BaseFragment

Kotlin |Java

open class BaseFragment : BrandedFragment

kotlin.Any
↳	android.app.Fragment
	↳	androidx.leanback.app.BrandedFragment
		↳	androidx.leanback.app.BaseFragment

Known Direct Subclasses

BrowseFragment, DetailsFragment, VerticalGridFragment

BrowseFragment	A fragment for creating Leanback browse screens.
DetailsFragment	A fragment for creating Leanback details screens.
VerticalGridFragment	A fragment for creating leanback vertical grids.

Base class for leanback Fragments. This class is not intended to be subclassed by apps.

Summary

Public methods
ProgressBarManager!	`getProgressBarManager()` Returns the `ProgressBarManager`.
open Unit	`onCreate(savedInstanceState: Bundle?)`
open Unit	`onViewCreated(@NonNull view: View, @Nullable savedInstanceState: Bundle?)`
open Unit	`prepareEntranceTransition()` Enables entrance transition.
open Unit	`startEntranceTransition()` When fragment finishes loading data, it should call startEntranceTransition() to execute the entrance transition.

Protected methods
open Any!	`createEntranceTransition()` Create entrance transition.
open Unit	`onEntranceTransitionEnd()` Callback when entrance transition is ended.
open Unit	`onEntranceTransitionPrepare()` Callback when entrance transition is prepared.
open Unit	`onEntranceTransitionStart()` Callback when entrance transition is started.
open Unit	`runEntranceTransition(entranceTransition: Any!)` Run entrance transition.

Inherited functions

From class BrandedFragment

`Drawable!`	`getBadgeDrawable()` Returns the badge drawable used in the fragment title.
`Int`	`getSearchAffordanceColor()` Returns the color used to draw the search affordance.
`SearchOrbView.Colors!`	`getSearchAffordanceColors()` Returns the `androidx.leanback.widget.SearchOrbView.Colors` used to draw the search affordance.
`CharSequence!`	`getTitle()` Returns the title text for the fragment.
`View!`	`getTitleView()` Returns the view that implements `TitleViewAdapter.Provider`.
`TitleViewAdapter!`	`getTitleViewAdapter()` Returns the `TitleViewAdapter` implemented by title view.
`Unit`	`installTitleView(inflater: LayoutInflater!, parent: ViewGroup!, savedInstanceState: Bundle!)` Inflate title view and add to parent. This method should be called in `Fragment#onCreateView(LayoutInflater, ViewGroup, Bundle)`.
`Boolean`	`isShowingTitle()` Returns true/false to indicate the visibility of TitleView.
`Unit`	`onDestroyView()`
`View!`	`onInflateTitleView(inflater: LayoutInflater!, parent: ViewGroup!, savedInstanceState: Bundle!)` Called by `installTitleView(LayoutInflater, ViewGroup, Bundle)` to inflate title view. Default implementation uses layout file lb_browse_title. Subclass may override and use its own layout, the layout must have a descendant with id browse_title_group that implements `TitleViewAdapter.Provider`. Subclass may return null if no title is needed.
`Unit`	`onPause()`
`Unit`	`onResume()`
`Unit`	`onSaveInstanceState(outState: Bundle!)`
`Unit`	`onStart()`
`Unit`	`setBadgeDrawable(drawable: Drawable!)` Sets the drawable displayed in the fragment title.
`Unit`	`setOnSearchClickedListener(listener: OnClickListener!)` Sets a click listener for the search affordance. The presence of a listener will change the visibility of the search affordance in the fragment title. When set to non-null, the title will contain an element that a user may click to begin a search. The listener's `onClick` method will be invoked when the user clicks on the search element.
`Unit`	`setSearchAffordanceColor(color: Int)` Sets the color used to draw the search affordance. A default brighter color will be set by the framework.
`Unit`	`setSearchAffordanceColors(colors: SearchOrbView.Colors!)` Sets the `androidx.leanback.widget.SearchOrbView.Colors` used to draw the search affordance.
`Unit`	`setTitle(title: CharSequence!)` Sets title text for the fragment.
`Unit`	`setTitleView(titleView: View!)` Sets the view that implemented `TitleViewAdapter`.
`Unit`	`showTitle(show: Boolean)` Shows or hides the title view.
`Unit`	`showTitle(flags: Int)` Changes title view's components visibility and shows title.

Public methods

getProgressBarManager

fun getProgressBarManager(): ProgressBarManager!

Returns the ProgressBarManager.

Return
`ProgressBarManager!`	The `ProgressBarManager`.

onCreate

open fun onCreate(savedInstanceState: Bundle?): Unit

onViewCreated

open fun onViewCreated(
    @NonNull view: View, 
    @Nullable savedInstanceState: Bundle?
): Unit

prepareEntranceTransition

open fun prepareEntranceTransition(): Unit

Enables entrance transition.

Entrance transition is the standard slide-in transition that shows rows of data in browse screen and details screen.

The method is ignored before LOLLIPOP (API21).

This method must be called in or before onCreate(). Typically entrance transition should be enabled when savedInstance is null so that fragment restored from instanceState does not run an extra entrance transition. When the entrance transition is enabled, the fragment will make headers and content hidden initially. When data of rows are ready, app must call startEntranceTransition() to kick off the transition, otherwise the rows will be invisible forever.

It is similar to android:windowsEnterTransition and can be considered a late-executed android:windowsEnterTransition controlled by app. There are two reasons that app needs it:

Workaround the problem that activity transition is not available between launcher and app. Browse activity must programmatically start the slide-in transition.

Separates DetailsOverviewRow transition from other rows transition. So that the DetailsOverviewRow transition can be executed earlier without waiting for all rows to be loaded.

Transition object is returned by createEntranceTransition(). Typically the app does not need override the default transition that browse and details provides.

startEntranceTransition

open fun startEntranceTransition(): Unit

When fragment finishes loading data, it should call startEntranceTransition() to execute the entrance transition. startEntranceTransition() will start transition only if both two conditions are satisfied:

prepareEntranceTransition() was called.

has not executed entrance transition yet.

If startEntranceTransition() is called before onViewCreated(), it will be pending and executed when view is created.

Protected methods

createEntranceTransition

protected open fun createEntranceTransition(): Any!

Create entrance transition. Subclass can override to load transition from resource or construct manually. Typically app does not need to override the default transition that browse and details provides.

onEntranceTransitionEnd

protected open fun onEntranceTransitionEnd(): Unit

Callback when entrance transition is ended.

onEntranceTransitionPrepare

protected open fun onEntranceTransitionPrepare(): Unit

Callback when entrance transition is prepared. This is when fragment should stop user input and animations.

onEntranceTransitionStart

protected open fun onEntranceTransitionStart(): Unit

Callback when entrance transition is started. This is when fragment should stop processing layout.

runEntranceTransition

protected open fun runEntranceTransition(entranceTransition: Any!): Unit

Run entrance transition. Subclass may use TransitionManager to perform go(Scene) or beginDelayedTransition(). App should not override the default implementation of browse and details fragment.