MediaMetadata

public final class MediaMetadata
extends Object implements VersionedParcelable

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


Contains metadata about an item, such as the title, artist, etc. This is optional, but you'd better to provide this as much as possible when you're using media widget and/or session APIs.

The media widget components build its UI based on the metadata here. For an example, MediaControlView will show title from the metadata.

The MediaLibraryService.MediaLibrarySession would require some metadata values when it provides MediaItems to MediaBrowser.

Topics covered here:

  1. Media ID
  2. Browsable type
  3. Playable
  4. Duration
  5. User rating

Media ID

If set, the media ID must be the persistent key for the underlying media contents, so MediaController and MediaBrowser can store the information and reuse it later. Some APIs requires a media ID (e.g. MediaController.setRating(String, Rating), so you'd better specify one.

Typical example of using media ID is the URI of the contents, but use it with the caution because the metadata is shared across the process in plain text.

The MediaLibraryService.MediaLibrarySession would require it for the library root, so MediaBrowser can call subsequent MediaBrowser.getChildren(String, int, int, MediaLibraryService.LibraryParams) with the ID.

Browsable type

Browsable defines whether the media item has children and type of children if any. With this, MediaBrowser can know whether the subsequent MediaBrowser.getChildren(String, int, int, MediaLibraryService.LibraryParams) would successfully run.

The MediaLibraryService.MediaLibrarySession would require the explicit browsable type for the media items returned by the MediaLibraryService.MediaLibrarySession.MediaLibrarySessionCallback.

Playable type

Playable defines whether the media item can be played or not. It may be possible for a playlist to contain a media item which isn't playable in order to show a disabled media item.

The MediaLibraryService.MediaLibrarySession would require the explicit playable value for the media items returned by the MediaLibraryService.MediaLibrarySession.MediaLibrarySessionCallback.

Duration

The duration is the length of the contents. The MediaController can only get the duration through the metadata. This tells when would the playback ends, and also tells about the allowed range of MediaController.seekTo(long).

If it's not set by developer, MediaSession would update the duration in the metadata with the SessionPlayer.getDuration().

User rating

Prefer to have unrated user rating instead of null, so MediaController can know the possible user rating type for calling MediaController.setRating(String, Rating).

Summary

Nested classes

class MediaMetadata.Builder

Use to build MediaMetadatax objects. 

Constants

long BROWSABLE_TYPE_ALBUMS

The type of browsable that contains browsable items categorized by album.

long BROWSABLE_TYPE_ARTISTS

The type of browsabl