public void onItemDragStart(RecyclerView.ViewHolder viewHolder) {
        if (mOnItemDragListener != null && itemDragEnabled) {
            mOnItemDragListener.onItemDragStart(viewHolder, getViewHolderPosition(viewHolder));
        }
    }
@param onItemDragListener Register a callback to be invoked when drag event happen.
common/src/main/java/com/sxjs/common/base/baseadapter/BaseItemDraggableAdapter.java