SessionManager

A class that manages Session instances. The application can attach a SessionManagerListener to be notified of session events.

SessionManager works with Android MediaRouter on managing session lifecycle. The current session always uses the current selected route (which corresponds to MediaRouter.getSelectedRoute()).

SessionManager listens to route changes from MediaRouter via MediaRouter.addCallback(MediaRouteSelector, MediaRouter.Callback). For each session type it supports, either a Cast session type or a custom session type as specified by a SessionProvider, a MediaRouter.Callback will be added to MediaRouter with a corresponding MediaRouteSelector generated using the category from SessionProvider.getCategory(). For Cast sessions, the category is generated according to CastOptions.getReceiverApplicationId().

When a route is selected in MediaRouter, the corresponding callback will be executed and SessionManager will call SessionProvider.createSession(String) to create a session. Then it will try to start a new session or resume the session that was shutdown incorrectly. When a session has ended, failed on start or failed on resume, SessionManager will unselect the corresponding route.

When a route is unselected in MediaRouter, the corresponding callback will be executed and SessionManager will end the current session if it is using the unselected route.

Because SessionManager listens to route selection signals to start and end sessions, Cast dialog must make sure to update the route selection state in Android MediaRouter. The device chooser dialog must call MediaRouter.selectRoute(MediaRouter.RouteInfo) or MediaRouter.RouteInfo.select() when the user selects a device. The route controller dialog must call MediaRouter.unselect(int) (or endCurrentSession(boolean) when the user clicks the "Stop Casting" (or "Disconnect") button.

Based on how an app creates Cast dialogs, the following actions needs to be done:

If the app creates Cast dialogs using MediaRouteChooserDialog and MediaRouteControllerDialog, then these dialogs will update route selection in MediaRouter automatically, so nothing needs to be done.
If the app sets up the Cast button using CastButtonFactory.setUpMediaRouteButton(Context, Menu, int) or CastButtonFactory.setUpMediaRouteButton(Context, MediaRouteButton), then the dialogs are actually created using MediaRouteChooserDialog and MediaRouteControllerDialog, so nothing needs to be done.
For other cases, the app will be creating custom Cast dialogs, so it needs to follow the above instructions to update the route selection state in MediaRouter.

Public Method Summary

void	addSessionManagerListener(SessionManagerListener<Session> listener) Adds a `SessionManagerListener` to monitor events from any type of `Session` instance.
<T extends Session> void	addSessionManagerListener(SessionManagerListener<T> listener, Class<T> sessionClass) Adds a `SessionManagerListener` to monitor events from a `Session` instance whose class is `sessionClass`.
void	endCurrentSession(boolean stopCasting) Ends the current session.
CastSession	getCurrentCastSession() Returns the current session if it is an instance of `CastSession`, otherwise returns `null`.
Session	getCurrentSession() Returns the currently active session.
void	removeSessionManagerListener(SessionManagerListener<Session> listener) Removes the `SessionManagerListener`.
<T extends Session> void	removeSessionManagerListener(SessionManagerListener<T> listener, Class<T> sessionClass) Removes the `SessionManagerListener`.
void	startSession(Intent startSessionIntent) Starts a session.

Inherited Method Summary

From class java.lang.Object

Object	clone()
boolean	equals(Object arg0)
void	finalize()
final Class<?>	getClass()
int	hashCode()
final void	notify()
final void	notifyAll()
String	toString()
final void	wait(long arg0, int arg1)
final void	wait(long arg0)
final void	wait()

Public Methods

public void addSessionManagerListener (SessionManagerListener<Session> listener)

Adds a SessionManagerListener to monitor events from any type of Session instance.

Throws

NullPointerException	If listener is `null`.
IllegalStateException	If this method is not called on the main thread.

public void addSessionManagerListener (SessionManagerListener<T> listener, Class<T> sessionClass)

Adds a SessionManagerListener to monitor events from a Session instance whose class is sessionClass.

Throws

NullPointerException	If `listener` or `sessionClass` are `null`.
IllegalStateException	If this method is not called on the main thread.

public void endCurrentSession (boolean stopCasting)

Ends the current session.

Parameters

stopCasting	Should the receiver application be stopped when ending the current Session.

Throws

IllegalStateException	If this method is not called on the main thread.

public CastSession getCurrentCastSession ()

Returns the current session if it is an instance of CastSession, otherwise returns null.

Throws

IllegalStateException	If this method is not called on the main thread.

public Session getCurrentSession ()

Returns the currently active session. Returns null if no session is active.

Throws

IllegalStateException	If this method is not called on the main thread.

public void removeSessionManagerListener (SessionManagerListener<Session> listener)

Removes the SessionManagerListener.

Parameters

listener	The `SessionManagerListener` to be removed.

Throws

IllegalStateException	If this method is not called on the main thread.

public void removeSessionManagerListener (SessionManagerListener<T> listener, Class<T> sessionClass)

Removes the SessionManagerListener.

Parameters

listener	The `SessionManagerListener` to be removed.
sessionClass

Throws

NullPointerException	If `sessionClass` is `null`.
IllegalStateException	If this method is not called on the main thread.

public void startSession (Intent startSessionIntent)

Starts a session. The sender app should call this method after the app is launched by an implicit intent fired by a component outside the app, such as Google Home app. We recommended calling this method in onResume() instead of onCreate() because onCreate() is called only when the app launches. If the app is running when the intent is fired, it will be brought to the foreground and onCreate() will not be called.

   public class MyActivity extends Activity {
     ...
     @Override
     protected void onResume() {
       ...
       Intent intent = getIntent();
       // You need define your own intent filter and figure out how to check if the intent is
       // for joining a cast session.
       if (intentIsForStartingSession(intent)) {
         CastContext castContext = CastContext.getSharedInstance(this);
         castContext.getSessionManager().startSession(intent);
       }
       ...
     }
   }

Parameters

startSessionIntent	The intent that is used to start the app and ask it to join a cast session. The intent contains necessary information for starting a session, such as the route ID, device name, session ID, etc. This information is set by the component that fires the intent.