具有平滑滑动/过渡的垂直ViewPager

Question

我正在尝试创建一个Vertical ViewPager，就像我们在应用程序InShorts中一样。 我成功地实现了相同但不顺利，有时它无法理解滑动。

这是我的垂直ViewPager类

public class VerticalViewPager  extends ViewPager {

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

public VerticalViewPager(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
}

private void init() {
    // The majority of the magic happens here
    setPageTransformer(true, new VerticalPageTransformer2());
    // The easiest way to get rid of the overscroll drawing that happens on the left and right
    setOverScrollMode(OVER_SCROLL_NEVER);
}


private static class VerticalPageTransformer2 implements PageTransformer {
    private static float MIN_SCALE = 0.75f;

    public void transformPage(View view, float position) {
        int pageWidth = view.getWidth();

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



        } else if (position <= 0) { // [-1,0]
            // Use the default slide transition when moving to the left page
            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) { // (0,1]
            // Fade the page out.
            view.setAlpha(1 - position);

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

            // Scale the page down (between MIN_SCALE and 1)
            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);
        }

    }
}

/**
 * Swaps the X and Y coordinates of your touch event.
 */
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 touch coordinates to original reference frame for any child views
    return intercepted;
}

@Override
public boolean onTouchEvent(MotionEvent ev) {
    return super.onTouchEvent(swapXY(ev));
}

@Override
public boolean canScrollHorizontally(int direction) {
    return false;
}
}

我该怎么做才能创建一个非常流畅和轻松的滑动。