How to handle both minor mode and major mode remapping a command? (was: Bug: org-kill-line shouldn't assume visual-line-mode means kill-visual-line)

How to handle both minor mode and major mode remapping a command? (was: Bug: org-kill-line shouldn't assume visual-line-mode means kill-visual-line)

[Ihor Radchenko]

Hi,

We have the following situation in Org mode:

1. Org mode remaps `kill-line' to `org-kill-line'
2. `org-kill-line' performs special action when point is on a heading
   and otherwise falls back to `kill-line'
3. visual-line-mode, if active, sets up minor mode map remapping
   `kill-line' to `kill-visual-line'

In the past, activating `visual-line-mode' caused Org mode binding to be
completely shadowed.

Later, we tried to fix the problem by
1. Overriding `visual-line-mode' remapping by force
2. Hard-coding a special case for `visual-line-mode' to call
   `kill-visual-line' instead of `kill-line' as a fallback in
   `org-kill-line'

However, the situation is not ideal.
Below is a recent bug report where user changed the default
remapping in `visual-line-mode-map' to something else (not considered by
Org)

I am wondering if there is some canonical way to handle similar scenarios
recommended for major modes.

Any suggestions?

Nathan Collins <nathan.collins@gmail.com> writes:

> Hello,
>
> In the latest version of org.el, at line 21367 [1], inside `defun
> org-kill-line`, we have
>
>      (if (bound-and-true-p visual-line-mode) 'kill-visual-line 'kill-line)))
>
> but I think instead this should just call whatever `kill-line` is
> bound to in `visual-line-mode-map`. By default, `visual-line-mode-map`
> remaps `kill-line` to `kill-visual-line`, but I remove this remap
> because I prefer the default `C-k` behavior. But in org-mode, I can't
> figure out a way to disable this behavior of `org-kill-line`, except
> by removing org-mode's remap of `kill-line` to `org-kill-line`, which
> loses the other fancy logic of `org-kill-line`.
>
> Cheers,
>
> -nathan
>
> [1]: https://git.savannah.gnu.org/cgit/emacs/org-mode.git/tree/lisp/org.el#n213667
>

-- 
Ihor Radchenko // yantar92,
Org mode maintainer,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: How to handle both minor mode and major mode remapping a command?

[Michael Heerdegen]

Ihor Radchenko <yantar92@posteo.net> writes:

> I am wondering if there is some canonical way to handle similar scenarios
> recommended for major modes.
>
> Any suggestions?

Why not, as in similar situations, define a `kill-line-function'
variable with default value `kill-line-default-function' which is a
function (more or less our current `kill-line').

Any mode that wants to modify the behavior would `add-function' on that
variable binding.  We would have one single place where the thing is
controlled, while the behavior can still be modified by future modes.

`add-function' has priorities that can be used to specify which mode
should win in case of conflicts.


Michael.

Re: How to handle both minor mode and major mode remapping a command?

[Ihor Radchenko]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> Ihor Radchenko <yantar92@posteo.net> writes:
>
>> I am wondering if there is some canonical way to handle similar scenarios
>> recommended for major modes.
>>
>> Any suggestions?
>
> Why not, as in similar situations, define a `kill-line-function'
> variable with default value `kill-line-default-function' which is a
> function (more or less our current `kill-line').
>
> Any mode that wants to modify the behavior would `add-function' on that
> variable binding.  We would have one single place where the thing is
> controlled, while the behavior can still be modified by future modes.

That will, of course, work. However, I feel that it will only solve this
exact problem, but nothing more.

Just in Org mode, we also need special handling of
`move-beginning-of-line' and `move-end-of-line' for visual mode (for the
same reasons). Does it mean that we need to introduce yet more
"*-function" variables? It will not be scalable.

What I was thinking about is some way for command remapping to:

1. remap overriding minor modes
2. be able to access commands (possible remapped) that are shadowed by
   current remapping

Maybe what I want is advice flexibility for keymaps. (not sure)

-- 
Ihor Radchenko // yantar92,
Org mode maintainer,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>