The app contains two juicy packages:
- repo
- ui
Repo provides the data to be displayed by the UI. There are two abstractions to interact with: AdsRepository and FavouritesRepository. Since there is only a single endpoint to be hit, I've made a bold decision not to use Retrofit, nor any of the standard data binding JSON libraries. I have ensured, however, that if we were to switch, the transition would be rather smooth, as the underlying implementations reside behind a more generic interface (e.g. JsonParser).
AdsViewModel is the glue between the UI and repositories. It utilises LiveData to handle the lifecycle events.
The UI consists of a single activity and two Fragments: MainFragment and FavouritesFragment. You may navigate between the two using the navigation drawer.
Favourites are persisted using Room.
I think the app is reasonably modular, meaning it would cope with changes.
The UI as a whole could & should be a bit more polished. Image loading in particular should be smoother. I planned for pagination, but did not implement it. While keeping it simple, I feel using the third party libs (e.g. RxJava) would make some things easier & less boilerplate heavy. I could also do a bit more in terms of testing. Error handling is also neglected. There is no accessibility and internationalisation (LTR) features. Stock icons/thumbnails are bad, and I should feel bad.
For a few hours' work, I'm reasonably happy with the outcome, although there is a lot more it could be done & improved.