NSColor question

[Chris B. Vetter]

Hi,

I was trying to create a splash window, you know like Acroread displays
during startup. For that, I figured to create a transparent window and
add a content view that draws an irregular shape in -drawRect:

Before working on the view I tried to create the transparent window,
using the following:

  color = [NSColor clearColor];

  window = [[NSWindow alloc] initWithContentRect: rect
             styleMask: NSBorderlessWindowMask
             backing: NSBackingStoreBuffered
             defer: NO];
  [window setBackgroundColor: color];
  [window setAlphaValue: 1.0];
  [window setOpaque: NO];


However, popping open the window, all I got was a _black_ background on
back-art and a _white_ background on back-xlib.

Looking at the source to NSColor, I saw that +clearColor really is just
a [self colorWithCalibratedWhite: 0.0 alpha: 0.0]

Playing around with various color settings I found out that both,
+colorWithCalibratedWhite:alpha: and +colorWithDeviceWhite:alpha: do
exactly the same thing: black on back-art, white on back-xlib, without
any regard of the values passed for 'white' or 'alpha'.
Using +setIgnoresAlpha: didn't seem to make a difference either.

All the +<color>Color and +colorWith<whatever>:a:b:c: seem to work fine.

Is this a known problem, or am I missing something?

-- 
Chris