From Xojo Documentation
The class interface that any data source supporting row recording must implement.
Any data source that supports reordering of rows must implement this interface.
When the table is made editable:
- The data source's AllowRowMove method is called for the visible rows and the movable rows get reordering controls.
- The user drags the row around the table, which can lead to more AllowRowMove invocations. While the user is moving the row, the table's visual state is updated to show where the row will go but the data source is not modified.
- The reorder finishes and the data source's RowMoved method is called so the data source can update its internal state.