Pixmaps

[Andy Connor <amc50 eng cam ac uk>]

Thanks to everyone who pointed out my last faux pas (not allocating
memory) for which I deserve to be taken out and shot at dawn.....

I have another problem for which any advice would be welcome.

I've got a set of radio buttons that essentially toggle a pixmap within
one column of a GtkCTree. I have no problems changing the pixmap from
one to another using;

gtk_clist_set_pixmap();

byt typecasting the GtkCtree as a GtkCList (I know the row and column
number of the cell as opposed to which node of the tree I'm working
with.

My problem arises if I want to remove the pixmap. If I use the above
function and set the pixmap argument to 'NULL' then it works fine, apart
from a run time error.

Gdk-CRITICAL **: file gdkpixmap.c: line 810 (gdk_pixmap_ref): assertion
`pixmap != NULL' failed.

Firstly, is there any way of removing a pixmap without causing this
error?


If not, I've considered having a blank pixmap that I set the cell to
contain. My problem here is in getting the background of the pixmap to
be transparent - which I think can be done using a mask, but every
example I've seen has a NULL mask so I'm not to sure as to how generate
the mask in relation to the XPM data. The other alternative I've tried
playing around with is setting a certain colour to be transparent, but
not much luck on that score.

Thanks in advance,


Andy