// Create scrolling variable if it doesn't exist
if (!Scrolling) var Scrolling = {};

//Scrollbar constructor
Scrolling.Scrollbar = function(o, s, t) {
    //private variables
    var self = this;
    var _components = {};
    var _dimensions = {};
    var _temporary = {};
    var _hasTween = t ? true : false;
    var _timer, _ratio;

    //public variables
    this.onMouseDown = function() { };
    this.onMouseUp = function() { };
    this.onScroll = function() { };
    this.scrollAmount = 5;
    this.scrollSpeed = 30;
    this.disabled = false;

    //private functions
    function initialize() {
        var c = _components;
        var d = _dimensions;
        var g = s.getDimensions();

        c.up = findComponent("Scrollbar-Up", o);
        c.down = findComponent("Scrollbar-Down", o);
        c.track = findComponent("Scrollbar-Track", o);
        c.handle = findComponent("Scrollbar-Handle", c.track);

        d.trackTop = findOffsetTop(c.track);
        d.trackHeight = c.track.offsetHeight;
        d.handleHeight = c.handle.offsetHeight;
        d.y = 0;

        if (_hasTween) t.apply(self);

        addEvent(s.getContent(), "mousewheel", scrollbarWheel);
        addEvent(s.getContent(), "DOMMouseScroll", scrollbarWheel);
        addEvent(o, "mousedown", scrollbarClickPrimer);

        self.reset();
    };

    function findOffsetTop(o) {
        var t = 0;
        if (o.offsetParent) {
            while (o.offsetParent) {
                t += o.offsetTop;
                o = o.offsetParent;
            }
        }
        return t;
    };

    function addEvent(o, t, f) {
        if (o.attachEvent) o.attachEvent('on' + t, f);
        else o.addEventListener(t, f, false);
    };

    function removeEvent(o, t, f) {
        if (o.detachEvent) o.detachEvent('on' + t, f);
        else o.removeEventListener(t, f, false);
    };

    function findComponent(c, o) {
        var kids = o.childNodes;
        for (var i = 0; i < kids.length; i++) {
            if (kids[i].className && kids[i].className.indexOf(c) >= 0) {
                return kids[i];
            }
        }
    };

    function scroll(y) {
        if (y < 0) y = 0;
        if (y > _dimensions.trackHeight - _dimensions.handleHeight)
            y = _dimensions.trackHeight - _dimensions.handleHeight;

        _components.handle.style.top = y + "px";
        _dimensions.y = y;

        s.scrollTo(0, Math.round(_dimensions.y * _ratio));
        self.onScroll();
    };

    function scrollbarClickPrimer(e) {
        if (self.disabled) return false;

        e = e ? e : event;
        if (!e.target) e.target = e.srcElement;

        _dimensions.trackTop = findOffsetTop(_components.track);
        scrollbarClick(e.target.className, e);
    };

    function scrollbarClick(c, e) {

        var d = _dimensions;
        var t = _temporary;
        var cy = e.clientY + document.body.scrollTop;

        if (c.indexOf("Scrollbar-Up") >= 0)
            startScroll(-self.scrollAmount);

        if (c.indexOf("Scrollbar-Down") >= 0)
            startScroll(self.scrollAmount);

        if (c.indexOf("Scrollbar-Track") >= 0) {
            cy = e.clientY + Math.max(document.body.scrollTop, document.documentElement.scrollTop); //Quang 20/01
            if (_hasTween) self.tweenTo((cy - d.trackTop - d.handleHeight / 2) * _ratio);
            else scroll(cy - d.trackTop - d.handleHeight / 2);
        }

        if (c.indexOf("Scrollbar-Handle") >= 0) {
            t.grabPoint = cy - findOffsetTop(_components.handle);
            addEvent(document, "mousemove", scrollbarDrag, false);
        }

        t.target = e.target;
        t.select = document.onselectstart;

        document.onselectstart = function() { return false; };
        self.onMouseDown(e.target, c, e);

        addEvent(document, "mouseup", stopScroll);
    };

    function scrollbarDrag(e) {
        e = e ? e : event;
        var d = _dimensions;
        var t = parseInt(_components.handle.style.top);
        var v = e.clientY + document.body.scrollTop - d.trackTop;

        if (v >= d.trackHeight - d.handleHeight + _temporary.grabPoint)
            v = d.trackHeight - d.handleHeight;

        else if (v <= _temporary.grabPoint)
            v = 0;

        else v = v - _temporary.grabPoint;

        scroll(v);
    };

    function scrollbarWheel(e) {
        if (self.disabled) return false;

        e = e ? e : event;
        var dir = 0;

        if (typeof e.wheelDelta == 'undefined') {
            if (e.detail > 0) dir = 1;
            if (e.detail < 0) dir = -1;
        } else {
            if (e.wheelDelta >= 120) dir = -1;
            if (e.wheelDelta <= -120) dir = 1;
        }

        self.scrollBy(dir * 20);

        if (e.stopPropagation) e.stopPropagation();
        if (e.preventDefault) e.preventDefault();
        e.cancelBubble = true;
        e.cancel = true;
        e.returnValue = false;
        return false;
    };

    function startScroll(y) {
        _temporary.disty = y;
        _timer = window.setInterval(function() {
            self.scrollBy(_temporary.disty);
        }, self.scrollSpeed);
    };

    function stopScroll(e) {
        e = e ? e : event;

        removeEvent(document, "mousemove", scrollbarDrag);
        removeEvent(document, "mouseup", stopScroll);

        document.onselectstart = _temporary.select;
        if (_timer) window.clearInterval(_timer);

        self.onMouseUp(_temporary.target, _temporary.target.className, e);
    };

    //public functions
    this.reset = function() {
        var d = _dimensions;
        var c = _components;
        var g = s.getDimensions();

        _ratio = (g.theight - g.vheight) / (d.trackHeight - d.handleHeight);

        c.handle.ondragstart = function() { return false; };
        c.handle.onmousedown = function() { return false; };
        c.handle.style.top = "0px";
        d.y = 0;

        s.reset();
        scroll(0);

        if (g.theight < g.vheight) {
            this.disable();
        } else this.enable();
    };

    this.scrollTo = function(y) {
        scroll(y / _ratio);
    };

    this.scrollBy = function(y) {
        scroll((s.getDimensions().y + y) / _ratio);
    };

    this.swapContent = function(n) {
        var d = s.getDimensions;
        s.swapContent(n, d.vwidth, d.vheight);
        initialize();
    };

    this.disable = function() {
        this.disabled = true;
        o.className += " Scrollbar-Disabled"; //o.className += "Scrollbar-Disabled";/*Quang 20/01*/	//
        o.style.display = 'none';
        s.getContent().style.position = 'static';
    };

    this.enable = function() {
        this.disabled = false;
        o.className = o.className.replace(/Scrollbar\-Disabled/, "");
        o.style.display = 'block';
        s.getContent().style.position = 'relative';
    };

    this.getContent = function() {
        return s.getContent();
    };

    this.getComponents = function() {
        return _components;
    };

    this.getDimensions = function() {
        var d = s.getDimensions();
        d.trackHeight = _dimensions.trackHeight;
        d.handleHeight = _dimensions.handleHeight;
        d.handleY = _dimensions.y;

        return d;
    };

    initialize();
};

/*----------------------------------------------------------------------------------------*/

//Scroller constructor
Scrolling.Scroller = function(o, w, h, t) {
    //get the container
    var list = o.getElementsByTagName("div");
    for (var i = 0; i < list.length; i++) {
        if (list[i].className.indexOf("Scroller-Container") > -1) {
            o = list[i];
        }
    }

    //private variables
    var self = this;
    var _vwidth = w;
    var _vheight = h;
    var _twidth = o.offsetWidth;
    var _theight = o.offsetHeight;
    var _hasTween = t ? true : false;
    var _timer, _x, _y;

    //public variables
    this.onScrollStart = function() { };
    this.onScrollStop = function() { };
    this.onScroll = function() { };
    this.scrollSpeed = 30;

    //private functions
    function setPosition(x, y) {
        if (x < _vwidth - _twidth)
            x = _vwidth - _twidth;
        if (x > 0) x = 0;
        if (y < _vheight - _theight)
            y = _vheight - _theight;
        if (y > 0) y = 0;

        _x = x;
        _y = y;

        o.style.left = _x + "px";
        o.style.top = _y + "px";
    };

    //public functions
    this.scrollBy = function(x, y) {
        setPosition(_x - x, _y - y);
        this.onScroll();
    };

    this.scrollTo = function(x, y) {
        setPosition(-x, -y);
        this.onScroll();
    };

    this.startScroll = function(x, y) {
        this.stopScroll();
        this.onScrollStart();
        _timer = window.setInterval(
			function() { self.scrollBy(x, y); }, this.scrollSpeed
		);
    };

    this.stopScroll = function() {
        if (_timer) window.clearInterval(_timer);
        this.onScrollStop();
    };

    this.reset = function() {
        _twidth = o.offsetWidth;
        _theight = o.offsetHeight;
        _x = 0;
        _y = 0;

        o.style.left = "0px";
        o.style.top = "0px";

        if (_hasTween) t.apply(this);
    };

    this.swapContent = function(c, w, h) {
        o = c;
        var list = o.getElementsByTagName("div");
        for (var i = 0; i < list.length; i++) {
            if (list[i].className.indexOf("Scroller-Container") > -1) {
                o = list[i];
            }
        }

        if (w) _vwidth = w;
        if (h) _vheight = h;
        this.reset();
    };

    this.getDimensions = function() {
        return {
            vwidth: _vwidth,
            vheight: _vheight,
            twidth: _twidth,
            theight: _theight,
            x: -_x, y: -_y
        };
    };

    this.getContent = function() {
        return o;
    };

    this.reset();
};

/*----------------------------------------------------------------------------------------*/

//ScrollTween constructor
Scrolling.ScrollTween = function() {
    //private variables
    var self = this;
    var _steps = [0, 25, 50, 70, 85, 95, 97, 99, 100];
    var _values = [];
    var _idle = true;
    var o, _inc, _timer;

    //private functions
    function tweenTo(y) {
        if (!_idle) return false;

        var d = o.getDimensions();
        if (y < 0) y = 0;
        if (y > d.theight - d.vheight)
            y = d.theight - d.vheight;

        var dist = y - d.y;
        _inc = 0;
        _timer = null;
        _values = [];
        _idle = false;

        for (var i = 0; i < _steps.length; i++) {
            _values[i] = Math.round(d.y + dist * (_steps[i] / 100));
        }

        _timer = window.setInterval(function() {
            o.scrollTo(_values[_inc]);
            if (_inc == _steps.length - 1) {
                window.clearInterval(_timer);
                _idle = true;
            } else _inc++;
        }, o.stepSpeed);
    };

    function tweenBy(y) {
        o.tweenTo(o.getDimensions().y + y);
    };

    function setSteps(s) {
        _steps = s;
    };

    //public functions
    this.apply = function(p) {
        o = p;
        o.tweenTo = tweenTo;
        o.tweenBy = tweenBy;
        o.setSteps = setSteps;
        o.stepSpeed = 30;
    };
};