problem blitting to fullscreen window

FROM : George Marlin
DATE : Tue May 01 21:36:47 2007

In my app I'm blitting a simple bitmap to a window.  It all works fine
when I make a window in the canonical manner with a nib file:

    [NSBundle loadNibNamed:@"MainMenu" owner:NSApp] ;
    NSWindow* main_window = [self mainWindow] ;
    [main_window makeKeyAndOrderFront:nil] ;

However it all goes to pot when I replace the above with code to make
a fullscreen window:

    if (CGDisplayCapture( kCGDirectMainDisplay ) != kCGErrorSuccess) {
        NSLog(@"Couldn't capture the main display!") ;
        assert(0) ;
    }

    int windowLevel = CGShieldingWindowLevel() ;
    NSRect screenRect = [[NSScreen mainScreen] frame] ;
    NSWindow* main_window =
        [[MyWindow alloc]
            initWithContentRect:screenRect
            styleMask:NSBorderlessWindowMask
            backing:NSBackingStoreBuffered
            defer:NO
            screen:[NSScreen mainScreen]] ;
    [main_window makeMainWindow] ;
    [main_window setLevel:windowLevel] ;
    [main_window makeKeyAndOrderFront:nil] ;

(MyWindow has overridden canBecomeMainWindow to return true.)  The app
does take over the whole screen, but the screen is just solid black;
none of my blits show up.  All data appears legit; the window's
content view is not nil, for example.  The blit is from a
NSBitmapImageRep using drawAtPoint, between lockFocus/unlockFocus on
the window's content view.

Any ideas what could be wrong?

Thanks,
George Marlin


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