PlaybackGlue

Kotlin |Java

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

Protected methods
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	`onHostPause()` This method is called when `PlaybackGlueHost` is paused.
open Unit	`onHostResume()` This method is called when `PlaybackGlueHost` is resumed.
open Unit	`onHostStart()` This method is called when `PlaybackGlueHost` is started.
open Unit	`onHostStop()` This method is called when `PlaybackGlueHost` is stopped.

Public constructors

<init>

PlaybackGlue(context: Context!)

Constructor.

Public methods

addPlayerCallback

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

Add a PlayerCallback.

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

getContext

open fun getContext(): Context!

Returns the context.

getHost

open fun getHost(): PlaybackGlueHost!

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

isPlaying

open fun isPlaying(): Boolean

Returns true if media is currently playing.

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.

open fun next(): Unit

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

pause

open fun pause(): Unit

Pauses the media player.

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().

playWhenPrepared

open fun playWhenPrepared(): Unit

Starts play when isPrepared() becomes true.

open fun previous(): Unit

Goes to the previous 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.

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.

Protected methods

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.

onHostPause

protected open fun onHostPause(): Unit

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

onHostResume

protected open fun onHostResume(): Unit

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

onHostStart

protected open fun onHostStart(): Unit

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

onHostStop

protected open fun onHostStop(): Unit

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