Read the range from Event.getSource, which is where the listened cells are now. It is
invalid (ICellRange.isInvalid) when the cells were deleted (#REF!) or the workbook
was restored to a revision from before the listener was added (#N/A); the listener stays
registered through both, and hears the range come back.
Called with what changed at a listened range. See ICellRange.addListener.
Remarks
Read the range from Event.getSource, which is where the listened cells are now. It is invalid (ICellRange.isInvalid) when the cells were deleted (
#REF!) or the workbook was restored to a revision from before the listener was added (#N/A); the listener stays registered through both, and hears the range come back.