Re: window groups

[Richard M Stallman <rms@gnu.org>]

    One of the problems of integrating ECB into Emacs is to avoid that
    "other" Emacs operations interfere with those of ECB (where other
    operations include popping up a *help*, *info*, or *backtrace* window).

This is an attempt to design a feature to distinguish between the
"editing area" and other add-ons, it seems.  Is that right?

But it also attempts to generalize this by allowing for more than one
group.  Do you see a scenario in which having more than one window
group in one frame would be used?  Without such a scenario, we have no
basis to think about what operations ought to do in such a case, and thus
no basis for the generalization.

Based on what you've said, it seems that there are three kinds of
buffers that might appear in something like ECB.  (I am partly guessing,
since I have not seen ECB itself.)

* File buffers

* Special buffers of ECB

* Other buffers such as *Help*, *Info*, and so on.

I think the right way to design this feature is to figure out the
right thing to do with windows for these three kinds of buffers,
and then design an interface to request that.

But we should not try to make it any more general than that
until we have use cases to guide our thinking about them.

    By default `display-buffer' does not invoke `split-window' with GROUP
    set to t - hence these windows always appear outside the rectangular
    ares reserved for group windows.  The same holds for any application
    that is not aware of the group the selected window belongs to.

    ...

    Interactively, `split-window-horizontally' and `split-window-vertically'
    would call `split-window' with GROUP set to t iff WINDOW is part of a
    group.

What about C-x 4 C-f?  If you do that inside ECB, should the new window
be part of the ECB group?