Android 点击屏幕其他位置隐藏Floating Action Button

compile 'net.i2p.android.ext:floatingactionbutton:1.9.0'

public class MainActivity extends AppCompatActivity {

    private FloatingActionsMenu fab_menu;

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

        fab_menu = (FloatingActionsMenu) findViewById(R.id.fab_activity);
        fab_menu.setOnFloatingActionsMenuUpdateListener(new FloatingActionsMenu.OnFloatingActionsMenuUpdateListener() {
            @Override
            public void onMenuExpanded() {
                getSupportFragmentManager()
                        .beginTransaction()
                        .add(android.R.id.content, new FabFragment(), "fragment_fab")
                        .addToBackStack("fragment:fab")
                        .commit();
                //点击之后回复原状，这样在从fragment返回之后仍然是原来的样子
                fab_menu.collapse();
            }

            @Override
            public void onMenuCollapsed() {

            }
        });
    }
}

public class FabFragment extends Fragment implements View.OnClickListener, View.OnTouchListener {
    private FloatingActionButton fab_commmon;
    private FloatingActionButton fab_help;
    private FloatingActionsMenu fab;

    public FabFragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View v = inflater.inflate(R.layout.fragment_blank, container, false);
        v.setOnClickListener(this);
        initView(v);
        initEvent();
        return v;
    }

    private void initView(View v) {
        fab = (FloatingActionsMenu) v.findViewById(R.id.fab);
        fab_commmon = (FloatingActionButton) v.findViewById(R.id.action_a);
        fab_help = (FloatingActionButton) v.findViewById(R.id.action_b);
        fab.expand();
    }

    private void initEvent() {
        fab_commmon.setOnClickListener(this);
        fab_help.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.root:
                getActivity().getSupportFragmentManager().popBackStack();
                break;
            case R.id.action_a:
                //执行某些操作
                getActivity().getSupportFragmentManager().popBackStack();
                break;
            case R.id.action_b:
                //执行某些操作
                getActivity().getSupportFragmentManager().popBackStack();
                break;
        }

    }

    @Override
    public boolean onTouch(View view, MotionEvent motionEvent) {
        return true;
    }
}