Re: Suggestion: Add discussion of input focus handling to select-window; add select-frame-window

[Eli Zaretskii <eliz@gnu.org>]

> From: Robert Weiner <rsw@gnu.org>
> Date: Sat, 16 Dec 2017 13:16:48 -0500
> Cc: Stefan Monnier <monnier@iro.umontreal.ca>, martin rudalics <rudalics@gmx.at>, 
> 	emacs-devel <emacs-devel@gnu.org>
> 
> ​When the user selects another window within the selected frame
> or a select-window is done on the selected frame, user input
> (typing) and programmatic input (insert) shifts from the prior
> window to the new window.

Correct for user input (but note the important exception of the
mini-window).  Not necessarily correct for 'insert' etc. -- many of
these APIs can work on a specified window, which is different from the
selected one.

> No frame change has occurred yet
> where user input like self-inserting characters goes is different.
> How can this not be part of your Emacs model?

As long as the selected frame is unchanged, the model holds: you need
only select the window.

> ​​Frame-level input focus is insufficient to describe the window to which
> keyboard input goes in all cases.

Keyboard input goes to the selected window of the selected frame.
Why isn't that description sufficient?

> Plus, if we want to see any changes in buffer-to-window mappings
> during the course of a function, we must invoke redisplay.

Not normally, no.  Normally, you select the frame and the window, and
then redisplay will do the rest automatically after your command
completes.  To need some change displayed in the middle of a command
is unusual.

> It is the description of the interrelations of these things that
> is not described in a single place anywhere, especially with code samples,
> making it difficult for programmers to see what must be done.

I don't understand why a complex task involving several steps must
necessarily be described in a single place.

Once again, I suggest to add a few notes with cross-references to the
existing nodes; I think this should be enough for those rare cases
where the reader might not realize that the complete job requires
doing several things together.