Connecting to the session

Next, we will connect to the Vonage Video session. You must do this before you can publish your audio-video stream to the session or view other participants streams.

1. Add a session property to the MainActivity class (right after the last lines you added in Step 3):

private Session session;

The Session class is defined in the Android SDK. It represents a Vonage Video session and includes methods for interacting with the session.

2. To facilitate logging, add a TAG property at the top of the MainActivity class:

private static final String TAG = "MainActivity";

3. In the requestPermissions() method you created in the last step, add the following lines of code under the // initialize and connect to the session comment to instantiate the Session object and call its connect(token) method:

initializeSession(VonageVideoConfig.APP_ID, VonageVideoConfig.SESSION_ID, VonageVideoConfig.TOKEN);

4. below the requestPermissions() method, add the following lines of code:

private void initializeSession(String appId, String sessionId, String token) {
    Log.i(TAG, "appId: " + appId);
    Log.i(TAG, "sessionId: " + sessionId);
    Log.i(TAG, "token: " + token);

    session = new Session.Builder(this, apiKey, sessionId).build();
    session.setSessionListener(sessionListener);
    session.connect(token);
}

This code uses the Session.Builder() to instantiate a Session object. The constructor takes three parameters:

• The Android application context associated with this process
• The Vonage Video APP ID
• The session ID

The Session.Builder.build() method returns a new Session instance.

The Session.setSessionListener() method sets the object that will implement the SessionListener interface. This interface includes callback methods are called in response to session-related events. (We will implement them in the next steps).

The Session.connect() method of the session object connects the client application to the Vonage Video session. You must connect before sending or receiving audio-video streams in the session (or before interacting with the session in any way). The connect() method takes one parameter: the authentication token for this client to connect to the session.

5. Next we will create the sessionListener property. Add the following code at the top of the MainActivity class:

private Session.SessionListener sessionListener = new Session.SessionListener() {
@Override
public void onConnected(Session session) {
    Log.d(TAG, "onConnected: Connected to session: " + session.getSessionId());
}

@Override
public void onDisconnected(Session session) {
    Log.d(TAG, "onDisconnected: Disconnected from session: " + session.getSessionId());
}

@Override
public void onStreamReceived(Session session, Stream stream) {
    Log.d(TAG, "onStreamReceived: New Stream Received " + stream.getStreamId() + " in session: " + session.getSessionId());
}

@Override
public void onStreamDropped(Session session, Stream stream) {
    Log.d(TAG, "onStreamDropped: Stream Dropped: " + stream.getStreamId() + " in session: " + session.getSessionId());
}

@Override
public void onError(Session session, OpentokError opentokError) {
    Log.e(TAG, "Session error: " + opentokError.getMessage());
}
}; 

• When the client connects to the session, the implementation of the SessionListener.onConnected(session) method is called.
• When the client disconnects from the session, the implementation of the SessionListener.onDisconnected(session) method is called.
• If the client fails to connect to the session, the implementation of the SessionListener.onError(session, error) method is called.
• When another client publishes a stream to the session, the implementation of the SessionListener.onStreamReceived(session, stream) method is called.
• When another client stops publishing a stream to the session, the implementation of the SessionListener.onStreamDropped(session, stream) method is called.

For now, the app prints to the debugger console when any of these events occur.

Debug your application. If the app successfully connects to the Vonage Video session, the SessionListener.onConnected(session) method logs to the debug console.

7. Add the methods below to the MainActivity class to notify the session about Activity lifecycle events:

@Override
protected void onPause() {
    super.onPause();

    if (session != null) {
        session.onPause();
    }
}

@Override
protected void onResume() {
    super.onResume();

    if (session != null) {
        session.onResume();
    }
}