public class LoginPresenter {

    private final String TAG = "LoginPresenter";

    public void performLogin(String userName, String password) {
        Log.d(TAG, "Username: " + userName + " & Password:" + password);

        // Some awesome code for authentication
    }

    public void setPasswordVisible(View view, boolean isVisible) {

        Log.d(TAG, isVisible ? "Password is visible" : "Password is not visible");
    }
}