Android Jetpack Weekly #7

Review of the most interesting updates in Android Jetpack libraries

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Update in AndroidX for period September 1–8 2019. The week was very rich and many stable versions were released:

Fragment

1.1.0 (compare to 1.0.0)

• FragmentScenario class for testing Fragment in isolation
• Now you can set a FragmentFractory on a FragmentManager to override creation of fragment. Now default constructor isn’t required for Fragment. Welcome injection into constructors with Dagger 2!
• Kotlin Property Delegates for ViewModels: by viewModels() and by activityViewModels()
• Max Lifecycle state for a Fragment by calling setMaxLifecycle() on a FragmentTransaction. It allows setting a ceiling for the state of an active fragment in this FragmentManager.
  The new API replace deprecatedsetUserVisibleHint(). ViewPager 1 added support of Max Lifecycle in FragmentPagerAdapter and FragmentStatePagerAdapter in constructors.
• Set layout id for Fragment and FragmentActivity via new constructors. No need to override Fragment.onCreateView() or call Activity.sentContentView()
• Postpone Fragment transaction with a timeout using postponeEnterTransition().

1.2.0-alpha03 (compare to 1.2.0-alpha02)

• API changes
• Bug fixes

Preference

1.1.0

• PreferenceFragment and other classes using framework Fragments have been deprecated; you should use PreferenceFragmentCompat and other *compat classes instead
• You can now set a SummaryProvider on a Preference to dynamically configure its summary (second text) whenever the Preference is updated or becomes visible to the user. See the guide for more information.
• Added EditTextPreference.OnBindEditTextListener interface that allows customizing the EditText displayed in the corresponding dialog after the dialog has been bound. This is a direct replacement for using attributes such as android:inputType directly on the EditTextPreference, which is not supported in the AndroidX library. See the guide for more information.
• Added possibility to show a context menu when long pressing on the Preference that allows copying the summary of the Preference. Use Preference.setCopyingEnabled() to enable/disable that.
• Updated SeekBarPreference styling to match Material specifications: the value label is now hidden by default; the value label now updates while the SeekBar is being dragged, instead of when it is released; you should avoid setting a summary on a SeekBarPreference
• SeekBarPreference: Added support for continuous updates, allowing the SeekBar to update its saved value
• A large number of bug fixes, style updates, API level compatibility fixes, and general QOL (quality of life) improvements.

Lifecycle

2.1.0 (compare to 2.0.0)

• Added LifecycleEventObserver for the cases when a stream of lifecycle events is needed. Use Lifcecycle.addObserver() to register a listener.
• Added ktx extensions for LiveData.observe methods and Transformations.* methods.
• Added Transformations.distinctUntilChanged, which creates a new LiveData object that does not emit a value until the source LiveData value has been changed.
• Added coroutine support in ViewModels by adding the extension property ViewModel.viewModelScope. The scope is bound to Dispatchers.Main.immediate

2.2.0-alpha04

• lifecycleScope, whenCreated, whenStarted, whenResumed, viewModelScope, and the underlying implementation of LiveData now use Dispatchers.Main.immediate instead of Dispatchers.Main

Activity

1.0.0

• New ComponentActivity servers as the new base class for FragmentActivity
• Kotlin Property Delegates for ViewModels: by viewModels()
• As a composable alternative to overriding onBackPressed(), you can now register a OnBackPressedCallback from any LifecycleOwner (such as a Fragment) to intercept system back button events.
• onRetainCustomNonConfigurationInstance() and the related getLastCustomNonConfigurationInstance() APIs have been deprecated. Use ViewModel instead.

1.1.0-alpha03 (compare to 1.1.0-alpha02)

• Dependencies updates
• Bug fixes

AppCompat

1.1.0 (compare to 1.0.0)

• Dark Mode Improvements: MODE_NIGHT_AUTO_BATTERY was replaced with MODE_NIGHT_AUTO
• AppCompatActivity now transitively extends from ComponentActivity
• Set layout id for AppComponentActivity via new constructors. No need to call Activity.sentContentView()

SavedState

1.0.0

This is a set of APIs that allow developers to plugin components into the restore / saveInstanceState process. That API provides a single way to how to save the state of any class without keeping a direct reference to it.

CameraX

Camera2 & Core 1.0.0-alpha05

• APIs refactoring
• Added CameraControl API w/Tap-to-Focus APIs
• Enforce calling some API methods on the Main (UI) thread
• API improvements
• Bug fixes

Core

1.1.0

• Updated accessibility APIs to match the Android 10 platform accessibility APIs
• Added improvements to Nested Scrolling; see NestedScrollingChild3 and NestedScrollingParent3.
• This library no longer depends on the androidx.collection dependency as part of its API
• Worked around an IPC compatibility issue caused by refactor to androidx
• Added a variety of fixes for AppCompat DayNight

Media

1.1.0

• AudioAttributesCompat was added

Media2

Media2 is the next generation of following Media APIs: MediaSession, MediaController, MediaBrowser, MediaBrowserService, VideoView, and MediaControlView.

1.0.0

• Base on ExoPlayer
• Support of custom layout in MediaSessions
• Better look and feel
• New possibilities compare to original Media API

MediaRouter

1.1.0

Dynamic group support was added:

• Allows users to add or remove route devices dynamically.
• To enable a dynamic group, call MediaRouteButton.enableDynamicGroup(); the app shows a new dialog for the dynamic group
• The installed MediaRouteProvider should also support dynamic group to actually enable the functionality.

Navigation

2.1.0

• Scoping ViewModels to a navigation graph: You can now create ViewModels that are scoped at the navigation graph level using the by navGraphViewModels() property delegate for Kotlin users or by using the NavController.getViewModelStoreOwner() . See Share UI-related data between destinations.
• Dialog destinations: You can now create <dialog> destinations that will show a DialogFragment when you navigate to them. NavHostFragment supports dialog destinations by default. See Create a destination from a DialogFragment.
• Navigating by Uri: You can now navigate using a Uri, which uses the <deepLink> you’ve added to a destination to navigate there. It helps to organizae navigation in multimodule projects. See Navigate using Uri.
• NavHostController: APIs used specifically for constructing a custom NavHost have been moved to NavHostController, allowing implementations to connect their NavController to the hosting LifecycleOwner, OnBackPressedDispatcher, and ViewModelStore.

2.2.0-alpha02

• Deep links with query parameters now support reordered query parameters: arguments that have a default value or are nullable are now optional when matching deep links.
• You can now call NavController.getBackStackEntry(), passing in the ID of a destination or navigation graph on the back stack. The returned NavBackStackEntry provides a Navigation-driven LifecycleOwner, ViewModelStoreOwner (the same returned by NavController.getViewModelStoreOwner()), and SavedStateRegistryOwner, in addition to providing the arguments used to start that destination.
• Bug fixes

ShareTarget

1.0.0-beta01

VectorDrawable

1.1.0 (since 1.0.0)

• fillType is now supported in ClipPath
• Tinting is now supported using ColorStateLists defined with theme attrs in VectorDrawableCompat
• Bug fixes

WebKit

1.1.0-beta01

• New InternalStoragePathHandler in WebViewAssetLoader to load files from the app's data directory.
• Small API changes
• Bug fixe