Re: Feature Request == Impl Howto question

[Eli Zaretskii]

> Date: Fri, 03 Mar 2023 20:41:19 -0800
> From: "T.V Raman" <raman@google.com>
> 
> In recent versions of Emacs, if you press a prefix key and wait,
> there is a message in the echo area that shows the prefix key that was
> pressed.

Actually, this feature is very old, probably as old as Emacs itself.

> Feature request: would it be possible to define an event handler from
> elisp for this; if so I could use it to play a short sound

You mean, to call a hook when we display that?  Should be easy, I
think; patches welcome.

> and preferably with a configurable timeout before that elisp-handler
> is invoked. Is this possible?

The timeout is already configurable, see the variable echo-keystrokes.