title: react-virtualized InfiniteLoader in both directions, top and bottom
body: <p>How to make infinite scrolling in both directions, up and down. I am using the InfiniteLoader and the List, both are react-virtualized components. I have a list of timestamps with initial date-time range. From there the list should be infinite in both directions. Currently, scroll-down to the bottom of the List will trigger the function _loadMoreRows(). However, I would like to trigger the _loadMoreRows() with the same functionality when scrolling in the direction up.</p>