bug#39902: 28.0.50; Marking in dired with active region

[Drew Adams <drew.adams@oracle.com>]

> FWIW, most of these browsers have different
> kinds of "views", and I have in mind the view
> that is not line based but uses a grid of icons
> with names under them.  Marking a region with
> the mouse happens continuously.
> 
> What I want to say here is that the current
> behavior makes no sense to me.  And I very much
> think that I'm not the only one.  I don't want
> to justify why I have this expectation and be
> told that my mental model is wrong...
> When some users are confused by the current
> behavior, it would be good to improve Emacs when
> it's simple as it is here.

Ah, I think maybe I'm starting to understand.  (Maybe.)

In your external app you'll select some files, in
a particular order (e.g. as presented in that app).
You might do so using the mouse (in that app), but
that's not really important for the use of Emacs.

Then, you want that selection, made in that app, in
its particular order, to be reflected as a selection
in Dired.

Is that right, so far?

If so, what if the order is so different from the
sort order in Dired that the resulting "selection"
in Dired would be a noncontiguous region - multiple
zones, as Juri mentioned?  Is that a problem?

Assuming that's not a problem (e.g. Dired has the
same order, since the original order came from
Dired - but see below), how would you transfer a
selection in the external app to a selection
(region) in Emacs?

If that's not really needed, then why wouldn't
just `g' in Dired (to refresh the listing)
followed by, say, `C-u 9999 m' work?

I guess `g' might not do what you want if Dired's
sort order is by date/time, since the external app
could have updated some files, making them more
recent, so the order in Dired would change from
what it was originally, and the Dired selection
you would need might even be noncontiguous (?).

Dunno whether I'm on the right track in starting
to understand.  Let me know.

(I'm not trying to make you justify why you want
what you want.  I'm just trying to understand it
better.)