PlaybackGlue

abstract class PlaybackGlue

kotlin.Any
↳	androidx.leanback.media.PlaybackGlue

Known Direct Subclasses PlaybackBaseControlGlue, PlaybackControlGlue PlaybackBaseControlGlue A base abstract class for managing a PlaybackControlsRow being displayed in PlaybackGlueHost. PlaybackControlGlue A helper class for managing a PlaybackControlsRow and PlaybackGlueHost that implements a recommended approach to handling standard playback control actions such as play/pause, fast forward/rewind at progressive speed levels, and skip to next/previous.

Known Indirect Subclasses MediaControllerGlue, PlaybackBannerControlGlue, PlaybackTransportControlGlue MediaControllerGlue A helper class for implementing a glue layer for MediaControllerCompat. PlaybackBannerControlGlue A helper class for managing a PlaybackControlsRow being displayed in PlaybackGlueHost. PlaybackTransportControlGlue A helper class for managing a PlaybackControlsRow being displayed in PlaybackGlueHost, it supports standard playback control actions play/pause, and skip next/previous.

Base class for abstraction of media play/pause feature. A subclass of PlaybackGlue will contain implementation of Media Player or a connection to playback Service. App initializes PlaybackGlue subclass, associated it with a PlaybackGlueHost. PlaybackGlueHost is typically implemented by a Fragment or an Activity, it provides the environment to render UI for PlaybackGlue object, it optionally provides SurfaceHolder via SurfaceHolderGlueHost to render video. A typical PlaybackGlue should release resources (e.g. MediaPlayer or connection to playback Service) in onDetachedFromHost(). onDetachedFromHost() is called in two cases:

• app manually change it using setHost(PlaybackGlueHost) call
• When host (fragment or activity) is destroyed

In rare case if an PlaybackGlue wants to live outside fragment / activity life cycle, it may manages resource release by itself.

Summary

Nested classes
abstract	PlayerCallback Interface to allow clients to take action once the video is ready to play and start stop.

Public constructors
<init>(context: Context!) Constructor.

Public methods
open Boolean	isPlaying() Returns true if media is currently playing.
open Unit	playWhenPrepared() Starts play when isPrepared() becomes true.
open Unit	pause() Pauses the media player.
open PlaybackGlueHost!	getHost()
open Unit	previous() Goes to the previous media item.
open Boolean	isPrepared() Returns true when the media player is prepared to start media playback.
open Context!	getContext() Returns the context.
Unit	setHost(host: PlaybackGlueHost!) This method is used to associate a PlaybackGlue with the PlaybackGlueHost which provides UI and optional SurfaceHolderGlueHost.
open Unit	play() Starts the media player.
open Unit	next() Goes to the next media item.
open Unit	removePlayerCallback(callback: PlaybackGlue.PlayerCallback!) Remove a PlayerCallback.
open Unit	addPlayerCallback(playerCallback: PlaybackGlue.PlayerCallback!) Add a PlayerCallback.

Protected methods
open Unit	onHostStart() This method is called when PlaybackGlueHost is started.
open MutableList<PlaybackGlue.PlayerCallback!>!	getPlayerCallbacks()
open Unit	onAttachedToHost(host: PlaybackGlueHost!) This method is called attached to associated PlaybackGlueHost.
open Unit	onDetachedFromHost() This method is called when current associated PlaybackGlueHost is attached to a different PlaybackGlue or PlaybackGlueHost is destroyed .
open Unit	onHostResume() This method is called when PlaybackGlueHost is resumed.
open Unit	onHostStop() This method is called when PlaybackGlueHost is stopped.
open Unit	onHostPause() This method is called when PlaybackGlueHost is paused.

Public constructors

<init>

PlaybackGlue(context: Context!)

Constructor.

Public methods

isPlaying

open fun isPlaying(): Boolean

Returns true if media is currently playing.

playWhenPrepared

open fun playWhenPrepared(): Unit

Starts play when isPrepared() becomes true.

pause

open fun pause(): Unit

Pauses the media player.

getHost

open fun getHost(): PlaybackGlueHost!

Return
PlaybackGlueHost!: Associated PlaybackGlueHost or null if not attached to host.

previous

open fun previous(): Unit

Goes to the previous media item. This method is optional.

isPrepared

open fun isPrepared(): Boolean

Returns true when the media player is prepared to start media playback. When returning false, app may listen to PlayerCallback#onPreparedStateChanged(PlaybackGlue) event.

Return
Boolean: True if prepared, false otherwise.

getContext

open fun getContext(): Context!

Returns the context.

setHost

fun setHost(host: PlaybackGlueHost!): Unit

This method is used to associate a PlaybackGlue with the PlaybackGlueHost which provides UI and optional SurfaceHolderGlueHost.

Parameters
host	PlaybackGlueHost!: The host for the PlaybackGlue. Set to null to detach from the host.

play

open fun play(): Unit

Starts the media player. Does nothing if isPrepared() is false. To wait isPrepared() to be true before playing, use playWhenPrepared().

next

open fun next(): Unit

Goes to the next media item. This method is optional.

removePlayerCallback

open fun removePlayerCallback(callback: PlaybackGlue.PlayerCallback!): Unit

Remove a PlayerCallback.

Parameters
callback	PlaybackGlue.PlayerCallback!: The callback to remove.

addPlayerCallback

open fun addPlayerCallback(playerCallback: PlaybackGlue.PlayerCallback!): Unit

Add a PlayerCallback.

Parameters
playerCallback	PlaybackGlue.PlayerCallback!: The callback to add.

Protected methods

onHostStart

protected open fun onHostStart(): Unit

This method is called when PlaybackGlueHost is started. Subclass may override.

getPlayerCallbacks

protected open fun getPlayerCallbacks(): MutableList<PlaybackGlue.PlayerCallback!>!

Return
MutableList<PlaybackGlue.PlayerCallback!>!: A snapshot of list of PlayerCallbacks set on the Glue.

onAttachedToHost

@CallSuper protected open fun onAttachedToHost(host: PlaybackGlueHost!): Unit

This method is called attached to associated PlaybackGlueHost. Subclass may override and call super.onAttachedToHost().

onDetachedFromHost

@CallSuper protected open fun onDetachedFromHost(): Unit

This method is called when current associated PlaybackGlueHost is attached to a different PlaybackGlue or PlaybackGlueHost is destroyed . Subclass may override and call super.onDetachedFromHost() at last. A typical PlaybackGlue will release resources (e.g. MediaPlayer or connection to playback service) in this method.

onHostResume

protected open fun onHostResume(): Unit

This method is called when PlaybackGlueHost is resumed. Subclass may override.

onHostStop

protected open fun onHostStop(): Unit

This method is called when PlaybackGlueHost is stopped. Subclass may override.

onHostPause

protected open fun onHostPause(): Unit

This method is called when PlaybackGlueHost is paused. Subclass may override.