I have an NSWindow with a custom view, InnerView as its contentView. Here’s the code for InnerView

• (void) drawRect:(NSRect)rect { rect = [self frame]; [[NSColor whiteColor] set]; NSRect clearRect = rect; clearRect.origin.y += margin; clearRect.size.height -= margin; NSRectFill(clearRect);

  if (winCapture==nil || (NSEqualSizes([winCapture size],[SolWin frame].size)==NO)) { if (inCapture++ == 0) { NSTimer *timer = [NSTimer timerWithTimeInterval:0.1f target:self selector:@selector(captureWin:) userInfo:nil repeats:NO]; [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode]; } } else { NSRect wrect = [SolWin frame]; wrect.origin = NSZeroPoint; [winCapture drawInRect:clearRect fromRect:wrect operation:NSCompositeSourceOver fraction:1.0]; } }

• (void)captureWin:(NSTimer*)timer { NSRect wrect = [SolWin frame]; wrect.origin = NSZeroPoint; NSData *data = [SolWin dataWithPDFInsideRect:wrect]; if (winCapture!=nil) [winCapture release]; winCapture = [[NSImage alloc] initWithData:data]; [self setNeedsDisplay:YES]; inCapture = 0; }

The result looks like this: http://lavacat.com/wiki.gif

Why do I get black corners? – gekko513

What you are seeing is an RGBA image that isn’t drawing its alpha component correctly. If you save a tiff of the image and view the tiff in “Preview” you will see the corners drawn correctly. –zootbobbalu

• (void)drawRect:(NSRect)rect { [[NSColor redColor] set]; NSRectFill(rect); }

• (void)captureWindow { NSLog(@”<%p>%s:”, self, PRETTY_FUNCTION); NSRect windowFrame = self window] frame]; windowFrame.origin = [[NSZeroPoint; NSData *data = self window] dataWithPDFInsideRect:windowFrame]; [[NSImage *image = [[NSImage alloc] initWithData:data]; NSData *tiff = [image TIFFRepresentation]; [tiff writeToFile:@”/tmp/window.tiff” atomically:YES]; }

• (void)mouseDown:(NSEvent *)theEvent { [self captureWindow]; }

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You’ll need to override -isOpaque to return NO if you want to draw anything with alpha or transparency.

Strange. None of your suggestions seem to work. I even copied the example code from –zoot directly and I still got black corners, also on /tmp/window.tiff. I tried to override isOpaque, for all additional 3 combinations of adding the method to my NSWindow subclass SolWindow and the InnerView. I finally tried to remove the [self setOpaque:NO] that I had called in SolWindow.

Thanks, by the way, for trying to help out, and so quickly, too. – gekko513

(And if I swap dataWithPDFInsideRect with dataWithEPSInsideRect, I get 3 corners almost correct but the bottom left corner has an even larger black square.)