com.google.android.exoplayer2.offline

Class DownloadHelper

java.lang.Object

com.google.android.exoplayer2.offline.DownloadHelper

Direct Known Subclasses:

ProgressiveDownloadHelper

public abstract class DownloadHelper
extends java.lang.Object

A helper for initializing and removing downloads.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	DownloadHelper.Callback A callback to be notified when the DownloadHelper is prepared.

Constructor Summary

Constructors

Constructor and Description
DownloadHelper()

Method Summary

Modifier and Type	Method and Description
abstract DownloadAction	getDownloadAction(byte[] data, java.util.List<TrackKey> trackKeys) Builds a DownloadAction for downloading the specified tracks.
abstract int	getPeriodCount() Returns the number of periods for which media is available.
abstract DownloadAction	getRemoveAction(byte[] data) Builds a DownloadAction for removing the media.
abstract TrackGroupArray	getTrackGroups(int periodIndex) Returns the track groups for the given period.
void	prepare(DownloadHelper.Callback callback) Initializes the helper for starting a download.
protected abstract void	prepareInternal() Called on a background thread during preparation.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DownloadHelper

public DownloadHelper()

Method Detail

prepare

public void prepare(DownloadHelper.Callback callback)

Initializes the helper for starting a download.

Parameters:

callback - A callback to be notified when preparation completes or fails. The callback will be invoked on the calling thread unless that thread does not have an associated Looper, in which case it will be called on the application's main thread.

prepareInternal

protected abstract void prepareInternal()
                                 throws java.io.IOException

Called on a background thread during preparation.

Throws:

java.io.IOException - If preparation fails.

getPeriodCount

public abstract int getPeriodCount()

Returns the number of periods for which media is available. Must not be called until after preparation completes.

getTrackGroups

public abstract TrackGroupArray getTrackGroups(int periodIndex)

Returns the track groups for the given period. Must not be called until after preparation completes.

Parameters:

periodIndex - The period index.

Returns:

The track groups for the period. May be TrackGroupArray.EMPTY for single stream content.

getDownloadAction

public abstract DownloadAction getDownloadAction(@Nullable
                                                 byte[] data,
                                                 java.util.List<TrackKey> trackKeys)

Builds a DownloadAction for downloading the specified tracks. Must not be called until after preparation completes.

Parameters:

data - Application provided data to store in DownloadAction.data.

trackKeys - The selected tracks. If empty, all streams will be downloaded.

Returns:

The built DownloadAction.

getRemoveAction

public abstract DownloadAction getRemoveAction(@Nullable
                                               byte[] data)

Builds a DownloadAction for removing the media. May be called in any state.

Parameters:

data - Application provided data to store in DownloadAction.data.

Returns:

The built DownloadAction.