/*Sag Content Scroller (Aug 7th, 2010)
 * This notice must stay intact for usage 
 * Author: Dynamic Drive at http://www.dynamicdrive.com/
 * Visit http://www.dynamicdrive.com/ for full source code
 */

//Updated Aug 28th, 10 to v1.3

var sagscroller_constants={
    navpanel: {height:'16px', downarrow:'images/down.gif', opacity:0.6, title:'Go to Next Content', background:'black'},
    loadingimg: {src:'images/ajaxloading.gif', dimensions:[100,15]}
}

    function sagscroller(options){

	this.setting={mode:'manual', inittype:'stunted', pause:3000, animatespeed:500, ajaxsource:null, rssdata:null, refreshsecs:0, navpanel:{show:true, cancelauto:false}} //default settings
	jQuery.extend(this.setting, options) //merge default settings with options
	    options=null
	    this.curmsg=0
	    this.addloadingpanel(jQuery, 'preload')
	    if (this.setting.rssdata) //if rss contents
		google.load("feeds", "1") //init google ajax api
		    var slider=this
		    jQuery(function($){ //on document.ready
			    slider.$slider=$('#'+slider.setting.id)
			    if (slider.setting.ajaxsource||slider.setting.rssdata)
				slider.$slider.empty()
				    slider.addloadingpanel(jQuery, 'show')
				    if (slider.setting.ajaxsource) //if ajax data
					slider.getajaxul(slider.setting.ajaxsource)
					else if (slider.setting.rssdata){ //if rss data
					    slider.fetchfeeds()
					}
					else{ //if inline content
					    if (slider.setting.inittype=="onload") //load scroller when page has completely loaded?
						$(window).load(function(){slider.init($)})
						else //load scroller immediately and get dimensions progressively instead
						    slider.init($)
							}
			})
		    }

sagscroller.prototype={

    getajaxul:function(path){
	var $=jQuery, slider=this
	this.stopscroll() //stop animation/ scrolling of slider, in the event this is a subsequent call to getajaxul()
	this.$loadingpanel.show()
	$.ajax({
		url: path, //path to external content
		async: true,
		error:function(ajaxrequest){
		    slider.$slider.html('Error fetching content.<br />Server Response: '+ajaxrequest.responseText)
		},
		success:function(content){
		    slider.reloadul(content)
		    if (slider.setting.refreshsecs>0) //refetch contents every x sec?
			setTimeout(function(){slider.getajaxul(path)}, slider.setting.refreshsecs*1000)
			    }
	    })
    },

    addloadingpanel:function($, mode){
	var loadingimgref=sagscroller_constants.loadingimg
	if (mode=="preload"){
	    var loadingimg=new Image(loadingimgref.dimensions[0], loadingimgref.dimensions[1])
	    loadingimg.src=loadingimgref.src
	    this.$loadingimg=$(loadingimg).css({position:'absolute', zIndex:1003})
	}
	else{
	    var sliderdimensions=[this.$slider.width(), this.$slider.height()]
	    var $loadingpanel=$('<div />').css({position:'absolute', left:0, top:0, background:'black', opacity:0.5, width:sliderdimensions[0], height:sliderdimensions[1], zIndex:1002}).appendTo(this.$slider)
	    this.$loadingimg.css({left:sliderdimensions[0]/2-loadingimgref.dimensions[0]/2, top:sliderdimensions[1]/2-loadingimgref.dimensions[1]/2}).appendTo(this.$slider)
	    this.$loadingpanel=$loadingpanel.add(this.$loadingimg)
	}
    },

    addnavpanel:function(){
	var slider=this, setting=this.setting
	var $navpanel=$('<div class="sliderdesc"><div class="sliderdescbg"></div><div class="sliderdescfg"><div class="sliderdesctext"></div></div></div>')
	.css({position:'absolute', width:'100%', left:0, top:-1000, zIndex:'1001'})
	.find('div').css({position:'absolute', left:0, top:0, width:'100%'})
	.eq(0).css({background:sagscroller_constants.navpanel.background, opacity:sagscroller_constants.navpanel.opacity}).end() //"sliderdescbg" div
	.eq(1).css({color:'white'}).end() //"sliderdescfg" div
	.eq(2).css({textAlign:'center', cursor:'pointer', paddingTop:'2px'}).html('<img src="'+sagscroller_constants.navpanel.downarrow+'"/>').end().end()
	.appendTo(this.$slider)
	var $descpanel=$navpanel.find('div.sliderdesctext').attr('title', sagscroller_constants.navpanel.title).click(function(){ //action when nav bar is clicked on
		slider.stopscroll()
		slider.scrollmsg(setting.mode=="auto" && !setting.navpanel.cancelauto? true : false)
	    })
	$navpanel.css({top:this.$slider.height()-parseInt(sagscroller_constants.navpanel.height), height:sagscroller_constants.navpanel.height}).find('div').css({height:'100%'})
    },

    resetuls:function(){ //function to swap between primary and secondary ul
	var $tempul=this.$mainul
	this.$mainul=this.$secul.css({zIndex:1000})
	this.$secul=$tempul.css({zIndex:999})
	this.$secul.css('top', this.ulheight)
    },

    reloadul:function(newhtml){ //function to empty out SAG scroller UL contents then reload with new contents
	this.$slider.find('ul').remove()
	this.ulheight=null
	this.curmsg=0;
	this.$slider.append(newhtml)
	this.init($)
    },

    setgetoffset:function($li){
	var recaldimensions=(this.setting.ajaxsource || this.setting.rssdata) && this.setting.inittype=="onload" //bool to see if script should always refetch dimensions
	if (this.curmsg==this.$lis.length)
	    return (!this.ulheight || recaldimensions)? this.ulheight=this.$mainul.height() : this.ulheight
	    else{
		if (!$li.data('toppos') || recaldimensions)
		    $li.data('toppos', $li.position().top)
			return $li.data('toppos')
			}
    },

    scrollmsg:function(repeat){
	var slider=this, setting=this.setting
	var ulheight=this.ulheight || this.$mainul.height()
	var endpoint=-this.setgetoffset(this.$lis.eq(this.curmsg))
	this.$mainul.animate({top: endpoint}, setting.animatespeed, function(){
		slider.curmsg=(slider.curmsg<slider.$lis.length+1)? slider.curmsg+1 : 0
		if (slider.curmsg==slider.$lis.length+1){ //if at end of UL
		    slider.resetuls() //swap between main and sec UL
		    slider.curmsg=1
		}
		if (repeat)
		    slider.scrolltimer=setTimeout(function(){slider.scrollmsg(repeat)}, setting.pause)
			})
	var secendpoint=endpoint+ulheight
	this.$secul.animate({top: secendpoint}, setting.animatespeed)
    },

    stopscroll:function(){
	if (this.$mainul){
	    this.$mainul.add(this.$secul).stop(true, false)
	    clearTimeout(this.scrolltimer)
	}
    },

    init:function($){
	var setting=this.setting
	this.$loadingpanel.hide()
	this.$mainul=this.$slider.find('ul:eq(0)').css({zIndex:1000})
	this.$lis=this.$mainul.find('li')
	if (setting.navpanel.show)
	    this.addnavpanel()
		this.$secul=this.$mainul.clone().css({top:this.$mainul.height(), zIndex:999}).appendTo(this.$slider) //create sec UL and add it to the end of main UL
		this.scrollmsg(setting.mode=="auto")
		},

    ///////////////////////RSS related methods below///////////////////


    fetchfeeds:function(){
	var slider=this, rssdata=this.setting.rssdata
	this.stopscroll() //stop animation/ scrolling of slider, in the event this is a subsequent call to fetchfeeds()
	this.$loadingpanel.show()
	this.entries=[] //array holding combined RSS feeds' entries from Feed API (result.feed.entries)
	this.feedsfetched=0
	for (var i=0; i<rssdata.feeds.length; i++){ //loop through the specified RSS feeds' URLs
	    var feedpointer=new google.feeds.Feed(rssdata.feeds[i][1]) //create new instance of Google Ajax Feed API
	    feedpointer.setNumEntries(rssdata.entries) //set number of items to display
	    feedpointer.load(function(label){
		    return function(r){
			slider.storefeeds(r, label)
		    }
		}(rssdata.feeds[i][0])) //call Feed.load() to retrieve and output RSS feed.
	}
    },

    storefeeds:function(result, label){
	var thisfeed=(!result.error)? result.feed.entries : "" //get all feed entries as a JSON array or "" if failed
	if (thisfeed==""){ //if error has occured fetching feed
	    alert("Google Feed API Error: "+result.error.message)
	}
	for (var i=0; i<thisfeed.length; i++){ //For each entry within feed
	    result.feed.entries[i].label=label //extend it with a "label" property
	}
	this.entries=this.entries.concat(thisfeed) //add entry to array holding all feed entries
	this.feedsfetched+=1
	if (this.feedsfetched==this.setting.rssdata.feeds.length){ //if all feeds fetched
	    if (this.setting.rssdata.groupbylabel){ //sort by label name?
		this.entries.sort(function(a,b){
			var fielda=a.label.toLowerCase(), fieldb=b.label.toLowerCase()
			return (fielda<fieldb)? -1 : (fielda>fieldb)? 1 : 0
		    })
	    }
	    else{ //just sort by date
		this.entries.sort(function(a,b){return new Date(b.publishedDate)-new Date(a.publishedDate)})
	    }
	    this.formatfeeds()
	}
    },

    formatfeeds:function(){
	function formatdate(datestr, showoptions){
	    var itemdate=new Date(datestr)
	    var parseddate=(showoptions.indexOf("datetime")!=-1)? itemdate.toLocaleString() : (showoptions.indexOf("date")!=-1)? itemdate.toLocaleDateString() : ""
	    return "<span class='datefield'>"+parseddate+"</span>"
	}
	var sagcontent='<ul>'
	var slider=this, rssdata=this.setting.rssdata, entries=this.entries
	for (var i=0; i<entries.length; i++){
	    sagcontent+='<li><a href="'+entries[i].link+'" target="'+rssdata.linktarget+'">'+entries[i].title+'</a>'
	    +'<div class="rsscontent">'
	    +(/description/.test(rssdata.displayoptions)? entries[i].content : entries[i].contentSnippet)
	    +'</div>'
	    +'<div class="rsslabel">'
	    +(/label/.test(rssdata.displayoptions)? "<b>Source("+(i+1)+"):</b> "+entries[i].label+" " : "")
	    +(/date/.test(rssdata.displayoptions)? formatdate(entries[i].publishedDate, rssdata.displayoptions): "")
	    +'</div>'
	    +'</li>\n\n'
	}
	sagcontent+='</ul>'
	this.reloadul(sagcontent)
	if (slider.setting.refreshsecs>0) //refetch contents every x sec?
	    setTimeout(function(){slider.fetchfeeds()}, slider.setting.refreshsecs*1000)
		}
}