orhanobut

public class AccountActivity extends ImageActivity {
  
  @Override public void onCreate(Bundle bundle){
    // init
  }
  
  public void onAvatarClicked() {
    showGalery();
  }
  

orhanobut

public class ImageActivity extends Activity {
  
  @Override public void onCreate(Bundle bundle){
    super.onCreate(bundle);
    
    // init image operations
  }
  
  @Override public void onDestroy() {
    // release allocations

orhanobut

public interface ApiService {
  
  <T> void login(Callback<T> callback);
  
  <T> void register(Callback<T> callback);
  
}

orhanobut

public class LoginActivity extends Activity 
    implements LoginFragment.LoginListener {
  
  @Override public void onLogin() {
    login(new Callback<User>() {
      
      @Override public void onSuccess(User user){
        EventBus.getDefault().post(new UserEvent(user));
      }
    }

orhanobut

public class LoginActivity extends Activity implements LoginFragment.LoginListener {
  
  @Override public void onLogin() {
    login();
  }
  
  @Override public void onRegister() {
    displayRegister();
  }
}

orhanobut

public class LoginFragment extends Fragment {
  
  private LoginListener listener;
  
  @Override public void onAttach(Activity activity) {
    super.onAttach(activity);
    loginListener = (LoginListener) activity;
  }
  
  void onLoginClicked() {

orhanobut

public class MyView extends View {
  
  private boolean editMode;
  
  public MyView(Context context, boolean editMode){
    super(context);
    this.editMode = editMode;
  }
  
  //a new method

orhanobut

public class MyView extends View {
  
  private boolean editMode;
  
  public MyView(Context context, boolean editMode){
    super(context);
    this.editMode = editMode;
  }
  
  @Override

orhanobut

public class BaseActivity extends Activity {
  
  ApiService apiService = new ApiManager(new GsonParser());
  
}

orhanobut

public class ApiManager implements ApiService {
  
  private final Parser parser;
  
  public ApiManager(Parser parser) {
    this.parser = parser;
  }
  
  @Override
  public void login(Callback callback) {