MediaLibrarySession

Kotlin |Java

class MediaLibrarySession : MediaSession

kotlin.Any
↳	androidx.media2.session.MediaSession
	↳	androidx.media2.session.MediaLibraryService.MediaLibrarySession

Session for the MediaLibraryService. Build this object with Builder and return in MediaSessionService#onGetSession(ControllerInfo).

Backward compatibility with legacy media browser APIs

Media library session supports connection from both MediaBrowser and android.support.v4.media.MediaBrowserCompat, but ControllerInfo may not be precise. Here are current limitations with details.

SDK version	`ControllerInfo#getPackageName()` for legacy browser	`ControllerInfo#getUid()` for legacy browser
`SDK_VERSION` < 21	Actual package name via `Context#getPackageName()`	Actual UID
21 ≥ `SDK_VERSION` < 28, `MediaLibrarySessionCallback#onConnect` and `MediaLibrarySessionCallback#onGetLibraryRoot`	Actual package name via `Context#getPackageName()`	Actual UID
21 ≥ `SDK_VERSION` < 28, for other callbacks	`RemoteUserInfo#LEGACY_CONTROLLER`	Negative value
28 ≥ `SDK_VERSION`	Actual package name via `Context#getPackageName()`	Actual UID

Summary

Nested classes
	`Builder` Builder for `MediaLibrarySession`.
	`MediaLibrarySessionCallback` Callback for the `MediaLibrarySession`.

Public methods
Unit	`notifyChildrenChanged(@NonNull controller: MediaSession.ControllerInfo, @NonNull parentId: String, @IntRange(0) itemCount: Int, @Nullable params: MediaLibraryService.LibraryParams?)` Notifies the controller of the change in a parent's children.
Unit	`notifyChildrenChanged(@NonNull parentId: String, itemCount: Int, @Nullable params: MediaLibraryService.LibraryParams?)` Notifies all controllers that subscribed to the parent about change in the parent's children, regardless of the library params supplied by MediaBrowser#subscribe(String, LibraryParams).
Unit	`notifySearchResultChanged(@NonNull controller: MediaSession.ControllerInfo, @NonNull query: String, @IntRange(0) itemCount: Int, @Nullable params: MediaLibraryService.LibraryParams?)` Notifies controller about change in the search result.

Inherited functions

From class MediaSession

Unit

broadcastCustomCommand(@NonNull command: SessionCommand, @Nullable args: Bundle?)

Broadcasts a custom command to all connected controllers.

This is synchronous call and doesn't wait for result from the controller. Use sendCustomCommand(ControllerInfo, SessionCommand, Bundle) for getting the result.

A command is not accepted if it is not a custom command.

Unit

close()

MutableList<MediaSession.ControllerInfo!>

getConnectedControllers()

Returns the list of connected controller.

String

getId()

Gets the session ID

SessionPlayer

getPlayer()

Gets the underlying SessionPlayer.

When the session is closed, it returns the lastly set player.

MediaSessionCompat.Token

getSessionCompatToken()

Gets the MediaSessionCompat.Token for the MediaSessionCompat created internally by this session.

SessionToken

getToken()

Returns the SessionToken for creating MediaController.

ListenableFuture<SessionResult!>

sendCustomCommand(@NonNull controller: MediaSession.ControllerInfo, @NonNull command: SessionCommand, @Nullable args: Bundle?)

Sends a custom command to a specific controller.

A command is not accepted if it is not a custom command.

Unit

setAllowedCommands(@NonNull controller: MediaSession.ControllerInfo, @NonNull commands: SessionCommandGroup)

Sets the new allowed command group for the controller.

This is synchronous call. Changes in the allowed commands take effect immediately regardless of the controller notified about the change through #onAllowedCommandsChanged(MediaController, SessionCommandGroup)

ListenableFuture<SessionResult!>

setCustomLayout(@NonNull controller: MediaSession.ControllerInfo, @NonNull layout: MutableList<MediaSession.CommandButton!>)

Sets ordered list of CommandButton for controllers to build UI with it.

It's up to controller's decision how to represent the layout in its own UI. Here are some examples.

Note: layout[i] means a CommandButton at index i in the given list

Controller UX layout	Layout example
Row with 3 icons	`layout[1]` `layout[0]` `layout[2]`
Row with 5 icons	`layout[3]` `layout[1]` `layout[0]` `layout[2]` `layout[4]`
Row with 5 icons and an overflow icon, and another expandable row with 5 extra icons	`layout[3]` `layout[1]` `layout[0]` `layout[2]` `layout[4]`
	`layout[3]` `layout[1]` `layout[0]` `layout[2]` `layout[4]`

This API can be called in the SessionCallback#onConnect(MediaSession, ControllerInfo).

Unit

updatePlayer(@NonNull player: SessionPlayer)

Updates the underlying SessionPlayer for this session to dispatch incoming event to.

Public methods

notifyChildrenChanged

fun notifyChildrenChanged(
    @NonNull controller: MediaSession.ControllerInfo, 
    @NonNull parentId: String, 
    @IntRange(0) itemCount: Int, 
    @Nullable params: MediaLibraryService.LibraryParams?
): Unit

Notifies the controller of the change in a parent's children.

If the controller hasn't subscribed to the parent, the API will do nothing.

Controllers will use MediaBrowser#getChildren(String, int, int, LibraryParams) to get the list of children.

Parameters
`controller`	MediaSession.ControllerInfo: controller to notify
`parentId`	String: non-empty parent id with changes in its children
`itemCount`	Int: number of children.
`params`	MediaLibraryService.LibraryParams?: library params

notifyChildrenChanged

fun notifyChildrenChanged(
    @NonNull parentId: String, 
    itemCount: Int, 
    @Nullable params: MediaLibraryService.LibraryParams?
): Unit

Notifies all controllers that subscribed to the parent about change in the parent's children, regardless of the library params supplied by MediaBrowser#subscribe(String, LibraryParams).

Parameters
`parentId`	String: non-empty parent id
`itemCount`	Int: number of children
`params`	MediaLibraryService.LibraryParams?: library params

notifySearchResultChanged

fun notifySearchResultChanged(
    @NonNull controller: MediaSession.ControllerInfo, 
    @NonNull query: String, 
    @IntRange(0) itemCount: Int, 
    @Nullable params: MediaLibraryService.LibraryParams?
): Unit

Notifies controller about cha