Creating the Overview activity

The travel claim example app needs a nice overview activity to tie together the allowance overview, a list of the claim items, and a way for the user to create new claim items. As we have a Room database, things can become significantly more decoupled, and that's a really good thing. Having a central reactive source of data allows different parts of your application to always reflect the actual state of the application as it changes, without having to coordinate with each other.

The first part of building the OverviewActivity is creating the Activity class itself and populating it with the claim items that the user has entered. Follow these steps to create a skeleton OverviewActivity and register it as the main Activity for the application:

1. Start by right-clicking on your main package (that is, com.packtpub.claim) and selecting New |Activity |Empty Activity from the menu.

2. Name the new class OverviewActivity.
3. Leave all the other fields as their defaults and select...