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

//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;
        reset();
    };
    
    this.getDimensions = function () {
        return {
            vwidth  : _vwidth,
            vheight : _vheight,
            twidth  : _twidth,
            theight : _theight,
            x : -_x, y : -_y
        };
    };
    
    this.getContent = function () {
        return o;
    };
    
    this.reset();
};
// 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.x = 0;
        d.y = 0
        
        if (_hasTween) t.apply(self);
        
        addEvent(s.getContent(), "mousewheel", 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;
        
        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)
            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 (e.wheelDelta >= 120) dir = -1;
        if (e.wheelDelta <= -120) dir = 1;

        self.scrollBy(dir * 20);
        e.returnValue = 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.disabled = true;
            o.className  += " Scrollbar-Disabled";
        }
    };
    
    this.scrollTo = function (y) {
        scroll(y / _ratio);
    };
    
    this.scrollBy = function (y) {
        scroll((s.getDimensions().y + y) / _ratio);
    };
    
    this.swapContent = function (n, w, h) {
        o = n;
        s.swapContent(o, w, h);
        initialize();
    };
    
    this.disable = function () {
        this.disabled = true;
        o.className  += "Scrollbar-Disabled";
    };
    
    this.enable = function () {
        this.disabled = false;
        o.className = o.className.replace(/Scrollbar\-Disabled/, "");
    };
    
    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;
        
        return d;
    };
    
    initialize();
};
// Create scrolling variable if it doesn't exist
if (!Scrolling) var Scrolling = {};

//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;
    };
};