Re: xterm [menu] key definition

[Ergus <spacibba@aol.com>]

On Wed, Aug 25, 2021 at 12:47:17PM +0200, tomas@tuxteam.de wrote:
>On Wed, Aug 25, 2021 at 11:32:12AM +0200, Ergus wrote:
>> On Wed, Aug 25, 2021 at 09:06:40AM +0200, tomas@tuxteam.de wrote:
>
>[...]
>
>> >I wouldn't expect an "xterm API". The "API" are the escape sequences :)
>> >
>> I meant an api to ask xterm about modifyFunctionKeys value for a general
>> solution.
>
>I see.
>
>> For this specific case kf16=\E[29~ unconditionally; so we don't care.
>
>FWIW, I am surprised about the correspondence "F16" to "menu". For
>one, most (PC) keyboards only go up to 12 [1], for the other, CUA [2]
>(the only "written" standard I can come up on those things) states
>that "menu" is F10. Probably some popular application started with
>it or something.
>
There is a miss understanding here. What is normally called menu in
  <f10> refers to the menu-bar in all the applications (usually the File
  section in the menu-bar; something emacs gui already has and works fine
  BTW)

The [menu] key we are discussing here is a completely different
beast. Associated normally with right click action. You can try on any
editor, office or graphical application around.

>> >When you say "emacs assumes" you are referring to some "GUI guts"?
>> >
>> I am referring to what emacs understand for the same key on gui or xterm.
>
>OK.
>
>> >>Part of my intention is to minimize the "special" customization required
>> >>when using xterm+emacs (either in Xdefaults or in init.el); any fancy
>> >>more specific customization can be made latter by the user when he gets
>> >>familiar with the rest of the environment (GNU/Linux, xterm, emacs,
>> >>Elisp, the command line interface, the OS configuration system...) for
>> >>new users it is like getting into Narnia the fist week/month.
>
>The best, IMO, would be to agree upon whatever escape sequences for
>those newer keys and convince terminal folks to implement that.
>
This is already in xterm give a look to the Yuri Khan email:

https://github.com/Maximus5/xterm/blob/master/src/input.c#L1429
https://github.com/Maximus5/xterm/blob/master/src/input.c#L1460

>Guessing around (aka "F16" == "menu") is only going to make the tangle
>deeper.  It is deep already :)

>> >The lowest common denominator would be to assume that there is no
>> >"print" (aka PrintSc) key, same for "menu", more so for "windows".
>> >
>> I started the thread asking because now I understand that in general the
>> [menu] key seems to emit the same than <f16>. What I don't know is if
>> the PrintSc does the same with a another key.
>
>See above.
>
>> The other think clear now is that \E[29~ is NOT [print]. It is either
>> <f16> (from xterm's source code and terminfo) or [menu] (as menu key
>> seems to emit the same X event in all the cases.)
>>
>> So [menu] in general seems to be a shortcut for <f16>? Probably you know
>> better than me about this conventions or where can be found in some X
>> sources?
>
>See above. I didn't know that and I can't even find hints about who
>has come up with it. If xterm maps both to the same escape sequence,
>perhaps one avenue could be to research whence that commit comes and
>ask the person whodunit. Perhaps she's still around :-)
>
>Who knows... perhaps that was the labeling on one particularly venerated
>workstation at some MIT lab ;-)
>
xterm maintenance is currently a single man effort; the other emulators
try to keep compatibility with it; including applications like tmux.

>> >>I expect that most of the emacs features work and behave as similar as
>> >>possible when using the xterm, tty or gui without customization,
>> >>everything out of the box.
>
>Don't get me wrong, I understand your goal and think it's a laudable
>one, but the layers you are talking to didn't know a "menu" key (or
>a "print" key, for that) exists when they were born. Some people
>(me included) don't have yet a "menu" key on their keyboards (nor an
>F16 key). So that kind of keyboards is around and will be with us
>for the next, say, 5 to 10 years. By then, we'll have a new key,
>this time it'll be Google's vanity key, say "search" [4].
>
The probably google will make it's kay an alias for fX where X is any
vale > 12 not taken already.

>Relying too much on a "menu" key being there doesn't look to me like
>a smart move just yet.
>
>But, of course, getting those exotic keys into the different terms
>(I'd try to include the Linux console) seems a worthy goal in
>itself.
>
>Perhaps a smart move would be to get a Linux distro (e.g. Debian)
>on board? They go to some lengths in making keyboard behaviour
>uniform across worlds (e.g. xterm/Linux console).
>
look at the links above.

>Cheers
>
>[1] https://xkcd.com/670/
>[2] https://en.wikipedia.org/wiki/Common_User_Access
>[3] It's a refurb Thinkpad X230, which was introduced around 2012.
>   So it's not /quite yet/ a museum piece. The last ones in refurb
>   shops seem to have been flushed out pretty recently, possibly
>   accelerated by pandemics.
>[4] I should set up a bet.
>
> - t