apply<T extends DataGridRow> method

@override DataGridState<T>? apply<T extends DataGridRow>(EventContext<T> context)

Apply this event's transformation to the state. Returns the new state, or null if no state change should occur. Can return a Future for async operations.

Implementation

@override
DataGridState<T>? apply<T extends DataGridRow>(EventContext<T> context) {
  final currentContextState = context.state;
  final paginationState = currentContextState.pagination;

  if (paginationState.enabled == enabled) return null;

  final newPagination = paginationState.copyWith(enabled: enabled);
  final List<double> newDisplayOrder;
  int totalItems = currentContextState.totalItems;

  if (enabled) {
    if (paginationState.serverSide) {
      newDisplayOrder = currentContextState.displayOrder;
    } else {
      final allIds = currentContextState.displayOrder;
      totalItems = allIds.length;
      final startIndex = newPagination.startIndex(totalItems);
      final endIndex = newPagination.endIndex(totalItems);
      newDisplayOrder = allIds.sublist(
        math.min(startIndex, allIds.length),
        math.min(endIndex, allIds.length),
      );
    }
  } else {
    final allIds = currentContextState.rowsById.keys.toList();
    totalItems = allIds.length;
    newDisplayOrder = allIds;
  }

  return currentContextState.copyWith(
    pagination: newPagination,
    displayOrder: newDisplayOrder,
    totalItems: totalItems,
  );
}