On iOS, persistence is golden. When starting or resuming your application from termination or interruption, always return users to a state that closely matches where they left off. This lets your users continue whatever tasks they were involved with and provides a user interface that matches the previous session. Listing 7-1 introduces an example of doing exactly that.
This update to Recipe 7-5 stores both the current tab order and the currently selected tab, and it does so whenever those items are updated. When a user launches the application, the code searches for previous settings and applies them if they are found.
To respond to updates, a tab bar delegate must declare the
UITabBarControllerDelegate protocol. The approach ...