/* Copyright (c) 2006 Kelvin Luck (kelvin AT kelvinluck DOT com || http://www.kelvinluck.com)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php) 
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 * 
 * See http://kelvinluck.com/assets/jquery/jScrollPane/
 * $Id: jScrollPane.js 2762 2007-08-18 11:04:47Z kelvin.luck $
 */

jQuery.jScrollPane={active:[]};jQuery.fn.jScrollPane=function(settings){settings=jQuery.extend({scrollbarWidth:10,scrollbarMargin:5,wheelSpeed:18,showArrows:false,arrowSize:0,animateTo:false,dragMinHeight:1,dragMaxHeight:99999,animateInterval:100,animateStep:3,maintainPosition:true},settings);return this.each(function(){var $this=jQuery(this);if(jQuery(this).parent().is('.jScrollPaneContainer')){var currentScrollPosition=settings.maintainPosition?$this.offset({relativeTo:jQuery(this).parent()[0]}).top:0;var $c=jQuery(this).parent();var paneWidth=$c.innerWidth();var paneHeight=$c.outerHeight();var trackHeight=paneHeight;if($c.unmousewheel){$c.unmousewheel()}jQuery('>.jScrollPaneTrack, >.jScrollArrowUp, >.jScrollArrowDown',$c).remove();$this.css({'top':0})}else{var currentScrollPosition=0;this.originalPadding=$this.css('paddingTop')+' '+$this.css('paddingRight')+' '+$this.css('paddingBottom')+' '+$this.css('paddingLeft');this.originalSidePaddingTotal=(parseInt($this.css('paddingLeft'))||0)+(parseInt($this.css('paddingRight'))||0);var paneWidth=$this.innerWidth();var paneHeight=$this.innerHeight();var trackHeight=paneHeight;$this.wrap(jQuery('<div>').attr({'className':'jScrollPaneContainer'}).css({'height':paneHeight+'px','width':paneWidth+'px'}));JQ(document).bind('emchange',function(e,cur,prev){$this.jScrollPane(settings)})}var p=this.originalSidePaddingTotal;$this.css({'height':'auto','width':paneWidth-settings.scrollbarWidth-settings.scrollbarMargin-p+'px','paddingRight':settings.scrollbarMargin+'px'});var contentHeight=$this.outerHeight();var percentInView=paneHeight/contentHeight;if(percentInView<.99){var $container=$this.parent();$container.append(jQuery('<div>').attr({'className':'jScrollPaneTrack'}).css({'width':settings.scrollbarWidth+'px'}).append(jQuery('<div>').attr({'className':'jScrollPaneDrag'}).css({'width':settings.scrollbarWidth+'px'}).append(jQuery('<div>').attr({'className':'jScrollPaneDragTop'}).css({'width':settings.scrollbarWidth+'px'}),jQuery('<div>').attr({'className':'jScrollPaneDragBottom'}).css({'width':settings.scrollbarWidth+'px'}))));var $track=jQuery('>.jScrollPaneTrack',$container);var $drag=jQuery('>.jScrollPaneTrack .jScrollPaneDrag',$container);if(settings.showArrows){var currentArrowButton;var currentArrowDirection;var currentArrowInterval;var currentArrowInc;var whileArrowButtonDown=function(){if(currentArrowInc>4||currentArrowInc%4==0){positionDrag(dragPosition+currentArrowDirection*mouseWheelMultiplier)}currentArrowInc++};var onArrowMouseUp=function(event){jQuery('body').unbind('mouseup',onArrowMouseUp);currentArrowButton.removeClass('jScrollActiveArrowButton');clearInterval(currentArrowInterval)};var onArrowMouseDown=function(){jQuery('body').bind('mouseup',onArrowMouseUp);currentArrowButton.addClass('jScrollActiveArrowButton');currentArrowInc=0;whileArrowButtonDown();currentArrowInterval=setInterval(whileArrowButtonDown,100)};$container.append(jQuery('<a>').attr({'href':'javascript:;','className':'jScrollArrowUp'}).css({'width':settings.scrollbarWidth+'px'}).html('Scroll up').bind('mousedown',function(){currentArrowButton=jQuery(this);currentArrowDirection=-1;onArrowMouseDown();this.blur();return false}),jQuery('<a>').attr({'href':'javascript:;','className':'jScrollArrowDown'}).css({'width':settings.scrollbarWidth+'px'}).html('Scroll down').bind('mousedown',function(){currentArrowButton=jQuery(this);currentArrowDirection=1;onArrowMouseDown();this.blur();return false}));if(settings.arrowSize){trackHeight=paneHeight-settings.arrowSize-settings.arrowSize;$track.css({'height':trackHeight+'px',top:settings.arrowSize+'px'})}else{var topArrowHeight=jQuery('>.jScrollArrowUp',$container).height();settings.arrowSize=topArrowHeight;trackHeight=paneHeight-topArrowHeight-jQuery('>.jScrollArrowDown',$container).height();$track.css({'height':trackHeight+'px',top:topArrowHeight+'px'})}}var $pane=jQuery(this).css({'position':'absolute','overflow':'visible'});var currentOffset;var maxY;var mouseWheelMultiplier;var dragPosition=0;var dragMiddle=percentInView*paneHeight/2;var getPos=function(event,c){var p=c=='X'?'Left':'Top';return event['page'+c]||(event['client'+c]+(document.documentElement['scroll'+p]||document.body['scroll'+p]))||0};var ignoreNativeDrag=function(){return false};var initDrag=function(){ceaseAnimation();currentOffset=$drag.offset(false);currentOffset.top-=dragPosition;maxY=trackHeight-$drag[0].offsetHeight;mouseWheelMultiplier=2*settings.wheelSpeed*maxY/contentHeight};var onStartDrag=function(event){initDrag();dragMiddle=getPos(event,'Y')-dragPosition-currentOffset.top;jQuery('body').bind('mouseup',onStopDrag).bind('mousemove',updateScroll);if(jQuery.browser.msie){jQuery('body').bind('dragstart',ignoreNativeDrag).bind('selectstart',ignoreNativeDrag)}return false};var onStopDrag=function(){jQuery('body').unbind('mouseup',onStopDrag).unbind('mousemove',updateScroll);dragMiddle=percentInView*paneHeight/2;if(jQuery.browser.msie){jQuery('body').unbind('dragstart',ignoreNativeDrag).unbind('selectstart',ignoreNativeDrag)}};var positionDrag=function(destY){destY=destY<0?0:(destY>maxY?maxY:destY);dragPosition=destY;$drag.css({'top':destY+'px'});var p=destY/maxY;$pane.css({'top':((paneHeight-contentHeight)*p)+'px'});$this.trigger('scroll')};var updateScroll=function(e){positionDrag(getPos(e,'Y')-currentOffset.top-dragMiddle)};var dragH=Math.max(Math.min(percentInView*(paneHeight-settings.arrowSize*2),settings.dragMaxHeight),settings.dragMinHeight);$drag.css({'height':dragH+'px'}).bind('mousedown',onStartDrag);var trackScrollInterval;var trackScrollInc;var trackScrollMousePos;var doTrackScroll=function(){if(trackScrollInc>8||trackScrollInc%4==0){positionDrag((dragPosition-((dragPosition-trackScrollMousePos)/2)))}trackScrollInc++};var onStopTrackClick=function(){clearInterval(trackScrollInterval);jQuery('body').unbind('mouseup',onStopTrackClick).unbind('mousemove',onTrackMouseMove)};var onTrackMouseMove=function(event){trackScrollMousePos=getPos(event,'Y')-currentOffset.top-dragMiddle};var onTrackClick=function(event){initDrag();onTrackMouseMove(event);trackScrollInc=0;jQuery('body').bind('mouseup',onStopTrackClick).bind('mousemove',onTrackMouseMove);trackScrollInterval=setInterval(doTrackScroll,100);doTrackScroll()};$track.bind('mousedown',onTrackClick);if($container.mousewheel){$container.mousewheel(function(event,delta){initDrag();ceaseAnimation();var d=dragPosition;positionDrag(dragPosition-delta*mouseWheelMultiplier);var dragOccured=d!=dragPosition;return!dragOccured},false)}var _animateToPosition;var _animateToInterval;function animateToPosition(){var diff=(_animateToPosition-dragPosition)/settings.animateStep;if(diff>1||diff<-1){positionDrag(dragPosition+diff)}else{positionDrag(_animateToPosition);ceaseAnimation()}}var ceaseAnimation=function(){if(_animateToInterval){clearInterval(_animateToInterval);delete _animateToPosition}};var scrollTo=function(pos,preventAni){if(typeof pos=="string"){$e=$(pos,this);if(!$e.length)return;pos=$e.offset({relativeTo:this}).top}ceaseAnimation();var destDragPosition=-pos/(paneHeight-contentHeight)*maxY;if(!preventAni||settings.animateTo){_animateToPosition=destDragPosition;_animateToInterval=setInterval(animateToPosition,settings.animateInterval)}else{positionDrag(destDragPosition)}};$this[0].scrollTo=scrollTo;$this[0].scrollBy=function(delta){var currentPos=-parseInt($pane.css('top'))||0;scrollTo(currentPos+delta)};initDrag();scrollTo(-currentScrollPosition,true);jQuery.jScrollPane.active.push($this[0])}else{$this.css({'height':paneHeight+'px','width':paneWidth-this.originalSidePaddingTotal+'px','padding':this.originalPadding})}})};jQuery(window).bind('unload',function(){var els=jQuery.jScrollPane.active;for(var i=0;i<els.length;i++){els[i].scrollTo=els[i].scrollBy=null}});