private void destroyFloatView() {
        if (mFloatView != null) {
            mFloatView.setVisibility(GONE);
            if (mFloatViewManager != null) {
                mFloatViewManager.onDestroyFloatView(mFloatView);
            }
            mFloatView = null;
            invalidate();
        }
    }
Sets float View location based on suggested values and
constraints set in mDragFlags.
third_party/DragSortListView/src/com/mobeta/android/dslv/DragSortListView.java