/*!
 * jScrollPane - v2.0.0beta10 - 2011-04-04
 * http://jscrollpane.kelvinluck.com/
 *
 * Copyright (c) 2010 Kelvin Luck
 * Dual licensed under the MIT and GPL licenses.
 */

/* Script: jScrollPane - cross browser customisable scrollbars

 *Version: 2.0.0beta10, Last updated: 2011-04-04*

 Project Home - http://jscrollpane.kelvinluck.com/
 GitHub       - http://github.com/vitch/jScrollPane
 Source       - http://github.com/vitch/jScrollPane/raw/master/script/jquery.jscrollpane.js
 (Minified)   - http://github.com/vitch/jScrollPane/raw/master/script/jquery.jscrollpane.min.js

 About: License

 Copyright (c) 2011 Kelvin Luck
 Dual licensed under the MIT or GPL Version 2 licenses.
 http://jscrollpane.kelvinluck.com/MIT-LICENSE.txt
 http://jscrollpane.kelvinluck.com/GPL-LICENSE.txt

 About: Examples

 All examples and demos are available through the jScrollPane example site at:
 http://jscrollpane.kelvinluck.com/

 About: Support and Testing

 This plugin is tested on the browsers below and has been found to work reliably on them. If you run
 into a problem on one of the supported browsers then please visit the support section on the jScrollPane
 website (http://jscrollpane.kelvinluck.com/) for more information on getting support. You are also
 welcome to fork the project on GitHub if you can contribute a fix for a given issue. 

 jQuery Versions - tested in 1.4.2+ - reported to work in 1.3.x
 Browsers Tested - Firefox 3.6.8, Safari 5, Opera 10.6, Chrome 5.0, IE 6, 7, 8

 About: Release History

 2.0.0beta10 - (in progress)
 2.0.0beta9 - (2011-01-31) new API methods, bug fixes and correct keyboard support for FF/OSX
 2.0.0beta8 - (2011-01-29) touchscreen support, improved keyboard support
 2.0.0beta7 - (2011-01-23) scroll speed consistent (thanks Aivo Paas)
 2.0.0beta6 - (2010-12-07) scrollToElement horizontal support
 2.0.0beta5 - (2010-10-18) jQuery 1.4.3 support, various bug fixes
 2.0.0beta4 - (2010-09-17) clickOnTrack support, bug fixes
 2.0.0beta3 - (2010-08-27) Horizontal mousewheel, mwheelIntent, keyboard support, bug fixes
 2.0.0beta2 - (2010-08-21) Bug fixes
 2.0.0beta1 - (2010-08-17) Rewrite to follow modern best practices and enable horizontal scrolling, initially hidden
							 elements and dynamically sized elements.
 1.x - (2006-12-31 - 2010-07-31) Initial version, hosted at googlecode, deprecated
*/

(function($,window,undefined){

	$.fn.jScrollPane = function(settings)
	{
		/* JScrollPane "class" - public methods are available through $('selector').data('jsp') */
		function JScrollPane(elem, s)
		{
			var settings, jsp = this, pane, paneWidth, paneHeight, container, contentWidth, contentHeight,
				percentInViewH, percentInViewV, isScrollableV, isScrollableH, verticalDrag, dragMaxY,
				verticalDragPosition, horizontalDrag, dragMaxX, horizontalDragPosition,
				verticalBar, verticalTrack, scrollbarWidth, verticalTrackHeight, verticalDragHeight, arrowUp, arrowDown,
				horizontalBar, horizontalTrack, horizontalTrackWidth, horizontalDragWidth, arrowLeft, arrowRight,
				reinitialiseInterval, originalPadding, originalPaddingTotalWidth, previousContentWidth,
				wasAtTop = true, wasAtLeft = true, wasAtBottom = false, wasAtRight = false,
				originalElement = elem.clone(false, false).empty(),
				mwEvent = $.fn.mwheelIntent ? 'mwheelIntent.jsp' : 'mousewheel.jsp';

			originalPadding = elem.css('paddingTop') + ' ' +
								elem.css('paddingRight') + ' ' +
								elem.css('paddingBottom') + ' ' +
								elem.css('paddingLeft');
			originalPaddingTotalWidth = (parseInt(elem.css('paddingLeft'), 10) || 0) +
										(parseInt(elem.css('paddingRight'), 10) || 0);

			function initialise(s)
			{

				var clonedElem, tempWrapper, /*firstChild, lastChild, */isMaintainingPositon, lastContentX, lastContentY,
						hasContainingSpaceChanged, originalScrollTop, originalScrollLeft,
						maintainAtBottom = false, maintainAtRight = false;

				settings = s;

				if (pane === undefined) {
					originalScrollTop = elem.scrollTop();
					originalScrollLeft = elem.scrollLeft();
					elem.css(
						{
							overflow: 'hidden',
							padding: 0
						}
					);
					/* TODO: Deal with where width/ height is 0 as it probably means the element is hidden and we should
					 come back to it later and check once it is unhidden... */
					paneWidth = elem.innerWidth() + originalPaddingTotalWidth;
					paneHeight = elem.innerHeight();

					elem.width(paneWidth);
					
					pane = $('<div class="jspPane" />').css('padding', originalPadding).append(elem.children());
					container = $('<div class="jspContainer" />')
						.css({
							'width': paneWidth + 'px',
							'height': paneHeight + 'px'
						}
					).append(pane).appendTo(elem);

					/*
					Move any margins from the first and last children up to the container so they can still
					collapse with neighbouring elements as they would before jScrollPane 
					firstChild = pane.find(':first-child');
					lastChild = pane.find(':last-child');
					elem.css(
						{
							'margin-top': firstChild.css('margin-top'),
							'margin-bottom': lastChild.css('margin-bottom')
						}
					);
					firstChild.css('margin-top', 0);
					lastChild.css('margin-bottom', 0);
					*/
				} else {
					elem.css('width', '');

					maintainAtBottom = settings.stickToBottom && isCloseToBottom();
					maintainAtRight  = settings.stickToRight  && isCloseToRight();

					hasContainingSpaceChanged = elem.innerWidth() + originalPaddingTotalWidth != paneWidth || elem.outerHeight() != paneHeight;

					if (hasContainingSpaceChanged) {
						paneWidth = elem.innerWidth() + originalPaddingTotalWidth;
						paneHeight = elem.innerHeight();
						container.css({
							width: paneWidth + 'px',
							height: paneHeight + 'px'
						});
					}

					/* If nothing changed since last check... */
					if (!hasContainingSpaceChanged && previousContentWidth == contentWidth && pane.outerHeight() == contentHeight) {
						elem.width(paneWidth);
						return;
					}
					previousContentWidth = contentWidth;
					
					pane.css('width', '');
					elem.width(paneWidth);

					container.find('>.jspVerticalBar,>.jspHorizontalBar').remove().end();
				}

				if (s.contentWidth) {
					contentWidth = s.contentWidth;
				} else {
					/* Unfortunately it isn't that easy to find out the width of the element as it will always report the
					 width as allowed by its container, regardless of overflow settings.
					 A cunning workaround is to clone the element, set its position to absolute and place it in a narrow
					 container. Now it will push outwards to its maxium real width... */
					clonedElem = pane.clone(false, false).css('position', 'absolute');
					tempWrapper = $('<div style="width:1px; position: relative;" />').append(clonedElem);
					$('body').append(tempWrapper);
					contentWidth = Math.max(pane.outerWidth(), clonedElem.outerWidth());
					tempWrapper.remove();
				}

				contentHeight = pane.outerHeight();
				percentInViewH = contentWidth / paneWidth;
				percentInViewV = contentHeight / paneHeight;
				isScrollableV = percentInViewV > 1;

				isScrollableH = percentInViewH > 1;

				/* console.log(paneWidth, paneHeight, contentWidth, contentHeight, percentInViewH, percentInViewV, isScrollableH, isScrollableV); */

				if (!(isScrollableH || isScrollableV)) {
					elem.removeClass('jspScrollable');
					pane.css({
						top: 0,
						width: container.width() - originalPaddingTotalWidth
					});
					removeMousewheel();
					removeFocusHandler();
					removeKeyboardNav();
					removeClickOnTrack();
					unhijackInternalLinks();
				} else {
					elem.addClass('jspScrollable');

					isMaintainingPositon = settings.maintainPosition && (verticalDragPosition || horizontalDragPosition);
					if (isMaintainingPositon) {
						lastContentX = contentPositionX();
						lastContentY = contentPositionY();
					}

					initialiseVerticalScroll();
					initialiseHorizontalScroll();
					resizeScrollbars();

					if (isMaintainingPositon) {
						scrollToX(maintainAtRight  ? (contentWidth  - paneWidth ) : lastContentX, false);
						scrollToY(maintainAtBottom ? (contentHeight - paneHeight) : lastContentY, false);
					}

					initFocusHandler();
					initMousewheel();
					initTouch();
					
					if (settings.enableKeyboardNavigation) {
						initKeyboardNav();
					}
					if (settings.clickOnTrack) {
						initClickOnTrack();
					}
					
					observeHash();
					if (settings.hijackInternalLinks) {
						hijackInternalLinks();
					}
				}

				if (settings.autoReinitialise && !reinitialiseInterval) {
					reinitialiseInterval = setInterval(
						function()
						{
							initialise(settings);
						},
						settings.autoReinitialiseDelay
					);
				} else if (!settings.autoReinitialise && reinitialiseInterval) {
					clearInterval(reinitialiseInterval);
				}

				originalScrollTop && elem.scrollTop(0) && scrollToY(originalScrollTop, false);
				originalScrollLeft && elem.scrollLeft(0) && scrollToX(originalScrollLeft, false);

				elem.trigger('jsp-initialised', [isScrollableH || isScrollableV]);
			}

			function initialiseVerticalScroll()
			{
				if (isScrollableV) {

					container.append(
						$('<div class="jspVerticalBar" />').append(
							$('<div class="jspCap jspCapTop" />'),
							$('<div class="jspTrack" />').append(
								$('<div class="jspDrag" />').append(
									$('<div class="jspDragTop" />'),
									$('<div class="jspDragBottom" />')
								)
							),
							$('<div class="jspCap jspCapBottom" />')
						)
					);

					verticalBar = container.find('>.jspVerticalBar');
					verticalTrack = verticalBar.find('>.jspTrack');
					verticalDrag = verticalTrack.find('>.jspDrag');

					if (settings.showArrows) {
						arrowUp = $('<a class="jspArrow jspArrowUp" />').bind(
							'mousedown.jsp', getArrowScroll(0, -1)
						).bind('click.jsp', nil);
						arrowDown = $('<a class="jspArrow jspArrowDown" />').bind(
							'mousedown.jsp', getArrowScroll(0, 1)
						).bind('click.jsp', nil);
						if (settings.arrowScrollOnHover) {
							arrowUp.bind('mouseover.jsp', getArrowScroll(0, -1, arrowUp));
							arrowDown.bind('mouseover.jsp', getArrowScroll(0, 1, arrowDown));
						}

						appendArrows(verticalTrack, settings.verticalArrowPositions, arrowUp, arrowDown);
					}

					verticalTrackHeight = paneHeight;
					container.find('>.jspVerticalBar>.jspCap:visible,>.jspVerticalBar>.jspArrow').each(
						function()
						{
							verticalTrackHeight -= $(this).outerHeight();
						}
					);


					verticalDrag.hover(
						function()
						{
							verticalDrag.addClass('jspHover');
						},
						function()
						{
							verticalDrag.removeClass('jspHover');
						}
					).bind(
						'mousedown.jsp',
						function(e)
						{
							/* Stop IE from allowing text selection */
							$('html').bind('dragstart.jsp selectstart.jsp', nil);

							verticalDrag.addClass('jspActive');

							var startY = e.pageY - verticalDrag.position().top;

							$('html').bind(
								'mousemove.jsp',
								function(e)
								{
									positionDragY(e.pageY - startY, false);
								}
							).bind('mouseup.jsp mouseleave.jsp', cancelDrag);
							return false;
						}
					);
					sizeVerticalScrollbar();
				}
			}

			function sizeVerticalScrollbar()
			{
				verticalTrack.height(verticalTrackHeight + 'px');
				verticalDragPosition = 0;
				scrollbarWidth = settings.verticalGutter + verticalTrack.outerWidth();

				/* Make the pane thinner to allow for the vertical scrollbar */
				pane.width(paneWidth - scrollbarWidth - originalPaddingTotalWidth);

				/* Add margin to the left of the pane if scrollbars are on that side (to position
				 the scrollbar on the left or right set it's left or right property in CSS) */
				try {
					if (verticalBar.position().left === 0) {
						pane.css('margin-left', scrollbarWidth + 'px');
					}
				} catch (err) {
				}
			}

			function initialiseHorizontalScroll()
			{
				if (isScrollableH) {

					container.append(
						$('<div class="jspHorizontalBar" />').append(
							$('<div class="jspCap jspCapLeft" />'),
							$('<div class="jspTrack" />').append(
								$('<div class="jspDrag" />').append(
									$('<div class="jspDragLeft" />'),
									$('<div class="jspDragRight" />')
								)
							),
							$('<div class="jspCap jspCapRight" />')
						)
					);

					horizontalBar = container.find('>.jspHorizontalBar');
					horizontalTrack = horizontalBar.find('>.jspTrack');
					horizontalDrag = horizontalTrack.find('>.jspDrag');

					if (settings.showArrows) {
						arrowLeft = $('<a class="jspArrow jspArrowLeft" />').bind(
							'mousedown.jsp', getArrowScroll(-1, 0)
						).bind('click.jsp', nil);
						arrowRight = $('<a class="jspArrow jspArrowRight" />').bind(
							'mousedown.jsp', getArrowScroll(1, 0)
						).bind('click.jsp', nil);
						if (settings.arrowScrollOnHover) {
							arrowLeft.bind('mouseover.jsp', getArrowScroll(-1, 0, arrowLeft));
							arrowRight.bind('mouseover.jsp', getArrowScroll(1, 0, arrowRight));
						}
						appendArrows(horizontalTrack, settings.horizontalArrowPositions, arrowLeft, arrowRight);
					}

					horizontalDrag.hover(
						function()
						{
							horizontalDrag.addClass('jspHover');
						},
						function()
						{
							horizontalDrag.removeClass('jspHover');
						}
					).bind(
						'mousedown.jsp',
						function(e)
						{
							/* Stop IE from allowing text selection */
							$('html').bind('dragstart.jsp selectstart.jsp', nil);

							horizontalDrag.addClass('jspActive');

							var startX = e.pageX - horizontalDrag.position().left;

							$('html').bind(
								'mousemove.jsp',
								function(e)
								{
									positionDragX(e.pageX - startX, false);
								}
							).bind('mouseup.jsp mouseleave.jsp', cancelDrag);
							return false;
						}
					);
					horizontalTrackWidth = container.innerWidth();
					sizeHorizontalScrollbar();
				}
			}

			function sizeHorizontalScrollbar()
			{
				container.find('>.jspHorizontalBar>.jspCap:visible,>.jspHorizontalBar>.jspArrow').each(
					function()
					{
						horizontalTrackWidth -= $(this).outerWidth();
					}
				);

				horizontalTrack.width(horizontalTrackWidth + 'px');
				horizontalDragPosition = 0;
			}

			function resizeScrollbars()
			{
				if (isScrollableH && isScrollableV) {
					var horizontalTrackHeight = horizontalTrack.outerHeight(),
						verticalTrackWidth = verticalTrack.outerWidth();
					verticalTrackHeight -= horizontalTrackHeight;
					$(horizontalBar).find('>.jspCap:visible,>.jspArrow').each(
						function()
						{
							horizontalTrackWidth += $(this).outerWidth();
						}
					);
					horizontalTrackWidth -= verticalTrackWidth;
					paneHeight -= verticalTrackWidth;
					paneWidth -= horizontalTrackHeight;
					horizontalTrack.parent().append(
						$('<div class="jspCorner" />').css('width', horizontalTrackHeight + 'px')
					);
					sizeVerticalScrollbar();
					sizeHorizontalScrollbar();
				}
				/* reflow content */
				if (isScrollableH) {
					pane.width((container.outerWidth() - originalPaddingTotalWidth) + 'px');
				}
				contentHeight = pane.outerHeight();
				percentInViewV = contentHeight / paneHeight;

				if (isScrollableH) {
					horizontalDragWidth = Math.ceil(1 / percentInViewH * horizontalTrackWidth);
					if (horizontalDragWidth > settings.horizontalDragMaxWidth) {
						horizontalDragWidth = settings.horizontalDragMaxWidth;
					} else if (horizontalDragWidth < settings.horizontalDragMinWidth) {
						horizontalDragWidth = settings.horizontalDragMinWidth;
					}
					horizontalDrag.width(horizontalDragWidth + 'px');
					dragMaxX = horizontalTrackWidth - horizontalDragWidth;
					_positionDragX(horizontalDragPosition); /* To update the state for the arrow buttons */
				}
				if (isScrollableV) {
					verticalDragHeight = Math.ceil(1 / percentInViewV * verticalTrackHeight);
					if (verticalDragHeight > settings.verticalDragMaxHeight) {
						verticalDragHeight = settings.verticalDragMaxHeight;
					} else if (verticalDragHeight < settings.verticalDragMinHeight) {
						verticalDragHeight = settings.verticalDragMinHeight;
					}
					verticalDrag.height(verticalDragHeight + 'px');
					dragMaxY = verticalTrackHeight - verticalDragHeight;
					_positionDragY(verticalDragPosition); /* To update the state for the arrow buttons */
				}
			}

			function appendArrows(ele, p, a1, a2)
			{
				var p1 = "before", p2 = "after", aTemp;
				
				/* Sniff for mac... Is there a better way to determine whether the arrows would naturally appear
				 at the top or the bottom of the bar? */
				if (p == "os") {
					p = /Mac/.test(navigator.platform) ? "after" : "split";
				}
				if (p == p1) {
					p2 = p;
				} else if (p == p2) {
					p1 = p;
					aTemp = a1;
					a1 = a2;
					a2 = aTemp;
				}

				ele[p1](a1)[p2](a2);
			}

			function getArrowScroll(dirX, dirY, ele)
			{
				return function()
				{
					arrowScroll(dirX, dirY, this, ele);
					this.blur();
					return false;
				};
			}

			function arrowScroll(dirX, dirY, arrow, ele)
			{
				arrow = $(arrow).addClass('jspActive');

				var eve,
					scrollTimeout,
					isFirst = true,
					doScroll = function()
					{
						if (dirX !== 0) {
							jsp.scrollByX(dirX * settings.arrowButtonSpeed);
						}
						if (dirY !== 0) {
							jsp.scrollByY(dirY * settings.arrowButtonSpeed);
						}
						scrollTimeout = setTimeout(doScroll, isFirst ? settings.initialDelay : settings.arrowRepeatFreq);
						isFirst = false;
					};

				doScroll();

				eve = ele ? 'mouseout.jsp' : 'mouseup.jsp';
				ele = ele || $('html');
				ele.bind(
					eve,
					function()
					{
						arrow.removeClass('jspActive');
						scrollTimeout && clearTimeout(scrollTimeout);
						scrollTimeout = null;
						ele.unbind(eve);
					}
				);
			}

			function initClickOnTrack()
			{
				removeClickOnTrack();
				if (isScrollableV) {
					verticalTrack.bind(
						'mousedown.jsp',
						function(e)
						{
							if (e.originalTarget === undefined || e.originalTarget == e.currentTarget) {
								var clickedTrack = $(this),
									offset = clickedTrack.offset(),
									direction = e.pageY - offset.top - verticalDragPosition,
									scrollTimeout,
									isFirst = true,
									doScroll = function()
									{
										var offset = clickedTrack.offset(),
											pos = e.pageY - offset.top - verticalDragHeight / 2,
											contentDragY = paneHeight * settings.scrollPagePercent,
											dragY = dragMaxY * contentDragY / (contentHeight - paneHeight);
										if (direction < 0) {
											if (verticalDragPosition - dragY > pos) {
												jsp.scrollByY(-contentDragY);
											} else {
												positionDragY(pos);
											}
										} else if (direction > 0) {
											if (verticalDragPosition + dragY < pos) {
												jsp.scrollByY(contentDragY);
											} else {
												positionDragY(pos);
											}
										} else {
											cancelClick();
											return;
										}
										scrollTimeout = setTimeout(doScroll, isFirst ? settings.initialDelay : settings.trackClickRepeatFreq);
										isFirst = false;
									},
									cancelClick = function()
									{
										scrollTimeout && clearTimeout(scrollTimeout);
										scrollTimeout = null;
										$(document).unbind('mouseup.jsp', cancelClick);
									};
								doScroll();
								$(document).bind('mouseup.jsp', cancelClick);
								return false;
							}
						}
					);
				}
				
				if (isScrollableH) {
					horizontalTrack.bind(
						'mousedown.jsp',
						function(e)
						{
							if (e.originalTarget === undefined || e.originalTarget == e.currentTarget) {
								var clickedTrack = $(this),
									offset = clickedTrack.offset(),
									direction = e.pageX - offset.left - horizontalDragPosition,
									scrollTimeout,
									isFirst = true,
									doScroll = function()
									{
										var offset = clickedTrack.offset(),
											pos = e.pageX - offset.left - horizontalDragWidth / 2,
											contentDragX = paneWidth * settings.scrollPagePercent,
											dragX = dragMaxX * contentDragX / (contentWidth - paneWidth);
										if (direction < 0) {
											if (horizontalDragPosition - dragX > pos) {
												jsp.scrollByX(-contentDragX);
											} else {
												positionDragX(pos);
											}
										} else if (direction > 0) {
											if (horizontalDragPosition + dragX < pos) {
												jsp.scrollByX(contentDragX);
											} else {
												positionDragX(pos);
											}
										} else {
											cancelClick();
											return;
										}
										scrollTimeout = setTimeout(doScroll, isFirst ? settings.initialDelay : settings.trackClickRepeatFreq);
										isFirst = false;
									},
									cancelClick = function()
									{
										scrollTimeout && clearTimeout(scrollTimeout);
										scrollTimeout = null;
										$(document).unbind('mouseup.jsp', cancelClick);
									};
								doScroll();
								$(document).bind('mouseup.jsp', cancelClick);
								return false;
							}
						}
					);
				}
			}

			function removeClickOnTrack()
			{
				if (horizontalTrack) {
					horizontalTrack.unbind('mousedown.jsp');
				}
				if (verticalTrack) {
					verticalTrack.unbind('mousedown.jsp');
				}
			}

			function cancelDrag()
			{
				$('html').unbind('dragstart.jsp selectstart.jsp mousemove.jsp mouseup.jsp mouseleave.jsp');

				if (verticalDrag) {
					verticalDrag.removeClass('jspActive');
				}
				if (horizontalDrag) {
					horizontalDrag.removeClass('jspActive');
				}
			}

			function positionDragY(destY, animate)
			{
				if (!isScrollableV) {
					return;
				}
				if (destY < 0) {
					destY = 0;
				} else if (destY > dragMaxY) {
					destY = dragMaxY;
				}

				/* can't just check if(animate) because false is a valid value that could be passed in... */
				if (animate === undefined) {
					animate = settings.animateScroll;
				}
				if (animate) {
					jsp.animate(verticalDrag, 'top', destY,	_positionDragY);
				} else {
					verticalDrag.css('top', destY);
					_positionDragY(destY);
				}

			}

			function _positionDragY(destY)
			{
				if (destY === undefined) {
					destY = verticalDrag.position().top;
				}

				container.scrollTop(0);
				verticalDragPosition = destY;

				var isAtTop = verticalDragPosition === 0,
					isAtBottom = verticalDragPosition == dragMaxY,
					percentScrolled = destY/ dragMaxY,
					destTop = -percentScrolled * (contentHeight - paneHeight);

				if (wasAtTop != isAtTop || wasAtBottom != isAtBottom) {
					wasAtTop = isAtTop;
					wasAtBottom = isAtBottom;
					elem.trigger('jsp-arrow-change', [wasAtTop, wasAtBottom, wasAtLeft, wasAtRight]);
				}
				
				updateVerticalArrows(isAtTop, isAtBottom);
				pane.css('top', destTop);
				elem.trigger('jsp-scroll-y', [-destTop, isAtTop, isAtBottom]).trigger('scroll');
			}

			function positionDragX(destX, animate)
			{
				if (!isScrollableH) {
					return;
				}
				if (destX < 0) {
					destX = 0;
				} else if (destX > dragMaxX) {
					destX = dragMaxX;
				}

				if (animate === undefined) {
					animate = settings.animateScroll;
				}
				if (animate) {
					jsp.animate(horizontalDrag, 'left', destX,	_positionDragX);
				} else {
					horizontalDrag.css('left', destX);
					_positionDragX(destX);
				}
			}

			function _positionDragX(destX)
			{
				if (destX === undefined) {
					destX = horizontalDrag.position().left;
				}

				container.scrollTop(0);
				horizontalDragPosition = destX;

				var isAtLeft = horizontalDragPosition === 0,
					isAtRight = horizontalDragPosition == dragMaxX,
					percentScrolled = destX / dragMaxX,
					destLeft = -percentScrolled * (contentWidth - paneWidth);

				if (wasAtLeft != isAtLeft || wasAtRight != isAtRight) {
					wasAtLeft = isAtLeft;
					wasAtRight = isAtRight;
					elem.trigger('jsp-arrow-change', [wasAtTop, wasAtBottom, wasAtLeft, wasAtRight]);
				}
				
				updateHorizontalArrows(isAtLeft, isAtRight);
				pane.css('left', destLeft);
				elem.trigger('jsp-scroll-x', [-destLeft, isAtLeft, isAtRight]).trigger('scroll');
			}

			function updateVerticalArrows(isAtTop, isAtBottom)
			{
				if (settings.showArrows) {
					arrowUp[isAtTop ? 'addClass' : 'removeClass']('jspDisabled');
					arrowDown[isAtBottom ? 'addClass' : 'removeClass']('jspDisabled');
				}
			}

			function updateHorizontalArrows(isAtLeft, isAtRight)
			{
				if (settings.showArrows) {
					arrowLeft[isAtLeft ? 'addClass' : 'removeClass']('jspDisabled');
					arrowRight[isAtRight ? 'addClass' : 'removeClass']('jspDisabled');
				}
			}

			function scrollToY(destY, animate)
			{
				var percentScrolled = destY / (contentHeight - paneHeight);
				positionDragY(percentScrolled * dragMaxY, animate);
			}

			function scrollToX(destX, animate)
			{
				var percentScrolled = destX / (contentWidth - paneWidth);
				positionDragX(percentScrolled * dragMaxX, animate);
			}

			function scrollToElement(ele, stickToTop, animate)
			{
				var e, eleHeight, eleWidth, eleTop = 0, eleLeft = 0, viewportTop, viewportLeft, maxVisibleEleTop, maxVisibleEleLeft, destY, destX;

				/* Legal hash values aren't necessarily legal jQuery selectors so we need to catch any
				 errors from the lookup... */
				try {
					e = $(ele);
				} catch (err) {
					return;
				}
				eleHeight = e.outerHeight();
				eleWidth= e.outerWidth();

				container.scrollTop(0);
				container.scrollLeft(0);
				
				/* loop through parents adding the offset top of any elements that are relatively positioned between
				 the focused element and the jspPane so we can get the true distance from the top
				 of the focused element to the top of the scrollpane... */
				while (!e.is('.jspPane')) {
					eleTop += e.position().top;
					eleLeft += e.position().left;
					e = e.offsetParent();
					if (/^body|html$/i.test(e[0].nodeName)) {
						/* we ended up too high in the document structure. Quit! */
						return;
					}
				}

				viewportTop = contentPositionY();
				maxVisibleEleTop = viewportTop + paneHeight;
				if (eleTop < viewportTop || stickToTop) { /* element is above viewport */
					destY = eleTop - settings.verticalGutter;
				} else if (eleTop + eleHeight > maxVisibleEleTop) { /* element is below viewport */
					destY = eleTop - paneHeight + eleHeight + settings.verticalGutter;
				}
				if (destY) {
					scrollToY(destY, animate);
				}
				
				viewportLeft = contentPositionX();
	            maxVisibleEleLeft = viewportLeft + paneWidth;
	            if (eleLeft < viewportLeft || stickToTop) { /* element is to the left of viewport */
	                destX = eleLeft - settings.horizontalGutter;
	            } else if (eleLeft + eleWidth > maxVisibleEleLeft) { /* element is to the right viewport */
	                destX = eleLeft - paneWidth + eleWidth + settings.horizontalGutter;
	            }
	            if (destX) {
	                scrollToX(destX, animate);
	            }

			}
			function contentPositionX()
			{
				try {
					return -pane.position().left;
				} catch(err) {					
					return 0;
				}
			}

			function contentPositionY()
			{
				try {
					return -pane.position().top;
				} catch(err){
					return 0;
				}
			
			}

			function isCloseToBottom()
			{
				var scrollableHeight = contentHeight - paneHeight;
				return (scrollableHeight > 20) && (scrollableHeight - contentPositionY() < 10);
			}

			function isCloseToRight()
			{
				var scrollableWidth = contentWidth - paneWidth;
				return (scrollableWidth > 20) && (scrollableWidth - contentPositionX() < 10);
			}

			function initMousewheel()
			{
				container.unbind(mwEvent).bind(
					mwEvent,
					function (event, delta, deltaX, deltaY) {
						var dX = horizontalDragPosition, dY = verticalDragPosition;
						jsp.scrollBy(deltaX * settings.mouseWheelSpeed, -deltaY * settings.mouseWheelSpeed, false);
						/* return true if there was no movement so rest of screen can scroll */
						return dX == horizontalDragPosition && dY == verticalDragPosition;
					}
				);
			}

			function removeMousewheel()
			{
				container.unbind(mwEvent);
			}

			function nil()
			{
				return false;
			}

			function initFocusHandler()
			{
				pane.find(':input,a').unbind('focus.jsp').bind(
					'focus.jsp',
					function(e)
					{
						scrollToElement(e.target, false);
					}
				);
			}

			function removeFocusHandler()
			{
				pane.find(':input,a').unbind('focus.jsp');
			}
			
			function initKeyboardNav()
			{
				var keyDown, elementHasScrolled, validParents = [];
				isScrollableH && validParents.push(horizontalBar[0]);
				isScrollableV && validParents.push(verticalBar[0]);
				
				/* IE also focuses elements that don't have tabindex set. */
				pane.focus(
					function()
					{
						elem.focus();
					}
				);
				
				elem.attr('tabindex', 0)
					.unbind('keydown.jsp keypress.jsp')
					.bind(
						'keydown.jsp',
						function(e)
						{
							if (e.target !== this && !(validParents.length && $(e.target).closest(validParents).length)){
								return;
							}
							var dX = horizontalDragPosition, dY = verticalDragPosition;
							switch(e.keyCode) {
								case 40: /* down */
								case 38: /* up */
								case 34: /* page down */
								case 32: /* space */
								case 33: /* page up */
								case 39: /* right */
								case 37: /* left */
									keyDown = e.keyCode;
									keyDownHandler();
									break;
								case 35: /* end */
									scrollToY(contentHeight - paneHeight);
									keyDown = null;
									break;
								case 36: /* home */
									scrollToY(0);
									keyDown = null;
									break;
							}

							elementHasScrolled = e.keyCode == keyDown && dX != horizontalDragPosition || dY != verticalDragPosition;
							return !elementHasScrolled;
						}
					).bind(
						'keypress.jsp', /* For FF/ OSX so that we can cancel the repeat key presses if the JSP scrolls... */
						function(e)
						{
							if (e.keyCode == keyDown) {
								keyDownHandler();
							}
							return !elementHasScrolled;
						}
					);
				
				if (settings.hideFocus) {
					elem.css('outline', 'none');
					if ('hideFocus' in container[0]){
						elem.attr('hideFocus', true);
					}
				} else {
					elem.css('outline', '');
					if ('hideFocus' in container[0]){
						elem.attr('hideFocus', false);
					}
				}
				
				function keyDownHandler()
				{
					var dX = horizontalDragPosition, dY = verticalDragPosition;
					switch(keyDown) {
						case 40: /* down */
							jsp.scrollByY(settings.keyboardSpeed, false);
							break;
						case 38: /* up */
							jsp.scrollByY(-settings.keyboardSpeed, false);
							break;
						case 34: /* page down */
						case 32: /* space */
							jsp.scrollByY(paneHeight * settings.scrollPagePercent, false);
							break;
						case 33: /* page up */
							jsp.scrollByY(-paneHeight * settings.scrollPagePercent, false);
							break;
						case 39: /* right */
							jsp.scrollByX(settings.keyboardSpeed, false);
							break;
						case 37: /* left */
							jsp.scrollByX(-settings.keyboardSpeed, false);
							break;
					}

					elementHasScrolled = dX != horizontalDragPosition || dY != verticalDragPosition;
					return elementHasScrolled;
				}
			}
			
			function removeKeyboardNav()
			{
				elem.attr('tabindex', '-1')
					.removeAttr('tabindex')
					.unbind('keydown.jsp keypress.jsp');
			}

			function observeHash()
			{
				if (location.hash && location.hash.length > 1) {
					var e, retryInt;
					try {
						e = $(location.hash);
					} catch (err) {
						return;
					}

					if (e.length && pane.find(location.hash)) {
						/* nasty workaround but it appears to take a little while before the hash has done its thing
						to the rendered page so we just wait until the container's scrollTop has been messed up. */
						if (container.scrollTop() === 0) {
							retryInt = setInterval(
								function()
								{
									if (container.scrollTop() > 0) {
										scrollToElement(location.hash, true);
										$(document).scrollTop(container.position().top);
										clearInterval(retryInt);
									}
								},
								50
							);
						} else {
							scrollToElement(location.hash, true);
							$(document).scrollTop(container.position().top);
						}
					}
				}
			}

			function unhijackInternalLinks()
			{
				$('a.jspHijack').unbind('click.jsp-hijack').removeClass('jspHijack');
			}

			function hijackInternalLinks()
			{
				unhijackInternalLinks();
				$('a[href^=#]').addClass('jspHijack').bind(
					'click.jsp-hijack',
					function()
					{
						var uriParts = this.href.split('#'), hash;
						if (uriParts.length > 1) {
							hash = uriParts[1];
							if (hash.length > 0 && pane.find('#' + hash).length > 0) {
								scrollToElement('#' + hash, true);
								/* Need to return false otherwise things mess up... Would be nice to maybe also scroll
								 the window to the top of the scrollpane? */
								return false;
							}
						}
					}
				);
			}
			
			/* Init touch on iPad, iPhone, iPod, Android */
			function initTouch()
			{
				var startX,
					startY,
					touchStartX,
					touchStartY,
					moved,
					moving = false;
  
				container.unbind('touchstart.jsp touchmove.jsp touchend.jsp click.jsp-touchclick').bind(
					'touchstart.jsp',
					function(e)
					{
						var touch = e.originalEvent.touches[0];
						startX = contentPositionX();
						startY = contentPositionY();
						touchStartX = touch.pageX;
						touchStartY = touch.pageY;
						moved = false;
						moving = true;
					}
				).bind(
					'touchmove.jsp',
					function(ev)
					{
						if(!moving) {
							return;
						}
						
						var touchPos = ev.originalEvent.touches[0],
							dX = horizontalDragPosition, dY = verticalDragPosition;
						
						jsp.scrollTo(startX + touchStartX - touchPos.pageX, startY + touchStartY - touchPos.pageY);
						
						moved = moved || Math.abs(touchStartX - touchPos.pageX) > 5 || Math.abs(touchStartY - touchPos.pageY) > 5;
						
						/* return true if there was no movement so rest of screen can scroll */
						return dX == horizontalDragPosition && dY == verticalDragPosition;
					}
				).bind(
					'touchend.jsp',
					function(e)
					{
						moving = false;
						/*if(moved) {
							return false;
						}*/
					}
				).bind(
					'click.jsp-touchclick',
					function(e)
					{
						if(moved) {
							moved = false;
							return false;
						}
					}
				);
			}
			
			function destroy(){
				var currentY = contentPositionY(),
					currentX = contentPositionX();
				elem.removeClass('jspScrollable').unbind('.jsp');
				elem.replaceWith(originalElement.append(pane.children()));
				originalElement.scrollTop(currentY);
				originalElement.scrollLeft(currentX);
			}

			/* Public API */
			$.extend(
				jsp,
				{
					/* Reinitialises the scroll pane (if it's internal dimensions have changed since the last time it
					 was initialised). The settings object which is passed in will override any settings from the
					 previous time it was initialised - if you don't pass any settings then the ones from the previous
					 initialisation will be used. */
					reinitialise: function(s)
					{
						s = $.extend({}, settings, s);
						initialise(s);
					},
					/* Scrolls the specified element (a jQuery object, DOM node or jQuery selector string) into view so
					 that it can be seen within the viewport. If stickToTop is true then the element will appear at
					 the top of the viewport, if it is false then the viewport will scroll as little as possible to
					 show the element. You can also specify if you want animation to occur. If you don't provide this
					 argument then the animateScroll value from the settings object is used instead. */
					scrollToElement: function(ele, stickToTop, animate)
					{
						scrollToElement(ele, stickToTop, animate);
					},
					/* Scrolls the pane so that the specified co-ordinates within the content are at the top left
					 of the viewport. animate is optional and if not passed then the value of animateScroll from
					 the settings object this jScrollPane was initialised with is used. */
					scrollTo: function(destX, destY, animate)
					{
						scrollToX(destX, animate);
						scrollToY(destY, animate);
					},
					/* Scrolls the pane so that the specified co-ordinate within the content is at the left of the
					 viewport. animate is optional and if not passed then the value of animateScroll from the settings
					 object this jScrollPane was initialised with is used. */
					scrollToX: function(destX, animate)
					{
						scrollToX(destX, animate);
					},
					/* Scrolls the pane so that the specified co-ordinate within the content is at the top of the
					 viewport. animate is optional and if not passed then the value of animateScroll from the settings
					 object this jScrollPane was initialised with is used. */
					scrollToY: function(destY, animate)
					{
						scrollToY(destY, animate);
					},
					/* Scrolls the pane to the specified percentage of its maximum horizontal scroll position. animate
					 is optional and if not passed then the value of animateScroll from the settings object this
					 jScrollPane was initialised with is used. */
					scrollToPercentX: function(destPercentX, animate)
					{
						scrollToX(destPercentX * (contentWidth - paneWidth), animate);
					},
					/* Scrolls the pane to the specified percentage of its maximum vertical scroll position. animate
					 is optional and if not passed then the value of animateScroll from the settings object this
					 jScrollPane was initialised with is used. */
					scrollToPercentY: function(destPercentY, animate)
					{
						scrollToY(destPercentY * (contentHeight - paneHeight), animate);
					},
					/* Scrolls the pane by the specified amount of pixels. animate is optional and if not passed then
					 the value of animateScroll from the settings object this jScrollPane was initialised with is used. */
					scrollBy: function(deltaX, deltaY, animate)
					{
						jsp.scrollByX(deltaX, animate);
						jsp.scrollByY(deltaY, animate);
					},
					/* Scrolls the pane by the specified amount of pixels. animate is optional and if not passed then
					 the value of animateScroll from the settings object this jScrollPane was initialised with is used. */
					scrollByX: function(deltaX, animate)
					{
						var destX = contentPositionX() + deltaX,
							percentScrolled = destX / (contentWidth - paneWidth);
						positionDragX(percentScrolled * dragMaxX, animate);
					},
					/* Scrolls the pane by the specified amount of pixels. animate is optional and if not passed then
					 the value of animateScroll from the settings object this jScrollPane was initialised with is used. */
					scrollByY: function(deltaY, animate)
					{
						var destY = contentPositionY() + deltaY,
							percentScrolled = destY / (contentHeight - paneHeight);
						positionDragY(percentScrolled * dragMaxY, animate);
					},
					/* Positions the horizontal drag at the specified x position (and updates the viewport to reflect
					 this). animate is optional and if not passed then the value of animateScroll from the settings
					 object this jScrollPane was initialised with is used. */
					positionDragX: function(x, animate)
					{
						positionDragX(x, animate);
					},
					/* Positions the vertical drag at the specified y position (and updates the viewport to reflect
					 this). animate is optional and if not passed then the value of animateScroll from the settings
					 object this jScrollPane was initialised with is used. */
					positionDragY: function(y, animate)
					{
						positionDragX(y, animate);
					},
					/* This method is called when jScrollPane is trying to animate to a new position. You can override
					 it if you want to provide advanced animation functionality. It is passed the following arguments:
					  * ele          - the element whose position is being animated
					  * prop         - the property that is being animated
					  * value        - the value it's being animated to
					  * stepCallback - a function that you must execute each time you update the value of the property
					 You can use the default implementation (below) as a starting point for your own implementation. */
					animate: function(ele, prop, value, stepCallback)
					{
						var params = {};
						params[prop] = value;
						ele.animate(
							params,
							{
								'duration'	: settings.animateDuration,
								'ease'		: settings.animateEase,
								'queue'		: false,
								'step'		: stepCallback
							}
						);
					},
					/* Returns the current x position of the viewport with regards to the content pane. */
					getContentPositionX: function()
					{
						return contentPositionX();
					},
					/* Returns the current y position of the viewport with regards to the content pane. */
					getContentPositionY: function()
					{
						return contentPositionY();
					},
					/* Returns the width of the content within the scroll pane. */
					getContentWidth: function()
					{
						return contentWidth;
					},
					/* Returns the height of the content within the scroll pane. */
					getContentHeight: function()
					{
						return contentHeight;
					},
					/* Returns the horizontal position of the viewport within the pane content. */
					getPercentScrolledX: function()
					{
						return contentPositionX() / (contentWidth - paneWidth);
					},
					/* Returns the vertical position of the viewport within the pane content. */
					getPercentScrolledY: function()
					{
						return contentPositionY() / (contentHeight - paneHeight);
					},
					/* Returns whether or not this scrollpane has a horizontal scrollbar. */
					getIsScrollableH: function()
					{
						return isScrollableH;
					},
					/* Returns whether or not this scrollpane has a vertical scrollbar. */
					getIsScrollableV: function()
					{
						return isScrollableV;
					},
					/* Gets a reference to the content pane. It is important that you use this method if you want to
					 edit the content of your jScrollPane as if you access the element directly then you may have some
					 problems (as your original element has had additional elements for the scrollbars etc added into
					 it). */
					getContentPane: function()
					{
						return pane;
					},
					/* Scrolls this jScrollPane down as far as it can currently scroll. If animate isn't passed then the
					 animateScroll value from settings is used instead. */
					scrollToBottom: function(animate)
					{
						positionDragY(dragMaxY, animate);
					},
					/* Hijacks the links on the page which link to content inside the scrollpane. If you have changed
					 the content of your page (e.g. via AJAX) and want to make sure any new anchor links to the
					 contents of your scroll pane will work then call this function. */
					hijackInternalLinks: function()
					{
						hijackInternalLinks();
					},
					/* Removes the jScrollPane and returns the page to the state it was in before jScrollPane was
					 initialised. */
					destroy: function()
					{
							destroy();
					}
				}
			);
			
			initialise(s);
		}

		/* Pluginifying code... */
		settings = $.extend({}, $.fn.jScrollPane.defaults, settings);
		
		/* Apply default speed */
		$.each(['mouseWheelSpeed', 'arrowButtonSpeed', 'trackClickSpeed', 'keyboardSpeed'], function() {
			settings[this] = settings[this] || settings.speed;
		});

		var ret;
		this.each(
			function()
			{
				var elem = $(this), jspApi = elem.data('jsp');
				if (jspApi) {
					jspApi.reinitialise(settings);
				} else {
					jspApi = new JScrollPane(elem, settings);
					elem.data('jsp', jspApi);
				}
				ret = ret ? ret.add(elem) : elem;
			}
		);
		return ret;
	};

	$.fn.jScrollPane.defaults = {
		showArrows					: false,
		maintainPosition			: true,
		stickToBottom				: false,
		stickToRight				: false,
		clickOnTrack				: true,
		autoReinitialise			: false,
		autoReinitialiseDelay		: 500,
		verticalDragMinHeight		: 0,
		verticalDragMaxHeight		: 99999,
		horizontalDragMinWidth		: 0,
		horizontalDragMaxWidth		: 99999,
		contentWidth				: undefined,
		animateScroll				: false,
		animateDuration				: 300,
		animateEase					: 'linear',
		hijackInternalLinks			: false,
		verticalGutter				: 4,
		horizontalGutter			: 4,
		mouseWheelSpeed				: 0,
		arrowButtonSpeed			: 0,
		arrowRepeatFreq				: 50,
		arrowScrollOnHover			: false,
		trackClickSpeed				: 0,
		trackClickRepeatFreq		: 70,
		verticalArrowPositions		: 'split',
		horizontalArrowPositions	: 'split',
		enableKeyboardNavigation	: true,
		hideFocus					: false,
		keyboardSpeed				: 0,
		initialDelay                : 300,        /* Delay before starting repeating */
		speed						: 30,		/* Default speed when others falsey */
		scrollPagePercent			: .8		/* Percent of visible area scrolled when pageUp/Down or track area pressed */
	};

})(jQuery,this);