("ul", div), tLi = $("li", ul), tl = tLi.size(), v = o.visible;
		
	       	if(tl == 0) {
				return false;
			}
        if(o.circular) {
            ul.prepend(tLi.slice(tl-v-1+1).clone())
              .append(tLi.slice(0,v).clone());
            o.start += v;
        }

        var li = $("li", ul), itemLength = li.size(), curr = o.start;
        div.css("visibility", "visible");

        li.css({overflow: "hidden", 'float': o.vertical ? "none" : "left"});
        ul.css({margin: "0", padding: "0", position: "relative", "list-style-type": "none", "z-index": "1"});
        div.css({overflow: "hidden", position: "relative", "z-index": "2", left: "0px"});

        var liSize = o.vertical ? height(li) : width(li);   // Full li size(incl margin)-Used for animation
        var ulSize = liSize * itemLength;                   // size of full ul(total length, not just for the visible items)
        var divSize = liSize * v;                           // size of entire div(total length for just the visible items)

        li.css({width: li.width(), height: li.height()});
        ul.css(sizeCss, ulSize+"px").css(animCss, -(curr*liSize));

        div.css(sizeCss, divSize+"px");                     // Width of the DIV. length of visible images

        if(o.btnPrev)
            $(o.btnPrev).click(function() {
                return go(curr-o.scroll);
            });

        if(o.btnNext)
            $(o.btnNext).click(function() {
                return go(curr+o.scroll);
            });

        if(o.btnGo)
            $.each(o.btnGo, function(i, val) {
                $(val).click(function() {
                    return go(o.circular ? o.visible+i : i);
                });
            });

        if(o.mouseWheel && div.mousewheel)
            div.mousewheel(function(e, d) {
                return d>0 ? go(curr-o.scroll) : go(curr+o.scroll);
            });
		var jcarouselliteAutoId;
        if(o.auto) {
            jcarouselliteAutoId = setInterval(function() {
                go(curr+o.scroll);
            }, o.auto+o.speed);
			/* 2009年7月30日 添加鼠标浮动停止滚动 */
			ul.hover(function(){
					clearInterval(jcarouselliteAutoId);
				},function(){
					jcarouselliteAutoId = setInterval(function() {
						go(curr+o.scroll);
					}, o.auto+o.speed);
			});
        };

        function vis() {
            return li.slice(curr).slice(0,v);
        };

        function go(to) {
	       	if(tl <= 3) {
				return false;
			}
	        
            if(!running) {

                if(o.beforeStart)
                    o.beforeStart.call(this, vis());

                if(o.circular) {            // If circular we are in first or last, then goto the other end
                    if(to<=o.start-v-1) {           // If first, then goto last
                        ul.css(animCss, -((itemLength-(v*2))*liSize)+"px");
                        // If "scroll" > 1, then the "to" might not be equal to the condition; it can be lesser depending on the number of elements.
                        curr = to==o.start-v-1 ? itemLength-(v*2)-1 : itemLength-(v*2)-o.scroll;
                    } else if(to>=itemLength-v+1) { // If last, then goto first
                        ul.css(animCss, -( (v) * liSize ) + "px" );
                        // If "scroll" > 1, then the "to" might not be equal to the condition; it can be greater depending on the number of elements.
                        curr = to==itemLength-v+1 ? v+1 : v+o.scroll;
                    } else curr = to;
                } else {                    // If non-circular and to points to first or last, we just return.
                    if(to<0 || to>itemLength-v) return;
                    else curr = to;
                }                           // If neither overrides it, the curr will still be "to" and we can proceed.

                running = true;

                ul.animate(
                    animCss == "left" ? { left: -(curr*liSize) } : { top: -(curr*liSize) } , o.speed, o.easing,
                    function() {
                        if(o.afterEnd)
                            o.afterEnd.call(this, vis());
                        running = false;
                    }
                );
                // Disable buttons when the carousel reaches the last/first, and enable when not
                if(!o.circular) {
                    $(o.btnPrev + "," + o.btnNext).removeClass("disabled");
                    $( (curr-o.scroll<0 && o.btnPrev)
                        ||
                       (curr+o.scroll > itemLength-v && o.btnNext)
                        ||
                       []
                     ).addClass("disabled");
                }

            }
            return false;
        };
    });
};

function css(el, prop) {
    return parseInt($.css(el[0], prop)) || 0;
};
function width(el) {
    return  el[0].offsetWidth + css(el, 'marginLeft') + css(el, 'marginRight');
};
function height(el) {
    return el[0].offsetHeight + css(el, 'marginTop') + css(el, 'marginBottom');
};

})(jQuery);