Long vertical forms that scroll with the tabbing to keep cursor on screen

Question

I have a tall vertical form that is roughly 2000px in height.
If the user tabs through the fields they will 'fall off' the bottom
of the screen. Meaning, the cursor will move to a field out of view
but the scrollbar will not nudge down automatically to compensate
and keep the cursor in view. Ideally the scrollbars would move with
the cursor as they do when tabbing through a traditional html form.
Any help is appreciated. Thanks.
--Lokesh

Answer 1

I have had to do this very thing myself. Kinda wish it were
part of the normal framework...
anyway, here is an example application that does what you are
trying to do:
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="
http://www.adobe.com/2006/mxml">
<mx:Script>
<![CDATA[
private function checkPos(target:Object=null):void {
var yPos:Number = target.y+target.height;
debug.text = "";
var shiftAmt:Number = 0;
if (yPos>cont.verticalScrollPosition+cont.height) {
shiftAmt = yPos-(cont.verticalScrollPosition+cont.height);
debug.text+="move down: "+shiftAmt+"\n";
} else if (yPos<=cont.verticalScrollPosition) {
shiftAmt = yPos-(cont.verticalScrollPosition+target.height);
debug.text+="move up: "+shiftAmt+"\n";
cont.verticalScrollPosition+=shiftAmt;
debug.text+="yPos: "+yPos+" view space:
"+cont.verticalScrollPosition+" -
"+(cont.verticalScrollPosition+cont.height);
]]>
</mx:Script>
<mx:Text id="debug" width="200" height="200" />
<mx:Canvas id="cont" width="200" height="200">
<mx:Button label="blorch1" y="0"
focusIn="checkPos(event.currentTarget)" height="20" />
<mx:TextInput focusIn="checkPos(event.currentTarget)"
y="100" height="20" />
<mx:Button label="blorch2" y="200"
focusIn="checkPos(event.currentTarget)" height="20" />
<mx:TextInput focusIn="checkPos(event.currentTarget)"
y="300" height="20" />
<mx:Button label="blorch3" y="400"
focusIn="checkPos(event.currentTarget)" height="20" />
</mx:Canvas>
</mx:Application>
If your form has a TON of controls, then you might want to
just make a function to automatically attach the listener in
actionscript... dunno which is easier. Writing onFocus="blahblah"
for each component is a drag but it's simple...
If there is an easier way to do this, I hope someone will say
so because this is how I have to do it and it's not very
fun.