// scroll.js

// pausing up-down scroller - © Dynamic Drive (www.dynamicdrive.com)

// refer to scroll.css for associated css

function pausescroller(content,divId,divClass,delay){
 this.content=content //message array content
 this.tickerid=divId //ID of ticker div to display information
 this.delay=delay //Delay between msg change, in miliseconds.
 this.mouseoverBol=0 //Boolean to indicate whether mouse is currently over scroller (and pause it if it is)
 this.hiddendivpointer=1 //index of message array for hidden div
 document.write('<div id="'+divId+'" class="'+divClass+'" style="position: relative; overflow: hidden"><div class="innerDiv" style="position: absolute; width: 100%" id="'+divId+'1">'+content[0]+'</div><div class="innerDiv" style="position: absolute; width: 100%; visibility: hidden" id="'+divId+'2">'+content[1]+'</div></div>')
 var scrollerinstance=this
 if (window.addEventListener) //run onload in DOM2 browsers
  window.addEventListener("load", function(){scrollerinstance.initialize()}, false)
 else if (window.attachEvent) //run onload in IE5.5+
  window.attachEvent("onload", function(){scrollerinstance.initialize()})
 else if (document.getElementById) //if legacy DOM browsers, just start scroller after 0.5 sec
  setTimeout(function(){scrollerinstance.initialize()}, 500)
}

// initialize scroller method. get div objects, set initial positions, start up down animation
pausescroller.prototype.initialize=function(){
 this.tickerdiv=document.getElementById(this.tickerid)
 this.visiblediv=document.getElementById(this.tickerid+"1")
 this.hiddendiv=document.getElementById(this.tickerid+"2")
 this.visibledivtop=parseInt(pausescroller.getCSSpadding(this.tickerdiv))
 //set width of inner DIVs to outer DIV's width minus padding (padding assumed to be top padding x 2)
 this.visiblediv.style.width=this.hiddendiv.style.width=this.tickerdiv.offsetWidth-(this.visibledivtop*2)+"px"
 this.getinline(this.visiblediv, this.hiddendiv)
 this.hiddendiv.style.visibility="visible"
 var scrollerinstance=this
 document.getElementById(this.tickerid).onmouseover=function(){scrollerinstance.mouseoverBol=1}
 document.getElementById(this.tickerid).onmouseout=function(){scrollerinstance.mouseoverBol=0}
 if (window.attachEvent) //Clean up loose references in IE
  window.attachEvent("onunload", function(){scrollerinstance.tickerdiv.onmouseover=scrollerinstance.tickerdiv.onmouseout=null})
 setTimeout(function(){scrollerinstance.animateup()}, this.delay)
}

// move the two inner divs of the scroller up and in sync
pausescroller.prototype.animateup=function(){
 var scrollerinstance=this

 // dtf
 var stepSize=2; // default=5
 var stepSpeed=25; // default=50

 if (parseInt(this.hiddendiv.style.top)>(this.visibledivtop+5)){

  // dtf
  // this.visiblediv.style.top=parseInt(this.visiblediv.style.top)-5+"px"
  // this.hiddendiv.style.top=parseInt(this.hiddendiv.style.top)-5+"px"
  // setTimeout(function(){scrollerinstance.animateup()}, 50)
  this.visiblediv.style.top=parseInt(this.visiblediv.style.top)-stepSize+"px"
  this.hiddendiv.style.top=parseInt(this.hiddendiv.style.top)-stepSize+"px"
  setTimeout(function(){scrollerinstance.animateup()}, stepSpeed)

 }else{
  this.getinline(this.hiddendiv, this.visiblediv)
  this.swapdivs()
  setTimeout(function(){scrollerinstance.setmessage()}, this.delay)
 }
}

// swap between which is the visible and which is the hidden div
pausescroller.prototype.swapdivs=function(){
 var tempcontainer=this.visiblediv
 this.visiblediv=this.hiddendiv
 this.hiddendiv=tempcontainer
}

pausescroller.prototype.getinline=function(div1, div2){
 div1.style.top=this.visibledivtop+"px"
 div2.style.top=Math.max(div1.parentNode.offsetHeight, div1.offsetHeight)+"px"
}

// populate the hidden div with the next message before it's visible
pausescroller.prototype.setmessage=function(){
 var scrollerinstance=this
 if (this.mouseoverBol==1) //if mouse is currently over scoller, do nothing (pause it)
  setTimeout(function(){scrollerinstance.setmessage()}, 100)
 else{
  var i=this.hiddendivpointer
  var ceiling=this.content.length
  this.hiddendivpointer=(i+1>ceiling-1)? 0 : i+1
  this.hiddendiv.innerHTML=this.content[this.hiddendivpointer]
  this.animateup()
 }
}

pausescroller.getCSSpadding=function(tickerobj){ //get CSS padding value, if any
 if (tickerobj.currentStyle)
  return tickerobj.currentStyle["paddingTop"]
 else if (window.getComputedStyle) //if DOM2
  return window.getComputedStyle(tickerobj, "").getPropertyValue("padding-top")
 else
  return 0
}