RE: View-quit in *Help* restores wrong window when display-buffer-reuse-frames is t

[Drew Adams]

>  > I have a dedicated *Help* frame.
>
> What is the semantics of a "dedicated frame"?

I should have said "special-display".

(add-to-list
 'special-display-buffer-names
 (list "*Help*" 'my-display-*Help*-frame...))

>  > Because of `pop-up-frames', `display-buffer' uses another
>  > frame, but I do sometimes switch to a different buffer in
>  > the same window. And I do sometimes split a window, so my
>  > frames are not always `one-window-p'.
>
> If you "dedicate" a frame to the Help buffer why do you want to switch
> to a different buffer in that frame?  Why do you want to split that
> frame's window?

I don't; I never said I did. I was describing my overall use, including my
use of `pop-up-frames', not my use of *Help*. You expressed some assumptions
about users with non-nil `pop-up-frames' and their never reusing a window
and never splitting a window. I was explaining that although I have
`pop-up-frames' non-nil, I still sometimes reuse or split some windows (not
*Help*, but others).

>  > If a new window or frame was popped up to display a view-mode
>  > buffer, then I expect quitting to delete the window and, if
>  > one-window-p, delete the frame too.
>
> I already explained that by default Help buffers are not dedicated thus
> `quit-window' won't necessarily delete the associated frame.

And I explained that I don't personally need you to delete the frame - I do
that myself. Deleting the window is sufficient (for *Help* or any other
buffer).

> If people want that we can change the behavior of view-mode
> but that would affect all clients of view-mode.  Alternatively
> we could make help-windows dedicated (if that helps).
>
> Currently `view-remove-frame-by-deleting' has to be set to get the
> effect you want.  We could make that non-nil by default.

I don't know or care what the default value is.
FWIW, I have that set to `t'.

>  > FWIW, my own code takes care of the latter part, so it is
>  > enough for me if the view-mode code simply does `quit-window'.
>  >
>  > If a new window or frame was not popped up to display the
>  > view-mode buffer, that is, if I manually switched to it in
>  > an existing window, then I want quitting that buffer/mode
>  > to restore the previous buffer that was in that window.
>  >
>  > Summary:
>  >     if pop-up, then quit => delete the window/frame
>  > if not pop-up, then quit => restore previous buffer for window
>
> Suppose you (1) pop up a view-mode window, (2) display a non view-mode
> buffer in that window, (3) display a view-mode buffer in that window,
> and (4) quit view-mode.  Whatever `view-mode-exit' does now, you'll
> complain.

No I won't. In that case, you can show again the non-view-mode buffer that
inhabited the window before the view-mode buffer that was quit.

If there was a buffer in the window before the view-mode buffer is placed in
it, then it's OK to show that buffer after quitting the view-mode buffer. If
there was no other buffer in the window before the view-mode buffer, then
there is no reason to display any buffer at all there - just delete the
window. And if the view-mode buffer is `one-window-p', then delete the frame
also.

>  >>- Exiting view-mode should ideally (1) kill a window that
>  >>  has been popped up for view-mode purposes and (2) show
>  >>  the earlier contents of the window when it has been
>  >>  usurpated by view-mode.
>  >
>  > That would be good. In my case, #1 is what I expect for the
>  > *Help* buffer. I have no problem with #2, assuming that it
>  > applies to buffers that were not popped up in another window.
>
> I wrote "ideally" and I had your usage pattern in mind.  But keep in
> mind that killing a window doesn't necessarily imply killing its frame.

I understand. Don't worry about the frame-killing part, at least for me. My
own code does that.

I personally think that the test of `one-window-p' should be sufficient for
deciding whether `delete-window' should also delete the frame, but I think
that some others might disagree with that. For my own needs, it is enough
that Emacs delete the window - my own code will then DTRT (for me) wrt the
frame.

>  > I haven't followed the current thread closely. If you have a
>  > Lisp-only patch I can try, I will do that.
>
> It's still the patch I sent you earlier.

Then I already provided my feedback, IIRC.

Thanks for working on this, BTW. I realize that it is not so easy to juggle
the many possibilities, including different use patterns.