Re: Bikeshedding go! Why is <M-f4> unbound?

[Lennart Borgman <lennart.borgman@gmail.com>]

On Mon, Jan 17, 2011 at 3:37 PM, Óscar Fuentes <ofv@wanadoo.es> wrote:
> grischka <grishka@gmx.de> writes:
>
>>> What I really hoped to discuss where the technical difficulties. Emacs
>>> does not currently have a way to let key binding fall back to the OS
>>> binding. I am not sure it is trivial and I have forgotten the details.
>>
>> It is nontrivial to say the least.
>>
>> Unlike XEmacs, GNU Emacs is still a console application at its heart.
>> It wants to "read" events in a loop from an input stream until it
>> finds them complete as a "key-sequence".  No function seems to exist
>> that could deal with events that are already read.
>
> This is unnecesary. The Windows event loop coded into Emacs already
> receives Alt-F4 in a single event. What is needed is to determine from
> that event loop if there is a binding for Alt-F4 (created with *-set-key
> etc). Once we know that there is no such binding, it is trivial to send
> back the Alt-F4 event back to Windows.

That is correct IF you can send it back directly, i.e. just forward it
to w32 default message loop. If you can't do it directly (because for
example that it is hard to determine directly if there is a key
binding) then I do not think it is that simple. (See my other reply
for why.)