MainActivity.java (Sinch sample)

package kiretech.com.sinchtest;

import android.media.AudioManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import com.sinch.android.rtc.ClientRegistration;
import com.sinch.android.rtc.PushPair;
import com.sinch.android.rtc.Sinch;
import com.sinch.android.rtc.SinchClient;
import com.sinch.android.rtc.SinchClientListener;
import com.sinch.android.rtc.SinchError;
import com.sinch.android.rtc.calling.Call;
import com.sinch.android.rtc.calling.CallClient;
import com.sinch.android.rtc.calling.CallClientListener;
import com.sinch.android.rtc.calling.CallListener;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    private static final String APP_KEY = "d2c0c095-5468-4953-9a42-d91d23bcd52a";
    private static final String APP_SECRET = "20GMb2GNdkK/N+NbAP9KbA==";
    private static final String ENVIRONMENT = "sandbox.sinch.com";
    Button btnStartClient;
    Button btnCall;
    EditText etAppUser, etCallUser;
    TextView tvCallStatus;
    private Call call;
    SinchClient sinchClient;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        etAppUser = (EditText)findViewById(R.id.appUser);

        btnStartClient = (Button) findViewById(R.id.btnStartClient);
        btnStartClient.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                sinchClient = Sinch.getSinchClientBuilder().context(getApplicationContext())
                        .applicationKey(APP_KEY)
                        .applicationSecret(APP_SECRET)
                        .environmentHost(ENVIRONMENT)
                        .userId(etAppUser.getText().toString())
                        .build();
                sinchClient.setSupportCalling(true);
                sinchClient.setSupportActiveConnectionInBackground(true);
                sinchClient.startListeningOnActiveConnection();
                sinchClient.addSinchClientListener(new SinchClientListener() {
                    public void onClientStarted(SinchClient client) {
                        Log.d("onClientStarted",client.toString());
                    }

                    public void onClientStopped(SinchClient client) {
                        Log.d("onClientStopped", "");
                    }

                    public void onClientFailed(SinchClient client, SinchError error) {
                        Log.d("onClientFailed", error.getMessage());
                    }

                    public void onRegistrationCredentialsRequired(SinchClient client, ClientRegistration registrationCallback) {
                    }

                    public void onLogMessage(int level, String area, String message) {
                        Log.d("onLogMessage", message);
                    }
                });
                sinchClient.getCallClient().addCallClientListener(new CallClientListener() {
                    @Override
                    public void onIncomingCall(CallClient callClient, Call incomingCall) {
                        call = incomingCall;
                        call.answer();
                        call.addCallListener(new CallListener() {
                            @Override
                            public void onCallProgressing(Call call) {
                                Log.d("CallListener", "Call progressing");
                                tvCallStatus.setText("connecting");
                            }

                            @Override
                            public void onCallEstablished(Call call) {
                                Log.d("CallListener", "Call established");
                                tvCallStatus.setText("connected");
                                setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);
                            }

                            @Override
                            public void onCallEnded(Call call) {
                                Log.d("CallListener", "Call ended");
                                tvCallStatus.setText("disconnected");
                                setVolumeControlStream(AudioManager.USE_DEFAULT_STREAM_TYPE);
                            }

                            @Override
                            public void onShouldSendPushNotification(Call call, List<PushPair> list) {

                            }
                        });
                        btnCall.setText("HANG UP");
                    }
                });
                sinchClient.start();
            }
        });
        tvCallStatus = (TextView)findViewById(R.id.callStatus);
        etCallUser = (EditText)findViewById(R.id.callUser);

        btnCall = (Button)findViewById(R.id.btnCall);
        btnCall.setOnClickListener(new View.OnClickListener() {
            String userToCall;
            @Override
            public void onClick(View v) {
                if(call == null){
                    userToCall = etCallUser.getText().toString();
                    Log.d("CallListener", "Calling user: "+userToCall);
                    call = sinchClient.getCallClient().callConference(userToCall);
                    call.addCallListener(new CallListener() {
                        @Override
                        public void onCallProgressing(Call call) {
                            Log.d("CallListener", "Call progressing");
                            tvCallStatus.setText("connecting");
                        }

                        @Override
                        public void onCallEstablished(Call call) {
                            Log.d("CallListener", "Call established");
                            tvCallStatus.setText("connected");
                            setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);
                        }

                        @Override
                        public void onCallEnded(Call call) {
                            Log.d("CallListener", "Call ended");
                            tvCallStatus.setText("disconnected");
                            setVolumeControlStream(AudioManager.USE_DEFAULT_STREAM_TYPE);
                        }

                        @Override
                        public void onShouldSendPushNotification(Call call, List<PushPair> list) {

                        }
                    });

                    btnCall.setText("HANG UP");
                }else{
                    call.hangup();
                    call = null;
                    btnCall.setText("CALL");
                }
            }
        });
    }

}