Android How to Program, 3/e

9.9 MainActivity Class

Class MainActivity manages the app’s fragments and coordinates the interactions between them. On phones, MainActivity displays one Fragment at a time, starting with the ContactsFragment. On tablets, MainActivity always displays the ContactsFragment at the left of the layout and, depending on the context, displays either the DetailFragment or the AddEditFragment in the right two-thirds of the layout.

9.9.1 Superclass, Implemented Interfaces and Fields

Class MainActivity (Fig. 9.24) uses class FragmentTransaction from the v4 support library to add and remove the app’s Fragments. MainActivity implements three interfaces:

Fig. 9.24 MainActivity’s superclass, implemented interfaces and fields,

Figure 9.24 Full Alternative ...