https://www.jewishgen.org/JG/scripts/dropdowncontent.js

1//Drop Down/ Overlapping Content: http://www.dynamicdrive.com
2//**Updated: Dec 19th, 07': Added ability to dynamically populate a Drop Down content using an external file (Ajax feature)
3//**Updated: Feb 29th, 08':
4				//1) Added ability to reveal drop down content via "click" of anchor link (instead of default "mouseover")
5				//2) Added ability to disable drop down content from auto hiding when mouse rolls out of it
6				//3) Added hidediv(id) public function to directly hide drop down div dynamically
7
8//**Updated: Sept 11th, 08': Fixed bug whereby drop down content isn't revealed onClick of anchor in Safari/ Google Chrome
9//**Updated: April 9th, 10': Minor change
10
11var dropdowncontent={
12	disableanchorlink: true, //when user clicks on anchor link, should link itself be disabled (always true if "revealbehavior" above set to "click")
13	hidedivmouseout: [true, 2000], //Set hiding behavior within Drop Down DIV itself: [hide_div_onmouseover?, miliseconds_before_hiding]
14	ajaxloadingmsg: "Loading content. Please wait...", //HTML to show while ajax page is being feched, if applicable
15	ajaxbustcache: true, //Bust cache when fetching Ajax pages?
16
17	getposOffset:function(what, offsettype){
18		return (what.offsetParent)? what[offsettype]+this.getposOffset(what.offsetParent, offsettype) : what[offsettype]
19	},
20
21	isContained:function(m, e){
22		var e=window.event || e
23		var c=e.relatedTarget || ((e.type=="mouseover")? e.fromElement : e.toElement)
24		while (c && c!=m)try {c=c.parentNode} catch(e){c=m}
25		if (c==m)
26			return true
27		else
28			return false
29	},
30
31	show:function(anchorobj, subobj, e){
32		if (!this.isContained(anchorobj, e) || (e && e.type=="click")){
33			var e=window.event || e
34			if (e.type=="click" && subobj.style.visibility=="visible"){
35				subobj.style.visibility="hidden"
36				return
37			}
38
39			var horizontaloffset=(subobj.dropposition[0]=="left")? -(subobj.offsetWidth-anchorobj.offsetWidth) : 0 //calculate user added horizontal offset
40			var verticaloffset=(subobj.dropposition[1]=="top")? -subobj.offsetHeight : anchorobj.offsetHeight //calculate user added vertical offset
41			subobj.style.left=this.getposOffset(anchorobj, "offsetLeft") + horizontaloffset + "px"
42			subobj.style.top=this.getposOffset(anchorobj, "offsetTop")+verticaloffset+"px"
43			subobj.style.clip=(subobj.dropposition[1]=="top")? "rect(auto auto auto 0)" : "rect(0 auto 0 0)" //hide drop down box initially via clipping
44			subobj.style.visibility="visible"
45			subobj.startTime=new Date().getTime()
46			subobj.contentheight=parseInt(subobj.offsetHeight)
47			if (typeof window["hidetimer_"+subobj.id]!="undefined") //clear timer that hides drop down box?
48				clearTimeout(window["hidetimer_"+subobj.id])
49			this.slideengine(subobj, (subobj.dropposition[1]=="top")? "up" : "down")
50		}
51	},
52
53	curveincrement:function(percent){
54		return (1-Math.cos(percent*Math.PI)) / 2 //return cos curve based value from a percentage input
55	},
56
57	slideengine:function(obj, direction){
58		var elapsed=new Date().getTime()-obj.startTime //get time animation has run
59		if (elapsed<obj.glidetime){ //if time run is less than specified length
60			var distancepercent=(direction=="down")? this.curveincrement(elapsed/obj.glidetime) : 1-this.curveincrement(elapsed/obj.glidetime)
61			var currentclip=(distancepercent*obj.contentheight)+"px"
62			obj.style.clip=(direction=="down")? "rect(0 auto "+currentclip+" 0)" : "rect("+currentclip+" auto auto 0)"
63			window["glidetimer_"+obj.id]=setTimeout(function(){dropdowncontent.slideengine(obj, direction)}, 10)
64		}
65		else{ //if animation finished
66			obj.style.clip="rect(0 auto auto 0)"
67		}
68	},
69
70	hide:function(activeobj, subobj, e){
71		if (!dropdowncontent.isContained(activeobj, e)){
72			window["hidetimer_"+subobj.id]=setTimeout(function(){
73				subobj.style.visibility="hidden"
74				subobj.style.left=subobj.style.top=0
75				clearTimeout(window["glidetimer_"+subobj.id])
76			}, dropdowncontent.hidedivmouseout[1])
77		}
78	},
79
80	hidediv:function(subobjid){
81		document.getElementById(subobjid).style.visibility="hidden"
82	},
83
84	ajaxconnect:function(pageurl, divId){
85		var page_request = false
86		var bustcacheparameter=""
87		if (window.XMLHttpRequest) // if Mozilla, IE7, Safari etc
88			page_request = new XMLHttpRequest()
89		else if (window.ActiveXObject){ // if IE6 or below
90			try {
91			page_request = new ActiveXObject("Msxml2.XMLHTTP")
92			}
93			catch (e){

94				try{
95				page_request = new ActiveXObject("Microsoft.XMLHTTP")
96				}
97				catch (e){}
98			}
99		}
100		else
101			return false
102		document.getElementById(divId).innerHTML=this.ajaxloadingmsg //Display "fetching page message"
103		page_request.onreadystatechange=function(){dropdowncontent.loadpage(page_request, divId)}
104		if (this.ajaxbustcache) //if bust caching of external page
105			bustcacheparameter=(pageurl.indexOf("?")!=-1)? "&"+new Date().getTime() : "?"+new Date().getTime()
106		page_request.open('GET', pageurl+bustcacheparameter, true)
107		page_request.send(null)
108	},
109
110	loadpage:function(page_request, divId){
111		if (page_request.readyState == 4 && (page_request.status==200 || window.location.href.indexOf("http")==-1)){
112			document.getElementById(divId).innerHTML=page_request.responseText
113		}
114	},
115
116 init:function(anchorid, pos, glidetime, revealbehavior){
117		var anchorobj=document.getElementById(anchorid)
118		if (anchorobj)
119			var subobj=document.getElementById(anchorobj.getAttribute("rel"))
120		if (!anchorobj || !subobj)
121			return
122
123		var subobjsource=anchorobj.getAttribute("rev")
124		if (subobjsource!=null && subobjsource!="")
125			this.ajaxconnect(subobjsource, anchorobj.getAttribute("rel"))
126
127		subobj.dropposition=pos.split("-")
128		subobj.glidetime=glidetime || 1000
129		subobj.style.left=subobj.style.top=0
130		if (typeof revealbehavior=="undefined" || revealbehavior=="mouseover"){
131			anchorobj.onmouseover=function(e){dropdowncontent.show(this, subobj, e)}
132			anchorobj.onmouseout=function(e){dropdowncontent.hide(subobj, subobj, e)}
133			if (this.disableanchorlink) anchorobj.onclick=function(){return false}
134		}
135		else
136			anchorobj.onclick=function(e){dropdowncontent.show(this, subobj, e); return false}
137
138		if (this.hidedivmouseout[0]==true) //hide drop down DIV when mouse rolls out of it?
139			subobj.onmouseout=function(e){dropdowncontent.hide(this, subobj, e)}
140	}
141}