Single Activity with MVVM

1.

TakuSemba CyberAgent.Inc Single Activity with MVVM

2.

TakuSemba CyberAgent.Inc Single Activity with MVVM

3.

@takusemba https://github.com/TakuSemba

4.

https://developer.android.com/jetpack/docs/guide MVVM

5.

Navigation https://developer.android.com/guide/navigation/navigation-getting-started

6.

<?xml version="1.0" encoding="utf-8"?> <navigation xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/nav_graph"> </navigation>

7.

<?xml version="1.0" encoding="utf-8"?> <navigation xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/nav_graph"> <fragment android:id="@+id/firstFragment"
android:name=“your.package.FirstFragment” /> <fragment android:id="@+id/secondFragment" android:name=“your.package.SecondFragment”/> </navigation> <navigation <fragment android:id="@+id/firstFragment" android:name=“your.package.FirstFragment" /> <fragment android:id="@+id/secondFragment" android:name="your.package.SecondFragment"/> </navigation>

8.

<?xml version="1.0" encoding="utf-8"?> <navigation xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/nav_graph" app:startDestination="@id/firstFragment"> <fragment
android:id="@+id/firstFragment" android:name=“your.package.FirstFragment” /> <fragment android:id="@+id/secondFragment" android:name=“your.package.SecondFragment”/> </navigation> <navigation app:startDestination="@id/firstFragment"> <fragment android:id="@+id/firstFragment" android:name=“your.package.FirstFragment" /> <fragment android:id="@+id/secondFragment" android:name="your.package.SecondFragment"/> </navigation>

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android:id="@+id/firstFragment" android:name=“your.package.FirstFragment"> <action android:id="@+id/to_secondFragment" app:destination="@id/secondFragment"/> </fragment> <fragment android:id="@+id/secondFragment" android:name=“your.package.SecondFragment"/> </navigation> <fragment android:id="@+id/firstFragment" android:name="your.package.FirstFragment"> <action android:id="@+id/to_secondFragment" app:destination="@id/secondFragment"/> </fragment>

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android:id="@+id/firstFragment" android:name="your.package.FirstFragment"> <action android:id="@+id/to_secondFragment" app:destination="@id/secondFragment"/> </fragment> <fragment android:id="@+id/secondFragment" android:name=“your.package.SecondFragment"> <argument android:name="userId" app:argType="string"/> </fragment> </navigation> <fragment android:id="@+id/secondFragment" android:name=“your.package.SecondFragment"> <argument android:name="userId" app:argType="string"/> </fragment>

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android:id="@+id/firstFragment" android:name="your.package.FirstFragment"> <action android:id="@+id/to_secondFragment" app:destination="@id/secondFragment"/> </fragment> <fragment android:id="@+id/secondFragment" android:name=“your.package.SecondFragment"> <argument android:name="userId" app:argType="string"/> </fragment> </navigation>

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None

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val navController = findNavController(R.id.host_fragment) // find from activity

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val navController = findNavController(R.id.host_fragment) // find from activity val navController
= findNavController() // find from fragment

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= findNavController() // find from fragment val navController = findNavController() // find from view

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= findNavController() // find from fragment val navController = findNavController() // find from view val args = bundleOf(SecondFragment.KEY_USER_ID to userId) navController.navigate(R.id.toSecondFragment, args) // navigate to secondFragment.kt

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= findNavController() // find from fragment val navController = findNavController() // find from view // navigate to secondFragment.kt val directions = FirstFragmentDirections.toSecondFragment(userId) navController.navigate(directions)

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= findNavController() // find from fragment val navController = findNavController() // find from view // navigate to secondFragment.kt val directions = FirstFragmentDirections.toSecondFragment(userId) navController.navigate(directions) // get userId from arguments val args = SecondFragmentArgs.fromBundle(requireArguments()) val userId = args.userId

19.

= findNavController() // find from fragment val navController = findNavController() // find from view // navigate to secondFragment.kt val directions = FirstFragmentDirections.toSecondFragment(userId) navController.navigate(directions) // get userId from arguments private val args by navArgs<SecondFragmentArgs>() val userId = args.userId

20.

Global Action a common action that multiple destinations can use

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Global Action a common action that multiple destinations can use
ɾMaintenance ɾForceUpdate ɾError

22.

// global action

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<?xml version="1.0" encoding="utf-8"?> <navigation xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:id="@+id/nav_graph" app:startDestination="@id/launcherFragment" > <action
android:id="@+id/action_global_ maintainanceFragment” app:destination="@id/maintainanceFragment" /> <fragment … /> <fragment … /> </navigation> // global action

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// navigate to maintainanceFragment using GlobalAction val directions = NavGraphDirections.actionGlobalMaintainanceFragment()

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// navigate to maintainanceFragment using GlobalAction val directions = NavGraphDirections.actionGlobalMaintainanceFragment()
navController.navigate(directions)

26.

Nav Options special options for navigate actions public NavOptions.Builder setPopUpTo
(int destinationId, boolean inclusive) public NavOptions.Builder setLaunchSingleTop (boolean singleTop) …

27.

// navigate with stacked fragmetns popoed up

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val directions = SplashDirections.showLoginFragment() navController.navigate(directions) // navigate with stacked fragmetns
popoed up

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val directions = SplashDirections.showLoginFragment() val options = NavOptions.Builder() .setPopUpTo(R.id.splashFragment, true)
.build() navController.navigate(directions, options) // navigate with stacked fragmetns popoed up

30.

// navigate to loginFragment val directions = SplashDirections.showLoginFragment() navController.navigate(directions) <?xml
version="1.0" encoding="utf-8"?> <navigation> <fragment android:id="@+id/splashFragment" android:name="your.package.SplashFragment" tools:layout="@layout/fragment_splash"> <action android:id="@+id/showLoginFragment" app:destination="@id/loginFragment" app:popUpTo="@id/splashFragment" app:popUpToInclusive="true"/> </fragment> </navigation> <action app:popUpTo="@id/splashFragment" app:popUpToInclusive="true"/> // navigate with stacked fragmetns popoed up

31.

// navigate as single-top val directions = NavGraphDirections.showBarFragment() navController.navigate(directions) val
directionsAgain = NavGraphDirections.showBarFragment() navController.navigate(directionsAgain)

32.

val directions = NavGraphDirections.showBarFragment() navController.navigate(directions) val directionsAgain = NavGraphDirections.showBarFragment() val
options = NavOptions.Builder() .setLaunchSingleTop(true) .build() navController.navigate(directions, options) // navigate as single-top

33.

// navigate to barFragment val directions = NavGraphDirections.showBarFragment() navController.navigate(directions) <?xml
version="1.0" encoding="utf-8"?> <navigation> <fragment android:id="@+id/splashFragment" android:name="your.package.SplashFragment" tools:layout="@layout/fragment_splash"> <action android:id="@+id/showLoginFragment" app:destination="@id/loginFragment" app:launchSingleTop="true"/> </fragment> </navigation> <action app:launchSingleTop="true"/> // navigate as single-top

34.

// navigate back

35.

navController.popBackStack() // navigate back

36.

navController.popBackStack() // navigate back // observe data override fun onViewCreated(view:
View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) viewModel.user.observe(this) { user -> textView.text = user.name } }

37.

View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) viewModel.user.observe(this) { user -> textView.text = user.name } } observe(this) { user -> }

38.

View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) viewModel.user.observe(this) { user -> textView.text = user.name } } observe(this) { user -> } override fun onDestroy() { super.onDestroy() // not called yet }

39.

View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) viewModel.user.observe(viewLifecycleOwner) { user -> textView.text = user.name } } override fun onDestroy() { super.onDestroy() // not called yet } observe(viewLifecycleOwner) { user -> }

40.

View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) viewModel.user.observe(viewLifecycleOwner) { user -> textView.text = user.name } } override fun onDestroyView() { super.onDestroyView() // observer is removed. } observe(viewLifecycleOwner) { user -> }

41.

IUUQTNFEJVNDPN!UBLVTFNCB

42.

class FooViewModel : ViewModel() { val snackbarMessage: LiveData<SnackbarMessage> = MutableLiveData()
} // viewModel

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class FooViewModel : ViewModel() { val snackbarMessage: LiveData<SnackbarMessage> = MutableLiveData()
} // viewModel // observe data override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) viewModel.snackbarMessage.observe(viewLifecycleOwner) { message -> // show snackbar } }

44.

class FooViewModel : ViewModel() { val snackbarMessage: LiveData<Event<SnackbarMessage>> = MutableLiveData()
} // viewModel // observe data override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) viewModel.snackbarMessage.observe(viewLifecycleOwner) { message -> // show snackbar } }

45.

class FooViewModel : ViewModel() { val snackbarMessage: LiveData<Event<SnackbarMessage>> = MutableLiveData()
} // viewModel // observe data override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) viewModel.snackbarMessage.observe(viewLifecycleOwner) { message -> // show snackbar } } // Event.kt from https://github.com/google/iosched LiveData<Event<SnackbarMessage>>

46.

class FooViewModel : ViewModel() { // Event.kt from https://github.com/google/iosched val
snackbarMessage: LiveData<Event<SnackbarMessage>> = MutableLiveData() } // viewModel // observe data override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) viewModel.snackbarMessage.observe(viewLifecycleOwner) { event -> event.getContentIfNotHandled()?.let { message -> // show snackbar } } }

47.

IUUQTNFEJVNDPNBOESPJEEFWFMPQFSTMJWFEBUBXJUITOBDLCBSOBWJHBUJPOBOEPUIFSFWFOUTUIF TJOHMFMJWFFWFOUDBTFBD

48.

// scope for viewModel val activityScopedViewModel = ViewModelProviders .of(requireActivity(), viewModelFactory)
.get(FooViewModel::class.java)

49.

// scope for viewModel private val activityScopedViewModel: FooViewModel by activityViewModels
{ viewModelFactory }

50.

{ viewModelFactory } Activity Scope

51.

{ viewModelFactory } Activity Scope ≒ App Scope

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{ viewModelFactory } private val fragmentScopedViewModel: BarViewModel by viewModels { viewModelFactory } Activity Scope ≒ App Scope

53.

{ viewModelFactory } private val fragmentScopedViewModel: BarViewModel by viewModels { viewModelFactory } Activity Scope ≒ App Scope … Fragment Scope Fragment Scope

54.

https://www.youtube.com/watch?v=2k8x8V77CrU&t=1300s

55.

https://github.com/takusemba https://twitter.com/takusemba Single Activity with MVVM

Single Activity with MVVM

Single Activity with MVVM

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