/*
 *
 * ImageScroller - a Image Horizental Scroll Viewer
 * Version 0.1
 * @requires jQuery v1.2.1
 *
 * Copyright (c) 2007 Luan
 * Email verycss-ok@yahoo.com.cn
 *
 * Dual licensed under the MIT and GPL licenses:
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.gnu.org/licenses/gpl.html
 *
 * Example:
 *   #viewer {height:100px; width:300px; clear:both; overflow:hidden; border:3px solid #e5e5e5;}
 *   #viewerFrame {width:505px; clear:both; padding:0;}
 *   #viewer img {width:90px; height:90px; margin:5px; display:inline; border:0;}
 *   #viewer a {display:block; float:left; width:100px; height:100px;}
 *   <script type="text/javascript">
 *   $(function(){
 *   	$("#viewer").imageScroller({
 *   	next:"btn1",
 *   	prev:"btn2",
 *   	frame:"viewerFrame",
 *   	width:100,
 *   	child:"a",
 *   	auto:true
 *   	});
 *   });
 *   </script>
 *   <div id="viewer"><div id="viewerFrame">
 *   <a href=""><img src="pre1.jpg"></a>
 *   <a href=""><img src="pre2.jpg"></a>
 *   <a href=""><img src="pre3.jpg"></a>
 *   <a href=""><img src="pre4.jpg"></a>
 *   <a href=""><img src="pre5.jpg"></a>
 *   </div></div>
 *   <span id="btn1">prev</span><br/><span id="btn2">next</span>
 */
(function($){
    jQuery.fn.imageScroller = function(params){
        var p = params ||
        {
            next: "buttonNext",
            prev: "buttonPrev",
            frame: "viewerFrame",
            width: 100,
            child: "a",
            auto: true
        };
        var _btnNext = $("#" + p.next);
        var _btnPrev = $("#" + p.prev);
        var _imgFrame = $("#" + p.frame);
        var _width = p.width;
        var _child = p.child;
        var _auto = p.auto;
        var _itv;
        var _offset = 0;
        
        var turnLeft = function(){
            _btnPrev.unbind("click", turnLeft);
            if (_auto) 
                autoStop();
            _imgFrame.animate({
                marginLeft: -_width
            }, 'fast', '', function(){
                _imgFrame.find(_child + ":first").appendTo(_imgFrame);
                _imgFrame.css("marginLeft", 0);
                _btnPrev.bind("click", turnLeft);
                if (_auto) 
                    autoPlay();
            });
            
            _offset++;
        };
        
        var turnRight = function(){
            if (_offset == 0) 
                return false;
            _btnNext.unbind("click", turnRight);
            if (_auto) 
                autoStop();
            _imgFrame.find(_child + ":last").clone().show().prependTo(_imgFrame);
            _imgFrame.css("marginLeft", -_width);
            _imgFrame.animate({
                marginLeft: 0
            }, 'fast', '', function(){
                _imgFrame.find(_child + ":last").remove();
                _btnNext.bind("click", turnRight);
                if (_auto) 
                    autoPlay();
            });
            _offset--;
        };
        
        _btnNext.css("cursor", "pointer").click(turnRight);
        _btnPrev.css("cursor", "pointer").click(turnLeft);
        
        var autoPlay = function(){
            _itv = window.setInterval(turnRight, 3000);
        };
        var autoStop = function(){
            window.clearInterval(_itv);
        };
        if (_auto) 
            autoPlay();
    };
    
})(jQuery);