The width of the title field.
- macOS 10.0+
The width of the title field, measured in points in the user coordinate space. You usually do not need to set this property. AppKit automatically sets the title width whenever the title changes. If the automatic width doesn’t suit your needs, though, you can use this property to set the width explicitly.
After you have set the width this way, AppKit stops setting the width automatically, so you must set this property every time the title changes. If you want AppKit to resume automatic width assignments, set this property to a negative value.