BrowseFragment

Kotlin |Java

open class BrowseFragment : BaseFragment

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

A fragment for creating Leanback browse screens. It is composed of a RowsFragment and a HeadersFragment.

A BrowseFragment renders the elements of its ObjectAdapter as a set of rows in a vertical list. The elements in this adapter must be subclasses of Row.

The HeadersFragment can be set to be either shown or hidden by default, or may be disabled entirely. See setHeadersState for details.

By default the BrowseFragment includes support for returning to the headers when the user presses Back. For Activities that customize , you must disable this default Back key support by calling setHeadersTransitionOnBackEnabled(boolean) with false and use BrowseFragment.BrowseTransitionListener and startHeadersTransition(boolean).

The recommended theme to use with a BrowseFragment is androidx.leanback.R.style#Theme_Leanback_Browse.

Summary

Nested classes
open	`BrowseTransitionListener` Listener for transitions between browse headers and rows.
abstract	`FragmentFactory` Factory class responsible for creating fragment given the current item.
abstract	`FragmentHost` Possible set of actions that `BrowseFragment` exposes to clients.
open	`ListRowFragmentFactory` FragmentFactory implementation for `ListRow`.
open	`MainFragmentAdapter` Interface that defines the interaction between `BrowseFragment` and its main content fragment.
abstract	`MainFragmentAdapterProvider` Interface to be implemented by all fragments for providing an instance of `MainFragmentAdapter`.
	`MainFragmentAdapterRegistry` Registry class maintaining the mapping of `Row` subclasses to `FragmentFactory`.
open	`MainFragmentRowsAdapter` This is used to pass information to `RowsFragment` or its subclasses.
abstract	`MainFragmentRowsAdapterProvider` Interface to be implemented by `RowsFragment` and its subclasses for providing an instance of `MainFragmentRowsAdapter`.

Constants
static Int	`HEADERS_DISABLED` The headers fragment is disabled and will never be shown.
static Int	`HEADERS_ENABLED` The headers fragment is enabled and shown by default.
static Int	`HEADERS_HIDDEN` The headers fragment is enabled and hidden by default.

Public constructors
`<init>()` A fragment for creating Leanback browse screens.

Public methods
open static Bundle!	`createArgs(args: Bundle!, title: String!, headersState: Int)` Creates arguments for a browse fragment.
open Unit	`enableMainFragmentScaling(enable: Boolean)` Enables scaling of main fragment when headers are present.
open Unit	`enableRowScaling(enable: Boolean)`
open ObjectAdapter!	`getAdapter()` Returns the adapter containing the rows for the fragment.
open Int	`getBrandColor()` Returns the brand color for the browse fragment.
open HeadersFragment!	`getHeadersFragment()` Get currently bound HeadersFragment or null if HeadersFragment has not been created yet.
open Int	`getHeadersState()` Returns the state of the headers column in the browse fragment.
open Fragment!	`getMainFragment()`
BrowseFragment.MainFragmentAdapterRegistry!	`getMainFragmentRegistry()`
open OnItemViewClickedListener!	`getOnItemViewClickedListener()` Returns the item Clicked listener.
open OnItemViewSelectedListener!	`getOnItemViewSelectedListener()` Returns an item selection listener.
open RowsFragment!	`getRowsFragment()` Get RowsFragment if it's bound to BrowseFragment or null if either BrowseFragment has not been created yet or a different fragment is bound to it.
open Int	`getSelectedPosition()` Gets position of currently selected row.
open RowPresenter.ViewHolder!	`getSelectedRowViewHolder()`
Boolean	`isHeadersTransitionOnBackEnabled()` Returns true if headers transition on back key support is enabled.
open Boolean	`isInHeadersTransition()` Returns true if the headers transition is currently running.
open Boolean	`isShowingHeaders()` Returns true if headers are shown.
open Unit	`onCreate(savedInstanceState: Bundle?)`
open HeadersFragment!	`onCreateHeadersFragment()` Creates a new `HeadersFragment` instance.
open View?	`onCreateView(inflater: LayoutInflater!, container: ViewGroup?, savedInstanceState: Bundle!)`
open Unit	`onDestroy()`
open Unit	`onDestroyView()`
open Unit	`onSaveInstanceState(outState: Bundle!)`
open Unit	`onStart()`
open Unit	`onStop()`
open Unit	`setAdapter(adapter: ObjectAdapter!)` Sets the adapter containing the rows for the fragment.
open Unit	`setBrandColor(@ColorInt color: Int)` Sets the brand color for the browse fragment.
open Unit	`setBrowseTransitionListener(listener: BrowseFragment.BrowseTransitionListener!)` Sets a listener for browse fragment transitions.
open Unit	`setHeaderPresenterSelector(headerPresenterSelector: PresenterSelector!)` Sets the `PresenterSelector` used to render the row headers.
open Unit	`setHeadersState(headersState: Int)` Sets the state for the headers column in the browse fragment.
Unit	`setHeadersTransitionOnBackEnabled(headersBackStackEnabled: Boolean)` Enables/disables headers transition on back key support.
open Unit	`setOnItemViewClickedListener(listener: OnItemViewClickedListener!)` Sets an item clicked listener on the fragment.
open Unit	`setOnItemViewSelectedListener(listener: OnItemViewSelectedListener!)` Sets an item selection listener.
open Unit	`setSelectedPosition(position: Int)` Sets the selected row position with smooth animation.
open Unit	`setSelectedPosition(position: Int, smooth: Boolean)` Sets the selected row position.
open Unit	`setSelectedPosition(rowPosition: Int, smooth: Boolean, rowHolderTask: Presenter.ViewHolderTask!)` Selects a Row and perform an optional task on the Row.
open Unit	`startHeadersTransition(withHeaders: Boolean)` Starts a headers transition.

Protected methods
open Any!	`createEntranceTransition()`
open Unit	`onEntranceTransitionEnd()`
open Unit	`onEntranceTransitionPrepare()`
open Unit	`onEntranceTransitionStart()`
open Unit	`runEntranceTransition(entranceTransition: Any!)`

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.

From class BaseFragment

`ProgressBarManager!`	`getProgressBarManager()` Returns the `ProgressBarManager`.
`Unit`	`onViewCreated(@NonNull view: View, @Nullable savedInstanceState: Bundle?)`
`Unit`	`prepareEntranceTransition()` 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.
`Unit`	`startEntranceTransition()` 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.

Constants

HEADERS_DISABLED

static val HEADERS_DISABLED: Int

The headers fragment is disabled and will never be shown.

Value: 3

HEADERS_ENABLED

static val HEADERS_ENABLED: Int

The headers fragment is enabled and shown by default.

Value: 1

HEADERS_HIDDEN

static val HEADERS_HIDDEN: Int

The headers fragment is enabled and hidden by default.

Value: 2

Public constructors

<init>

BrowseFragment()

Deprecated: use BrowseSupportFragment

A fragment for creating Leanback browse screens. It is composed of a RowsFragment and a HeadersFragment.

A BrowseFragment renders the elements of its ObjectAdapter as a set of rows in a vertical list. The elements in this adapter must be subclasses of Row.

The HeadersFragment can be set to be either shown or hidden by default, or may be disabled entirely. See setHeadersState for details.

The recommended theme to use with a BrowseFragment is androidx.leanback.R.style#Theme_Leanback_Browse.

Public methods

createArgs

open static fun createArgs(
    args: Bundle!, 
    title: String!, 
    headersState: Int
): Bundle!

Creates arguments for a browse fragment.

Parameters
`args`	Bundle!: The Bundle to place arguments into, or null if the method should return a new Bundle.
`title`	String!: The title of the BrowseFragment.
`headersState`	Int: The initial state of the headers of the BrowseFragment. Must be one of `HEADERS_ENABLED`, , or `HEADERS_DISABLED`.

Return
`Bundle!`	A Bundle with the given arguments for creating a BrowseFragment.

enableMainFragmentScaling

open fun enableMainFragmentScaling(enable: Boolean): Unit

Enables scaling of main fragment when headers are present. For the page/row fragment, scaling is enabled only when both this method and MainFragmentAdapter#isScalingEnabled() are enabled.

Parameters
`enable`	Boolean: true to enable row scaling

enableRowScaling

open fun enableRowScaling(enable: Boolean): Unit

Deprecated: use BrowseFragment#enableMainFragmentScaling(boolean) instead.

Parameters
`enable`	Boolean: true to enable row scaling

getAdapter

open fun getAdapter(): ObjectAdapter!

Returns the adapter containing the rows for the fragment.

getBrandColor

@ColorInt open fun getBrandColor(): Int

Returns the brand color for the browse fragment. The default is transparent.

getHeadersFragment

open fun getHeadersFragment(): HeadersFragment!

Get currently bound HeadersFragment or null if HeadersFragment has not been created yet.

Return
`HeadersFragment!`	Currently bound HeadersFragment or null if HeadersFragment has not been created yet.

getHeadersState

open fun getHeadersState(): Int

Returns the state of the headers column in the browse fragment.

getMainFragment

open fun getMainFragment(): Fragment!

Return
`Fragment!`	Current main fragment or null if not created.

getMainFragmentRegistry

fun getMainFragmentRegistry(): BrowseFragment.MainFragmentAdapterRegistry!

getOnItemViewClickedListener

open fun getOnItemViewClickedListener(): OnItemViewClickedListener!

Returns the item Clicked listener.

getOnItemViewSelectedListener

open fun getOnItemViewSelectedListener(): OnItemViewSelectedListener!

Returns an item selection listener.

getRowsFragment

open fun getRowsFragment(): RowsFragment!

Get RowsFragment if it's bound to BrowseFragment or null if either BrowseFragment has not been created yet or a different fragment is bound to it.

Return
`RowsFragment!`	RowsFragment if it's bound to BrowseFragment or null otherwise.

getSelectedPosition

open fun getSelectedPosition(): Int

Gets position of currently selected row.

Return
`Int`	Position of currently selected row.

getSelectedRowViewHolder

open fun getSelectedRowViewHolder(): RowPresenter.ViewHolder!

Return
`RowPresenter.ViewHolder!`	selected row ViewHolder inside fragment created by `MainFragmentRowsAdapter`.

isHeadersTransitionOnBackEnabled

fun isHeadersTransitionOnBackEnabled(): Boolean

Returns true if headers transition on back key support is enabled.

isInHeadersTransition

open fun isInHeadersTransition(): Boolean

Returns true if the headers transition is currently running.

isShowingHeaders

open fun isShowingHeaders(): Boolean

Returns true if headers are shown.

onCreate

open fun onCreate(savedInstanceState: Bundle?): Unit

onCreateHeadersFragment

open fun onCreateHeadersFragment(): HeadersFragment!

Creates a new HeadersFragment instance. Subclass of BrowseFragment may override and return an instance of subclass of HeadersFragment, e.g. when app wants to replace presenter to render HeaderItem.

Return
`HeadersFragment!`	A new instance of `HeadersFragment` or its subclass.

onCreateView

open fun onCreateView(
    inflater: LayoutInflater!, 
    container: ViewGroup?, 
    savedInstanceState: Bundle!
): View?

onDestroy

open fun onDestroy(): Unit

onDestroyView

open fun onDestroyView(): Unit

onSaveInstanceState

open fun onSaveInstanceState(outState: Bundle!): Unit

onStart

open fun onStart(): Unit

onStop

open fun onStop(): Unit

setAdapter

open fun setAdapter(adapter: ObjectAdapter!): Unit

Sets the adapter containing the rows for the fragment.

The items referenced by the adapter must be be derived from Row. These rows will be used by the rows fragment and the headers fragment (if not disabled) to render the browse rows.

Parameters
`adapter`	ObjectAdapter!: An ObjectAdapter for the browse rows. All items must derive from `Row`.

setBrandColor

open fun setBrandColor(@ColorInt color: Int): Unit

Sets the brand color for the browse fragment. The brand color is used as the primary color for UI elements in the browse fragment. For example, the background color of the headers fragment uses the brand color.

Parameters
`color`	Int: The color to use as the brand color of the fragment.

setBrowseTransitionListener

open fun setBrowseTransitionListener(listener: BrowseFragment.BrowseTransitionListener!): Unit

Sets a listener for browse fragment transitions.

Parameters
`listener`	BrowseFragment.BrowseTransitionListener!: The listener to call when a browse headers transition begins or ends.

setHeaderPresenterSelector

open fun setHeaderPresenterSelector(headerPresenterSelector: PresenterSelector!): Unit

Sets the PresenterSelector used to render the row headers.

Parameters
`headerPresenterSelector`	PresenterSelector!: The PresenterSelector that will determine the Presenter for each row header.

setHeadersState

open fun setHeadersState(headersState: Int): Unit

Sets the state for the headers column in the browse fragment. Must be one of HEADERS_ENABLED, HEADERS_HIDDEN, or HEADERS_DISABLED.

Parameters
`headersState`	Int: The state of the headers for the browse fragment.

setHeadersTransitionOnBackEnabled

fun setHeadersTransitionOnBackEnabled(headersBackStackEnabled: Boolean): Unit

Enables/disables headers transition on back key support. This is enabled by default. The BrowseFragment will add a back stack entry when headers are showing. Running a headers transition when the back key is pressed only works when the headers state is HEADERS_ENABLED or HEADERS_HIDDEN.

NOTE: If an Activity has its own onBackPressed() handling, you must disable this feature. You may use startHeadersTransition(boolean) and BrowseTransitionListener in your own back stack handling.

setOnItemViewClickedListener

open fun setOnItemViewClickedListener(listener: OnItemViewClickedListener!): Unit

Sets an item clicked listener on the fragment. OnItemViewClickedListener will override View.OnClickListener that item presenter sets during Presenter#onCreateViewHolder(ViewGroup). So in general, developer should choose one of the listeners but not both.

setOnItemViewSelectedListener

open fun setOnItemViewSelectedListener(listener: OnItemViewSelectedListener!): Unit

Sets an item selection listener.

setSelectedPosition

open fun setSelectedPosition(position: Int): Unit

Sets the selected row position with smooth animation.

setSelectedPosition

open fun setSelectedPosition(
    position: Int, 
    smooth: Boolean
): Unit

Sets the selected row position.

setSelectedPosition

open fun setSelectedPosition(
    rowPosition: Int, 
    smooth: Boolean, 
    rowHolderTask: Presenter.ViewHolderTask!
): Unit

Selects a Row and perform an optional task on the Row. For example setSelectedPosition(10, true, new ListRowPresenterSelectItemViewHolderTask(5)) scrolls to 11th row and selects 6th item on that row. The method will be ignored if RowsFragment has not been created (i.e. before onCreateView(LayoutInflater, * ViewGroup, Bundle)).

Parameters
`rowPosition`	Int: Which row to select.
`smooth`	Boolean: True to scroll to the row, false for no animation.
`rowHolderTask`	Presenter.ViewHolderTask!: Optional task to perform on the Row. When the task is not null, headers fragment will be collapsed.

startHeadersTransition

open fun startHeadersTransition(withHeaders: Boolean): Unit

Starts a headers transition.

This method will begin a transition to either show or hide the headers, depending on the value of withHeaders. If headers are disabled for this browse fragment, this method will throw an exception.

Parameters
`withHeaders`	Boolean: True if the headers should transition to being shown, false if the transition should result in headers being hidden.

Protected methods

createEntranceTransition

protected open fun createEntranceTransition(): Any!

onEntranceTransitionEnd

protected open fun onEntranceTransitionEnd(): Unit

onEntranceTransitionPrepare

protected open fun onEntranceTransitionPrepare(): Unit

onEntranceTransitionStart

protected open fun onEntranceTransitionStart(): Unit

runEntranceTransition

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