private void measureFloatView() {
        if (mFloatView != null) {
            measureItem(mFloatView);
            mFloatViewHeight = mFloatView.getMeasuredHeight();
            mFloatViewHeightHalf = mFloatViewHeight / 2;
        }
    }
Sets layout param height, gravity, and visibility  on
wrapped item.
third_party/DragSortListView/src/com/mobeta/android/dslv/DragSortListView.java