A Boolean value indicating whether the view can draw its contents on a background thread.
- macOS 10.6+
If your view’s
draw(_:) implementation can draw safely on a background thread, set this property to
true. Doing so gives AppKit the ability to run your view’s drawing code off the app’s main thread, which can improve performance. The view's window must also have its
allows property set to
true (the default) for threaded view drawing to occur.