RowPresenter

public abstract class RowPresenter
extends Presenter

java.lang.Object
↳	android.support.v17.leanback.widget.Presenter
	↳	android.support.v17.leanback.widget.RowPresenter

Known Direct Subclasses AbstractMediaItemPresenter,AbstractMediaListHeaderPresenter,DetailsOverviewRowPresenter,FullWidthDetailsOverviewRowPresenter,ListRowPresenter,PlaybackRowPresenter AbstractMediaItemPresenter Abstract Presenter class for rendering media items in a playlist format.  AbstractMediaListHeaderPresenter Abstract presenter class for rendering the header for a list of media items in a playlist.  DetailsOverviewRowPresenter This class was deprecated in API level 24.1.0. Use FullWidthDetailsOverviewRowPresenter   FullWidthDetailsOverviewRowPresenter Renders a DetailsOverviewRow to display an overview of an item.  ListRowPresenter ListRowPresenter renders ListRow using a HorizontalGridView hosted in a ListRowView.  PlaybackRowPresenter Subclass of RowPresenter that can define the desired behavior when the view reappears.

Known Indirect Subclasses PlaybackControlsRowPresenter,PlaybackTransportRowPresenter PlaybackControlsRowPresenter A PlaybackControlsRowPresenter renders a PlaybackControlsRow to display a series of playback control buttons.  PlaybackTransportRowPresenter A PlaybackTransportRowPresenter renders a PlaybackControlsRow to display a series of playback control buttons.

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An abstract Presenter that renders an Object in RowsFragment, the object can be subclass Row or a generic one. When the object is not Row class, getRow() returns null.

Customize UI widgets

When a subclass of RowPresenter adds UI widgets, it should subclass RowPresenter.ViewHolder and override createRowViewHolder(ViewGroup) and initializeRowViewHolder(ViewHolder). The subclass must use layout id "row_content" for the widget that will be aligned to the title of any HeadersFragment that may exist in the parent fragment. RowPresenter contains an optional and replaceable RowHeaderPresenter that renders the header. You can disable the default rendering or replace the Presenter with a new header presenter by calling setHeaderPresenter(RowHeaderPresenter).

UI events from fragments

RowPresenter receives calls from its parent (typically a Fragment) when:

• A row is selected via setRowViewSelected(Presenter.ViewHolder, boolean). The event is triggered immediately when there is a row selection change before the selection animation is started. Selected status may control activated status of the row (see "Activated status" below). Subclasses of RowPresenter may override onRowViewSelected(ViewHolder, boolean).
• A row is expanded to full height via setRowViewExpanded(Presenter.ViewHolder, boolean) when BrowseFragment hides fast lane on the left. The event is triggered immediately before the expand animation is started. Row title is shown when row is expanded. Expanded status may control activated status of the row (see "Activated status" below). Subclasses of RowPresenter may override onRowViewExpanded(ViewHolder, boolean).

Activated status

The activated status of a row is applied to the row view and its children via setActivated(boolean). The activated status is typically used to control BaseCardView info region visibility. The row's activated status can be controlled by selected status and/or expanded status. Call setSyncActivatePolicy(int) and choose one of the four policies:

• SYNC_ACTIVATED_TO_EXPANDED Activated status is synced with row expanded status
• SYNC_ACTIVATED_TO_SELECTED Activated status is synced with row selected status
• SYNC_ACTIVATED_TO_EXPANDED_AND_SELECTED Activated status is set to true when both expanded and selected status are true
• SYNC_ACTIVATED_CUSTOM Activated status is not controlled by selected status or expanded status, application can control activated status by its own. Application should call setActivated(boolean) to change activated status of row view.

User events

RowPresenter provides OnItemViewSelectedListener and OnItemViewClickedListener. If a subclass wants to add its own View.OnFocusChangeListener or View.OnClickListener, it must do that in createRowViewHolder(ViewGroup) to be properly chained by the library. Adding View listeners after createRowViewHolder(ViewGroup) is undefined and may result in incorrect behavior by the library's listeners.

Selection animation

When a user scrolls through rows, a fragment will initiate animation and call setSelectLevel(Presenter.ViewHolder, float) with float value between 0 and 1. By default, the RowPresenter draws a dim overlay on top of the row view for views that are not selected. Subclasses may override this default effect by having isUsingDefaultSelectEffect() return false and overriding onSelectLevelChanged(ViewHolder) to apply a different selection effect.

Call setSelectEffectEnabled(boolean) to enable/disable the select effect, This will not only enable/disable the default dim effect but also subclasses must respect this flag as well.

Summary

Nested classes
class	RowPresenter.ViewHolder A ViewHolder for a Row.

Constants
int	SYNC_ACTIVATED_CUSTOM Don't synchronize row view activated status with selected status or expanded status, application will do its own through setActivated(boolean).
int	SYNC_ACTIVATED_TO_EXPANDED Synchronizes row view's activated status to expand status of the row view holder.
int	SYNC_ACTIVATED_TO_EXPANDED_AND_SELECTED Sets the row view's activated status to true when both expand and selected are true.
int	SYNC_ACTIVATED_TO_SELECTED Synchronizes row view's activated status to selected status of the row view holder.

Public constructors
RowPresenter() Constructs a RowPresenter.

Public methods
void	freeze(RowPresenter.ViewHolder holder, boolean freeze) Freezes/unfreezes the row, typically used when a transition starts/ends.
final RowHeaderPresenter	getHeaderPresenter() Returns the Presenter used for rendering the header, or null if none has been set.
final RowPresenter.ViewHolder	getRowViewHolder(Presenter.ViewHolder holder) Returns the RowPresenter.ViewHolder from the given RowPresenter ViewHolder.
final boolean	getSelectEffectEnabled() Returns true if the row selection effect is enabled.
final float	getSelectLevel(Presenter.ViewHolder vh) Returns the current select level.
final int	getSyncActivatePolicy() Returns the policy of updating row view activated status.
boolean	isUsingDefaultSelectEffect() Returns true if this RowPresenter is using the default dimming effect.
final void	onBindViewHolder(Presenter.ViewHolder viewHolder, Object item) Binds a View to an item.
final Presenter.ViewHolder	onCreateViewHolder(ViewGroup parent) Creates a new View.
final void	onUnbindViewHolder(Presenter.ViewHolder viewHolder) Unbinds a View from an item.
final void	onViewAttachedToWindow(Presenter.ViewHolder holder) Called when a view created by this presenter has been attached to a window.
final void	onViewDetachedFromWindow(Presenter.ViewHolder holder) Called when a view created by this presenter has been detached from its window.
void	setEntranceTransitionState(RowPresenter.ViewHolder holder, boolean afterEntrance) Changes the visibility of views.
final void	setHeaderPresenter(RowHeaderPresenter headerPresenter) Sets the Presenter used for rendering the header.
final void	setRowViewExpanded(Presenter.ViewHolder holder, boolean expanded) Sets the expanded state of a Row view.
final void	setRowViewSelected(Presenter.ViewHolder holder, boolean selected) Sets the selected state of a Row view.
final void	setSelectEffectEnabled(boolean applyDimOnSelect) Enables or disables the row selection effect.
final void	setSelectLevel(Presenter.ViewHolder vh, float level) Sets the current select level to a value between 0 (unselected) and 1 (selected).
final void	setSyncActivatePolicy(int syncActivatePolicy) Sets the policy of updating row view activated status.

Protected methods
abstract RowPresenter.ViewHolder	createRowViewHolder(ViewGroup parent) Called to create a ViewHolder object for a Row.
void	dispatchItemSelectedListener(RowPresenter.ViewHolder vh, boolean selected) This method is only called from onRowViewSelected(ViewHolder, boolean) onRowViewSelected.
void	initializeRowViewHolder(RowPresenter.ViewHolder vh) Called after a RowPresenter.ViewHolder is created for a Row.
boolean	isClippingChildren() Returns true if the Row view should clip its children.
void	onBindRowViewHolder(RowPresenter.ViewHolder vh, Object item) Binds the given row object to the given ViewHolder.
void	onRowViewAttachedToWindow(RowPresenter.ViewHolder vh) Invoked when the row view is attached to the window.
void	onRowViewDetachedFromWindow(RowPresenter.ViewHolder vh) Invoked when the row view is detached from the window.
void	onRowViewExpanded(RowPresenter.ViewHolder vh, boolean expanded) Called when the row view's expanded state changes.
void	onRowViewSelected(RowPresenter.ViewHolder vh, boolean selected) Called when the given row view changes selection state.
void	onSelectLevelChanged(RowPresenter.ViewHolder vh) Callback when the select level changes.
void	onUnbindRowViewHolder(RowPresenter.ViewHolder vh) Unbinds the given ViewHolder.

Inherited methods

From class android.support.v17.leanback.widget.Presenter static void cancelAnimationsRecursive(View view) Utility method for removing all running animations on a view. final Object getFacet(Class<?> facetClass) Queries optional implemented facet. abstract void onBindViewHolder(Presenter.ViewHolder viewHolder, Object item) Binds a View to an item. void onBindViewHolder(Presenter.ViewHolder viewHolder, Object item, List<Object> payloads) Binds a View to an item with a list of payloads. abstract Presenter.ViewHolder onCreateViewHolder(ViewGroup parent) Creates a new View.