The issue here is that people are treating reference materials as tutorials intended to cover your exact concern at the moment. You are expected to know what a narg is and what flargling means. In more real terms, the documentation for screen savers https://developer.apple.com/documentation/screensaver?langua... won't explain what a view is, what subclassing is, or what a Rect is. Those are required knowledge to consume the documentation and it's not a documentation failure that this is true.