Facebook authentication without login button

Question

I have followed some Facebook API 3.0 tutorials, including the Login/Logout and the Publish To Feed examples. So the login works this way:

1. App opens, shows a f

Answer 1

This worked for me

    import android.os.Bundle;
    import android.app.Activity;
    import android.content.Intent;
    import android.widget.TextView;
    import com.facebook.*;
    import com.facebook.model.*;

    public class MainActivity extends Activity {

      @Override
      public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // start Facebook Login
        Session.openActiveSession(this, true, new Session.StatusCallback() {

          // callback when session changes state
          @Override
          public void call(Session session, SessionState state, Exception exception) {
            if (session.isOpened()) {

              // make request to the /me API
              Request.newMeRequest(session, new Request.GraphUserCallback() {

                // callback after Graph API response with user object
                @Override
                public void onCompleted(GraphUser user, Response response) {
                  if (user != null) {
                    TextView welcome = (TextView) findViewById(R.id.welcome);
                    welcome.setText("Hello " + user.getName() + "!");
                  }
                }
              }).executeAsync();
            }
          }
        });
      }

      @Override
      public void onActivityResult(int requestCode, int resultCode, Intent data) {
          super.onActivityResult(requestCode, resultCode, data);
          Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
      }

    }

if you need to get authorizations after verify that session is open ,add this way:

List permissions = session.getPermissions();             
                 Session.NewPermissionsRequest newPermissionsRequest = new         Session.NewPermissionsRequest(getActivity(), Arrays.asList("read_mailbox"));
                 session.requestNewReadPermissions(newPermissionsRequest);