java 使手势监听器在片段中可行

Posted 2021-05-08

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_fragment_test, container, false);
        final GestureDetector gesture = new GestureDetector(getActivity(),
                new GestureDetector.SimpleOnGestureListener() {

                    @Override
                    public boolean onDown(MotionEvent e) {
                        return true;
                    }

                    @Override
                    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
                                           float velocityY) {
                        Log.i("in fragment", "onFling has been called!");
                        final int SWIPE_MIN_DISTANCE = 120;
                        final int SWIPE_MAX_OFF_PATH = 250;
                        final int SWIPE_THRESHOLD_VELOCITY = 200;
                        try {
                            if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
                                return false;
                            if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
                                    && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                                Log.i("in fragment", "Right to Left");
                            } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
                                    && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                                Log.i("in fragment", "Left to Right");
                            }
                        } catch (Exception e) {
                            // nothing
                        }
                        return super.onFling(e1, e2, velocityX, velocityY);
                    }
                });

        //have to bound view touch listener with gesture listener
        view.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                return gesture.onTouchEvent(event);
            }
        });

        return view;
    }