a parallax navigation jQuery plugin

parallax.js

(function( $ ){
  
    var constants = {//static vars don't change this unless you're rewriting the plugin.
    defaultMethod: 'init',
    version: '0.0.5',
    name: 'parallax.js',
    author: 'Adam Siegel'
  };

  var settings = {//default settigns overidden by arguments given during instantiation.
    debug: false,
    lazyLoad: true,
    target: 'default',
    index: 0,
    mediaIndex: 0,
    locationHashes: ["#home",["#media-gallery","#media-gallery/video/video-1","#media-gallery/video/video-2","#media-gallery/video/video-3","#media-gallery/video/video-4","#media-gallery/video/video-5","#media-gallery/image/screenshot-1","#media-gallery/image/screenshot-2","#media-gallery/image/screenshot-3","#media-gallery/image/screenshot-4", "#media-gallery/image/screenshot-5", "#media-gallery/image/screenshot-6"],"#game-info","#characters","#characters-2","#characters-3","#characters-4","#characters-5","#characters-5"],
    timing: 3000,
    varSpeed: true,
    negMargin: 110 // number in px to pull in margin per parallaxed layer
  };

    var methods = {
     info: function info(){// version info and author info for debugging
      return constants.name + " ver: " + constants.version +  " by " + constants.author;
   },
     debugMsg: function debugMessage(massage,caller){// prevents console.logs from ending up in the code when debugging, YAY!
        caller = typeof(caller) != 'undefined' ? caller : debugMessage.caller;
      if(settings.debug){
        var outputName = caller.name?caller.name + "::":"";
        output = constants.name + ":" + outputName + massage;
        try {
          console.log(output);
        }
        catch(e) {
          try {
            opera.postError(output);
          }
          catch(e){
            alert(output);
            
          }
        }
          if(typeof(console) === 'undefined') {
          console = {}
          console.log = console.error = console.info = console.debug = console.warn = console.trace = console.dir = console.dirxml = console.group = console.groupEnd = console.time = console.timeEnd = console.assert = console.profile = function() {};
        }
      }
     },
     init : function init( options ) {//init method
    return this.each(function(){
      $instance = this;
      $instance.options = $.extend({}, settings, options);
      if(location.hash.length){//assigns the current location.hash to the current index
          $.inArray(location.hash,$instance.options.locationHashes)>-1?$instance.options.index=$.inArray(location.hash,$instance.options.locationHashes):$instance.options.index;
        }
        if(location.hash.length){//assigns the current location.hash to the current index
          $.inArray(location.hash,$instance.options.locationHashes[1])>-1?$instance.options.index=1:$instance.options.index;
        }
      $instance.properties = {
        $zfix: $(".videoplayer , #info div.plane-4", $instance),
        $next: $(".parallax-next",$instance),
        $prev: $(".parallax-prev",$instance),
        $moveTo: $("li.nav-item"),
        $preOrder: $("li.nav-item:last-child"),
        $layers: $("ul.layer", $instance),
        $firstLayer: $("ul.layer:first-child li.mainelement",$instance),
        length: $("ul.layer:first-child li.mainelement",$instance).length
      };
        var scrollerScreenOffset = (0-$(".transition").width()) + "px";
        methods.debugMsg("scrollerScreenOffset == " +scrollerScreenOffset, methods.init);
        $instance.properties.$layers.css("left",scrollerScreenOffset);
      $instance.properties.$next.click(function(e){
        e.preventDefault();
        methods.next()
      });
      $instance.properties.$prev.click(function(e){
        e.preventDefault();
        methods.prev()
      });
      $instance.properties.$moveTo.click(function(e){
        e.preventDefault();
        methods.moveTo($instance.options.index,$(this).index());
      });
      $instance.properties.$moveTo.click(function(e){
        e.preventDefault();
        window.location = $("a", this).attr("href");
      });
      $("body").keydown(function(event){
        if(event.keyCode== '37' && $instance.options.index){
          event.preventDefault();
          methods.prev();
        }
        if(event.keyCode== '39'){
          event.preventDefault();
          methods.next();
        }
      });
      if(location.hash){
        if($.inArray(location.hash,$instance.options.locationHashes[1])>-1){
          $instance.options.mediaIndex=$.inArray(location.hash,$instance.options.locationHashes[1])
        }
      }
        methods.moveTo($instance.options.index,$instance.options.index);
            //diagnostic info
            methods.debugMsg(methods.info());
            methods.debugMsg("$instance.properties.length:: " + $instance.properties.length);
    });
     },
     destroy : function destroy() {//unbinds the modal listeners. (useful for optimization)
    return this.each(function(){
      $(window).unbind('.parallax');
    })
     },
     next : function moveNext(){
      methods.move(1,1);
      
     },
     prev : function movePrev(){
      methods.move(-1,1);
      
     },
   /**
    * @params action One of 'next' or 'prev'
    */
   gesture: function gesture(action) {
     if(action == 'prev') {
       if($instance.options.index > 0){methods.prev();}
     }
     else methods.next();
     return;
   },
     move: function move(direction,amount,instant){
      if($instance.options.lazyLoad){
        methods.lazyload(direction,amount);
      };
      instant = typeof(instant) != 'undefined' ? instant : false;//default argument in javascript
      methods.debugMsg("$instance.properties.length::"  + $instance.properties.length);
      methods.debugMsg("$instance.options.index::"  + $instance.options.index);
      $instance.properties.$layers.each(function(index) {
        if($instance.options.index + (direction * amount)>-1 && $instance.options.index + (direction * amount) < $instance.properties.length){
          methods.debugMsg("left::" + $($(this).find("li.mainelement")[$instance.options.index + (direction * amount)]).position().left);
          methods.debugMsg($instance.options.index + (direction * amount),methods.move);
          if($instance.options.negMargin){
            $(this).find("li.mainelement, li.transition").css("margin-left", "-" + $instance.options.negMargin*$(this).attr("rel") + "px")
          }
          if(instant){
            $(this).css({ left : -$($(this).find("li.mainelement")[$instance.options.index + (direction * amount)]).position().left + $instance.options.negMargin*$(this).attr("rel") }, $instance.options.timing).dequeue();
          }else{
            $("#HomeVideoPlayer").videoplayer("pause");
                  $("#MediaVideoPlayer").videoplayer("pause");
            $(this).animate({ left : -$($(this).find("li.mainelement")[$instance.options.index + (direction * amount)]).position().left + $instance.options.negMargin*$(this).attr("rel") }, $instance.options.timing).dequeue();
        }
        }else if ($instance.options.index + (direction * amount) >= $instance.properties.length){
          methods.debugMsg("second case",methods.move)
          if($instance.options.negMargin){
            $(this).find("li.mainelement, li.transition").css("margin-left", "-" + $instance.options.negMargin*$(this).attr("rel") + "px")
          }
          methods.debugMsg("pass",methods.move)
          if(instant){
            $(this).css({ left : -$($(this).find("li.mainelement")[$instance.properties.length -1]).next().position().left + $instance.options.negMargin*$(this).attr("rel") }, $instance.options.timing).dequeue();
          }else{
            $("#HomeVideoPlayer").videoplayer("pause");
                  $("#MediaVideoPlayer").videoplayer("pause");
            $(this).animate({ left : -$($(this).find("li.mainelement")[$instance.properties.length -1]).next().position().left + $instance.options.negMargin*$(this).attr("rel") }, $instance.options.timing).dequeue();
        }
        }
      });
      if($instance.options.index >= 0){ 
        $instance.options.index += (direction*amount);
      }
      methods.updateNav();
     },
     moveTo: function moveTo(startAt,endAt){// this triggers methods.move to and from a destination
      var amt = Math.abs(endAt-startAt);
      var dir = endAt-startAt>0?1:-1;
      if(endAt-startAt){
        methods.move(dir,amt);
      }else{
        methods.move(dir,amt,true);
      }
     },
     updateNav: function updateNav(){//makes sure the navigation buttons are displaying properly after a scroll, updates slider and sets link to preorder page when nessicary.
      $instance.properties.$zfix.css("z-index", "8");
      if($instance.options.index>-1){
        if($instance.options.index == 1){
          location.hash = $instance.options.locationHashes[1][$instance.options.mediaIndex]
        }else{
        location.hash = $instance.options.locationHashes[$instance.options.index];          
        }
      }
      sectCount = $instance.options.index;
      //animcount();
      $instance.properties.$moveTo.find("a").removeClass("selected");
      if(!$instance.options.index){
        $($instance.properties.$moveTo[0]).find("a").addClass("selected");
        $(".nav-anime").animate({left : "60px" });
        $instance.properties.$prev.css("display","none");
      }else if($instance.options.index > $instance.properties.$moveTo.length + 2 ){
        $($instance.properties.$moveTo[$instance.properties.$moveTo.length-1]).find("a").addClass("selected");
        window.location = $instance.properties.$next.attr("href");
        $(".nav-anime").animate({left : "523px" });
      }else{
        var pOffset = $instance.options.index > $instance.properties.$moveTo.length-2?$instance.properties.$moveTo.length-2:$instance.options.index;
        $($instance.properties.$moveTo[pOffset]).find("a").addClass("selected");
        var destination = $($instance.properties.$moveTo[pOffset]).position().left + 20 + "px";
        $(".nav-anime").animate({left : destination });
        $instance.properties.$next.css("display","block");
        $instance.properties.$prev.css("display","block");
      }
     },
     lazyload: function lazyLoad(direction,amount){// loads images with the class lazy on demand.
      $instance.properties.$layers.each(function(index) {
          $($(this).find("li.mainelement").slice(0,$instance.options.index + 2 + (direction * amount)))
            .find("img.lazy").each(function(index){
            $(this).attr("src",$(this).attr("rel")).removeClass("lazy");
            })
      })
     }
 };
 
 $.fn.parallax = function(params){
    params = Array.prototype.slice.call(arguments); 
    if ( !params ){// stupid anon function opt arg hack.
      params = []
    }

    if ( params[1] ){// extends the default settings with the parameters fed to the function
        $.extend( settings, params[1] );
      }
      if (settings.target == 'default'){// hacky way to ensure this pulls this out of the invoked scope and not the whole DOM.
        settings.target = this
      }
    
    if ( !params[0] ){// assigns a default method if there is no param value
      params = constants.defaultMethod;
    }
    
      if( typeof params === 'string' || params === 'function'){// assigns method based on params type
        method = params;
        }else if ( typeof params === 'object'){
          method = params[0];
        }else{
          method = constants.defaultMethod;
        }

      if ( methods[method] ) {// applies methods listed above
            return methods[method].apply( this, Array.prototype.slice.call( arguments, 1 ));
        } else if ( typeof method === 'object' || ! method ) {
          return methods.init.apply( this, arguments );
        } else {
            $.error(  method + '?! What the heck is ' + method + '?!!! ' + constants.name + ' doesn\'t have a ' + method +' method.'  );
        }    
   };

})( jQuery );