Topic awaiting preservation: js caps lock detection

Hi there,
I was just playing around with a form, and I was wondering if it's possible to detect when the Caps Lock is pressed.
I've seen a function that doesn't really detect the Caps Lock, it only assumes that the Caps Lock is pressed when it notices uppercase characters without the Shift key being pressed.

Is this possible? Can javascript detect the Caps Lock key?

Here's a small test, but it didn't seem to work:

<script type="text/javascript">
function capsLock(e){
if(e.which==20)
alert("Caps Lock");
}
document.onkeypress=capsLock;
</script>

You can't detect it correctly; in fact, as far as I'm aware, nothing at all in software can detect Caps Lock, because the keyboard handles it itself and just sends capital letters. Checking for capitals without shift is a good (and the only) way to do it.

I gotta believe that the machine knows if the caps lock is on. If you go to log into a Windows XP/2003 box, and the caps lock is on, you get a warning that caps lock is on.

So javascript can't detect Caps Lock state then? I was trying to make a function that when Caps Lock is ON, then there will be a indicator next to the form, and if it's OFF, the no indicator.

What you can do actually is when someone enters a text field, determine whether the shift key is down when they type. If the characters are upper case and the shift key isn't pressed then it means the caps lock is on.

But it wouldn't let you have a consistent indicator.



.:[ Never resist a perfect moment ]:.

I'm pretty sure your computer does know if Caps Lock is on. In Microsoft Word, pressing that key displays CAPS in the corner...somewhere. I think. I don't see it right now, but I'm sure I've seen it do that before.

[edit]Oh, and I agree with Pugzly's point.[/edit]



(Edited by Danaan on 07-25-2005 22:57)

Ok, thanks. I just wanted to confirm if this was possible.

quote:

---

bitdamaged said:

What you can do actually is when someone enters a text
field, determine whether the shift key is down when they type. If the
characters are upper case and the shift key isn't pressed then it means
the caps lock is on.

But it wouldn't let you have a consistent indicator.

---

That test is slightly flawed. Consider someone entering uppercase characters using ALT+keycode - neither shift nor caps lock have to be used to do this.

If that's not really an issue (i.e. if your users aren't likely to try and break your system), then there are plenty of examples that do just that (found via Google). Here is one such example:

http://www.howtocreate.co.uk/jslibs/htmlhigh/capsDetect.html

Hope this helps,
Dan