Re: Extend the existing alternative set of key bindings for terminals (was: Second Ctl in keychord not detected)

[Ihor Radchenko <yantar92@gmail.com>]

Tim Cross <theophilusx@gmail.com> writes:

> Ihor Radchenko <yantar92@gmail.com> writes:
>
>> Also, it appears to me that we may keep losing terminal-incompatible
>> keys in future unless we provide some mechanisms to check terminal
>> compatibility automatically. Any ideas?
>>
>
> No ideas on this. Problem being I don't think there is anything like a
> terminfo service which will tell you about what capabilities/bindings a
> terminal emulator has.
>
> Just some thoughts on this -
>
> I fear any such attempt is likely to end up in a game of 'wack-a-mole'.
> While it makes some sense to provide alternative key bindings for Emacs
> running under the GNU Linux console, especially given the limitations
> under the console are well defined and constant, I'm not sure
> we can provide reliable solutions or tests for different terminal
> emulators (which will often 'reserve' various key bindings for their own
> use. This is especially true for more advanced terminal emulators like
> tmux.

We cannot even handle GNU Linux console now. Technically, man 5 terminfo
describes all the details on how to obtain terminal specs, but I am not
sure how to extract useful information for key binding purposes. Can we
do it programatically?

> An alternative which might be worth considering would be to improve
> documentation on using different popular terminal emulators, like tmux
> which could cover both adapting org key bindings and adapting the key
> bindings the emulator uses (a very quick google on this indicates you
> can change the tmux bindings, but that detail is apparently not well
> documented). Such documentation could include some guidelines on how to
> identify the issue, identify at what layer (window manager, terminal
> emulator, communication protocol etc) the problematic binding is being
> intercepted etc. The interactions at this layer can be complex and
> confusing, especially for users who don't have a clear model of how all
> the layers interact.  

I am not aiming there for now. Just basic terminals. tmux, WMs,
system-wide key bindings, etc are all higher level and can be configured
by the user. We _might_ want to support the most popular shadowed
bindings, but the problem with terminals is a lot more pressing. Users
cannot really change what is supported.

> A more long term strategy which I wonder if we should consider is
> whether org would benefit from adopting the use of something like the
> hydra package. Org needs a lot of key bindings - many more than most
> other modes. Available bindings are in short supply. Perhaps leveraging
> off something like hydras would both offer more flexibility and make it
> easier to manage. Likewise, could transient mode help in this area?

It may be a good idea. However, not all the users like hydra style.

Note that we already have org-speed-commands. They provide somewhat
similar functionality. We may extend them, allow using via transient
keymap, or integrate org-speed-command-help with hydra/transient.el.
Patches are welcome!

Best,
Ihor