transient-prefix: Add display-action slot

[josephmturner]

This change lets each transient-prefix display according to its own display-buffer-action. Resolves this discussion:

#303

I have not thoroughly tested this code, but it seems to work.

If you think this kind of change is appropriate, I'll fixup this commit with an update to the manual and force push.

Thank you!!

[tarsius]

Let's name it just display-action and place it before refresh-suffixes.

[josephmturner]

Let's name it just display-action and place it before refresh-suffixes.

Done!

[josephmturner]

I pushed another commit which adds the :mode-line-format also.

[josephmturner]

And documentation.

[josephmturner]

This last force-push avoids an incorrect use of oref-default.

[josephmturner]

Should :display-action nil override transient-display-buffer-action in the same way that :mode-line-format nil overrides transient-mode-line-format?

[tarsius]

:initform is set to 'undefined so that passing :mode-line-format nil
to transient-define-prefix overrides transient-mode-line-format.

Eieio already has a "no value" value -- the value of the eieio--unbound variable. Just don't set :initform and that will be used. You then have to use slot-boundp to check whether a slot is unbound. If you skip that check and the slot is unbound, oref signals an unbound-slot error.

[tarsius]

Should :display-action nil override transient-display-buffer-action in the same way that :mode-line-format nil overrides transient-mode-line-format?

Probably not. Do you see a use-case for that?

[josephmturner]

:initform is set to 'undefined so that passing :mode-line-format nil
to transient-define-prefix overrides transient-mode-line-format.

Eieio already has a "no value" value -- the value of the eieio--unbound variable. Just don't set :initform and that will be used. You then have to use slot-boundp to check whether a slot is unbound. If you skip that check and the slot is unbound, oref signals an unbound-slot error.

Thanks, I had searched the eieio docs for "svar", but came up empty-handed. Force-pushed.

[josephmturner]

Should :display-action nil override transient-display-buffer-action in the same way that :mode-line-format nil overrides transient-mode-line-format?

Probably not. Do you see a use-case for that?

Nope, just checking.

[tarsius]

Thanks! I've rebased and squashed some minor rearrangements.

[josephmturner]

Thanks! I've rebased and squashed some minor rearrangements.

Thank you!!!