gtk on directfb problem

[Michael Trimarchi <trimarchi gandalf sssup it>]

Hi,
I just posted in directfb mailing list without answer :). This is a brief of the problem:

I'm trying to change the colormap only for a widget but I think that 
exists only one surface for rendering.  I don't understand why during 
the inizialization the directfb doesn't create a surface that matches my 
frame buffer setting. Example:
If I set RGB16 in the directfbrc, I hope that the surface has the same 
mapping. The problem can not be solved by setting to RGB16 because other 
things don't work correctly.

// window
 visual = gdk_directfb_visual_by_format (DSPF_RGB16);
 cmap = gdk_colormap_new (visual, FALSE);
 gtk_widget_push_colormap (cmap);
 main_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);

If I set this one my gdk_draw_pixmap is fast, but text and icons have trouble otherwise the application is slow.
Is there an answer?

Regards Michael