macOS window with integrated title bar and toolbar?

Question

In macOS how can I create a window with an "integrated title bar and toolbar" in Xcode and/or Interface Builder?

This is the "fat title bar" type

Answer 1

1. Create a standard toolbar.

2. When the window loads, set titleVisibility to hidden:

   // Objective-C
   window.titleVisibility = NSWindowTitleHidden;
   
   // Swift
   window?.titleVisibility = .hidden