Re: [Usability]clipboard/selection behavior

[Gregory Merchan <merchan phys lsu edu>]

On Sat, Nov 02, 2002 at 11:23:01AM -0500, Havoc Pennington wrote:
> Hi,
> 
> Some discussion on the KDE end about changing how CLIPBOARD/PRIMARY
> work:
> 
>   http://lists.kde.org/?t=103606013800001&r=1&w=2
>   http://lists.kde.org/?t=103614869600001&r=1&w=2

Check my summary. I'm going to say "text" but I mean anything which can
be cut, copied, or pasted.

1) CLIPBOARD is not to change.
2) Some conventions of the PRIMARY selection are not clear.
   Should text be available by the PRIMARY selection when:
   a) it has been highlighted by keyboard?
   b) nothing is highlighted?
      E.g., Text was highlighted and then the cursor was repositioned
       causing the highlighting to disappear.
   c) the text could not have been highlighted?
      E.g., A link in a web browser cannot be highlighted to be copied
       to the clipboard.
3) If text which is highlighted must be available by the PRIMARY selection,
   then:
   a) it is not possible to highlight text in more than one window at the
      same time, and
   b) as a consequence, highlighting text to allow speedy changes in text
      fields will cause loss of any pre-existing highlight.
4) Allowing text to be highlighted without being available by the PRIMARY
   selection would confuse users of Button2Click data transfer as exhibited,
   for example, by xterm.
5) Windows(tm) allows text to be highlighted in more than one window at the
   same time, and so users migrating from that platform may be confused
   by the uniqueness of highlighted text.


My comments:
1) Good.
2) a) Yes. Text highlighted by keyboard should be available by PRIMARY.
   b) Yes. Unless keeping the data presents a problem - e.g., the
      variables determining how the highlight is drawn also determine
      what data is available. 
      Programs which do not make text available beacuse the highlight was
      removed should also disown the PRIMARY selection.
   c) Yes. Even when text is normally highlighted there may be invisible
      parts. For example, an HTML renderer may make rendered text
      available as well as the underlying HTML code.
   For all of these there is also familiarity.
3) This is, perhaps unfortunately, true. But, see below.
4) It would also confuse users of programs such as the googlizer. There
   are many simple and useful programs which may be written in this way.
   It would be rash to abandon this without consideration of the interfaces
   which it makes possible. But, see below.
5) I never noticed that and don't know how or for what I'd make use of it.


The not-too-controversial question is:
  Should text which is not available by PRIMARY remain highlighted?

I say, "Why not? As long as it's a different color, or somehow
distinguishable."  GNU Emacs, despite being absurdly broken in its
clipboard use, allows use of the SECONDARY selection. I don't remember
what the default is, but I have it set up to highlight PRIMARY with
light blue and SECONDARY with pink. To use it, do what you would do to
use PRIMARY while holding down the Meta key. I can't use it much right
now because my Meta key is broken.

The problem I see with this for Gtk+ now is that it already changes the
color of the highlight when the window loses focus. PRIMARY hasn't changed,
but its indicator has.


Cheers,
Greg Merchan