The Need for UI Flexibility
You might imagine that a list-detail application consists of two activities: one managing the list and the other managing the detail view. Pressing on a crime in the list would start an instance of the detail activity. Pressing the Back button would destroy the detail activity and return you to the list, where you could select another crime.
That would work, but what if you wanted more sophisticated presentation and navigation between screens?
Consider the possibility of CriminalIntent running on a large device. Some devices have screens large enough to show the list and detail at the same time – at least in landscape orientation (Figure 8.2).
Figure 8.2 Ideal list-detail interface for varying screen ...