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

[Juri Linkov]

>     I guess this is not a problem because usually a border is visible around
>     non-transparent images with the cursor.
>
> How does the border change the outcome?

It is possible to visually distinguish images with the border
from images without it.

> Does the cursor appear in the border?

The hollow cursor is displayed on the image as the 1-pixel border around it.

> Why is there usually a border?  Is it because Lisp programs that
> display a non-transparent image usually request a border?  Is there
> something about these images that causes Emacs to add a border?

When Lisp programs request a border, then the margin explicitly specified
by the `:margin' keyword affects how the cursor in displayed on images.
After Kim's changes, the box cursor fills the margin with the cursor's
color, and the bar cursor doesn't fill the margin and uses the hollow
cursor with the 1-pixel border.  I think this is good behavior.

> In what circumstances would there not be a border?

The only problem I see now with Kim's changes is that the box cursor
on non-transparent images with no margin is not visible at all.

E.g. try to put the box cursor on this image:

(insert-image (create-image (make-string 8 0)
                            'xbm t :width 8 :height 8
                            :background "grey75"
                            :foreground "black"
                            :relief -2
                            :margin 0
                            :ascent 'center))

The box cursor is not visible.  Maybe it should be displayed as the hollow
cursor on non-transparent images?

-- 
Juri Linkov
http://www.jurta.org/emacs/