Flutter tabcontroller index does not respond to changes in the tabbarview

just remove the condition :

  if (_controller.indexIsChanging) {

Because every time you start changing from previousIndex to the currentIndex, you rebuild the widget and your _controller.index is the same as your initial index.

This should work :

            _handleTabSelection() {
                  setState(() {
                    _currentIndex = _controller.index;
                  });
              }

Doc Says:

indexIsChanging : True while we're animating from [previousIndex] to [index] as a
consequence of calling [animateTo]. This value is true during the [animateTo] animation that's triggered when /// the user taps a [TabBar] tab. It is false when [offset] is changing as a /// consequence of the user dragging (and "flinging") the [TabBarView].

  bool get indexIsChanging => _indexIsChangingCount != 0;
  int _indexIsChangingCount = 0;

Code:

  TabController _controller;
  int _selectedIndex = 0;

  List<Widget> list = [
    Tab(icon: Icon(Icons.card_travel)),
    Tab(icon: Icon(Icons.add_shopping_cart)),
  ];

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    // Create TabController for getting the index of current tab
    _controller = TabController(length: list.length, vsync: this);

    _controller.addListener(() {
      setState(() {
        _selectedIndex = _controller.index;
      });
      print("Selected Index: " + _controller.index.toString());
    });
  }

Sample: https://github.com/jitsm555/Flutter-Problems/tree/master/tab_bar_tricks

Output: