//Step Carousel Viewer: By Dynamic Drive, at http://www.dynamicdrive.com
//** Created: March 19th, 08'
//** Aug 16th, 08'- Updated to v 1.4:
   //1) Adds ability to set speed/duration of panel animation (in milliseconds)
   //2) Adds persistence support, so the last viewed panel is recalled when viewer returns within same browser session
   //3) Adds ability to specify whether panels should stop at the very last and first panel, or wrap around and start all over again
   //4) Adds option to specify two navigational image links positioned to the left and right of the Carousel Viewer to move the panels back and forth

//** Aug 27th, 08'- Nav buttons (if enabled) also repositions themselves now if window is resized

//** Sept 23rd, 08'- Updated to v 1.6:
   //1) Carousel now stops at the very last visible panel, instead of the last panel itself. In other words, no more white space at the end.
   //2) Adds ability for Carousel to auto rotate dictated by the new parameter: autostep: {enable:true, moveby:1, pause:3000}
   //2i) During Auto Rotate, Carousel pauses onMouseover, resumes onMouseout. Clicking Carousel halts auto rotate.

//** Oct 22nd, 08'- Updated to v 1.6.1, which fixes functions stepBy() and stepTo() not stopping auto stepping of Carousel when called.

var stepcarousel={
   ajaxloadingmsg: '<div style="margin: 1em; font-weight: bold"><img src="ajaxloadr.gif" style="vertical-align: middle" /> Fetching Content. Please wait...</div>', //customize HTML to show while fetching Ajax content
   defaultbuttonsfade: 0.4, //Fade degree for disabled nav buttons (0=completely transparent, 1=completely opaque)
   configholder: {},

   getCSSValue:function(val){ //Returns either 0 (if val contains 'auto') or val as an integer
      return (val=="auto")? 0 : parseInt(val)
   },

   getremotepanels:function($, config){ //function to fetch external page containing the panel DIVs
      config.$belt.html(this.ajaxloadingmsg)
      $.ajax({
         url: config.contenttype[1], //path to external content
         async: true,
         error:function(ajaxrequest){
            config.$belt.html('Error fetching content.<br />Server Response: '+ajaxrequest.responseText)
         },
         success:function(content){
            config.$belt.html(content)
            config.$panels=config.$gallery.find('.'+config.panelclass)
            stepcarousel.alignpanels($, config)
         }
      })
   },

   getoffset:function(what, offsettype){
      return (what.offsetParent)? what[offsettype]+this.getoffset(what.offsetParent, offsettype) : what[offsettype]
   },

   getCookie:function(Name){
      var re=new RegExp(Name+"=[^;]+", "i"); //construct RE to search for target name/value pair
      if (document.cookie.match(re)) //if cookie found
         return document.cookie.match(re)[0].split("=")[1] //return its value
      return null
   },

   setCookie:function(name, value){
      document.cookie = name+"="+value
   },

   fadebuttons:function(config, currentpanel){
      config.$leftnavbutton.fadeTo('fast', currentpanel==0? this.defaultbuttonsfade : 1)
      config.$rightnavbutton.fadeTo('fast', currentpanel==config.lastvisiblepanel? this.defaultbuttonsfade : 1)
   },

   addnavbuttons:function(config, currentpanel){
      config.$leftnavbutton=$('<img src="'+config.defaultbuttons.leftnav[0]+'">').css({zIndex:50, position:'absolute', left:config.offsets.left+config.defaultbuttons.leftnav[1]+'px', top:config.offsets.top+config.defaultbuttons.leftnav[2]+'px', cursor:'hand', cursor:'pointer'}).attr({title:'Back '+config.defaultbuttons.moveby+' panels'}).appendTo('body')
      config.$rightnavbutton=$('<img src="'+config.defaultbuttons.rightnav[0]+'">').css({zIndex:50, position:'absolute', left:config.offsets.left+config.$gallery.get(0).offsetWidth+config.defaultbuttons.rightnav[1]+'px', top:config.offsets.top+config.defaultbuttons.rightnav[2]+'px', cursor:'hand', cursor:'pointer'}).attr({title:'Forward '+config.defaultbuttons.moveby+' panels'}).appendTo('body')
      config.$leftnavbutton.bind('click', function(){ //assign nav button event handlers
         stepcarousel.stepBy(config.galleryid, -config.defaultbuttons.moveby)
      })
      config.$rightnavbutton.bind('click', function(){ //assign nav button event handlers
         stepcarousel.stepBy(config.galleryid, config.defaultbuttons.moveby)
      })
      if (config.panelbehavior.wraparound==false){ //if carousel viewer should stop at first or last panel (instead of wrap back or forth)
         this.fadebuttons(config, currentpanel)
      }
      return config.$leftnavbutton.add(config.$rightnavbutton)
   },

   stopautostep:function(config){
      clearTimeout(config.steptimer)
      clearTimeout(config.resumeautostep)
   },

   alignpanels:function($, config){
      var paneloffset=0
      config.paneloffsets=[paneloffset] //array to store upper left offset of each panel (1st element=0)
      config.panelwidths=[] //array to store widths of each panel
      config.$panels.each(function(index){ //loop through panels
         var $currentpanel=$(this)
         $currentpanel.css({float: 'none', position: 'absolute', left: paneloffset+'px'}) //position panel
         $currentpanel.bind('click', function(e){return config.onpanelclick(e.target)}) //bind onpanelclick() to onclick event
         paneloffset+=stepcarousel.getCSSValue($currentpanel.css('marginRight')) + parseInt($currentpanel.get(0).offsetWidth || $currentpanel.css('width')) //calculate next panel offset
         config.paneloffsets.push(paneloffset) //remember this offset
         config.panelwidths.push(paneloffset-config.paneloffsets[config.paneloffsets.length-2]) //remember panel width
      })
      config.paneloffsets.pop() //delete last offset (redundant)
      var addpanelwidths=0
      var lastpanelindex=config.$panels.length-1
      config.lastvisiblepanel=lastpanelindex
      for (var i=config.$panels.length-1; i>=0; i--){
         addpanelwidths+=(i==lastpanelindex? config.panelwidths[lastpanelindex] : config.paneloffsets[i+1]-config.paneloffsets[i])
         if (config.gallerywidth>addpanelwidths){
            config.lastvisiblepanel=i //calculate index of panel that when in 1st position reveals the very last panel all at once based on gallery width
         }
      }
      config.$belt.css({width: paneloffset+'px'}) //Set Belt DIV to total panels' widths
      config.currentpanel=(config.panelbehavior.persist)? parseInt(this.getCookie(window[config.galleryid+"persist"])) : 0 //determine 1st panel to show by default
      config.currentpanel=(typeof config.currentpanel=="number" && config.currentpanel<config.$panels.length)? config.currentpanel : 0
      if (config.currentpanel!=0){
         var endpoint=config.paneloffsets[config.currentpanel]+(config.currentpanel==0? 0 : config.beltoffset)
         config.$belt.css({left: -endpoint+'px'})
      }
      if (config.defaultbuttons.enable==true){ //if enable default back/forth nav buttons
         var $navbuttons=this.addnavbuttons(config, config.currentpanel)
         $(window).bind("load resize", function(){ //refresh position of nav buttons when page loads/resizes, in case offsets weren't available document.oncontentload
            config.offsets={left:stepcarousel.getoffset(config.$gallery.get(0), "offsetLeft"), top:stepcarousel.getoffset(config.$gallery.get(0), "offsetTop")}
            config.$leftnavbutton.css({left:config.offsets.left+config.defaultbuttons.leftnav[1]+'px', top:config.offsets.top+config.defaultbuttons.leftnav[2]+'px'})
            config.$rightnavbutton.css({left:config.offsets.left+config.$gallery.get(0).offsetWidth+config.defaultbuttons.rightnav[1]+'px', top:config.offsets.top+config.defaultbuttons.rightnav[2]+'px'})
         })
      }
      if (config.autostep && config.autostep.enable){ //enable auto stepping of Carousel?      
         var $carouselparts=config.$gallery.add(typeof $navbuttons!="undefined"? $navbuttons : null)
         $carouselparts.bind('click', function(){
            stepcarousel.stopautostep(config)
            config.autostep.status="stopped"
         })
         $carouselparts.hover(function(){ //onMouseover
            stepcarousel.stopautostep(config)
            config.autostep.hoverstate="over"
         }, function(){ //onMouseout
            if (config.steptimer && config.autostep.hoverstate=="over" && config.autostep.status!="stopped"){
               config.resumeautostep=setTimeout(function(){
                  stepcarousel.autorotate(config.galleryid)
                  config.autostep.hoverstate="out"
               }, 500)
            }
         })
         config.steptimer=setTimeout(function(){stepcarousel.autorotate(config.galleryid)}, config.autostep.pause) //automatically rotate Carousel Viewer
      } //end enable auto stepping check
      this.statusreport(config.galleryid)
      config.oninit()
      config.onslideaction(this)
   },

   stepTo:function(galleryid, pindex){ /*User entered pindex starts at 1 for intuitiveness. Internally pindex still starts at 0 */
      var config=stepcarousel.configholder[galleryid]
      if (typeof config=="undefined"){
         alert("There's an error with your set up of Carousel Viewer \""+galleryid+ "\"!")
         return
      }
      stepcarousel.stopautostep(config)
      var pindex=Math.min(pindex-1, config.paneloffsets.length-1)
      var endpoint=config.paneloffsets[pindex]+(pindex==0? 0 : config.beltoffset)
      if (config.panelbehavior.wraparound==false && config.defaultbuttons.enable==true){ //if carousel viewer should stop at first or last panel (instead of wrap back or forth)
         this.fadebuttons(config, pindex)
      }
      config.$belt.animate({left: -endpoint+'px'}, config.panelbehavior.speed, function(){config.onslideaction(this)})
      config.currentpanel=pindex
      this.statusreport(galleryid)
   },

   stepBy:function(galleryid, steps){ //isauto if defined indicates stepBy() is being called automatically
      var config=stepcarousel.configholder[galleryid]
      if (typeof config=="undefined"){
         alert("There's an error with your set up of Carousel Viewer \""+galleryid+ "\"!")
         return
      }
      stepcarousel.stopautostep(config)
      var direction=(steps>0)? 'forward' : 'back' //If "steps" is negative, that means backwards
      var pindex=config.currentpanel+steps //index of panel to stop at
      if (config.panelbehavior.wraparound==false){ //if carousel viewer should stop at first or last panel (instead of wrap back or forth)
         pindex=(direction=="back" && pindex<=0)? 0 : (direction=="forward")? Math.min(pindex, config.lastvisiblepanel) : pindex
         if (config.defaultbuttons.enable==true){ //if default nav buttons are enabled, fade them in and out depending on if at start or end of carousel
            stepcarousel.fadebuttons(config, pindex)
         }   
      }
      else{ //else, for normal stepBy behavior
         if (pindex>config.lastvisiblepanel && direction=="forward"){
            //if destination pindex is greater than last visible panel, yet we're currently not at the end of the carousel yet
            pindex=(config.currentpanel<config.lastvisiblepanel)? config.lastvisiblepanel : 0
         }
         else if (pindex<0 && direction=="back"){
            //if destination pindex is less than 0, yet we're currently not at the beginning of the carousel yet
            pindex=(config.currentpanel>0)? 0 : config.lastvisiblepanel /*wrap around left*/
         }
      }
      var endpoint=config.paneloffsets[pindex]+(pindex==0? 0 : config.beltoffset) //left distance for Belt DIV to travel to
      if (pindex==0 && direction=='forward' || config.currentpanel==0 && direction=='back' && config.panelbehavior.wraparound==true){ //decide whether to apply "push pull" effect
         config.$belt.animate({left: -config.paneloffsets[config.currentpanel]-(direction=='forward'? 100 : -30)+'px'}, 'normal', function(){
            config.$belt.animate({left: -endpoint+'px'}, config.panelbehavior.speed, function(){config.onslideaction(this)})
         })
      }
      else
         config.$belt.animate({left: -endpoint+'px'}, config.panelbehavior.speed, function(){config.onslideaction(this)})
      config.currentpanel=pindex
      this.statusreport(galleryid)
   },

   autorotate:function(galleryid){
      var config=stepcarousel.configholder[galleryid]
      if (config.$gallery.attr('_ismouseover')!="yes"){
         this.stepBy(galleryid, config.autostep.moveby)
      }
      config.steptimer=setTimeout(function(){stepcarousel.autorotate(galleryid)}, config.autostep.pause)
   },

   statusreport:function(galleryid){
      var config=stepcarousel.configholder[galleryid]
      var startpoint=config.currentpanel //index of first visible panel
      var visiblewidth=0
      for (var endpoint=startpoint; endpoint<config.paneloffsets.length; endpoint++){ //index (endpoint) of last visible panel
         visiblewidth+=config.panelwidths[endpoint]
         if (visiblewidth>config.gallerywidth){
            break
         }
      }
      startpoint+=1 //format startpoint for user friendiness
      endpoint=(endpoint+1==startpoint)? startpoint : endpoint //If only one image visible on the screen and partially hidden, set endpoint to startpoint
      var valuearray=[startpoint, endpoint, config.panelwidths.length]
      for (var i=0; i<config.statusvars.length; i++){
         window[config.statusvars[i]]=valuearray[i] //Define variable (with user specified name) and set to one of the status values
         config.$statusobjs[i].text(valuearray[i]+" ") //Populate element on page with ID="user specified name" with one of the status values
      }
   },

   setup:function(config){
      //Disable Step Gallery scrollbars ASAP dynamically (enabled for sake of users with JS disabled)
      document.write('<style type="text/css">\n#'+config.galleryid+'{overflow: hidden;}\n</style>')
      jQuery(document).ready(function($){
         config.$gallery=$('#'+config.galleryid)
         config.gallerywidth=config.$gallery.width()
         config.offsets={left:stepcarousel.getoffset(config.$gallery.get(0), "offsetLeft"), top:stepcarousel.getoffset(config.$gallery.get(0), "offsetTop")}
         config.$belt=config.$gallery.find('.'+config.beltclass) //Find Belt DIV that contains all the panels
         config.$panels=config.$gallery.find('.'+config.panelclass) //Find Panel DIVs that each contain a slide
         config.panelbehavior.wraparound=(config.autostep && config.autostep.enable)? true : config.panelbehavior.wraparound //if auto step enabled, set "wraparound" to true
         config.onpanelclick=(typeof config.onpanelclick=="undefined")? function(target){} : config.onpanelclick //attach custom "onpanelclick" event handler
         config.onslideaction=(typeof config.onslide=="undefined")? function(){} : function(beltobj){$(beltobj).stop(); config.onslide()} //attach custom "onslide" event handler
         config.oninit=(typeof config.oninit=="undefined")? function(){} : config.oninit //attach custom "oninit" event handler
         config.beltoffset=stepcarousel.getCSSValue(config.$belt.css('marginLeft')) //Find length of Belt DIV's left margin
         config.statusvars=config.statusvars || []  //get variable names that will hold "start", "end", and "total" slides info
         config.$statusobjs=[$('#'+config.statusvars[0]), $('#'+config.statusvars[1]), $('#'+config.statusvars[2])]
         config.currentpanel=0
         stepcarousel.configholder[config.galleryid]=config //store config parameter as a variable
         if (config.contenttype[0]=="ajax" && typeof config.contenttype[1]!="undefined") //fetch ajax content?
            stepcarousel.getremotepanels($, config)
         else
            stepcarousel.alignpanels($, config) //align panels and initialize gallery
      }) //end document.ready
      jQuery(window).bind('unload', function(){ //clean up
         if (config.panelbehavior.persist){
            stepcarousel.setCookie(window[config.galleryid+"persist"], config.currentpanel)
         }
         jQuery.each(config, function(ai, oi){
            oi=null
         })
         config=null
      })
   }
}