AddPersonActivity.java

public class AddPersonActivity extends Activity implements IAddPersonView {

    private TextView vPersonsAdded;
    private EditText vPersonName;
    private Button vAddPerson;

    private IAddPersonPresenter mPresenter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        vPersonsAdded = (TextView) findViewById(R.id.txt_added_persons);
        vPersonName = (EditText) findViewById(R.id.et_name_input);
        vAddPerson = (Button) findViewById(R.id.btn_save_person);
        mPresenter = new AddPersonPresenterImpl(this);

        vAddPerson.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mPresenter.onAddPersonButtonClicked(vPersonName.getText().toString());
            }
        });
    }

    @Override
    public void showNumberOfPersons(int size) {
         vPersonsAdded.setText(getString(R.string.added_persons, size));
    }
}