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View Full Version : How to horizontally offset a DHTML drop menu & add a filter



themind
08-29-2005, 08:53 PM
The below code is for a dhtml drop down menu. It can be viewed at www.pdmdigital.com/11DROPMENU.htm.

I have been learning as much as I can about scripting, but I cannot decipher what part of this script sets the visible (onMouseOver) div position. Right now it is set lined up to drop down exactly on the left side of the menu title. This isn't bad, but I think that a little offset to right (so it shows up diagonally down and to the right) might be appropriate for some applications.

Also, instead of just 'popping up' (making the invisible visible) I also cannot figure out where I would put in a transition filter (and yes I know they are not universally cross browser). I know that I would need to embed part into the CSS, but I was wondering if they only worked on images, or if they would work for the background color of the div itself, and where/how to do this. Hopefully one of you Javascripting wizards are up to the challenge of helping me (of course it may not even be a challenge for you guys). Any/all help is greatly appreciated, TM

<script type="text/javascript">

//Contents for menu 1
var menu1=new Array()
menu1[0]='<a href="#">Link 1 here</a>'
menu1[1]='<a href="#">Link 2 here</a>'
menu1[2]='<a href="#">Link 3 here</a>'
menu1[3]='<a href="#">Link 4 here</a>'

//Contents for menu 2
var menu2=new Array()
menu2[0]='<a href="#">Link 1</a>'
menu2[1]='<a href="#">Link 2</a>'
menu2[2]='<a href="#">Link 3</a>'

var menuwidth='200px' //default menu width
var menubgcolor='lightyellow' //menu bgcolor
var disappeardelay=400 //menu disappear speed onMouseout (in miliseconds)
var hidemenu_onclick="yes" //hide menu when user clicks within menu?

/////

var ie4=document.all
var ns6=document.getElementById&&!document.all

if (ie4||ns6)
document.write('<div id="dropmenudiv" style="visibility:hidden;width:'+menuwidth+';background-color:'+menubgcolor+'" onMouseover="clearhidemenu()" onMouseout="dynamichide(event)"></div>')

function getposOffset(what, offsettype){
var totaloffset=(offsettype=="left")? what.offsetLeft : what.offsetTop;
var parentEl=what.offsetParent;
while (parentEl!=null){
totaloffset=(offsettype=="left")? totaloffset+parentEl.offsetLeft : totaloffset+parentEl.offsetTop;
parentEl=parentEl.offsetParent;
}
return totaloffset;
}


function showhide(obj, e, visible, hidden, menuwidth){
if (ie4||ns6)
dropmenuobj.style.left=dropmenuobj.style.top=-500
if (menuwidth!=""){
dropmenuobj.widthobj=dropmenuobj.style
dropmenuobj.widthobj.width=menuwidth
}
if (e.type=="click" && obj.visibility==hidden || e.type=="mouseover")
obj.visibility=visible
else if (e.type=="click")
obj.visibility=hidden
}

function iecompattest(){
return (document.compatMode && document.compatMode!="BackCompat")? document.documentElement : document.body
}

function clearbrowseredge(obj, whichedge){
var edgeoffset=0
if (whichedge=="rightedge"){
var windowedge=ie4 && !window.opera? iecompattest().scrollLeft+iecompattest().clientWidth-15 : window.pageXOffset+window.innerWidth-15
dropmenuobj.contentmeasure=dropmenuobj.offsetWidth
if (windowedge-dropmenuobj.x < dropmenuobj.contentmeasure)
edgeoffset=dropmenuobj.contentmeasure-obj.offsetWidth
}
else{
var topedge=ie4 && !window.opera? iecompattest().scrollTop : window.pageYOffset
var windowedge=ie4 && !window.opera? iecompattest().scrollTop+iecompattest().clientHeight-15 : window.pageYOffset+window.innerHeight-18
dropmenuobj.contentmeasure=dropmenuobj.offsetHeight
if (windowedge-dropmenuobj.y < dropmenuobj.contentmeasure){ //move up?
edgeoffset=dropmenuobj.contentmeasure+obj.offsetHeight
if ((dropmenuobj.y-topedge)<dropmenuobj.contentmeasure) //up no good either?
edgeoffset=dropmenuobj.y+obj.offsetHeight-topedge
}
}
return edgeoffset
}

function populatemenu(what){
if (ie4||ns6)
dropmenuobj.innerHTML=what.join("")
}


function dropdownmenu(obj, e, menucontents, menuwidth){
if (window.event) event.cancelBubble=true
else if (e.stopPropagation) e.stopPropagation()
clearhidemenu()
dropmenuobj=document.getElementById? document.getElementById("dropmenudiv") : dropmenudiv
populatemenu(menucontents)

if (ie4||ns6){
showhide(dropmenuobj.style, e, "visible", "hidden", menuwidth)
dropmenuobj.x=getposOffset(obj, "left")
dropmenuobj.y=getposOffset(obj, "top")
dropmenuobj.style.left=dropmenuobj.x-clearbrowseredge(obj, "rightedge")+"px"
dropmenuobj.style.top=dropmenuobj.y-clearbrowseredge(obj, "bottomedge")+obj.offsetHeight+"px"
}

return clickreturnvalue()
}

function clickreturnvalue(){
if (ie4||ns6) return false
else return true
}

function contains_ns6(a, b) {
while (b.parentNode)
if ((b = b.parentNode) == a)
return true;
return false;
}

function dynamichide(e){
if (ie4&&!dropmenuobj.contains(e.toElement))
delayhidemenu()
else if (ns6&&e.currentTarget!= e.relatedTarget&& !contains_ns6(e.currentTarget, e.relatedTarget))
delayhidemenu()
}

function hidemenu(e){
if (typeof dropmenuobj!="undefined"){
if (ie4||ns6)
dropmenuobj.style.visibility="hidden"
}
}

function delayhidemenu(){
if (ie4||ns6)
delayhide=setTimeout("hidemenu()",disappeardelay)
}

function clearhidemenu(){
if (typeof delayhide!="undefined")
clearTimeout(delayhide)
}

if (hidemenu_onclick=="yes")
document.onclick=hidemenu

</script>