Making the detached scrollbar catch up faster to the actual scroll position.

                int diffScrollY = scrollBarY - thumbScrollY;

                if (diffScrollY * dy > 0f) {

                    // User is scrolling in the same direction the thumb needs to catch up to the

                    // current scroll position.

                    thumbScrollY += dy < 0 ? Math.max(dy, diffScrollY) : Math.min(dy, diffScrollY);

                    // current scroll position.  We do this by mapping the difference in movement

                    // from the original scroll bar position to the difference in movement necessary

                    // in the detached thumb position to ensure that both speed towards the same

                    // position at either end of the list.

                    if (dy < 0) {

                        int offset = (int) ((dy * thumbScrollY) / (float) scrollBarY);

                        thumbScrollY += Math.max(offset, diffScrollY);

                    } else {

                        int offset = (int) ((dy * (availableScrollBarHeight - thumbScrollY)) /

                                (float) (availableScrollBarHeight - scrollBarY));

                        thumbScrollY += Math.min(offset, diffScrollY);

                    }

                    thumbScrollY = Math.max(0, Math.min(availableScrollBarHeight, thumbScrollY));

                    mScrollbar.setThumbOffset(scrollBarX, thumbScrollY);

                    if (scrollBarY == thumbScrollY) {