Android overscroll for ScrollView

Question

I asked before about OverScroll in ListView. Default overScroll doesn't work on many devices (for ex.: Samsung Galaxy 2, HTC One X). So I made OverScrollListView

But now needed to do the same for ScrollView. I made the trick for top overscroll (by using positive number in overScrollBy). But when i'm trying to do the same for bottom (by using a negative number in overScrollBy), overscroll ScrollView scrolling to top position.

Can someone say why?

P.S. I also tried this. But even in top (or bottom) position scrollbar indicator shown somewhere in middle. This confuse the user...

Answer 1

Ok, i think i did it.

But it's really strange.

I had method for overscroll that i call in ACTION_MOVE:

private void pullDown(int deltaY, int lastY) {
    overScrollBy(0, mSlowEffect ? (int)getOverScrollYWithSlow(deltaY) : deltaY, 0, lastY, 5, 5, 0, mMaxYOverscrollDistance, true);
}

For ListView for overscroll i just set deltaY something like pullDown(lastScroll, 0);

It works for both: top and bottom overscroll.

But for ScrollView it doesn't work for bottom overscroll. So we should send to this method also current scrollY position, something like pullDown(lastScroll , lastY);

I share whole code on Github, if someone interested.