/*!
* Tiny Scrollbar 1.65
* http://www.baijs.nl/tinyscrollbar/
*
* Copyright 2010, Maarten Baijs
* Dual licensed under the MIT or GPL Version 2 licenses.
* http://www.opensource.org/licenses/mit-license.php
* http://www.opensource.org/licenses/gpl-2.0.php
*
* Date: 10 / 05 / 2011
* Depends on library: jQuery
* 
*/

(function ($) {
    $.tiny = $.tiny || {};

    $.tiny.scrollbar = {
        options: {
            axis: 'y', // vertical or horizontal scrollbar? ( x || y ).
            wheel: 40,  //how many pixels must the mouswheel scroll at a time.
            scroll: true, //enable or disable the mousewheel;
            size: 'auto', //set the size of the scrollbar to auto or a fixed number.
            sizethumb: 'auto' //set the size of the thumb to auto or a fixed number.
        }
    };

    $.fn.tinyscrollbar = function (options) {
        var options = $.extend({}, $.tiny.scrollbar.options, options);
        this.each(function () { $(this).data('tsb', new Scrollbar($(this), options)); });
        return this;
    };
    $.fn.tinyscrollbar_update = function (sScroll) { return $(this).data('tsb').update(sScroll); };

    function Scrollbar(root, options) {
        var oSelf = this;
        var oWrapper = root;
        var oViewport = { obj: $('.viewport', root) };
        var oContent = { obj: $('.overview', root) };
        var oScrollbar = { obj: $('.scrollbar', root) };
        var oTrack = { obj: $('.track', oScrollbar.obj) };
        var oThumb = { obj: $('.thumb', oScrollbar.obj) };
        var sAxis = options.axis == 'x', sDirection = sAxis ? 'left' : 'top', sSize = sAxis ? 'Width' : 'Height';
        var iScroll, iPosition = { start: 0, now: 0 }, iMouse = {};
        var twoFingerLastY = null;

        function initialize() {
            oSelf.update();
            setEvents();
            return oSelf;
        }
        this.update = function (sScroll) {
            if (oViewport.obj.length == 0)
                return;

            oViewport[options.axis] = oViewport.obj[0]['offset' + sSize];
            oContent[options.axis] = oContent.obj[0]['scroll' + sSize];
            oContent.ratio = oViewport[options.axis] / oContent[options.axis];
            oScrollbar.obj.toggleClass('disable', oContent.ratio >= 1);
            oTrack[options.axis] = options.size == 'auto' ? oViewport[options.axis] : options.size;
            oThumb[options.axis] = Math.min(oTrack[options.axis], Math.max(0, (options.sizethumb == 'auto' ? (oTrack[options.axis] * oContent.ratio) : options.sizethumb)));
            oScrollbar.ratio = options.sizethumb == 'auto' ? (oContent[options.axis] / oTrack[options.axis]) : (oContent[options.axis] - oViewport[options.axis]) / (oTrack[options.axis] - oThumb[options.axis]);
            iScroll = (sScroll == 'relative' && oContent.ratio <= 1) ? Math.min((oContent[options.axis] - oViewport[options.axis]), Math.max(0, iScroll)) : 0;
            iScroll = (sScroll == 'bottom' && oContent.ratio <= 1) ? (oContent[options.axis] - oViewport[options.axis]) : isNaN(parseInt(sScroll)) ? iScroll : parseInt(sScroll);
            setSize();
        };
        function setSize() {
            oThumb.obj.css(sDirection, iScroll / oScrollbar.ratio);
            oContent.obj.css(sDirection, -iScroll);
            iMouse['start'] = oThumb.obj.offset()[sDirection];
            var sCssSize = sSize.toLowerCase();
            oScrollbar.obj.css(sCssSize, oTrack[options.axis]);
            oTrack.obj.css(sCssSize, oTrack[options.axis]);
            oThumb.obj.css(sCssSize, oThumb[options.axis]);
        };
        function setEvents() {
            if (oThumb.obj.length == 0)
                return;

            oThumb.obj.bind('mousedown', start);
            oThumb.obj[0].ontouchstart = function (oEvent) {
                oEvent.preventDefault();
                oThumb.obj.unbind('mousedown');
                start(oEvent.touches[0]);
                return false;
            };
            oTrack.obj.bind('mouseup', drag);
            if (options.scroll && this.addEventListener) {
                oWrapper[0].addEventListener('DOMMouseScroll', wheel, false);
                oWrapper[0].addEventListener('mousewheel', wheel, false);
            }
            else if (options.scroll) { oWrapper[0].onmousewheel = wheel; }

            oViewport.obj.bind('touchmove', twofingerscroll);
            oViewport.obj.bind('touchend', twofingerscrollend);
        };
        function twofingerscroll(e) {
            if (e.originalEvent.touches.length == 2) {
                e.preventDefault();

                var newY = e.originalEvent.touches[0].pageY;
                if (twoFingerLastY != null) {
                    iScroll -= newY - twoFingerLastY;
                    iScroll = Math.min((oContent[options.axis] - oViewport[options.axis]), Math.max(0, iScroll));
                    oThumb.obj.css(sDirection, iScroll / oScrollbar.ratio);
                    oContent.obj.css(sDirection, -iScroll);
                }
                twoFingerLastY = newY;
            }
            else {
                twoFingerLastY = null;
            }
        }
        function twofingerscrollend(e) {
            twoFingerLastY = null;
        }

        function start(oEvent) {
            iMouse.start = sAxis ? oEvent.pageX : oEvent.pageY;
            var oThumbDir = parseInt(oThumb.obj.css(sDirection));
            iPosition.start = oThumbDir == 'auto' ? 0 : oThumbDir;
            $(document).bind('mousemove', drag);
            document.ontouchmove = function (oEvent) {
                $(document).unbind('mousemove');
                drag(oEvent.touches[0]);
            };
            $(document).bind('mouseup', end);
            oThumb.obj.bind('mouseup', end);
            oThumb.obj[0].ontouchend = document.ontouchend = function (oEvent) {
                $(document).unbind('mouseup');
                oThumb.obj.unbind('mouseup');
                end(oEvent.touches[0]);
            };
            return false;
        };

        function wheel(oEvent) {
            if (!(oContent.ratio >= 1)) {
                oEvent = $.event.fix(oEvent || window.event);
                var iDelta = oEvent.wheelDelta ? oEvent.wheelDelta / 120 : -oEvent.detail / 3;
                iScroll -= iDelta * options.wheel;
                iScroll = Math.min((oContent[options.axis] - oViewport[options.axis]), Math.max(0, iScroll));
                oThumb.obj.css(sDirection, iScroll / oScrollbar.ratio);
                oContent.obj.css(sDirection, -iScroll);
                oEvent.preventDefault();
            };
        };
        function end(oEvent) {
            $(document).unbind('mousemove', drag);
            $(document).unbind('mouseup', end);
            oThumb.obj.unbind('mouseup', end);
            document.ontouchmove = oThumb.obj[0].ontouchend = document.ontouchend = null;
            return false;
        };
        function drag(oEvent) {
            if (!(oContent.ratio >= 1)) {
                iPosition.now = Math.min((oTrack[options.axis] - oThumb[options.axis]), Math.max(0, (iPosition.start + ((sAxis ? oEvent.pageX : oEvent.pageY) - iMouse.start))));
                iScroll = iPosition.now * oScrollbar.ratio;
				var delta = iPosition.now - parseInt(oThumb.obj.css(sDirection));
				if(Math.abs(delta) > 1){ //reduce number of changes for performance
					oContent.obj.css(sDirection, -1*iScroll);
					oThumb.obj.css(sDirection, iPosition.now);
					if($.browser.msie){
						oWrapper.hide(0).show(0); //force IE8 refresh
					}
				}
            }
            return false;
        };

        return initialize();
    };
})(jQuery);