sortIconBuilder property

A builder function that returns a widget to use as the sorting indicator icon for the table's header cells.

When providing a custom sort icon via this builder, the default sort arrow's automatic rotation and opacity transitions are omitted. To achieve animated transitions for custom icons, wrap the returned widget in explicit transition widgets such as AnimatedRotation or AnimatedOpacity.

Custom icons should target a size of approximately 18.0 logical pixels or be wrapped in a fixed-size container to maintain visually balanced header labels. For columns where DataColumn.numeric is true, DataTable adds a leading 20.0 logical pixel spacer to mirror the space occupied by the sort icon and its padding, ensuring centered column labels remain properly aligned.

If null, DataTableThemeData.sortIconBuilder is used. If that is also null, the default Material design sort arrow animation is used.