In XCode 8.3.3 the only way I can find to make an NSWindow resizable is to include a Window Resize NSControl in the .xib. This is the green button in the top left corner of a window. I want my application not to be a full-screen app. It makes sense for this application to be able to zoom to the window's maximum size if it's resized to a smaller size, but I want to disable the Window Resize Control if the window's at its maximum size. I can access the window's frame by overriding the functions: Code: -(void) userResizedWindow: (NSNotification *) note and -(void) windowDidResize: (NSNotification *) note But I can't figure out how to get a pointer to the window's Window Resize NSControl. How could I do this? I'm using Objective C. There is an NSWindowButton class in the documentation declared as an enum to allow access to the window buttons but I can't figure out how to use these ints to get an NSControl *.