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

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

On 9/6/06, Kim F. Storm <storm@cua.dk> wrote:
> David Kastrup <dak@gnu.org> writes:
>
> > Richard Stallman <rms@gnu.org> writes:
> >
> >>     > What exactly is the workaround you recommend?
> >>
> >>     Use :mask ...
> >>
> >> Then how about changing the default value for :mask?
> >
> > There is no sensible default.  What is useful as a mask depends on the
> > image in question.  Using heuristic-mask can mean that the whole image
> > flashes, but it can also mean that just a single corner pixel blinks.
> >
> > Even when a mask is specified, using the whole mask as a cursor
> > indication is not a good idea, since a large image with a background
> > will then flash horribly.  The right fix in my opinion would be to use
> > the border of the image (extending into the image itself if the border
> > is too small, overwriting the image when no mask is given, but maybe
> > heeding the mask if it is given).  For a block cursor, there should be
> > a maximum number of pixels that is affected.  If this number is
> > exceeded, a box cursor would be used with a thickness that does not
> > cause the number of pixels to exceed the threshold, but lets it have
> > at least the thickness of a box cursor + 1 pixel.
> >
> > Something like that.  Yes, sounds tiresome.
>
> Indeed.  So...
>
> can we please postpone resolving this until after the release.
>
> There is currently a work-around (using :mask) in the FEW (if any)
> cases where there is no border around an image that could be used for
> the cursor.  And the other work-around is to specify a border.
>
> This is not a new bug -- it's been like this since 21.1, and only
> recently have we had just one user complaining about it.  And he
> seems satisfied with the changes I made to use a block cursor
> for small images.

the one catch is that i had not connected the :mask image spec with my
problem.  perhaps i'm dense, but i wonder whether the issue of
background, cursor, and image mask deserves some greater prominence in
the image documentation, so those floundering as i was get more
guidance.  as it currently stands, i wouldn't have connected the fact
that the mask can expose the "background of the frame" with the thing
i was trying to achieve, which is showing the cursor in the image.  (i
may have given it a try, but not been clear enough about whether to
expect the cursor to show through that i would notice whether or not
it worked.)

so i expect that at least some documentation improvement is in order.

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