SessionPlayer

public abstract class SessionPlayer
extends Object implements AutoCloseable

java.lang.Object
   ↳ androidx.media2.common.SessionPlayer


Base interface for all media players that want media session.

APIs that return ListenableFuture should be the asynchronous calls and shouldn't block the calling thread. This guarantees the APIs are safe to be called on the main thread.

Topics covered here are:

  1. Best practices
  2. Player states
  3. Invalid method calls

Best practices

Here are best practices when implementing/using SessionPlayer:
  • When updating UI, you should respond to SessionPlayer.PlayerCallback invocations instead of SessionPlayer.PlayerResult objects since the player can be controlled by others.
  • When a SessionPlayer object is no longer being used, call AutoCloseable.close() as soon as possible to release the resources used by the internal player engine associated with the SessionPlayer. For example, if a player uses hardware decoder, other player instances may fallback to software decoders or fail to play. You cannot use SessionPlayer instance after you call AutoCloseable.close(). There is no way to reuse the instance.
  • The current playback position can be retrieved with a call to getCurrentPosition(), which is helpful for applications such as a music player that need to keep track of the playback progress.
  • The playback position can be adjusted with a call to seekTo(long). Although the asynchronous seekTo(long) call returns right away, the actual seek operation may take a while to finish, especially for audio/video being streamed.
  • You can call seekTo(long) from the PLAYER_STATE_PAUSED. In these cases, if you are playing a video stream and the requested position is valid, one video frame may be displayed.

Player states

The playback control of audio/video files is managed as a state machine. The SessionPlayer defines four states:
  1. PLAYER_STATE_IDLE: Initial state after the instantiation.

    While in this state, you should call setMediaItem(MediaItem) or setPlaylist(List, MediaMetadata). Check returned ListenableFuture for potential error.

    Calling prepare() transfers this object to PLAYER_STATE_PAUSED.

  2. PLAYER_STATE_PAUSED: State when the audio/video playback is paused.

    Call play() to resume or start playback from the position where it paused.

  3. PLAYER_STATE_PLAYING: State when the player plays the media item.

    In this state, SessionPlayer.PlayerCallback.onBufferingStateChanged(SessionPlayer, MediaItem, int) will be called regularly to tell the buffering status.

    Playback state would remain PLAYER_STATE_PLAYING when the currently playing media item is changed.

    When the playback reaches the end of stream, the behavior depends on repeat mode, set by setRepeatMode(int). If the repeat mode was set to REPEAT_MODE_NONE, the player will transfer to the PLAYER_STATE_PAUSED. Otherwise, the SessionPlayer object remains in the PLAYER_STATE_PLAYING and playback will be ongoing.

  4. PLAYER_STATE_ERROR: State when the playback failed and player cannot be recovered by itself.

    In general, playback might fail due to various reasons such as unsupported audio/video format, poorly interleaved audio/video, resolution too high, streaming timeout, and others. In addition, due to programming errors, a playback control operation might be performed from an invalid state. In these cases the player may transition to this state.

Subclasses may have extra methods to reset the player state to PLAYER_STATE_IDLE from other states. Take a look at documentations of specific subclass that you're interested in.

Invalid method calls

The only method you safely call from the PLAYER_STATE_ERROR is AutoCloseable.close(). Any other methods might return meaningless data.

Subclasses of the SessionPlayer may have extra methods that are safe to be called in the error state and/or provide a method to recover from the error state. Take a look at documentations of specific subclass that you're interested in.

Most methods can be called from any non-Error state. In case they're called in invalid state, the implementation should ignore and would return SessionPlayer.PlayerResult with SessionPlayer.PlayerResult.RESULT_ERROR_INVALID_STATE. The following table lists the methods that aren't guaranteed to successfully running if they're called from the associated invalid states.

Method Name Invalid States
setAudioAttributes {Paused, Playing}
prepare {Paused, Playing}
play {Idle}
pause {Idle}
seekTo {Idle}

Summary

Nested classes

class SessionPlayer.PlayerCallback

A callback class to receive notifications for events on the session player. 

class SessionPlayer.PlayerResult

Result class of the asynchronous APIs. 

Constants

int BUFFERING_STATE_BUFFERING_AND_PLAYABLE

Buffering state indicating the player is buffering but enough has been buffered for this player to be able to play the content.

int BUFFERING_STATE_BUFFERING_AND_STARVED

Buffering state indicating the player is buffering, but the player is currently starved for data, and cannot play.

int BUFFERING_STATE_COMPLETE

Buffering state indicating the player is done buffering, and the remainder of the content is available for playback.

int BUFFERING_STATE_UNKNOWN

Buffering state is unknown.

int INVALID_ITEM_INDEX

Media item index is invalid.

int PLAYER_STATE_ERROR

State when the player is in error state and cannot be recovered self.

int PLAYER_STATE_IDLE

State when the player is idle, and needs configuration to start playback.

int PLAYER_STATE_PAUSED

State when the player's playback is paused

int PLAYER_STATE_PLAYING

State when the player's playback is ongoing

int REPEAT_MODE_ALL

Playing media list will be repeated.

int REPEAT_MODE_GROUP

Playback of the playing media group will be repeated.

int REPEAT_MODE_NONE

Playback will be stopped at the end of the playing media list.

int REPEAT_MODE_ONE

Playback of the current playing media item will be repeated.

int SHUFFLE_MODE_ALL

Media list will be played in shuffled order.

int SHUFFLE_MODE_GROUP

Media group will be played in shuffled order.

int SHUFFLE_MODE_NONE

Media list will be played in order.

long UNKNOWN_TIME

Value indicating the time is unknown

Public constructors

SessionPlayer()

Public methods

abstract ListenableFuture<SessionPlayer.PlayerResult> addPlaylistItem(int index, MediaItem item)

Adds the media item to the playlist at position index.

abstract AudioAttributesCompat getAudioAttributes()

Gets the AudioAttributesCompat that media player has.

abstract long getBufferedPosition()

Gets the position for how much has been buffered, or UNKNOWN_TIME if unknown.

abstract int getBufferingState()

Returns the current buffering state of the player.

abstract MediaItem getCurrentMediaItem()

Gets the current media item, which is currently playing or would be played with later play().

abstract int getCurrentMediaItemIndex()

Gets the index of current media item in playlist.

abstract long getCurrentPosition()

Gets the current playback head position.

abstract long getDuration()

Gets the duration of the current media item, or UNKNOWN_TIME if unknown.

abstract int getNextMediaItemIndex()

Gets the next item index in the playlist.

abstract float getPlaybackSpeed()

Gets the actual playback speed to be used by the player when playing.

abstract int getPlayerState()

Gets the current player state.

abstract List<MediaItem> getPlaylist()

Gets the playlist.

abstract MediaMetadata getPlaylistMetadata()

Gets the playlist metadata.

abstract int getPreviousMediaItemIndex()

Gets the previous item index in the playlist.

abstract int getRepeatMode()

Gets the repeat mode.

abstract int getShuffleMode()

Gets the shuffle mode.

abstract ListenableFuture<SessionPlayer.PlayerResult> pause()

Pauses playback.

abstract ListenableFuture<SessionPlayer.PlayerResult> play()

Starts or resumes playback.

abstract ListenableFuture<SessionPlayer.PlayerResult> prepare()

Prepares the media items for playback.

final void registerPlayerCallback(Executor executor, SessionPlayer.PlayerCallback callback)

Register SessionPlayer.PlayerCallback to listen changes.

abstract ListenableFuture<SessionPlayer.PlayerResult> removePlaylistItem(int index)

Removes the media item from the playlist

The implementation may not change the currently playing media item even when it's removed.

abstract ListenableFuture<SessionPlayer.PlayerResult> replacePlaylistItem(int index, MediaItem item)

Replaces the media item at index in the playlist.

abstract ListenableFuture<SessionPlayer.PlayerResult> seekTo(long position)

Seeks to the specified position.

abstract ListenableFuture<SessionPlayer.PlayerResult> setAudioAttributes(AudioAttributesCompat attributes)

Sets the AudioAttributesCompat to be used during the playback of the media.

abstract ListenableFuture<SessionPlayer.PlayerResult> setMediaItem(MediaItem item)

Sets a MediaItem for playback.

abstract ListenableFuture<SessionPlayer.PlayerResult> setPlaybackSpeed(float playbackSpeed)

Sets the playback speed.

abstract ListenableFuture<SessionPlayer.PlayerResult> setPlaylist(List<MediaItem> list, MediaMetadata metadata)

Sets a list of MediaItem with metadata.

abstract ListenableFuture<SessionPlayer.PlayerResult> setRepeatMode(int repeatMode)

Sets the repeat mode.

abstract ListenableFuture<SessionPlayer.PlayerResult> setShuffleMode(int shuffleMode)

Sets the shuffle mode.

abstract ListenableFuture<SessionPlayer.PlayerResult> skipToNextPlaylistItem()

Skips to the next item in the playlist.

abstract ListenableFuture<SessionPlayer.PlayerResult> skipToPlaylistItem(int index)

Skips to the the media item.

abstract ListenableFuture<SessionPlayer.PlayerResult> skipToPreviousPlaylistItem()

Skips to the previous item in the playlist.

final void unregisterPlayerCallback(SessionPlayer.PlayerCallback callback)

Unregister the previously registered SessionPlayer.PlayerCallback.

abstract ListenableFuture<SessionPlayer.PlayerResult> updatePlaylistMetadata(MediaMetadata metadata)

Updates the playlist metadata while keeping the playlist as-is.

Protected methods

final List<Pair<SessionPlayer.PlayerCallback, Executor>> getCallbacks()

Gets the callbacks with executors for subclasses to notify player events.

Inherited methods

Constants

BUFFERING_STATE_BUFFERING_AND_PLAYABLE

public static final int BUFFERING_STATE_BUFFERING_AND_PLAYABLE

Buffering state indicating the player is buffering but enough has been buffered for this player to be able to play the content. See getBufferedPosition() for how far is buffered already.

Constant Value: 1 (0x00000001)

BUFFERING_STATE_BUFFERING_AND_STARVED

public static final int BUFFERING_STATE_BUFFERING_AND_STARVED

Buffering state indicating the player is buffering, but the player is currently starved for data, and cannot play.

Constant Value: 2 (0x00000002)

BUFFERING_STATE_COMPLETE

public static final int BUFFERING_STATE_COMPLETE

Buffering state indicating the player is done buffering, and the remainder of the content is available for playback.

Constant Value: 3 (0x00000003)

BUFFERING_STATE_UNKNOWN

public static final int BUFFERING_STATE_UNKNOWN

Buffering state is unknown.

Constant Value: 0 (0x00000000)

INVALID_ITEM_INDEX

public static final int INVALID_ITEM_INDEX

Media item index is invalid. This value will be returned when the corresponding media item does not exist.

Constant Value: -1 (0xffffffff)

PLAYER_STATE_ERROR

public static final int PLAYER_STATE_ERROR

State when the player is in error state and cannot be recovered self.

Constant Value: 3 (0x00000003)

PLAYER_STATE_IDLE

public static final int PLAYER_STATE_IDLE

State when the player is idle, and needs configuration to start playback.

Constant Value: 0 (0x00000000)

PLAYER_STATE_PAUSED

public static final int PLAYER_STATE_PAUSED

State when the player's playback is paused

Constant Value: 1 (0x00000001)

PLAYER_STATE_PLAYING

public static final int PLAYER_STATE_PLAYING

State when the player's playback is ongoing

Constant Value: 2 (0x00000002)

REPEAT_MODE_ALL

public static final int REPEAT_MODE_ALL

Playing media list will be repeated.

Constant Value: 2 (0x00000002)

REPEAT_MODE_GROUP

public static final int REPEAT_MODE_GROUP

Playback of the playing media group will be repeated. A group is a logical block of media items which is specified in the section 5.7 of the Bluetooth AVRCP 1.6. An example of a group is the playlist.

Constant Value: 3 (0x00000003)

REPEAT_MODE_NONE

public static final int REPEAT_MODE_NONE

Playback will be stopped at the end of the playing media list.

Constant Value: 0 (0x00000000)

REPEAT_MODE_ONE

public static final int REPEAT_MODE_ONE

Playback of the current playing media item will be repeated.

Constant Value: 1 (0x00000001)

SHUFFLE_MODE_ALL

public static final int SHUFFLE_MODE_ALL

Media list will be played in shuffled order.

Constant Value: 1 (0x00000001)

SHUFFLE_MODE_GROUP

public static final int SHUFFLE_MODE_GROUP

Media group will be played in shuffled order. A group is a logical block of media items which is specified in the section 5.7 of the Bluetooth AVRCP 1.6. An example of a group is the playlist.

Constant Value: 2 (0x00000002)

SHUFFLE_MODE_NONE

public static final int SHUFFLE_MODE_NONE

Media list will be played in order.

Constant Value: 0 (0x00000000)

UNKNOWN_TIME

public static final long UNKNOWN_TIME

Value indicating the time is unknown

Constant Value: -9223372036854775808 (0x8000000000000000)

Public constructors

SessionPlayer

public SessionPlayer ()

Public methods

addPlaylistItem

public abstract ListenableFuture<SessionPlayer.PlayerResult> addPlaylistItem (int index, 
                MediaItem item)

Adds the media item to the playlist at position index. Index equals or greater than the current playlist size (e.g. Integer.MAX_VALUE) will add the item at the end of the playlist.

The implementation may not change the currently playing media item. If index is less than or equal to the current index of the playlist, the current index of the playlist will be increased correspondingly.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onPlaylistChanged(SessionPlayer, List, MediaMetadata) when it's completed.

The implementation must close the ParcelFileDescriptor in the FileMediaItem if the given media item is a FileMediaItem.

On success, a SessionPlayer.PlayerResult should be returned with item added.

Parameters
index int: the index of the item you want to add in the playlist

item MediaItem: the media item you want to add

Returns
ListenableFuture<SessionPlayer.PlayerResult>

getAudioAttributes

public abstract AudioAttributesCompat getAudioAttributes ()

Gets the AudioAttributesCompat that media player has.

Returns
AudioAttributesCompat

getBufferedPosition

public abstract long getBufferedPosition ()

Gets the position for how much has been buffered, or UNKNOWN_TIME if unknown.

Returns
long the buffered position in ms, or UNKNOWN_TIME.

getBufferingState

public abstract int getBufferingState ()

Returns the current buffering state of the player.

During the buffering, see getBufferedPosition() for the quantifying the amount already buffered.

Returns
int the buffering state.

getCurrentMediaItem

public abstract MediaItem getCurrentMediaItem ()

Gets the current media item, which is currently playing or would be played with later play(). This value may be updated when SessionPlayer.PlayerCallback.onCurrentMediaItemChanged(SessionPlayer, MediaItem) or SessionPlayer.PlayerCallback.onPlaylistChanged(SessionPlayer, List, MediaMetadata) is called.

Returns
MediaItem the current media item. Can be null only when media item or playlist hasn't been set.

getCurrentMediaItemIndex

public abstract int getCurrentMediaItemIndex ()

Gets the index of current media item in playlist. This value may be updated when SessionPlayer.PlayerCallback.onCurrentMediaItemChanged(SessionPlayer, MediaItem) or SessionPlayer.PlayerCallback.onPlaylistChanged(SessionPlayer, List, MediaMetadata) is called.

Returns
int the index of current media item. Can be INVALID_ITEM_INDEX when current media item is null or not in the playlist, and when the playlist hasn't been set.

Value is -1 or greater.

getCurrentPosition

public abstract long getCurrentPosition ()

Gets the current playback head position.

Returns
long the current playback position in ms, or UNKNOWN_TIME if unknown.

getDuration

public abstract long getDuration ()

Gets the duration of the current media item, or UNKNOWN_TIME if unknown.

Returns
long the duration in ms, or UNKNOWN_TIME.

getNextMediaItemIndex

public abstract int getNextMediaItemIndex ()

Gets the next item index in the playlist. The returned value can be outdated after SessionPlayer.PlayerCallback.onCurrentMediaItemChanged(SessionPlayer, MediaItem) or SessionPlayer.PlayerCallback.onPlaylistChanged(SessionPlayer, List, MediaMetadata) is called.

Returns
int the index of next media item. Can be INVALID_ITEM_INDEX only when next media item does not exist or playlist hasn't been set.

Value is -1 or greater.

getPlaybackSpeed

public abstract float getPlaybackSpeed ()

Gets the actual playback speed to be used by the player when playing. A value of 1.0f is the default playback value, and a negative value indicates reverse playback.

Note that it may differ from the speed set in setPlaybackSpeed(float).

Returns
float the actual playback speed

getPlayerState

public abstract int getPlayerState ()

Gets the current player state.

Returns
int the current player state

getPlaylist

public abstract List<MediaItem> getPlaylist ()

Gets the playlist. Can be null if the playlist hasn't been set or it's reset by setMediaItem(MediaItem).

Returns
List<MediaItem> playlist, or null

getPlaylistMetadata

public abstract MediaMetadata getPlaylistMetadata ()

Gets the playlist metadata.

Returns
MediaMetadata metadata metadata of the playlist, or null if none is set

getPreviousMediaItemIndex

public abstract int getPreviousMediaItemIndex ()

Gets the previous item index in the playlist. The returned value can be outdated after SessionPlayer.PlayerCallback.onCurrentMediaItemChanged(SessionPlayer, MediaItem) or SessionPlayer.PlayerCallback.onPlaylistChanged(SessionPlayer, List, MediaMetadata) is called.

Returns
int the index of previous media item. Can be INVALID_ITEM_INDEX only when previous media item does not exist or playlist hasn't been set.

Value is -1 or greater.

getRepeatMode

public abstract int getRepeatMode ()

Gets the repeat mode.

Returns
int repeat mode

getShuffleMode

public abstract int getShuffleMode ()

Gets the shuffle mode.

Returns
int The shuffle mode

pause

public abstract ListenableFuture<SessionPlayer.PlayerResult> pause ()

Pauses playback.

On success, this transfers the player state to PLAYER_STATE_PAUSED and a SessionPlayer.PlayerResult should be returned with the current media item when the command was completed. If it is called in PLAYER_STATE_IDLE or PLAYER_STATE_ERROR, it should be ignored and a SessionPlayer.PlayerResult should be returned with SessionPlayer.PlayerResult.RESULT_ERROR_INVALID_STATE.

Returns
ListenableFuture<SessionPlayer.PlayerResult>

play

public abstract ListenableFuture<SessionPlayer.PlayerResult> play ()

Starts or resumes playback.

On success, this transfers the player state to PLAYER_STATE_PLAYING and a SessionPlayer.PlayerResult should be returned with the current media item when the command was completed. If it is called in PLAYER_STATE_IDLE or PLAYER_STATE_ERROR, it should be ignored and a SessionPlayer.PlayerResult should be returned with SessionPlayer.PlayerResult.RESULT_ERROR_INVALID_STATE.

Returns
ListenableFuture<SessionPlayer.PlayerResult>

prepare

public abstract ListenableFuture<SessionPlayer.PlayerResult> prepare ()

Prepares the media items for playback. During this time, the player may allocate resources required to play, such as audio and video decoders. Before calling this API, sets media item(s) through either setMediaItem(MediaItem) or setPlaylist(List, MediaMetadata).

On success, this transfers the player state from PLAYER_STATE_IDLE to PLAYER_STATE_PAUSED and a SessionPlayer.PlayerResult should be returned with the prepared media item when the command completed. If it's not called in PLAYER_STATE_IDLE, it is ignored and SessionPlayer.PlayerResult should be returned with SessionPlayer.PlayerResult.RESULT_ERROR_INVALID_STATE.

Returns
ListenableFuture<SessionPlayer.PlayerResult>

registerPlayerCallback

public final void registerPlayerCallback (Executor executor, 
                SessionPlayer.PlayerCallback callback)

Register SessionPlayer.PlayerCallback to listen changes.

Parameters
executor Executor: a callback Executor

callback SessionPlayer.PlayerCallback: a PlayerCallback

Throws
IllegalArgumentException if executor or callback is null.

removePlaylistItem

public abstract ListenableFuture<SessionPlayer.PlayerResult> removePlaylistItem (int index)

Removes the media item from the playlist

The implementation may not change the currently playing media item even when it's removed.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onPlaylistChanged(SessionPlayer, List, MediaMetadata) when it's completed.

On success, a SessionPlayer.PlayerResult should be returned with item removed.

Parameters
index int: the index of the item you want to remove in the playlist

Returns
ListenableFuture<SessionPlayer.PlayerResult>

replacePlaylistItem

public abstract ListenableFuture<SessionPlayer.PlayerResult> replacePlaylistItem (int index, 
                MediaItem item)

Replaces the media item at index in the playlist. This can be also used to update metadata of an item.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onPlaylistChanged(SessionPlayer, List, MediaMetadata) when it's completed.

The implementation must close the ParcelFileDescriptor in the FileMediaItem if the given media item is a FileMediaItem.

On success, a SessionPlayer.PlayerResult should be returned with item set.

Parameters
index int: the index of the item to replace in the playlist

item MediaItem: the new item

Returns
ListenableFuture<SessionPlayer.PlayerResult>

seekTo

public abstract ListenableFuture<SessionPlayer.PlayerResult> seekTo (long position)

Seeks to the specified position. Moves the playback head to the specified position.

On success, a SessionPlayer.PlayerResult should be returned with the current media item when the command completed. If it's called in PLAYER_STATE_IDLE, it is ignored and a SessionPlayer.PlayerResult should be returned with SessionPlayer.PlayerResult.RESULT_ERROR_INVALID_STATE.

Parameters
position long: the new playback position in ms. The value should be in the range of start and end positions defined in MediaItem.

Returns
ListenableFuture<SessionPlayer.PlayerResult>

setAudioAttributes

public abstract ListenableFuture<SessionPlayer.PlayerResult> setAudioAttributes (AudioAttributesCompat attributes)

Sets the AudioAttributesCompat to be used during the playback of the media.

You must call this method in PLAYER_STATE_IDLE in order for the audio attributes to become effective thereafter. Otherwise, the call would be ignored and SessionPlayer.PlayerResult should be returned with SessionPlayer.PlayerResult.RESULT_ERROR_INVALID_STATE.

On success, a SessionPlayer.PlayerResult should be returned with the current media item when the command completed.

Parameters
attributes AudioAttributesCompat: non-null AudioAttributes.

Returns
ListenableFuture<SessionPlayer.PlayerResult>

setMediaItem

public abstract ListenableFuture<SessionPlayer.PlayerResult> setMediaItem (MediaItem item)

Sets a MediaItem for playback. Use this or setPlaylist(List, MediaMetadata) to specify which items to play. If you want to change current item in the playlist, use one of skipToPlaylistItem(int), skipToNextPlaylistItem(), or skipToPreviousPlaylistItem() instead of this method.

This can be called multiple times in any states other than PLAYER_STATE_ERROR. This would override previous setMediaItem(MediaItem) or setPlaylist(List, MediaMetadata) calls.

It's recommended to fill MediaMetadata in MediaItem especially for the duration information with the key MediaMetadata.METADATA_KEY_DURATION. Without the duration information in the metadata, session will do extra work to get the duration and send it to the controller.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onPlaylistChanged(SessionPlayer, List, MediaMetadata) and SessionPlayer.PlayerCallback.onCurrentMediaItemChanged(SessionPlayer, MediaItem) when it's completed. The current item would be the item given here.

The implementation must close the ParcelFileDescriptor in the FileMediaItem if the given media item is a FileMediaItem.

On success, a SessionPlayer.PlayerResult should be returned with item set.

Parameters
item MediaItem: the descriptor of media item you want to play

Returns
ListenableFuture<SessionPlayer.PlayerResult> a ListenableFuture which represents the pending completion of the command.

Throws
IllegalArgumentException if the given item is null.

setPlaybackSpeed

public abstract ListenableFuture<SessionPlayer.PlayerResult> setPlaybackSpeed (float playbackSpeed)

Sets the playback speed. 1.0f is the default, negative values indicate reverse playback and 0.0f is not allowed.

The supported playback speed range depends on the underlying player implementation, so it is recommended to query the actual speed of the player via getPlaybackSpeed() after the operation completes. In particular, please note that player implementations may not support reverse playback.

On success, a SessionPlayer.PlayerResult should be returned with the current media item when the command completed.

Parameters
playbackSpeed float: The requested playback speed.

Returns
ListenableFuture<SessionPlayer.PlayerResult> A ListenableFuture representing the pending completion of the command.

setPlaylist

public abstract ListenableFuture<SessionPlayer.PlayerResult> setPlaylist (List<MediaItem> list, 
                MediaMetadata metadata)

Sets a list of MediaItem with metadata. Use this or setMediaItem(MediaItem) to specify which items to play.

This can be called multiple times in any states other than PLAYER_STATE_ERROR. This would override previous setMediaItem(MediaItem) or setPlaylist(List, MediaMetadata) calls.

Ensure uniqueness of each MediaItem in the playlist so the session can uniquely identity individual items. All MediaItems shouldn't be null as well.

It's recommended to fill MediaMetadata in each MediaItem especially for the duration information with the key MediaMetadata.METADATA_KEY_DURATION. Without the duration information in the metadata, session will do extra work to get the duration and send it to the controller.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onPlaylistChanged(SessionPlayer, List, MediaMetadata) and SessionPlayer.PlayerCallback.onCurrentMediaItemChanged(SessionPlayer, MediaItem) when it's completed. The current media item would be the first item in the playlist.

The implementation must close the ParcelFileDescriptor in the FileMediaItem when a media item in the playlist is a FileMediaItem.

On success, a SessionPlayer.PlayerResult should be returned with the first media item of the playlist when the command completed.

Parameters
list List: A list of MediaItem objects to set as a play list.

metadata MediaMetadata

Returns
ListenableFuture<SessionPlayer.PlayerResult> a ListenableFuture which represents the pending completion of the command.

Throws
IllegalArgumentException if the given list is null or empty, or has duplicated media items.

setRepeatMode

public abstract ListenableFuture<SessionPlayer.PlayerResult> setRepeatMode (int repeatMode)

Sets the repeat mode.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onRepeatModeChanged(SessionPlayer, int) when it's completed.

On success, a SessionPlayer.PlayerResult should be returned with the current media item when the command completed.

Parameters
repeatMode int: repeat mode

Returns
ListenableFuture<SessionPlayer.PlayerResult>

setShuffleMode

public abstract ListenableFuture<SessionPlayer.PlayerResult> setShuffleMode (int shuffleMode)

Sets the shuffle mode.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onShuffleModeChanged(SessionPlayer, int) when it's completed.

On success, a SessionPlayer.PlayerResult should be returned with the current media item when the command completed.

Parameters
shuffleMode int: The shuffle mode

Returns
ListenableFuture<SessionPlayer.PlayerResult>

skipToNextPlaylistItem

public abstract ListenableFuture<SessionPlayer.PlayerResult> skipToNextPlaylistItem ()

Skips to the next item in the playlist.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onCurrentMediaItemChanged(SessionPlayer, MediaItem) when it's completed.

On success, a SessionPlayer.PlayerResult should be returned with the current media item when the command completed.

Returns
ListenableFuture<SessionPlayer.PlayerResult>

skipToPlaylistItem

public abstract ListenableFuture<SessionPlayer.PlayerResult> skipToPlaylistItem (int index)

Skips to the the media item.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onCurrentMediaItemChanged(SessionPlayer, MediaItem) when it's completed.

On success, a SessionPlayer.PlayerResult should be returned with the current media item when the command completed.

Parameters
index int: The index of the item you want to play in the playlist

Returns
ListenableFuture<SessionPlayer.PlayerResult>

skipToPreviousPlaylistItem

public abstract ListenableFuture<SessionPlayer.PlayerResult> skipToPreviousPlaylistItem ()

Skips to the previous item in the playlist.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onCurrentMediaItemChanged(SessionPlayer, MediaItem) when it's completed.

On success, a SessionPlayer.PlayerResult should be returned with the current media item when the command completed.

Returns
ListenableFuture<SessionPlayer.PlayerResult>

unregisterPlayerCallback

public final void unregisterPlayerCallback (SessionPlayer.PlayerCallback callback)

Unregister the previously registered SessionPlayer.PlayerCallback.

Parameters
callback SessionPlayer.PlayerCallback: the callback to be removed

Throws
IllegalArgumentException if the callback is null.

updatePlaylistMetadata

public abstract ListenableFuture<SessionPlayer.PlayerResult> updatePlaylistMetadata (MediaMetadata metadata)

Updates the playlist metadata while keeping the playlist as-is.

The implementation must notify registered callbacks with SessionPlayer.PlayerCallback.onPlaylistMetadataChanged(SessionPlayer, MediaMetadata) when it's completed.

On success, a SessionPlayer.PlayerResult should be returned with the current media item when the command completed.

Parameters
metadata MediaMetadata: metadata of the playlist

Returns
ListenableFuture<SessionPlayer.PlayerResult>

Protected methods

getCallbacks

protected final List<Pair<SessionPlayer.PlayerCallback, Executor>> getCallbacks ()

Gets the callbacks with executors for subclasses to notify player events.

Returns
List<Pair<SessionPlayer.PlayerCallback, Executor>> map of callbacks and its executors