if (nativeGrabOwner != null) {
// awt.12F=Attempt to start nested mouse grab
throw new RuntimeException(Messages.getString("awt.12F")); //$NON-NLS-1$
}
NativeWindow win = grabWindow.getNativeWindow();
if (win == null) {
// awt.130=Attempt to grab mouse in not displayable window
throw new RuntimeException(Messages.getString("awt.130")); //$NON-NLS-1$
}
nativeGrabOwner = grabWindow;
this.whenCanceled = whenCanceled;
win.grabMouse();
}