//** DD Drop Down Panel- (c) Dynamic Drive DHTML code library: http://www.dynamicdrive.com
//** Oct 21st, 08'- Script created
//** March 23rd, 09' v1.01- Arrow images now preloaded

function ddpanel(setting){
 setting.dir="up" //initial state of panel (up="contracted")
 if (setting.stateconfig.persiststate && ddpanel.getCookie(setting.ids[0])=="down"){
  setting.dir="down"
 }
 if (setting.dir=="up"){ //if "up", output CSS to hide panel contents
  document.write('<style type="text/css">\n')
  document.write('#'+setting.ids[1]+'{height:' + parseInt(setting.stateconfig.initial) + 'px; overflow:hidden}\n')
  document.write('</style>\n')
 }
 setting.stateconfig.initial=parseInt(setting.stateconfig.initial)
 this.setting=setting
 if (setting.pointerimage.enabled){ //preload images
  var img1=new Image(), img2=new Image()
  img1.src=setting.pointerimage.src[0]
  img2.src=setting.pointerimage.src[1]
 }
 var thispanel=this
 if (window.addEventListener) //if non IE browsers, initialize panel window.onload
  ddpanel.addEvent(window, function(e){thispanel.initpanel(setting)}, "load")
 else //else if IE, add 100 millisec after window.onload before initializing
  ddpanel.addEvent(window, function(e){setTimeout(function(){thispanel.initpanel(setting)}, 100)}, "load")
 ddpanel.addEvent(window, function(e){thispanel.uninit(setting)}, "unload")
}

ddpanel.events_array=[] //object array to contain events created by script

ddpanel.addEvent=function(target, functionref, tasktype){
 var evtmodel=target.addEventListener? "w3c" : "ie"
 var evtaction=evtmodel=="w3c"? "addEventListener" : "attachEvent"
 var i=this.events_array.push({ //store event info in ddpanel.events_array[] and return current event's index within array
  target: target,
  tasktype: (evtmodel=="ie"? "on" : "")+tasktype,
  listener: evtmodel=="ie"? function(){return functionref.call(target, window.event)} : functionref
 })-1
 target[evtaction](this.events_array[i].tasktype, this.events_array[i].listener, evtmodel=="w3c"? false : null)
}

ddpanel.removeEvent=function(target, functionref, tasktype){
 var evtmodel=target.removeEventListener? "w3c" : "ie"
 var evtaction=evtmodel=="w3c"? "removeEventListener" : "detachEvent"
 target[evtaction](tasktype, functionref, evtmodel=="w3c"? false : null)
}

ddpanel.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
}

ddpanel.setCookie=function(name, value){
 document.cookie = name+"=" + value + ";path=/"
}

ddpanel.addpointer=function(target, className, imagesrc){
 var pointer=document.createElement("img")
 pointer.src=imagesrc
 pointer.className=className
 pointer.style.borderWidth=0
 target.appendChild(pointer)
 return pointer
}

ddpanel.prototype={

togglepanel:function(dir){ //public function that toggles the panel's state. Optional dir parameter ("up" or "down") to explicitly set state.
 var setting=this.setting
 setting.dir=dir || ((setting.dir=="up")? "down" : "up")
 var pcontent=setting.pcontent, dir=setting.dir
 pcontent._currentheight=(dir=="down")? pcontent._actualheight : setting.stateconfig.initial
 pcontent.style.height=pcontent._currentheight+"px"
 if (setting.pointerimage.enabled){
  setting.arrow.src=setting.pointerimage.src[(setting.dir=="down")? 1 : 0]
  setting.arrow.style.visibility="visible"
 }
 ddpanel.setCookie(setting.ids[0], setting.dir)
},

togglepanelplus:function(dir){ //public function that toggles the panel's state w/ animation. Optional dir parameter ("up" or "down") to explicitly set state.
 var setting=this.setting
 setting.dir=dir || ((setting.dir=="up")? "down" : "up")
 if (setting.pointerimage.enabled)
  setting.arrow.style.visibility="hidden"
 clearTimeout(setting.revealtimer)
 this.revealcontent()
},

revealcontent:function(){
 var setting=this.setting
 var pcontent=setting.pcontent, curH=pcontent._currentheight, maxH=pcontent._actualheight, minH=setting.stateconfig.initial, steps=setting.animate.steps, dir=setting.dir
 if (dir=="down" && curH<maxH || dir=="up" && curH>minH){
  var newH = curH + (Math.round((maxH-curH)/steps)+1) * (dir=="up"? -1 : 1)
  newH=(dir=="down")? Math.min(maxH, newH) : Math.max(minH, newH)
  pcontent.style.height=newH+"px"
  pcontent._currentheight=newH
 }
 else{
  if (setting.pointerimage.enabled){
   setting.arrow.src=setting.pointerimage.src[(setting.dir=="down")? 1 : 0]
   setting.arrow.style.visibility="visible"
  }
  return
 }
 var thispanel=this
 setting.revealtimer=setTimeout(function(){thispanel.revealcontent()}, 10)
},

initpanel:function(){
 var setting=this.setting
 var pcontainer=setting.pcontainer=document.getElementById(setting.ids[0])
 var pcontent=setting.pcontent=document.getElementById(setting.ids[1])
 var tdiv=setting.tdiv=document.getElementById(setting.ids[2])
 pcontent.style.overflow="scroll"
 pcontent._actualheight=pcontent.scrollHeight
 setTimeout(function(){pcontent._actualheight=pcontent.scrollHeight}, 100)
 pcontent.style.overflow="hidden"
 pcontent._currentheight=(setting.dir=="down")? pcontent._actualheight : setting.stateconfig.initial
 var thispanel=this
 ddpanel.addEvent(tdiv, function(e){ //assign click behavior when toggle DIV tab is clicked on
  if (setting.animate.enabled)
   thispanel.togglepanelplus()
  else
   thispanel.togglepanel()
  if (e.preventDefault) e.preventDefault()
  return false
 }, "click")
 if (setting.pointerimage.enabled){
  var pointer1=new Image(), pointer2=new Image()
  pointer1.src=setting.pointerimage.src[0]
  pointer2.src=setting.pointerimage.src[1]
  setting.arrow=ddpanel.addpointer(tdiv.getElementsByTagName("span")[0], "pointerimage", setting.pointerimage.src[setting.dir=="down"? 1:0])
 }
 if (setting.closepanelonclick.enabled){ //assign click behavior when panel content is clicked on (links within panel or elements with class "closepanel"
   ddpanel.addEvent(pcontent, function(e){
    var target=e.srcElement || e.target
    if (/(^|\s+)closepanel($|\s+)/.test(target.className) || target.tagName=="A" || (target.parentNode && target.parentNode.tagName=="A")){
     thispanel.togglepanel("up")
    }
   }, "click")
 }
},

uninit:function(){
 var setting=this.setting
 if (setting.stateconfig.persiststate){
  ddpanel.setCookie(setting.ids[0], setting.dir)
 }
 for (prop in setting){
  setting[prop]=null
 }
}

 

} //end of ddpanel object


//initialize instance of DD Drop Down Panel:

var defaultpanel=new ddpanel({
 ids: ["mypanel", "mypanelcontent", "mypaneltab"], // id of main panel DIV, content DIV, and tab DIV
 stateconfig: {initial: "1px", persiststate: true}, // initial: initial reveal amount in pixels (ie: 5px)
 animate: {enabled: true, steps: 5}, //steps: number of animation steps. Int between 1-20. Smaller=faster.
 pointerimage: {enabled: true, src: ["/ReadM/arrow-down.gif", "/ReadM/arrow-up.gif"]},
 closepanelonclick: {enabled: true} // close panel when links or elements with CSS class="closepanel" within container is clicked on?
})