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MediaRouter.javaAPI DocAndroid 5.1 API103140Thu Mar 12 22:22:56 GMT 2015android.support.v7.media

MediaRouter

public final class MediaRouter extends Object
MediaRouter allows applications to control the routing of media channels and streams from the current device to external speakers and destination devices.

A MediaRouter instance is retrieved through {@link #getInstance}. Applications can query the media router about the currently selected route and its capabilities to determine how to send content to the route's destination. Applications can also {@link RouteInfo#sendControlRequest send control requests} to the route to ask the route's destination to perform certain remote control functions such as playing media.

See also {@link MediaRouteProvider} for information on how an application can publish new media routes to the media router.

The media router API is not thread-safe; all interactions with it must be done from the main thread of the process.

Fields Summary
private static final String
TAG
private static final boolean
DEBUG
public static final int
UNSELECT_REASON_UNKNOWN
Passed to {@link android.support.v7.media.MediaRouteProvider.RouteController#onUnselect(int)} when the reason the route was unselected is unknown.
public static final int
UNSELECT_REASON_DISCONNECTED
Passed to {@link android.support.v7.media.MediaRouteProvider.RouteController#onUnselect(int)} when the user pressed the disconnect button to disconnect and keep playing.

public static final int
UNSELECT_REASON_STOPPED
Passed to {@link android.support.v7.media.MediaRouteProvider.RouteController#onUnselect(int)} when the user pressed the stop casting button.
public static final int
UNSELECT_REASON_ROUTE_CHANGED
Passed to {@link android.support.v7.media.MediaRouteProvider.RouteController#onUnselect(int)} when the user selected a different route.
static GlobalMediaRouter
sGlobal
final android.content.Context
mContext
final ArrayList
mCallbackRecords
public static final int
CALLBACK_FLAG_PERFORM_ACTIVE_SCAN
Flag for {@link #addCallback}: Actively scan for routes while this callback is registered.

When this flag is specified, the media router will actively scan for new routes. Certain routes, such as wifi display routes, may not be discoverable except when actively scanning. This flag is typically used when the route picker dialog has been opened by the user to ensure that the route information is up to date.

Active scanning may consume a significant amount of power and may have intrusive effects on wireless connectivity. Therefore it is important that active scanning only be requested when it is actually needed to satisfy a user request to discover and select a new route.

This flag implies {@link #CALLBACK_FLAG_REQUEST_DISCOVERY} but performing active scans is much more expensive than a normal discovery request.

public static final int
CALLBACK_FLAG_UNFILTERED_EVENTS
Flag for {@link #addCallback}: Do not filter route events.

When this flag is specified, the callback will be invoked for events that affect any route even if they do not match the callback's filter.

public static final int
CALLBACK_FLAG_REQUEST_DISCOVERY
Flag for {@link #addCallback}: Request passive route discovery while this callback is registered, except on {@link ActivityManager#isLowRamDevice low-RAM devices}.

When this flag is specified, the media router will try to discover routes. Although route discovery is intended to be efficient, checking for new routes may result in some network activity and could slowly drain the battery. Therefore applications should only specify {@link #CALLBACK_FLAG_REQUEST_DISCOVERY} when they are running in the foreground and would like to provide the user with the option of connecting to new routes.

Applications should typically add a callback using this flag in the {@link android.app.Activity activity's} {@link android.app.Activity#onStart onStart} method and remove it in the {@link android.app.Activity#onStop onStop} method. The {@link android.support.v7.app.MediaRouteDiscoveryFragment} fragment may also be used for this purpose.

On {@link ActivityManager#isLowRamDevice low-RAM devices} this flag will be ignored. Refer to {@link #addCallback(MediaRouteSelector, Callback, int) addCallback} for details.

public static final int
CALLBACK_FLAG_FORCE_DISCOVERY
Flag for {@link #addCallback}: Request passive route discovery while this callback is registered, even on {@link ActivityManager#isLowRamDevice low-RAM devices}.

This flag has a significant performance impact on low-RAM devices since it may cause many media route providers to be started simultaneously. It is much better to use {@link #CALLBACK_FLAG_REQUEST_DISCOVERY} instead to avoid performing passive discovery on these devices altogether. Refer to {@link #addCallback(MediaRouteSelector, Callback, int) addCallback} for details.

public static final int
AVAILABILITY_FLAG_IGNORE_DEFAULT_ROUTE
Flag for {@link #isRouteAvailable}: Ignore the default route.

This flag is used to determine whether a matching non-default route is available. This constraint may be used to decide whether to offer the route chooser dialog to the user. There is no point offering the chooser if there are no non-default choices.

public static final int
AVAILABILITY_FLAG_REQUIRE_MATCH
Flag for {@link #isRouteAvailable}: Require an actual route to be matched.

If this flag is not set, then {@link #isRouteAvailable} will return true if it is possible to discover a matching route even if discovery is not in progress or if no matching route has yet been found. This feature is used to save resources by removing the need to perform passive route discovery on {@link ActivityManager#isLowRamDevice low-RAM devices}.

If this flag is set, then {@link #isRouteAvailable} will only return true if a matching route has actually been discovered.

Constructors Summary
MediaRouter(android.content.Context context)


      
        mContext = context;
Methods Summary
public voidaddCallback(MediaRouteSelector selector, android.support.v7.media.MediaRouter$Callback callback)
Registers a callback to discover routes that match the selector and to receive events when they change.

This is a convenience method that has the same effect as calling {@link #addCallback(MediaRouteSelector, Callback, int)} without flags.

param
selector A route selector that indicates the kinds of routes that the callback would like to discover.
param
callback The callback to add.
see
#removeCallback

        addCallback(selector, callback, 0);
public voidaddCallback(MediaRouteSelector selector, android.support.v7.media.MediaRouter$Callback callback, int flags)
Registers a callback to discover routes that match the selector and to receive events when they change.

The selector describes the kinds of routes that the application wants to discover. For example, if the application wants to use live audio routes then it should include the {@link MediaControlIntent#CATEGORY_LIVE_AUDIO live audio media control intent category} in its selector when it adds a callback to the media router. The selector may include any number of categories.

If the callback has already been registered, then the selector is added to the set of selectors being monitored by the callback.

By default, the callback will only be invoked for events that affect routes that match the specified selector. Event filtering may be disabled by specifying the {@link #CALLBACK_FLAG_UNFILTERED_EVENTS} flag when the callback is registered.

Applications should use the {@link #isRouteAvailable} method to determine whether is it possible to discover a route with the desired capabilities and therefore whether the media route button should be shown to the user.

The {@link #CALLBACK_FLAG_REQUEST_DISCOVERY} flag should be used while the application is in the foreground to request that passive discovery be performed if there are sufficient resources to allow continuous passive discovery. On {@link ActivityManager#isLowRamDevice low-RAM devices} this flag will be ignored to conserve resources.

The {@link #CALLBACK_FLAG_FORCE_DISCOVERY} flag should be used when passive discovery absolutely must be performed, even on low-RAM devices. This flag has a significant performance impact on low-RAM devices since it may cause many media route providers to be started simultaneously. It is much better to use {@link #CALLBACK_FLAG_REQUEST_DISCOVERY} instead to avoid performing passive discovery on these devices altogether.

The {@link #CALLBACK_FLAG_PERFORM_ACTIVE_SCAN} flag should be used when the media route chooser dialog is showing to confirm the presence of available routes that the user may connect to. This flag may use substantially more power.

Example

public class MyActivity extends Activity {
private MediaRouter mRouter;
private MediaRouter.Callback mCallback;
private MediaRouteSelector mSelector;

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

mRouter = Mediarouter.getInstance(this);
mCallback = new MyCallback();
mSelector = new MediaRouteSelector.Builder()
.addControlCategory(MediaControlIntent.CATEGORY_LIVE_AUDIO)
.addControlCategory(MediaControlIntent.CATEGORY_REMOTE_PLAYBACK)
.build();
}

// Add the callback on start to tell the media router what kinds of routes
// the application is interested in so that it can try to discover suitable ones.
public void onStart() {
super.onStart();

mediaRouter.addCallback(mSelector, mCallback,
MediaRouter.CALLBACK_FLAG_REQUEST_DISCOVERY);

MediaRouter.RouteInfo route = mediaRouter.updateSelectedRoute(mSelector);
// do something with the route...
}

// Remove the selector on stop to tell the media router that it no longer
// needs to invest effort trying to discover routes of these kinds for now.
public void onStop() {
super.onStop();

mediaRouter.removeCallback(mCallback);
}

private final class MyCallback extends MediaRouter.Callback {
// Implement callback methods as needed.
}
}

param
selector A route selector that indicates the kinds of routes that the callback would like to discover.
param
callback The callback to add.
param
flags Flags to control the behavior of the callback. May be zero or a combination of {@link #CALLBACK_FLAG_PERFORM_ACTIVE_SCAN} and {@link #CALLBACK_FLAG_UNFILTERED_EVENTS}.
see
#removeCallback

        if (selector == null) {
            throw new IllegalArgumentException("selector must not be null");
        }
        if (callback == null) {
            throw new IllegalArgumentException("callback must not be null");
        }
        checkCallingThread();

        if (DEBUG) {
            Log.d(TAG, "addCallback: selector=" + selector
                    + ", callback=" + callback + ", flags=" + Integer.toHexString(flags));
        }

        CallbackRecord record;
        int index = findCallbackRecord(callback);
        if (index < 0) {
            record = new CallbackRecord(this, callback);
            mCallbackRecords.add(record);
        } else {
            record = mCallbackRecords.get(index);
        }
        boolean updateNeeded = false;
        if ((flags & ~record.mFlags) != 0) {
            record.mFlags |= flags;
            updateNeeded = true;
        }
        if (!record.mSelector.contains(selector)) {
            record.mSelector = new MediaRouteSelector.Builder(record.mSelector)
                    .addSelector(selector)
                    .build();
            updateNeeded = true;
        }
        if (updateNeeded) {
            sGlobal.updateDiscoveryRequest();
        }
public voidaddProvider(MediaRouteProvider providerInstance)
Registers a media route provider within this application process.

The provider will be added to the list of providers that all {@link MediaRouter} instances within this process can use to discover routes.

param
providerInstance The media route provider instance to add.
see
MediaRouteProvider
see
#removeCallback

        if (providerInstance == null) {
            throw new IllegalArgumentException("providerInstance must not be null");
        }
        checkCallingThread();

        if (DEBUG) {
            Log.d(TAG, "addProvider: " + providerInstance);
        }
        sGlobal.addProvider(providerInstance);
public voidaddRemoteControlClient(java.lang.Object remoteControlClient)
Adds a remote control client to enable remote control of the volume of the selected route.

The remote control client must have previously been registered with the audio manager using the {@link android.media.AudioManager#registerRemoteControlClient AudioManager.registerRemoteControlClient} method.

param
remoteControlClient The {@link android.media.RemoteControlClient} to register.

        if (remoteControlClient == null) {
            throw new IllegalArgumentException("remoteControlClient must not be null");
        }
        checkCallingThread();

        if (DEBUG) {
            Log.d(TAG, "addRemoteControlClient: " + remoteControlClient);
        }
        sGlobal.addRemoteControlClient(remoteControlClient);
static voidcheckCallingThread()
Ensures that calls into the media router are on the correct thread. It pays to be a little paranoid when global state invariants are at risk.

        if (Looper.myLooper() != Looper.getMainLooper()) {
            throw new IllegalStateException("The media router service must only be "
                    + "accessed on the application's main thread.");
        }
static booleanequal(T a, T b)

        return a == b || (a != null && b != null && a.equals(b));
private intfindCallbackRecord(android.support.v7.media.MediaRouter$Callback callback)

        final int count = mCallbackRecords.size();
        for (int i = 0; i < count; i++) {
            if (mCallbackRecords.get(i).mCallback == callback) {
                return i;
            }
        }
        return -1;
public android.support.v7.media.MediaRouter$RouteInfogetDefaultRoute()
Gets the default route for playing media content on the system.

The system always provides a default route.

return
The default route, which is guaranteed to never be null.

        checkCallingThread();
        return sGlobal.getDefaultRoute();
public static android.support.v7.media.MediaRoutergetInstance(android.content.Context context)
Gets an instance of the media router service associated with the context.

The application is responsible for holding a strong reference to the returned {@link MediaRouter} instance, such as by storing the instance in a field of the {@link android.app.Activity}, to ensure that the media router remains alive as long as the application is using its features.

In other words, the support library only holds a {@link WeakReference weak reference} to each media router instance. When there are no remaining strong references to the media router instance, all of its callbacks will be removed and route discovery will no longer be performed on its behalf.

return
The media router instance for the context. The application must hold a strong reference to this object as long as it is in use.

        if (context == null) {
            throw new IllegalArgumentException("context must not be null");
        }
        checkCallingThread();

        if (sGlobal == null) {
            sGlobal = new GlobalMediaRouter(context.getApplicationContext());
            sGlobal.start();
        }
        return sGlobal.getRouter(context);
public MediaSessionCompat.TokengetMediaSessionToken()

        return sGlobal.getMediaSessionToken();
public java.util.ListgetProviders()
Gets information about the {@link MediaRouter.ProviderInfo route providers} currently known to this media router.

        checkCallingThread();
        return sGlobal.getProviders();
public java.util.ListgetRoutes()
Gets information about the {@link MediaRouter.RouteInfo routes} currently known to this media router.

        checkCallingThread();
        return sGlobal.getRoutes();
public android.support.v7.media.MediaRouter$RouteInfogetSelectedRoute()
Gets the currently selected route.

The application should examine the route's {@link RouteInfo#getControlFilters media control intent filters} to assess the capabilities of the route before attempting to use it.

Example

public boolean playMovie() {
MediaRouter mediaRouter = MediaRouter.getInstance(context);
MediaRouter.RouteInfo route = mediaRouter.getSelectedRoute();

// First try using the remote playback interface, if supported.
if (route.supportsControlCategory(MediaControlIntent.CATEGORY_REMOTE_PLAYBACK)) {
// The route supports remote playback.
// Try to send it the Uri of the movie to play.
Intent intent = new Intent(MediaControlIntent.ACTION_PLAY);
intent.addCategory(MediaControlIntent.CATEGORY_REMOTE_PLAYBACK);
intent.setDataAndType("http://example.com/videos/movie.mp4", "video/mp4");
if (route.supportsControlRequest(intent)) {
route.sendControlRequest(intent, null);
return true; // sent the request to play the movie
}
}

// If remote playback was not possible, then play locally.
if (route.supportsControlCategory(MediaControlIntent.CATEGORY_LIVE_VIDEO)) {
// The route supports live video streaming.
// Prepare to play content locally in a window or in a presentation.
return playMovieInWindow();
}

// Neither interface is supported, so we can't play the movie to this route.
return false;
}

return
The selected route, which is guaranteed to never be null.
see
RouteInfo#getControlFilters
see
RouteInfo#supportsControlCategory
see
RouteInfo#supportsControlRequest

        checkCallingThread();
        return sGlobal.getSelectedRoute();
public booleanisRouteAvailable(MediaRouteSelector selector, int flags)
Returns true if there is a route that matches the specified selector.

This method returns true if there are any available routes that match the selector regardless of whether they are enabled or disabled. If the {@link #AVAILABILITY_FLAG_IGNORE_DEFAULT_ROUTE} flag is specified, then the method will only consider non-default routes.

On {@link ActivityManager#isLowRamDevice low-RAM devices} this method will return true if it is possible to discover a matching route even if discovery is not in progress or if no matching route has yet been found. Use {@link #AVAILABILITY_FLAG_REQUIRE_MATCH} to require an actual match.

param
selector The selector to match.
param
flags Flags to control the determination of whether a route may be available. May be zero or some combination of {@link #AVAILABILITY_FLAG_IGNORE_DEFAULT_ROUTE} and {@link #AVAILABILITY_FLAG_REQUIRE_MATCH}.
return
True if a matching route may be available.

        if (selector == null) {
            throw new IllegalArgumentException("selector must not be null");
        }
        checkCallingThread();

        return sGlobal.isRouteAvailable(selector, flags);
public voidremoveCallback(android.support.v7.media.MediaRouter$Callback callback)
Removes the specified callback. It will no longer receive events about changes to media routes.

param
callback The callback to remove.
see
#addCallback

        if (callback == null) {
            throw new IllegalArgumentException("callback must not be null");
        }
        checkCallingThread();

        if (DEBUG) {
            Log.d(TAG, "removeCallback: callback=" + callback);
        }

        int index = findCallbackRecord(callback);
        if (index >= 0) {
            mCallbackRecords.remove(index);
            sGlobal.updateDiscoveryRequest();
        }
public voidremoveProvider(MediaRouteProvider providerInstance)
Unregisters a media route provider within this application process.

The provider will be removed from the list of providers that all {@link MediaRouter} instances within this process can use to discover routes.

param
providerInstance The media route provider instance to remove.
see
MediaRouteProvider
see
#addCallback

        if (providerInstance == null) {
            throw new IllegalArgumentException("providerInstance must not be null");
        }
        checkCallingThread();

        if (DEBUG) {
            Log.d(TAG, "removeProvider: " + providerInstance);
        }
        sGlobal.removeProvider(providerInstance);
public voidremoveRemoteControlClient(java.lang.Object remoteControlClient)
Removes a remote control client.

param
remoteControlClient The {@link android.media.RemoteControlClient} to unregister.

        if (remoteControlClient == null) {
            throw new IllegalArgumentException("remoteControlClient must not be null");
        }

        if (DEBUG) {
            Log.d(TAG, "removeRemoteControlClient: " + remoteControlClient);
        }
        sGlobal.removeRemoteControlClient(remoteControlClient);
public voidselectRoute(android.support.v7.media.MediaRouter$RouteInfo route)
Selects the specified route.

param
route The route to select.

        if (route == null) {
            throw new IllegalArgumentException("route must not be null");
        }
        checkCallingThread();

        if (DEBUG) {
            Log.d(TAG, "selectRoute: " + route);
        }
        sGlobal.selectRoute(route);
public voidsetMediaSession(java.lang.Object mediaSession)
Sets the media session to enable remote control of the volume of the selected route. This should be used instead of {@link #addRemoteControlClient} when using media sessions. Set the session to null to clear it.

param
mediaSession The {@link android.media.session.MediaSession} to use.

        if (DEBUG) {
            Log.d(TAG, "addMediaSession: " + mediaSession);
        }
        sGlobal.setMediaSession(mediaSession);
public voidsetMediaSessionCompat(android.support.v4.media.session.MediaSessionCompat mediaSession)
Sets a compat media session to enable remote control of the volume of the selected route. This should be used instead of {@link #addRemoteControlClient} when using {@link MediaSessionCompat}. Set the session to null to clear it.

param
mediaSession

        if (DEBUG) {
            Log.d(TAG, "addMediaSessionCompat: " + mediaSession);
        }
        sGlobal.setMediaSessionCompat(mediaSession);
public voidunselect(int reason)
Unselects the current round and selects the default route instead.

The reason given must be one of:

  • {@link MediaRouter#UNSELECT_REASON_UNKNOWN}
  • {@link MediaRouter#UNSELECT_REASON_DISCONNECTED}
  • {@link MediaRouter#UNSELECT_REASON_STOPPED}
  • {@link MediaRouter#UNSELECT_REASON_ROUTE_CHANGED}

param
reason The reason for disconnecting the current route.

        if (reason < MediaRouter.UNSELECT_REASON_UNKNOWN ||
                reason > MediaRouter.UNSELECT_REASON_ROUTE_CHANGED) {
            throw new IllegalArgumentException("Unsupported reason to unselect route");
        }
        checkCallingThread();

        sGlobal.selectRoute(getDefaultRoute(), reason);
public android.support.v7.media.MediaRouter$RouteInfoupdateSelectedRoute(MediaRouteSelector selector)
Returns the selected route if it matches the specified selector, otherwise selects the default route and returns it.

param
selector The selector to match.
return
The previously selected route if it matched the selector, otherwise the newly selected default route which is guaranteed to never be null.
see
MediaRouteSelector
see
RouteInfo#matchesSelector
see
RouteInfo#isDefault

        if (selector == null) {
            throw new IllegalArgumentException("selector must not be null");
        }
        checkCallingThread();

        if (DEBUG) {
            Log.d(TAG, "updateSelectedRoute: " + selector);
        }
        RouteInfo route = sGlobal.getSelectedRoute();
        if (!route.isDefault() && !route.matchesSelector(selector)) {
            route = sGlobal.getDefaultRoute();
            sGlobal.selectRoute(route);
        }
        return route;