Not sure if it helps, but here is how I’m creating my editor.
[self.window setFrame:frame display:YES animate:YES];
NSView* view = self.window.contentView;
CRect r (0, 0, view.bounds.size.width, view.bounds.size.height);
[[self window] setContentAspectRatio:NSMakeSize(view.bounds.size.width, view.bounds.size.height)];
editor = new Editor((__bridge void*)view);