[comp.sys.amiga.tech] Help needed on icon data structures

duncant@mbunix.mitre.org (Thomson) (01/31/90)

I have a question about icons...

I created an icon using Dpaint and iff2icon.  It worked fine, except
the background color (blue if you use default workbench colors) is not
transparent.  When you select the icon and drag it around, it drags around
this big blue square which obscures everything behind it.  I notice that
some icons are like this, and some are not.  I searched the definitions
of the data structures which make up an icon 
(actuall a DiskObject), but
couldn't find any flag which would seem to control this.


Anyone know what it is that makes some icons have transparent backgrounds, 
and others not?

Thanks,
Duncan Thomson

davidj@cbmvax.commodore.com (David Junod - CATS) (02/04/90)

In article <92857@linus.UUCP> duncant@mbunix.mitre.org (Thomson) writes:
>I have a question about icons...
[stuff deleted]
>Anyone know what it is that makes some icons have transparent backgrounds, 
>and others not?

According to the workbench/workbench.h include file:  To get transparent back-
ground, set the GADGBACKFILL bit in the do_Gadget.Flags field.  In other words,
set an image in do_Gadget.GadgetRender, do_Gadget.SelectRender to NULL and
do_Gadget.Flags = GADGIMAGE | GADGBACKFILL.

Or, in an icon editor, select Backfill as the highlighting mode. Most icon
editors support this.

>Thanks,
>Duncan Thomson

Hope that helps!  ~DNJ~