bug#32536: displayed width of man pages

[martin rudalics]

> 1. In Man-mode we have to add hook window-size-change-functions only
>     buffer-locally (using the arg LOCAL of add-hook) rather than globally,
>     because otherwise we can't remove this hook when a Man buffer is
>     not displayed anymore.

I can't follow you here.  Shouldn't we remove the hook _when_ a Man
buffer is not displayed anymore.  That is, when
'Man-window-size-change' detects that no Man buffer is displayed
anymore, remove it from 'window-size-change-functions' and re-add it
as soon as a Man buffer gets displayed again.

>     But the problem is that buffer-local
>     window-size-change-functions is called only when the current buffer
>     is in Man-mode.  If it's not, it's not called even when resizing of
>     the current non-Man buffer causes the resize of a Man-mode buffer
>     in an adjacent window.
>
> 2. What if the same Man-mode buffer is displayed in two adjacent windows
>     side-by-side?  I guess we need to find all windows with the same buffer,
>     compare their widths, and call Man-update-manpage only in the window
>     with minimal width.  Also it seems window-size-change-functions is
>     not called twice for every window with Man-mode buffer, this is good.

I think 'Man-window-size-change' will have to take care of such cases.
Also we'll have to look into how 'follow-mode' works when displaying a
Man buffer in several side-by-side windows.

> 3. When windows are resized using the mouse, is it possible to call
>     window-size-change-functions only when the mouse button is released?
>     This will increase responsiveness.  But the same problem will remain
>     for keyboard resizing with e.g. C-x } } }
>     A debounce-like function could help, but I can't find its Emacs Lisp
>     implementation anywhere.   I mean something similar to
>     https://stackoverflow.com/questions/15927371/what-does-debounce-do
>     It's easy to implement using timers, but better to have idiomatic
>     implementation.

I used a timer in 'mouse-autoselect-window'.  It might be interesting
to come up with a generic function.

martin