Android Apps with Mortar and Flow

Transcript

1. Android Apps with Mortar and Flow Edward Dale @scompt
2. Agenda • Motivation • Flow • Mortar http://knowyourmeme.com/memes/business-cat
3. Motivation
4. Motivation • Lots of activities (old) • Lots of fragments (new) • Loaders • Lifecycle fun hell • Fragment transitions • Back stack The Android Way
5. Motivation • Lots of activities (old) • Lots of fragments (new) • Loaders • Lifecycle fun hell • Fragment transitions • Back stack The Android Way • Few activities • No fragments • Fatter views • Dependency injection • RxJava The Square Way
6. Sample App https://github.com/square/flow
7. Sample App https://github.com/square/flow
8. Flow A small library that helps with describing an app as a collection of moderately independent screens.
9. Flow • A screen in a POJO with the @Screen annotation saying which view or layout should be used to display it. • The Backstack is a stack of these objects. • The Flow is the interface for navigating the history of your app. http://www.rluxemburg.com/2013/09/01/kitten-flow-chart/
10. The conversation list screen @Screen(ConversationListView.class) public class ConversationList { }
11. The conversation view screen @Screen(ConversationView.class) public static class Conversation implements HasParent<ConversationList> { public final int conversationIndex; ! public Conversation(int conversationIndex) { this.conversationIndex = conversationIndex; } ! @Override public ConversationList getParent() { return new ConversationList(); } }
12. App start Object firstScreen = new ConversationList(); Backstack backstack = Backstack.single(firstScreen); Flow flow = new Flow(backstack, this); go(flow.getBackstack(), Flow.Direction.FORWARD);
13. On conversation tap Flow flow = ...; int position = <index of conversation>; flow.goTo(new Conversation(position));
14. • Controller layer is a bit 
 too ad-hoc But not quite enough This is nice • No fragments • Unified interface for navigating in the app • Power over the back stack http://www.catster.com/molz/happy-cat-is-happy
15. • Controller layer is a bit 
 too ad-hoc But not quite enough This is nice • No fragments • Unified interface for navigating in the app • Power over the back stack
16. Mortar Mortar eases the use of Dagger to divide Android apps into composable modules.
17. Mortar • View and controller destroyed in traditional android MVC • Only view destroyed with MVP under mortar. Presenter stays around. MVC MVP
18. Mortar • Every Screen has an associated Dagger Module • Every View has an associated ViewPresenter Implementation http://animals.desktopnexus.com/wallpaper/1386356/
19. Blueprint @Screen(ChatListView.class) public class ChatListScreen implements Blueprint { @Override public String getMortarScopeName() { return getClass().getName(); } @Override public Object getDaggerModule() { return new Module(); } }
20. ViewPresenter public class ChatListView extends ListView implements ChatListScreen.View { @Inject ChatListScreen.Presenter presenter; ! public ChatListView(Context context, AttributeSet attrs) { super(context, attrs); Mortar.inject(context, this); } ! @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); presenter.takeView(this); } }
21. http://www.catster.com/molz/happy-cat-is-happy This is nice • Screens are self-contained and injected, facilitating testing • Insulated from lifecycle events • Memory efficient
22. Mortar Flow A small library that helps with describing an app as a collection of moderately independent screens. Mortar eases the use of Dagger to divide Android apps into composable modules. Questions? Edward Dale @scompt