Android Apps with Mortar and Flow

Transcript

1. Android Apps
   with
   Mortar and Flow
   Edward Dale
   @scompt
   

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2. Agenda
   • Motivation
   • Flow
   • Mortar
   http://knowyourmeme.com/memes/business-cat
   

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3. Motivation
   

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4. Motivation
   • Lots of activities (old)
   • Lots of fragments (new)
   • Loaders
   • Lifecycle fun hell
   • Fragment transitions
   • Back stack
   The Android Way
   

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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
   

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6. Sample
   App
   https://github.com/square/flow
   

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7. Sample
   App
   https://github.com/square/flow
   

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8. Flow
   A small library that helps with describing an app
   as a collection of moderately independent
   screens.
   

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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/
   

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10. The conversation list screen
    @Screen(ConversationListView.class)
    public class ConversationList {
    }
    

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11. The conversation view
    screen
    @Screen(ConversationView.class)
    public static class Conversation
    implements HasParent {
    public final int conversationIndex;
    !
    public Conversation(int conversationIndex) {
    this.conversationIndex = conversationIndex;
    }
    !
    @Override public ConversationList getParent() {
    return new ConversationList();
    }
    }
    

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12. App start
    Object firstScreen = new ConversationList();
    Backstack backstack = Backstack.single(firstScreen);
    Flow flow = new Flow(backstack, this);
    go(flow.getBackstack(), Flow.Direction.FORWARD);
    

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13. On conversation tap
    Flow flow = ...;
    int position = ;
    flow.goTo(new Conversation(position));
    

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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
    

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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
    

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16. Mortar
    Mortar eases the use of Dagger to divide Android
    apps into composable modules.
    

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17. Mortar
    • View and controller destroyed in traditional
    android MVC
    • Only view destroyed with MVP under mortar.
    Presenter stays around.
    MVC MVP
    

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18. Mortar
    • Every Screen has an
    associated Dagger Module
    • Every View has an associated
    ViewPresenter
    Implementation
    http://animals.desktopnexus.com/wallpaper/1386356/
    

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19. Blueprint
    @Screen(ChatListView.class)
    public class ChatListScreen implements Blueprint {
    @Override public String getMortarScopeName() {
    return getClass().getName();
    }
    @Override public Object getDaggerModule() {
    return new Module();
    }
    }
    

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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);
    }
    }
    

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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
    

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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
    

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