On 3 Sep 2007, at 08:53, joakim@verona.se wrote:

> That said, I also wonder why converting png:s to xpm wouldnt be
> equivalent. Does the png library handle alpha channels and
> anti-aliasing to the background conveniently, which the xpm library
> presumably doesnt?

Correct.

For Aquamacs, I convert PNGs into XPMs with a pre-defined background  
color (matte), which is used in lieu of alpha blending. This works  
fine until the user changes the background color of the toolbar. A  
screenshot of the toolbar with some icons enabled is attached.

I tried using PNGs for the toolbar, and I wrote a patch to support  
that (see below, don't know if it still applies cleanly).

However, there always was a problem with the specification of  
selected / disabled states of the icons, which somehow didn't work  
correctly for PNGs at least in the Carbon port (IIRC - this is more  
than a year ago).

It would be very nice if PNGs worked, and if selected and disabled  
states were fully supported.

Alternatively, the IMHO much better solution would be to support  
toolkit toolbars, because that'll give users all the functionality of  
the toolkit (native look, best quality images, in some cases  
drag&drop / reordering). A fallback to XPM is always possible, of  
course, in non-toolkit builds.