Re: Selection changes in revno 100822

[Eli Zaretskii <eliz@gnu.org>]

> From: "Stephen J. Turnbull" <stephen@xemacs.org>
> Cc: David De La Harpe Golden <david@harpegolden.net>,
>     cyd@stupidchicken.com,
>     jan.h.d@swipnet.se,
>     emacs-devel@gnu.org
> Date: Sun, 15 Aug 2010 22:52:39 +0900
> 
> Eli Zaretskii writes:
> 
>  > I wasn't talking about clipboard pasting, I was talking about
>  > pasting from the primary selection.
> 
> AFAIK you can't copy/paste from the Windows primary selection (unless
> it's a situation where moving doesn't make sense, such as between
> disks in Explorer), although you can drag it somewhere else.

You are confused (not that it's hard to become one in this thread).  I
was talking about X here, not about Windows.

>  > Please give me some minimal credit that I know what I'm talking
>  > about.
> 
> That's kind of difficult when you also wrote this:
> 
>  > We've been there before.  As far as Windows use patterns are
>  > concerned, we disagree.  I expect most Windows users disagree with
>  > you, because there's only the clipboard, so no way of having 2
>  > different selection types and 2 different ways of pasting.
> 
> On X11 there are three different selection types, in fact, and two
> different ways of pasting.  That is a fact, and saying the Windows
> users don't believe it doesn't make it any less true.

You are confused.  The "as far as Windows use patterns" part is about
my past disagreements with David regarding how to map 3 selection
types on X to a single clipboard on Windows.  The "give me some
credit" part is about the distinction between these 3 selection types
on X: somehow, David thought I didn't understand that, and that I
needed a lecture about it.

> And in fact, there *is* an analog to the X11 primary selection on
> Windows, and it can only be manipulated with the mouse.  That's what
> is used for drag'n'drop.  AFAIK there is no way to paste that
> selection from the keyboard (C-v) without using cut (C-x) or copy
> (C-c) first (in fact C-v will overwrite it with the contents of the
> clipboard), but in some applications (eg, the Explorer) it can be
> dragged, which causes either movement or copying depending on context,
> and does not affect the clipboard.  Am I wrong?

You are talking about drag'n'drop, which does have a direct analog on
X.  I don't think drag'n'drop, in its current shape, could or should
be regarded as a kind of ``primary selection'' on Windows, that would
just make this discussion more confusing.  Drag'n'drop APIs _might_ be
a basis for implementing PRIMARY on Windows (assuming it can support
that -- I didn't research this issue, so I don't know), but unless and
until someone comes up with a patch to do that, MS-Windows users will
have to do without PRIMARY.

> Some experienced X
> users use the "drag to select, middle button to paste" and "drag to
> select, drag again to move" gestures a lot (when available, drag to
> move isn't standard part of toolkits AFAIK, although some apps
> implement it).  If available, Windows users might like to use it too.

But it isn't available on Windows, not without overwriting the
clipboard with selected text.  Unless you are willing to give up
having the primary selection available to other apps, which is what
the emulation of PRIMARY on Windows already does in Emacs.

Anyway, the issue of why the primary selection and the clipboard
should be set separately in Emacs and by different gestures is quite
clear (although it would be nice if it were explained in NEWS in more
detail), so let's not beat this dead horse anymore.  The only issue
that still needs to be discussed (IMO) is which gestures should cause
PRIMARY to be set with the selected text and which shouldn't.  This
should be decided for X first; the mapping to Windows' limitations
should come later.