/// <reference path="jquery-1.3.2.js" />

/*

* 

* tackerScroller - a Image Horizental Auto Scroll Viewer 

* Version 0.1.1

* @requires jQuery v1.3.2

* 

* Copyright (c) 2009 Tacker

* Eidtor: Tacker By 2009-10-18

* Email:tacker.cn@gmail.com

* WebSite:[url]www.ruiidea.com[/url]

* Dual licensed under the MIT and GPL licenses:

* [url]http://www.opensource.org/licenses/mit-license.php[/url]

* [url]http://www.gnu.org/licenses/gpl.html[/url]

* 

*/



jQuery.fn.tackerScroller = function(params) {

    var p = params || {

        container: "imgViewer",

        frame: "viewerFrame",

        width: 2,

        child: "li",

        time: 6000,

        visibleScroll: false,

        scrollwidth: 845

    };

    var _imgViewer = $("#" + p.container);

    var _imgFrame = $("#" + p.frame);

    var _width = p.width;

    var _child = p.child;

    var _time = p.time;

    var _framewidth = _imgFrame.find(_child).size() * _imgFrame.find(_child + ":first").width();

    var _positionX;

    var _scrollwidth = p.scrollwidth;

    var _visibleScroll = p.visibleScroll;

    var _scrollPositionX;



    var autoStop = function() {

        _imgFrame.stop();

        if (_visibleScroll === true) {

            $("#scrollcenter").stop();

        }

    };

    var turnLeft = function() {

        if (_imgFrame.offset().left < 0) {

            _imgFrame.animate({ marginLeft: 0 }, _time);

            if (_visibleScroll === true) {

                $("#scrollcenter").animate({ left: 0 }, _time);

            }

        }

        else {

            autoStop();

        }

    };

    var turnRight = function() {

        if (_imgFrame.offset().left > _imgViewer.width() - _imgFrame.width()) {

            _imgFrame.animate({ marginLeft: (_imgViewer.width() - _imgFrame.width()) }, _time);

            if (_visibleScroll == true) {

                $("#scrollcenter").animate({ left: (_scrollwidth - $("#scrollcenter").width()) }, _time);

            }

        }

        else {

            autoStop();

        }

    };

    var init = function() {

        _imgFrame.width(_framewidth);

        if (_visibleScroll == true) {

            var scrollerwidth = _imgViewer.width() * _scrollwidth / _imgFrame.width();

            var scrolleroffsetX;

            $("#scrollcenter").width(scrollerwidth);

            $("#scrollcenter").css("position", "absolute").css("left", "0px");

            $("#scrollcenter").parent().css("width", _scrollwidth + "px");

            $("#scrollcenter").animate({ left: (_scrollwidth - scrollerwidth) / 2 }, 2000);

            $("#scrollcenter").bind("mousedown", function(e) {

                autoStop();

                e = e ? e : window.event;

                //鼠标x坐标相对中间滚动条偏移位置

                scrolleroffsetX = parseInt(e.originalEvent.clientX - $("#scrollcenter").offset().left || e.originalEvent.layerX || 0);

                $("#msg").text(scrolleroffsetX);

                $("#scrollcenter").parent().mousemove(function(evt) {

                    evt = evt ? evt : window.event;

                    _scrollPositionX = parseInt((evt.originalEvent.clientX - scrolleroffsetX - $("#scrollcenter").parent().offset().left) || (evt.originalEvent.pageX - scrolleroffsetX - $("#scrollcenter").parent().offset().left) || 0)

                    if (_scrollPositionX >= 0 && _scrollPositionX <= _scrollwidth - $("#scrollcenter").width()) {

                        $("#scrollcenter").css("left", (_scrollPositionX) + "px");

                        _imgFrame.css("margin-left", (_imgViewer.width() - _imgFrame.width()) * _scrollPositionX / (_scrollwidth - $("#scrollcenter").width()) + "px");

                    }

                    return false; //阻止事件冒泡

                });

                $(document).mouseup(function() {

                    $("#scrollcenter").parent().unbind();

                });

                return false;  //阻止事件冒泡          

            });

            $("#scrollcenter").mouseover(function() {

                $(this).css("cursor", "pointer");

            });

        }

        _imgFrame.animate({ marginLeft: (_imgViewer.width() - _framewidth) / 2 }, 2000);

        _imgViewer.mouseout(autoStop);

        _imgViewer.mouseover(function(e) {

            //获取当前鼠标相对对象的x坐标

            _positionX = e.originalEvent.x - $(this).offset().left || e.originalEvent.layerX - $(this).offset().left || 0;

            if (_positionX < $(this).width() / 3) {

                autoStop();

                turnLeft();

            }

            else if (_positionX > ($(this).width() * 2) / 3) {

                autoStop();

                turnRight();

            }

            else {

                autoStop();

            }

            return false; //阻止事件冒泡

        });

    };

    init();

};