Flutter TabController with onChange callback

tab_controller_with_on_change.dart

import 'package:flutter/material.dart';

class TabControllerWithOnChange extends TabController {
  TabControllerWithOnChange({
    int initialIndex = 0,
    required int length,
    required TickerProvider vsync,
    required void Function(int) onChange,
  }) : super(initialIndex: initialIndex, length: length, vsync: vsync) {
    addListener(() {
      if (!indexIsChanging) {
        return;
      }
      onChange(index);
    });
  }
}