previous to HighSierra, we could take our main app window (with small title bar) and "expand" it such that the title bar was tucked underneath the menu bar, giving the app that "full screen" look. this worked fine when programmatically setting the window frame with 'setFrame'. However, under HighSierra, it initially goes to the right spot, but then resizes itself so that the title bar is visible. can we shut that off?
using [window setframe] no longer allows full-screen content?
Why not just take the hint and let the user employ macOS's full screen, instead. regardless of OS?
Otherwise, you may need to acquiesce and bifurcate based on OS.
The window frame is constrained to accomidate the Menubar and Dock rects. Subclass your NSWindow and override:
- (NSRect)constrainFrameRect:(NSRect)frameRect toScreen:(nullable NSScreen *)screen
{
return frameRect;
}