/*!
 * iscroll v4.2.5 ~ copyright (c) 2012 matteo spinelli, http://cubiq.org
 * released under mit license, http://cubiq.org/license
 */
(function(window, doc){
var m = math,
	dummystyle = doc.createelement('div').style,
	vendor = (function () {
		var vendors = 't,webkitt,mozt,mst,ot'.split(','),
			t,
			i = 0,
			l = vendors.length;

		for ( ; i < l; i++ ) {
			t = vendors[i] + 'ransform';
			if ( t in dummystyle ) {
				return vendors[i].substr(0, vendors[i].length - 1);
			}
		}

		return false;
	})(),
	cssvendor = vendor ? '-' + vendor.tolowercase() + '-' : '',

	// style properties
	transform = prefixstyle('transform'),
	transitionproperty = prefixstyle('transitionproperty'),
	transitionduration = prefixstyle('transitionduration'),
	transformorigin = prefixstyle('transformorigin'),
	transitiontimingfunction = prefixstyle('transitiontimingfunction'),
	transitiondelay = prefixstyle('transitiondelay'),

    // browser capabilities
	isandroid = (/android/gi).test(navigator.appversion),
	isidevice = (/iphone|ipad/gi).test(navigator.appversion),
	istouchpad = (/hp-tablet/gi).test(navigator.appversion),

    has3d = prefixstyle('perspective') in dummystyle,
    hastouch = 'ontouchstart' in window && !istouchpad,
    hastransform = vendor !== false,
    hastransitionend = prefixstyle('transition') in dummystyle,

	resize_ev = 'onorientationchange' in window ? 'orientationchange' : 'resize',
	start_ev = hastouch ? 'touchstart' : 'mousedown',
	move_ev = hastouch ? 'touchmove' : 'mousemove',
	end_ev = hastouch ? 'touchend' : 'mouseup',
	cancel_ev = hastouch ? 'touchcancel' : 'mouseup',
	trnend_ev = (function () {
		if ( vendor === false ) return false;

		var transitionend = {
				''			: 'transitionend',
				'webkit'	: 'webkittransitionend',
				'moz'		: 'transitionend',
				'o'			: 'otransitionend',
				'ms'		: 'mstransitionend'
			};

		return transitionend[vendor];
	})(),

	nextframe = (function() {
		return window.requestanimationframe ||
			window.webkitrequestanimationframe ||
			window.mozrequestanimationframe ||
			window.orequestanimationframe ||
			window.msrequestanimationframe ||
			function(callback) { return settimeout(callback, 1); };
	})(),
	cancelframe = (function () {
		return window.cancelrequestanimationframe ||
			window.webkitcancelanimationframe ||
			window.webkitcancelrequestanimationframe ||
			window.mozcancelrequestanimationframe ||
			window.ocancelrequestanimationframe ||
			window.mscancelrequestanimationframe ||
			cleartimeout;
	})(),

	// helpers
	translatez = has3d ? ' translatez(0)' : '',

	// constructor
	iscroll = function (el, options) {
		var that = this,
			i;

		that.wrapper = typeof el == 'object' ? el : doc.getelementbyid(el);
		that.wrapper.style.overflow = 'hidden';
		that.scroller = that.wrapper.children[0];

		// default options
		that.options = {
			hscroll: true,
			vscroll: true,
			x: 0,
			y: 0,
			bounce: true,
			bouncelock: false,
			momentum: true,
			lockdirection: true,
			usetransform: true,
			usetransition: false,
			topoffset: 0,
			checkdomchanges: false,		// experimental
			handleclick: true,

			// scrollbar
			hscrollbar: true,
			vscrollbar: true,
			fixedscrollbar: isandroid,
			hidescrollbar: isidevice,
			fadescrollbar: isidevice && has3d,
			scrollbarclass: '',

			// zoom
			zoom: false,
			zoommin: 1,
			zoommax: 4,
			doubletapzoom: 2,
			wheelaction: 'scroll',

			// snap
			snap: false,
			snapthreshold: 1,

			// events
			onrefresh: null,
			onbeforescrollstart: function (e) { e.preventdefault(); },
			onscrollstart: null,
			onbeforescrollmove: null,
			onscrollmove: null,
			onbeforescrollend: null,
			onscrollend: null,
			ontouchend: null,
			ondestroy: null,
			onzoomstart: null,
			onzoom: null,
			onzoomend: null
		};

		// user defined options
		for (i in options) that.options[i] = options[i];
		
		// set starting position
		that.x = that.options.x;
		that.y = that.options.y;

		// normalize options
		that.options.usetransform = hastransform && that.options.usetransform;
		that.options.hscrollbar = that.options.hscroll && that.options.hscrollbar;
		that.options.vscrollbar = that.options.vscroll && that.options.vscrollbar;
		that.options.zoom = that.options.usetransform && that.options.zoom;
		that.options.usetransition = hastransitionend && that.options.usetransition;

		// helpers fix android bug!
		// translate3d and scale doesn't work together!
		// ignoring 3d only when you set that.options.zoom
		if ( that.options.zoom && isandroid ){
			translatez = '';
		}
		
		// set some default styles
		that.scroller.style[transitionproperty] = that.options.usetransform ? cssvendor + 'transform' : 'top left';
		that.scroller.style[transitionduration] = '0';
		that.scroller.style[transformorigin] = '0 0';
		if (that.options.usetransition) that.scroller.style[transitiontimingfunction] = 'cubic-bezier(0.33,0.66,0.66,1)';
		
		if (that.options.usetransform) that.scroller.style[transform] = 'translate(' + that.x + 'px,' + that.y + 'px)' + translatez;
		else that.scroller.style.csstext += ';position:absolute;top:' + that.y + 'px;left:' + that.x + 'px';

		if (that.options.usetransition) that.options.fixedscrollbar = true;

		that.refresh();

		that._bind(resize_ev, window);
		that._bind(start_ev);
		if (!hastouch) {
			if (that.options.wheelaction != 'none') {
				that._bind('dommousescroll');
				that._bind('mousewheel');
			}
		}

		if (that.options.checkdomchanges) that.checkdomtime = setinterval(function () {
			that._checkdomchanges();
		}, 500);
	};

// prototype
iscroll.prototype = {
	enabled: true,
	x: 0,
	y: 0,
	steps: [],
	scale: 1,
	currpagex: 0, currpagey: 0,
	pagesx: [], pagesy: [],
	anitime: null,
	wheelzoomcount: 0,
	
	handleevent: function (e) {
		var that = this;
		switch(e.type) {
			case start_ev:
				if (!hastouch && e.button !== 0) return;
				that._start(e);
				break;
			case move_ev: that._move(e); break;
			case end_ev:
			case cancel_ev: that._end(e); break;
			case resize_ev: that._resize(); break;
			case 'dommousescroll': case 'mousewheel': that._wheel(e); break;
			case trnend_ev: that._transitionend(e); break;
		}
	},
	
	_checkdomchanges: function () {
		if (this.moved || this.zoomed || this.animating ||
			(this.scrollerw == this.scroller.offsetwidth * this.scale && this.scrollerh == this.scroller.offsetheight * this.scale)) return;

		this.refresh();
	},
	
	_scrollbar: function (dir) {
		var that = this,
			bar;

		if (!that[dir + 'scrollbar']) {
			if (that[dir + 'scrollbarwrapper']) {
				if (hastransform) that[dir + 'scrollbarindicator'].style[transform] = '';
				that[dir + 'scrollbarwrapper'].parentnode.removechild(that[dir + 'scrollbarwrapper']);
				that[dir + 'scrollbarwrapper'] = null;
				that[dir + 'scrollbarindicator'] = null;
			}

			return;
		}

		if (!that[dir + 'scrollbarwrapper']) {
			// create the scrollbar wrapper
			bar = doc.createelement('div');

			if (that.options.scrollbarclass) bar.classname = that.options.scrollbarclass + dir.touppercase();
			else bar.style.csstext = 'position:absolute;z-index:100;' + (dir == 'h' ? 'height:7px;bottom:1px;left:2px;right:' + (that.vscrollbar ? '7' : '2') + 'px' : 'width:7px;bottom:' + (that.hscrollbar ? '7' : '2') + 'px;top:2px;right:1px');

			bar.style.csstext += ';pointer-events:none;' + cssvendor + 'transition-property:opacity;' + cssvendor + 'transition-duration:' + (that.options.fadescrollbar ? '350ms' : '0') + ';overflow:hidden;opacity:' + (that.options.hidescrollbar ? '0' : '1');

			that.wrapper.appendchild(bar);
			that[dir + 'scrollbarwrapper'] = bar;

			// create the scrollbar indicator
			bar = doc.createelement('div');
			if (!that.options.scrollbarclass) {
				bar.style.csstext = 'position:absolute;z-index:100;background:rgba(0,0,0,0.5);border:1px solid rgba(255,255,255,0.9);' + cssvendor + 'background-clip:padding-box;' + cssvendor + 'box-sizing:border-box;' + (dir == 'h' ? 'height:100%' : 'width:100%') + ';' + cssvendor + 'border-radius:3px;border-radius:3px';
			}
			bar.style.csstext += ';pointer-events:none;' + cssvendor + 'transition-property:' + cssvendor + 'transform;' + cssvendor + 'transition-timing-function:cubic-bezier(0.33,0.66,0.66,1);' + cssvendor + 'transition-duration:0;' + cssvendor + 'transform: translate(0,0)' + translatez;
			if (that.options.usetransition) bar.style.csstext += ';' + cssvendor + 'transition-timing-function:cubic-bezier(0.33,0.66,0.66,1)';

			that[dir + 'scrollbarwrapper'].appendchild(bar);
			that[dir + 'scrollbarindicator'] = bar;
		}

		if (dir == 'h') {
			that.hscrollbarsize = that.hscrollbarwrapper.clientwidth;
			that.hscrollbarindicatorsize = m.max(m.round(that.hscrollbarsize * that.hscrollbarsize / that.scrollerw), 8);
			that.hscrollbarindicator.style.width = that.hscrollbarindicatorsize + 'px';
			that.hscrollbarmaxscroll = that.hscrollbarsize - that.hscrollbarindicatorsize;
			that.hscrollbarprop = that.hscrollbarmaxscroll / that.maxscrollx;
		} else {
			that.vscrollbarsize = that.vscrollbarwrapper.clientheight;
			that.vscrollbarindicatorsize = m.max(m.round(that.vscrollbarsize * that.vscrollbarsize / that.scrollerh), 8);
			that.vscrollbarindicator.style.height = that.vscrollbarindicatorsize + 'px';
			that.vscrollbarmaxscroll = that.vscrollbarsize - that.vscrollbarindicatorsize;
			that.vscrollbarprop = that.vscrollbarmaxscroll / that.maxscrolly;
		}

		// reset position
		that._scrollbarpos(dir, true);
	},
	
	_resize: function () {
		var that = this;
		settimeout(function () { that.refresh(); }, isandroid ? 200 : 0);
	},
	
	_pos: function (x, y) {
		if (this.zoomed) return;

		x = this.hscroll ? x : 0;
		y = this.vscroll ? y : 0;

		if (this.options.usetransform) {
			this.scroller.style[transform] = 'translate(' + x + 'px,' + y + 'px) scale(' + this.scale + ')' + translatez;
		} else {
			x = m.round(x);
			y = m.round(y);
			this.scroller.style.left = x + 'px';
			this.scroller.style.top = y + 'px';
		}

		this.x = x;
		this.y = y;

		this._scrollbarpos('h');
		this._scrollbarpos('v');
	},

	_scrollbarpos: function (dir, hidden) {
		var that = this,
			pos = dir == 'h' ? that.x : that.y,
			size;

		if (!that[dir + 'scrollbar']) return;

		pos = that[dir + 'scrollbarprop'] * pos;

		if (pos < 0) {
			if (!that.options.fixedscrollbar) {
				size = that[dir + 'scrollbarindicatorsize'] + m.round(pos * 3);
				if (size < 8) size = 8;
				that[dir + 'scrollbarindicator'].style[dir == 'h' ? 'width' : 'height'] = size + 'px';
			}
			pos = 0;
		} else if (pos > that[dir + 'scrollbarmaxscroll']) {
			if (!that.options.fixedscrollbar) {
				size = that[dir + 'scrollbarindicatorsize'] - m.round((pos - that[dir + 'scrollbarmaxscroll']) * 3);
				if (size < 8) size = 8;
				that[dir + 'scrollbarindicator'].style[dir == 'h' ? 'width' : 'height'] = size + 'px';
				pos = that[dir + 'scrollbarmaxscroll'] + (that[dir + 'scrollbarindicatorsize'] - size);
			} else {
				pos = that[dir + 'scrollbarmaxscroll'];
			}
		}

		that[dir + 'scrollbarwrapper'].style[transitiondelay] = '0';
		that[dir + 'scrollbarwrapper'].style.opacity = hidden && that.options.hidescrollbar ? '0' : '1';
		that[dir + 'scrollbarindicator'].style[transform] = 'translate(' + (dir == 'h' ? pos + 'px,0)' : '0,' + pos + 'px)') + translatez;
	},
	
	_start: function (e) {
		var that = this,
			point = hastouch ? e.touches[0] : e,
			matrix, x, y,
			c1, c2;

		if (!that.enabled) return;

		if (that.options.onbeforescrollstart) that.options.onbeforescrollstart.call(that, e);

		if (that.options.usetransition || that.options.zoom) that._transitiontime(0);

		that.moved = false;
		that.animating = false;
		that.zoomed = false;
		that.distx = 0;
		that.disty = 0;
		that.absdistx = 0;
		that.absdisty = 0;
		that.dirx = 0;
		that.diry = 0;

		// gesture start
		if (that.options.zoom && hastouch && e.touches.length > 1) {
			c1 = m.abs(e.touches[0].pagex-e.touches[1].pagex);
			c2 = m.abs(e.touches[0].pagey-e.touches[1].pagey);
			that.touchesdiststart = m.sqrt(c1 * c1 + c2 * c2);

			that.originx = m.abs(e.touches[0].pagex + e.touches[1].pagex - that.wrapperoffsetleft * 2) / 2 - that.x;
			that.originy = m.abs(e.touches[0].pagey + e.touches[1].pagey - that.wrapperoffsettop * 2) / 2 - that.y;

			if (that.options.onzoomstart) that.options.onzoomstart.call(that, e);
		}

		if (that.options.momentum) {
			if (that.options.usetransform) {
				// very lame general purpose alternative to cssmatrix
				matrix = getcomputedstyle(that.scroller, null)[transform].replace(/[^0-9\-.,]/g, '').split(',');
				x = +(matrix[12] || matrix[4]);
				y = +(matrix[13] || matrix[5]);
			} else {
				x = +getcomputedstyle(that.scroller, null).left.replace(/[^0-9-]/g, '');
				y = +getcomputedstyle(that.scroller, null).top.replace(/[^0-9-]/g, '');
			}
			
			if (x != that.x || y != that.y) {
				if (that.options.usetransition) that._unbind(trnend_ev);
				else cancelframe(that.anitime);
				that.steps = [];
				that._pos(x, y);
				if (that.options.onscrollend) that.options.onscrollend.call(that);
			}
		}

		that.absstartx = that.x;	// needed by snap threshold
		that.absstarty = that.y;

		that.startx = that.x;
		that.starty = that.y;
		that.pointx = point.pagex;
		that.pointy = point.pagey;

		that.starttime = e.timestamp || date.now();

		if (that.options.onscrollstart) that.options.onscrollstart.call(that, e);

		that._bind(move_ev, window);
		that._bind(end_ev, window);
		that._bind(cancel_ev, window);
	},
	
	_move: function (e) {
		var that = this,
			point = hastouch ? e.touches[0] : e,
			deltax = point.pagex - that.pointx,
			deltay = point.pagey - that.pointy,
			newx = that.x + deltax,
			newy = that.y + deltay,
			c1, c2, scale,
			timestamp = e.timestamp || date.now();

		if (that.options.onbeforescrollmove) that.options.onbeforescrollmove.call(that, e);

		// zoom
		if (that.options.zoom && hastouch && e.touches.length > 1) {
			c1 = m.abs(e.touches[0].pagex - e.touches[1].pagex);
			c2 = m.abs(e.touches[0].pagey - e.touches[1].pagey);
			that.touchesdist = m.sqrt(c1*c1+c2*c2);

			that.zoomed = true;

			scale = 1 / that.touchesdiststart * that.touchesdist * this.scale;

			if (scale < that.options.zoommin) scale = 0.5 * that.options.zoommin * math.pow(2.0, scale / that.options.zoommin);
			else if (scale > that.options.zoommax) scale = 2.0 * that.options.zoommax * math.pow(0.5, that.options.zoommax / scale);

			that.lastscale = scale / this.scale;

			newx = this.originx - this.originx * that.lastscale + this.x;
			newy = this.originy - this.originy * that.lastscale + this.y;

			this.scroller.style[transform] = 'translate(' + newx + 'px,' + newy + 'px) scale(' + scale + ')' + translatez;

			if (that.options.onzoom) that.options.onzoom.call(that, e);
			return;
		}

		that.pointx = point.pagex;
		that.pointy = point.pagey;

		// slow down if outside of the boundaries
		if (newx > 0 || newx < that.maxscrollx) {
			newx = that.options.bounce ? that.x + (deltax / 2) : newx >= 0 || that.maxscrollx >= 0 ? 0 : that.maxscrollx;
		}
		if (newy > that.minscrolly || newy < that.maxscrolly) {
			newy = that.options.bounce ? that.y + (deltay / 2) : newy >= that.minscrolly || that.maxscrolly >= 0 ? that.minscrolly : that.maxscrolly;
		}

		that.distx += deltax;
		that.disty += deltay;
		that.absdistx = m.abs(that.distx);
		that.absdisty = m.abs(that.disty);

		if (that.absdistx < 6 && that.absdisty < 6) {
			return;
		}

		// lock direction
		if (that.options.lockdirection) {
			if (that.absdistx > that.absdisty + 5) {
				newy = that.y;
				deltay = 0;
			} else if (that.absdisty > that.absdistx + 5) {
				newx = that.x;
				deltax = 0;
			}
		}

		that.moved = true;
		that._pos(newx, newy);
		that.dirx = deltax > 0 ? -1 : deltax < 0 ? 1 : 0;
		that.diry = deltay > 0 ? -1 : deltay < 0 ? 1 : 0;

		if (timestamp - that.starttime > 300) {
			that.starttime = timestamp;
			that.startx = that.x;
			that.starty = that.y;
		}
		
		if (that.options.onscrollmove) that.options.onscrollmove.call(that, e);
	},
	
	_end: function (e) {
		if (hastouch && e.touches.length !== 0) return;

		var that = this,
			point = hastouch ? e.changedtouches[0] : e,
			target, ev,
			momentumx = { dist:0, time:0 },
			momentumy = { dist:0, time:0 },
			duration = (e.timestamp || date.now()) - that.starttime,
			newposx = that.x,
			newposy = that.y,
			distx, disty,
			newduration,
			snap,
			scale;

		that._unbind(move_ev, window);
		that._unbind(end_ev, window);
		that._unbind(cancel_ev, window);

		if (that.options.onbeforescrollend) that.options.onbeforescrollend.call(that, e);

		if (that.zoomed) {
			scale = that.scale * that.lastscale;
			scale = math.max(that.options.zoommin, scale);
			scale = math.min(that.options.zoommax, scale);
			that.lastscale = scale / that.scale;
			that.scale = scale;

			that.x = that.originx - that.originx * that.lastscale + that.x;
			that.y = that.originy - that.originy * that.lastscale + that.y;
			
			that.scroller.style[transitionduration] = '200ms';
			that.scroller.style[transform] = 'translate(' + that.x + 'px,' + that.y + 'px) scale(' + that.scale + ')' + translatez;
			
			that.zoomed = false;
			that.refresh();

			if (that.options.onzoomend) that.options.onzoomend.call(that, e);
			return;
		}

		if (!that.moved) {
			if (hastouch) {
				if (that.doubletaptimer && that.options.zoom) {
					// double tapped
					cleartimeout(that.doubletaptimer);
					that.doubletaptimer = null;
					if (that.options.onzoomstart) that.options.onzoomstart.call(that, e);
					that.zoom(that.pointx, that.pointy, that.scale == 1 ? that.options.doubletapzoom : 1);
					if (that.options.onzoomend) {
						settimeout(function() {
							that.options.onzoomend.call(that, e);
						}, 200); // 200 is default zoom duration
					}
				} else if (this.options.handleclick) {
					that.doubletaptimer = settimeout(function () {
						that.doubletaptimer = null;

						// find the last touched element
						target = point.target;
						while (target.nodetype != 1) target = target.parentnode;

						if (target.tagname != 'select' && target.tagname != 'input' && target.tagname != 'textarea') {
							ev = doc.createevent('mouseevents');
							ev.initmouseevent('click', true, true, e.view, 1,
								point.screenx, point.screeny, point.clientx, point.clienty,
								e.ctrlkey, e.altkey, e.shiftkey, e.metakey,
								0, null);
							ev._fake = true;
							target.dispatchevent(ev);
						}
					}, that.options.zoom ? 250 : 0);
				}
			}

			that._resetpos(400);

			if (that.options.ontouchend) that.options.ontouchend.call(that, e);
			return;
		}

		if (duration < 300 && that.options.momentum) {
			momentumx = newposx ? that._momentum(newposx - that.startx, duration, -that.x, that.scrollerw - that.wrapperw + that.x, that.options.bounce ? that.wrapperw : 0) : momentumx;
			momentumy = newposy ? that._momentum(newposy - that.starty, duration, -that.y, (that.maxscrolly < 0 ? that.scrollerh - that.wrapperh + that.y - that.minscrolly : 0), that.options.bounce ? that.wrapperh : 0) : momentumy;

			newposx = that.x + momentumx.dist;
			newposy = that.y + momentumy.dist;

			if ((that.x > 0 && newposx > 0) || (that.x < that.maxscrollx && newposx < that.maxscrollx)) momentumx = { dist:0, time:0 };
			if ((that.y > that.minscrolly && newposy > that.minscrolly) || (that.y < that.maxscrolly && newposy < that.maxscrolly)) momentumy = { dist:0, time:0 };
		}

		if (momentumx.dist || momentumy.dist) {
			newduration = m.max(m.max(momentumx.time, momentumy.time), 10);

			// do we need to snap?
			if (that.options.snap) {
				distx = newposx - that.absstartx;
				disty = newposy - that.absstarty;
				if (m.abs(distx) < that.options.snapthreshold && m.abs(disty) < that.options.snapthreshold) { that.scrollto(that.absstartx, that.absstarty, 200); }
				else {
					snap = that._snap(newposx, newposy);
					newposx = snap.x;
					newposy = snap.y;
					newduration = m.max(snap.time, newduration);
				}
			}

			that.scrollto(m.round(newposx), m.round(newposy), newduration);

			if (that.options.ontouchend) that.options.ontouchend.call(that, e);
			return;
		}

		// do we need to snap?
		if (that.options.snap) {
			distx = newposx - that.absstartx;
			disty = newposy - that.absstarty;
			if (m.abs(distx) < that.options.snapthreshold && m.abs(disty) < that.options.snapthreshold) that.scrollto(that.absstartx, that.absstarty, 200);
			else {
				snap = that._snap(that.x, that.y);
				if (snap.x != that.x || snap.y != that.y) that.scrollto(snap.x, snap.y, snap.time);
			}

			if (that.options.ontouchend) that.options.ontouchend.call(that, e);
			return;
		}

		that._resetpos(200);
		if (that.options.ontouchend) that.options.ontouchend.call(that, e);
	},
	
	_resetpos: function (time) {
		var that = this,
			resetx = that.x >= 0 ? 0 : that.x < that.maxscrollx ? that.maxscrollx : that.x,
			resety = that.y >= that.minscrolly || that.maxscrolly > 0 ? that.minscrolly : that.y < that.maxscrolly ? that.maxscrolly : that.y;

		if (resetx == that.x && resety == that.y) {
			if (that.moved) {
				that.moved = false;
				if (that.options.onscrollend) that.options.onscrollend.call(that);		// execute custom code on scroll end
			}

			if (that.hscrollbar && that.options.hidescrollbar) {
				if (vendor == 'webkit') that.hscrollbarwrapper.style[transitiondelay] = '300ms';
				that.hscrollbarwrapper.style.opacity = '0';
			}
			if (that.vscrollbar && that.options.hidescrollbar) {
				if (vendor == 'webkit') that.vscrollbarwrapper.style[transitiondelay] = '300ms';
				that.vscrollbarwrapper.style.opacity = '0';
			}

			return;
		}

		that.scrollto(resetx, resety, time || 0);
	},

	_wheel: function (e) {
		var that = this,
			wheeldeltax, wheeldeltay,
			deltax, deltay,
			deltascale;

		if ('wheeldeltax' in e) {
			wheeldeltax = e.wheeldeltax / 12;
			wheeldeltay = e.wheeldeltay / 12;
		} else if('wheeldelta' in e) {
			wheeldeltax = wheeldeltay = e.wheeldelta / 12;
		} else if ('detail' in e) {
			wheeldeltax = wheeldeltay = -e.detail * 3;
		} else {
			return;
		}
		
		if (that.options.wheelaction == 'zoom') {
			deltascale = that.scale * math.pow(2, 1/3 * (wheeldeltay ? wheeldeltay / math.abs(wheeldeltay) : 0));
			if (deltascale < that.options.zoommin) deltascale = that.options.zoommin;
			if (deltascale > that.options.zoommax) deltascale = that.options.zoommax;
			
			if (deltascale != that.scale) {
				if (!that.wheelzoomcount && that.options.onzoomstart) that.options.onzoomstart.call(that, e);
				that.wheelzoomcount++;
				
				that.zoom(e.pagex, e.pagey, deltascale, 400);
				
				settimeout(function() {
					that.wheelzoomcount--;
					if (!that.wheelzoomcount && that.options.onzoomend) that.options.onzoomend.call(that, e);
				}, 400);
			}
			
			return;
		}
		
		deltax = that.x + wheeldeltax;
		deltay = that.y + wheeldeltay;

		if (deltax > 0) deltax = 0;
		else if (deltax < that.maxscrollx) deltax = that.maxscrollx;

		if (deltay > that.minscrolly) deltay = that.minscrolly;
		else if (deltay < that.maxscrolly) deltay = that.maxscrolly;
    
		if (that.maxscrolly < 0) {
			that.scrollto(deltax, deltay, 0);
		}
	},
	
	_transitionend: function (e) {
		var that = this;

		if (e.target != that.scroller) return;

		that._unbind(trnend_ev);
		
		that._startani();
	},


	/**
	*
	* utilities
	*
	*/
	_startani: function () {
		var that = this,
			startx = that.x, starty = that.y,
			starttime = date.now(),
			step, easeout,
			animate;

		if (that.animating) return;
		
		if (!that.steps.length) {
			that._resetpos(400);
			return;
		}
		
		step = that.steps.shift();
		
		if (step.x == startx && step.y == starty) step.time = 0;

		that.animating = true;
		that.moved = true;
		
		if (that.options.usetransition) {
			that._transitiontime(step.time);
			that._pos(step.x, step.y);
			that.animating = false;
			if (step.time) that._bind(trnend_ev);
			else that._resetpos(0);
			return;
		}

		animate = function () {
			var now = date.now(),
				newx, newy;

			if (now >= starttime + step.time) {
				that._pos(step.x, step.y);
				that.animating = false;
				if (that.options.onanimationend) that.options.onanimationend.call(that);			// execute custom code on animation end
				that._startani();
				return;
			}

			now = (now - starttime) / step.time - 1;
			easeout = m.sqrt(1 - now * now);
			newx = (step.x - startx) * easeout + startx;
			newy = (step.y - starty) * easeout + starty;
			that._pos(newx, newy);
			if (that.animating) that.anitime = nextframe(animate);
		};

		animate();
	},

	_transitiontime: function (time) {
		time += 'ms';
		this.scroller.style[transitionduration] = time;
		if (this.hscrollbar) this.hscrollbarindicator.style[transitionduration] = time;
		if (this.vscrollbar) this.vscrollbarindicator.style[transitionduration] = time;
	},

	_momentum: function (dist, time, maxdistupper, maxdistlower, size) {
		var deceleration = 0.0006,
			speed = m.abs(dist) / time,
			newdist = (speed * speed) / (2 * deceleration),
			newtime = 0, outsidedist = 0;

		// proportinally reduce speed if we are outside of the boundaries
		if (dist > 0 && newdist > maxdistupper) {
			outsidedist = size / (6 / (newdist / speed * deceleration));
			maxdistupper = maxdistupper + outsidedist;
			speed = speed * maxdistupper / newdist;
			newdist = maxdistupper;
		} else if (dist < 0 && newdist > maxdistlower) {
			outsidedist = size / (6 / (newdist / speed * deceleration));
			maxdistlower = maxdistlower + outsidedist;
			speed = speed * maxdistlower / newdist;
			newdist = maxdistlower;
		}

		newdist = newdist * (dist < 0 ? -1 : 1);
		newtime = speed / deceleration;

		return { dist: newdist, time: m.round(newtime) };
	},

	_offset: function (el) {
		var left = -el.offsetleft,
			top = -el.offsettop;
			
		while (el = el.offsetparent) {
			left -= el.offsetleft;
			top -= el.offsettop;
		}
		
		if (el != this.wrapper) {
			left *= this.scale;
			top *= this.scale;
		}

		return { left: left, top: top };
	},

	_snap: function (x, y) {
		var that = this,
			i, l,
			page, time,
			sizex, sizey;

		// check page x
		page = that.pagesx.length - 1;
		for (i=0, l=that.pagesx.length; i<l; i++) {
			if (x >= that.pagesx[i]) {
				page = i;
				break;
			}
		}
		if (page == that.currpagex && page > 0 && that.dirx < 0) page--;
		x = that.pagesx[page];
		sizex = m.abs(x - that.pagesx[that.currpagex]);
		sizex = sizex ? m.abs(that.x - x) / sizex * 500 : 0;
		that.currpagex = page;

		// check page y
		page = that.pagesy.length-1;
		for (i=0; i<page; i++) {
			if (y >= that.pagesy[i]) {
				page = i;
				break;
			}
		}
		if (page == that.currpagey && page > 0 && that.diry < 0) page--;
		y = that.pagesy[page];
		sizey = m.abs(y - that.pagesy[that.currpagey]);
		sizey = sizey ? m.abs(that.y - y) / sizey * 500 : 0;
		that.currpagey = page;

		// snap with constant speed (proportional duration)
		time = m.round(m.max(sizex, sizey)) || 200;

		return { x: x, y: y, time: time };
	},

	_bind: function (type, el, bubble) {
		(el || this.scroller).addeventlistener(type, this, !!bubble);
	},

	_unbind: function (type, el, bubble) {
		(el || this.scroller).removeeventlistener(type, this, !!bubble);
	},


	/**
	*
	* public methods
	*
	*/
	destroy: function () {
		var that = this;

		that.scroller.style[transform] = '';

		// remove the scrollbars
		that.hscrollbar = false;
		that.vscrollbar = false;
		that._scrollbar('h');
		that._scrollbar('v');

		// remove the event listeners
		that._unbind(resize_ev, window);
		that._unbind(start_ev);
		that._unbind(move_ev, window);
		that._unbind(end_ev, window);
		that._unbind(cancel_ev, window);
		
		if (!that.options.hastouch) {
			that._unbind('dommousescroll');
			that._unbind('mousewheel');
		}
		
		if (that.options.usetransition) that._unbind(trnend_ev);
		
		if (that.options.checkdomchanges) clearinterval(that.checkdomtime);
		
		if (that.options.ondestroy) that.options.ondestroy.call(that);
	},

	refresh: function () {
		var that = this,
			offset,
			i, l,
			els,
			pos = 0,
			page = 0;

		if (that.scale < that.options.zoommin) that.scale = that.options.zoommin;
		that.wrapperw = that.wrapper.clientwidth || 1;
		that.wrapperh = that.wrapper.clientheight || 1;

		that.minscrolly = -that.options.topoffset || 0;
		that.scrollerw = m.round(that.scroller.offsetwidth * that.scale);
		that.scrollerh = m.round((that.scroller.offsetheight + that.minscrolly) * that.scale);
		that.maxscrollx = that.wrapperw - that.scrollerw;
		that.maxscrolly = that.wrapperh - that.scrollerh + that.minscrolly;
		that.dirx = 0;
		that.diry = 0;

		if (that.options.onrefresh) that.options.onrefresh.call(that);

		that.hscroll = that.options.hscroll && that.maxscrollx < 0;
		that.vscroll = that.options.vscroll && (!that.options.bouncelock && !that.hscroll || that.scrollerh > that.wrapperh);

		that.hscrollbar = that.hscroll && that.options.hscrollbar;
		that.vscrollbar = that.vscroll && that.options.vscrollbar && that.scrollerh > that.wrapperh;

		offset = that._offset(that.wrapper);
		that.wrapperoffsetleft = -offset.left;
		that.wrapperoffsettop = -offset.top;

		// prepare snap
		if (typeof that.options.snap == 'string') {
			that.pagesx = [];
			that.pagesy = [];
			els = that.scroller.queryselectorall(that.options.snap);
			for (i=0, l=els.length; i<l; i++) {
				pos = that._offset(els[i]);
				pos.left += that.wrapperoffsetleft;
				pos.top += that.wrapperoffsettop;
				that.pagesx[i] = pos.left < that.maxscrollx ? that.maxscrollx : pos.left * that.scale;
				that.pagesy[i] = pos.top < that.maxscrolly ? that.maxscrolly : pos.top * that.scale;
			}
		} else if (that.options.snap) {
			that.pagesx = [];
			while (pos >= that.maxscrollx) {
				that.pagesx[page] = pos;
				pos = pos - that.wrapperw;
				page++;
			}
			if (that.maxscrollx%that.wrapperw) that.pagesx[that.pagesx.length] = that.maxscrollx - that.pagesx[that.pagesx.length-1] + that.pagesx[that.pagesx.length-1];

			pos = 0;
			page = 0;
			that.pagesy = [];
			while (pos >= that.maxscrolly) {
				that.pagesy[page] = pos;
				pos = pos - that.wrapperh;
				page++;
			}
			if (that.maxscrolly%that.wrapperh) that.pagesy[that.pagesy.length] = that.maxscrolly - that.pagesy[that.pagesy.length-1] + that.pagesy[that.pagesy.length-1];
		}

		// prepare the scrollbars
		that._scrollbar('h');
		that._scrollbar('v');

		if (!that.zoomed) {
			that.scroller.style[transitionduration] = '0';
			that._resetpos(400);
		}
	},

	scrollto: function (x, y, time, relative) {
		var that = this,
			step = x,
			i, l;

		that.stop();

		if (!step.length) step = [{ x: x, y: y, time: time, relative: relative }];
		
		for (i=0, l=step.length; i<l; i++) {
			if (step[i].relative) { step[i].x = that.x - step[i].x; step[i].y = that.y - step[i].y; }
			that.steps.push({ x: step[i].x, y: step[i].y, time: step[i].time || 0 });
		}

		that._startani();
	},

	scrolltoelement: function (el, time) {
		var that = this, pos;
		el = el.nodetype ? el : that.scroller.queryselector(el);
		if (!el) return;

		pos = that._offset(el);
		pos.left += that.wrapperoffsetleft;
		pos.top += that.wrapperoffsettop;

		pos.left = pos.left > 0 ? 0 : pos.left < that.maxscrollx ? that.maxscrollx : pos.left;
		pos.top = pos.top > that.minscrolly ? that.minscrolly : pos.top < that.maxscrolly ? that.maxscrolly : pos.top;
		time = time === undefined ? m.max(m.abs(pos.left)*2, m.abs(pos.top)*2) : time;

		that.scrollto(pos.left, pos.top, time);
	},

	scrolltopage: function (pagex, pagey, time) {
		var that = this, x, y;
		
		time = time === undefined ? 400 : time;

		if (that.options.onscrollstart) that.options.onscrollstart.call(that);

		if (that.options.snap) {
			pagex = pagex == 'next' ? that.currpagex+1 : pagex == 'prev' ? that.currpagex-1 : pagex;
			pagey = pagey == 'next' ? that.currpagey+1 : pagey == 'prev' ? that.currpagey-1 : pagey;

			pagex = pagex < 0 ? 0 : pagex > that.pagesx.length-1 ? that.pagesx.length-1 : pagex;
			pagey = pagey < 0 ? 0 : pagey > that.pagesy.length-1 ? that.pagesy.length-1 : pagey;

			that.currpagex = pagex;
			that.currpagey = pagey;
			x = that.pagesx[pagex];
			y = that.pagesy[pagey];
		} else {
			x = -that.wrapperw * pagex;
			y = -that.wrapperh * pagey;
			if (x < that.maxscrollx) x = that.maxscrollx;
			if (y < that.maxscrolly) y = that.maxscrolly;
		}

		that.scrollto(x, y, time);
	},

	disable: function () {
		this.stop();
		this._resetpos(0);
		this.enabled = false;

		// if disabled after touchstart we make sure that there are no left over events
		this._unbind(move_ev, window);
		this._unbind(end_ev, window);
		this._unbind(cancel_ev, window);
	},
	
	enable: function () {
		this.enabled = true;
	},
	
	stop: function () {
		if (this.options.usetransition) this._unbind(trnend_ev);
		else cancelframe(this.anitime);
		this.steps = [];
		this.moved = false;
		this.animating = false;
	},
	
	zoom: function (x, y, scale, time) {
		var that = this,
			relscale = scale / that.scale;

		if (!that.options.usetransform) return;

		that.zoomed = true;
		time = time === undefined ? 200 : time;
		x = x - that.wrapperoffsetleft - that.x;
		y = y - that.wrapperoffsettop - that.y;
		that.x = x - x * relscale + that.x;
		that.y = y - y * relscale + that.y;

		that.scale = scale;
		that.refresh();

		that.x = that.x > 0 ? 0 : that.x < that.maxscrollx ? that.maxscrollx : that.x;
		that.y = that.y > that.minscrolly ? that.minscrolly : that.y < that.maxscrolly ? that.maxscrolly : that.y;

		that.scroller.style[transitionduration] = time + 'ms';
		that.scroller.style[transform] = 'translate(' + that.x + 'px,' + that.y + 'px) scale(' + scale + ')' + translatez;
		that.zoomed = false;
	},
	
	isready: function () {
		return !this.moved && !this.zoomed && !this.animating;
	}
};

function prefixstyle (style) {
	if ( vendor === '' ) return style;

	style = style.charat(0).touppercase() + style.substr(1);
	return vendor + style;
}

dummystyle = null;	// for the sake of it

if (typeof exports !== 'undefined') exports.iscroll = iscroll;
else window.iscroll = iscroll;

})(window, document);