Re: Selection changes in revno 100822

[Eli Zaretskii <eliz@gnu.org>]

> From: "Drew Adams" <drew.adams@oracle.com>
> Cc: <jan.h.d@swipnet.se>, <emacs-devel@gnu.org>,
>         "'David De La Harpe Golden'" <david@harpegolden.net>
> Date: Sat, 14 Aug 2010 21:48:50 -0700
> 
> You don't say here whether selecting using the mouse copies to the
> kill-ring.

Since the default value of mouse-drag-copy-region is now nil, it
doesn't by default.

> And you don't say whether C-y after selecting with the mouse yanks what was
> selected.

No, it doesn't yank, for the same reason (I think).

> > if you mark a region with C-SPC and do C-w, you won't be able
> > to paste the text in with mouse-2, unlike earlier Emacs versions.
> 
> My primary concern right now (because it is what I use most now) is the behavior
> on Windows, but I do care also about the behavior on other platforms.
> 
> And I'm curious.  What is the rationale for such behavior (C-w followed by
> mouse-2 will prevent it from yanking what was killed)?

Apparently, the GUI recommendations on X are now that the primary
selection is used only in conjunction with the mouse, while the
clipboard is used only in conjunction with keyboard cut/paste (C-c,
C-v, etc.).  IOW, mouse selection and mouse-2 style copy/paste is no
longer regarded as _the_ copy/cat-n-paste operations, only the
keyboard ops are.

See David's mail a few hours ago in this thread.

> Apparently C-SPC plus motion to select, followed by mouse-2, does
> yank what was selected (good)

Since C-SPC+motion selects the text, and selected text is "yank"able
with mouse-2, yes.

> but if you use C-w (or M-w, for that matter) before clicking
> mouse-2 then nothing is yanked (bad).

If the text was selected with the mouse (or any other way that
activates the mark) prior to C-w, then you can still "yank" with
mouse-2, by virtue of that selection.  So this is still "good" in most
use-cases.

> I really don't understand what is going on (why).  Is this all just about
> limiting Emacs to make it more like other apps on X?

That's my current understanding, yes.  "User expectations" and all
that.

> AFAICS we haven't yet gotten a simple description of the proposed changes, in
> terms of how they will affect users: use cases, pros & cons, what will change
> and why.

David's mail comes close, except that Emacs currently does not behave
100% according to what he describes:

  clipboards aren't overwritten when you merely select text.
  clipboards are overwritten when you cut/copy (C-x/C-c)
  clipboards are not inserted when you click mouse-2.
  clipboards are inserted when you paste (C-v)
  primary selections are overwritten when you merely select text.
  primary selections are not overwritten when you cut/copy (C-x/C-c)
   (but they've probably already just been overwritten because you
    selected text just before you cut/copied).
  primary selections are inserted when you click mouse-2.
  primary selections are not inserted when you paste (C-v)