SessionManager

  • SessionManager is a class that manages Session instances and allows applications to listen for session events using a SessionManagerListener.

  • SessionManager integrates with Android MediaRouter to manage the session lifecycle, always using the currently selected route.

  • SessionManager adds MediaRouter.Callback listeners for each supported session type (Cast or custom) to respond to route changes and create sessions via SessionProvider.

  • When a route is selected or unselected in MediaRouter, SessionManager handles the creation, resumption, or ending of the corresponding session.

  • Apps using standard MediaRouteChooserDialog and MediaRouteControllerDialog or CastButtonFactory helper methods do not need to manually manage route selection state in MediaRouter, while custom dialogs must call MediaRouter.selectRoute() or MediaRouter.unselect().
public class SessionManager extends Object

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:

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

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.