Как реализовать жест Fling в viewpager

Question

Я разрабатываю одно приложение для Android, в котором приложение работает отлично, я хочу реализовать жест FLING также для того, чтобы сделать его эффективным, я получил пример кода для горизонтального перемещения, мне нужно изменить его на жест вертикального перемещения, может кто-нибудь помочь в этом, спасибо заблаговременно

public class VerticalViewPager extends ViewPager implements GestureDetector.OnGestureListener {
private GestureDetector mGestureDetector;
private FlingRunnable mFlingRunnable = new FlingRunnable();
private boolean mScrolling = false;



public VerticalViewPager(Context context) {
    super(context);
    init();
    //setMyScroller();
}

public VerticalViewPager(Context context, AttributeSet attrs) {

    super(context, attrs);
    mGestureDetector = new GestureDetector(context, this);
    init();
}

private void init() {
    // The majority of the magic happens here
    setPageTransformer(true, new VerticalPageTransformer());
    // The easiest way to get rid of the overscroll drawing that happens on the left and right
    setOverScrollMode(OVER_SCROLL_NEVER);
}


private static class VerticalPageTransformer implements ViewPager.PageTransformer {
    private static float MIN_SCALE = 0.95f;
    @Override
    public void transformPage(View view, float position) {

        if (position < -1) { // [-Infinity,-1)
            // This page is way off-screen to the left.
            view.setAlpha(0);

        }
        else if (position <= 0) { // [-1,0]

            view.setAlpha(1);
            //view.setTranslationX(1);
            view.setScaleX(1);
            view.setScaleY(1);
            float yPosition = position * view.getHeight();
            view.setTranslationY(yPosition);
            view.setTranslationX(-1 * view.getWidth() * position);

        }
        else if (position <= 1) { // [-1,1]
            view.setAlpha(1-position);//fade in value


            view.setTranslationX(-1 * view.getWidth() * position);

            float scaleFactor=MIN_SCALE
                    + (1 - MIN_SCALE) * (1 - Math.abs(position));
            view.setScaleX(scaleFactor);
            view.setScaleY(scaleFactor);


        } else { // (1,+Infinity]
            // This page is way off-screen to the right.
            view.setAlpha(0);
        }
    }

}

private MotionEvent swapXY(MotionEvent ev) {

    float width = getWidth();
    float height = getHeight();

    float newX = (ev.getY() / height) * width;
    float newY = (ev.getX() / width) * height;

    ev.setLocation(newX, newY);

    return ev;
}

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
    swapXY(ev);
    return intercepted;
    //return super.onInterceptTouchEvent(swapXY(ev));

}
private void setMyScroller() {
    try {
        Class<?> viewpager = ViewPager.class;
        Field scroller = viewpager.getDeclaredField("mScroller");
        scroller.setAccessible(true);
        scroller.set(this, new MyScroller(getContext()));
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public class MyScroller extends Scroller {
    public MyScroller(Context context) {
        super(context, new DecelerateInterpolator());
    }

    @Override
    public void startScroll(int startX, int startY, int dx, int dy, int duration) {
        super.startScroll(startX, startY, dx, dy, 200);


    }
}




@Override
public boolean onTouchEvent(MotionEvent event) {
    // give all the events to the gesture detector. I'm returning true here so the viewpager doesn't
    // get any events at all, I'm sure you could adjust this to make that not true.
    mGestureDetector.onTouchEvent(event);
    return true;
    //return false;
}

@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velX, float velY) {
    mFlingRunnable.startUsingVelocity((int)velX);
    return false;
}

private void trackMotion(float distX) {

    // The following mimics the underlying calculations in ViewPager
    float scrollX = getScrollX() - distX;
    final int width = getWidth();
    final int widthWithMargin = width + this.getPageMargin();
    final float leftBound = Math.max(0, (this.getCurrentItem() - 1) * widthWithMargin);
    final float rightBound = Math.min(this.getCurrentItem() + 1, this.getAdapter().getCount() - 1) * widthWithMargin;

    if (scrollX < leftBound) {
        scrollX = leftBound;
        // Now we know that we've hit the bound, flip the page
        if (this.getCurrentItem() > 0) {
            this.setCurrentItem(this.getCurrentItem() - 1, false);
        }
    }
    else if (scrollX > rightBound) {
        scrollX = rightBound;
        // Now we know that we've hit the bound, flip the page
        if (this.getCurrentItem() < (this.getAdapter().getCount() - 1) ) {
            this.setCurrentItem(this.getCurrentItem() + 1, false);
        }
    }

    // Do the fake dragging
    if (mScrolling) {
        this.fakeDragBy(distX);
    }
    else {
        this.beginFakeDrag();
        this.fakeDragBy(distX);
        mScrolling = true;
    }

}

private void endFlingMotion() {
    mScrolling = false;
    this.endFakeDrag();
}


private class FlingRunnable implements Runnable {
    private Scroller mScroller; // use this to store the points which will be used to create the scroll
    private int mLastFlingX;

    private FlingRunnable() {
        mScroller = new Scroller(getContext());
    }

    public void startUsingVelocity(int initialVel) {


        Log.e("touch","touch");
        if (initialVel == 0) {
            // there is no velocity to fling!
            return;
        }

        removeCallbacks(this); // stop pending flings

        int initialX = initialVel < 0 ? Integer.MAX_VALUE : 0;
        mLastFlingX = initialX;
        // setup the scroller to calulate the new x positions based on the initial velocity. Impose no cap on the min/max x values.
        mScroller.fling(initialX, 0, initialVel, 0, 0, Integer.MAX_VALUE, 0, Integer.MAX_VALUE);

        post(this);
    }

    private void endFling() {
        mScroller.forceFinished(true);
        endFlingMotion();
    }

    @Override
    public void run() {

        final Scroller scroller = mScroller;
        boolean animationNotFinished = scroller.computeScrollOffset();
        final int x = scroller.getCurrX();
        int delta = x - mLastFlingX;

        trackMotion(delta);

        if (animationNotFinished) {
            mLastFlingX = x;
            post(this);
        }
        else {
            endFling();
        }

    }
}

@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distX, float distY) {
    trackMotion(-distX);
    return false;
}

// Unused Gesture Detector functions below

@Override
public boolean onDown(MotionEvent event) {
    return false;
}

@Override
public void onLongPress(MotionEvent event) {
    // we don't want to do anything on a long press, though you should probably feed this to the page being long-pressed.
}

@Override
public void onShowPress(MotionEvent event) {
    // we don't want to show any visual feedback
}

@Override
public boolean onSingleTapUp(MotionEvent event) {
    // we don't want to snap to the next page on a tap so ignore this
    return false;
}