NSWindow Categories to get screen capture of NSWindow including the shadow

FRBWindow+Extra.h

@interface NSWindow (FRBExtra)
- (NSImage *)windowImage;
- (CGImageRef)windowImageShot;
@end

FRBWindow+Extra.m

@implementation NSWindow (FRBExtra)

- (NSImage *)windowImage
{  
  NSImage * image = [[NSImage alloc] initWithCGImage:[self windowImageShot] size:[self frame].size];
  [image setDataRetained:YES];
  [image setCacheMode:NSImageCacheNever];
  return [image autorelease];
}


- (CGImageRef)windowImageShot
{
  CGWindowID windowID = (CGWindowID)[self windowNumber];
  CGWindowImageOption imageOptions = kCGWindowImageDefault;
  CGWindowListOption singleWindowListOptions = kCGWindowListOptionIncludingWindow;
  CGRect imageBounds = CGRectNull;
  
	CGImageRef windowImage = CGWindowListCreateImage(imageBounds, singleWindowListOptions, windowID, imageOptions);
  
  return (CGImageRef)[NSMakeCollectable(windowImage) autorelease];
}

@end