Re: cursor doesn't show through transparent images in emacs 22, unlike emacs 21

["Ken Manheimer" <ken.manheimer@gmail.com>]

On 8/22/06, David Kastrup <dak@gnu.org> wrote:
> Richard Stallman <rms@gnu.org> writes:
>
> >       with this bug, however, it's hard to
> >     tell whether or not the cursor is in the window or another.
> >
> > I see why this is a problem.
> >
> > So I suppose that anything which makes the cursor visible
> > would solve the problem.  Right?
>
> I don't know why Ken has chosen not to reply on the list, but he told
> me in private that he has disabled cursor blinking (or rather, lets it
> commence only after 30 seconds).

it was just an oversight - i meant to reply to the list and you, but
forgot to hit "reply-to".

what i wrote:

  sorry, i didn't realize you had directed that to me.

  no, but i delay cursor bliking for 20 seconds, because i find it
  distracting, and only want it happening when imy attention has gone
  away to something else and is coming back.

  are you suggesting that the blinking would be enough of a cue for an
  active buffer?

> Of course, the blinking will make a very visible difference for the
> default settings.  So our worry is just for people who have tampered
> with the defaults.

the blink of the border is a distinct cue.  i still think the absence
of the solid cursor is misleading, in this case.  to put it in an
affirmative sense, the presence of the solid cursor would be more
clear.

> His proposal to use transparency is not really useful except for
> special cases since
> a) images are not always the size of his small icons, and so could be
> vastly more obnoxious when blinking

i understand that icons are often large, so that a solid cursor would
be distracting and garish, doubly so with blinking.

> b) images don't all have transparency.

i think it's reasonable in those cases to not expect the cursor to
show through.  that said, i wouldn't mind having a display option for
the images to xor the image colors, or something like that, when the
cursor is on them.

> Different ways to do this:
>
> a) offer to make the cursor border on selected frames thicker
>
> b) offer to use a different cursor color for selected frames

i suppose both of those would work.  from seeing the effect of the
solid cursor showing through in emacs 21, my impression is that it's
the most natural - consistent and clear - signal, in cases like my
character-sized icons, where it is suitable.

as i think i suggested in a previous message, the solution i would
prefer would be to have some way to qualify icons so that they get a
solid cursor in their transparent areas, and the default would be to
have it inactive.  eg, a qualifier for xpm, png, gif, and other
transparent-capable images, like :solid-cursor:

 `:solid-cursor-shows BOOLEAN'
       When true, the cursor will appear solid through the transparent
regions of the image
       when the cursor is situated on the image and the window is
active.  The default is for
       only the cursor border to show, whether or not the window is active.

by having the default be off, then the disruption of oversize blinking
icons will be avoided.

i am hardly acquainted with display system, so don't know whether this
is doable without undue effort.  xor for non-transparent icons (and
transparent ones, for that matter) could be a related option, if it
were doable.

-- 
ken
ken.manheimer@gmail.com
http://myriadicity.net