Как сделать чтобы каждому элементу были свои значения, при том изначально неизвестны количество элементов Flutter

Когда я нажимаю на кнопку "Сохранить в избранные" меняются все, логично y всеx одно значение, вот как сделать каждому по отдельности с index

class _FavoritesPageState extends State<FavoritesPage> {
  bool _isFav = false;

  void _toggleFav() {
    setState(() {
      _isFav = !_isFav;
    });
  }

Widget _build(BuildContext context, Animal animal) {
    String gen = animal.animalGenderId == 1 ? "Еркек" : "Ұрғашы";

    return Container(
      margin: EdgeInsets.symmetric(horizontal: 8, vertical: 6),
//      height: 110,
      decoration: BoxDecoration(
        color: Theme.of(context).brightness == Brightness.light
            ? Colors.white
            : Color.fromRGBO(28, 28, 30, 1),
        borderRadius: BorderRadius.circular(15),
        boxShadow: [
          BoxShadow(
            offset: Offset(0, 1),
            blurRadius: 3,
            color: Color(0xFF12153D).withOpacity(0.2),
          ),
        ],
      ),
      child: InkWell(
        onTap: () {
          Navigator.push(
              context,
              MaterialPageRoute(
                  builder: (context) => AnimalDetails(
                        animalId: animal.id,
                      )));
        },
        child: Container(
          margin: EdgeInsets.all(10),
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(15),
          ),
          child: Row(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              //Image
              ClipRRect(
                borderRadius: BorderRadius.only(
                    bottomLeft: Radius.circular(10),
                    topLeft: Radius.circular(10),
                    topRight: Radius.circular(10),
                    bottomRight: Radius.circular(10)),
                child: Image.asset(
                  _findPhotoById(animal.photoId),
                  fit: BoxFit.cover,
                  height: 90,
                  width: 90,
                ),
              ),
              //Desc
              Expanded(
                child: Container(
                  margin: EdgeInsets.only(left: 10),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    mainAxisAlignment: MainAxisAlignment.start,
                    children: <Widget>[
                      //title
                      Container(
                        margin: EdgeInsets.only(bottom: 5, top: 0),
                        padding: EdgeInsets.only(top: 0),
                        child: Text(
                          "${_findAnimalTypeById(animal.animalType)}, ${animal.breed}, ${animal.weight}кг, $gen, ${animal.age} жас",
                          style: TextStyle(
                              fontSize: 20, fontWeight: FontWeight.bold),
                          textAlign: TextAlign.left,
                        ),
                      ),
                      //Cost
                      Container(
                        margin: EdgeInsets.symmetric(
                          vertical: 5,
                        ),
                        padding: EdgeInsets.all(4),
                        constraints:
                            BoxConstraints(maxHeight: 40, minWidth: 20),
                        decoration: BoxDecoration(
                            borderRadius: BorderRadius.circular(5),
                            color:
                                Theme.of(context).brightness == Brightness.light
                                    ? mainColor
                                    : Color(0XFF2D2D2D)),
                        child: Text(
                          '${animal.cost}$tenge',
                          style: TextStyle(
                              color: Colors.white, fontWeight: FontWeight.w500),
                        ),
                      ),
                    ],
                  ),
                ),
              ),
              Container(
                child: IconButton(
                  icon: Icon(_isFav ? Icons.favorite : Icons.favorite_border,
                      color: _isFav
                          ? Colors.red[700]
                          : Theme.of(context).brightness == Brightness.light
                              ? mainColor
                              : Colors.white),
                  onPressed: _toggleFav,
                ),
              )
            ],
          ),
        ),
      ),
    );
  }

String _findPhotoById(int photosId) {
    String res = '';
    for (int i = 0; i < animalPhotos.length; i++) {
      if (photosId == animalPhotos[i].id) {
        res = animalPhotos[i].imgUrl;
      }
    }
    return res;
  }

  String _findAnimalTypeById(int animalId) {
    String res = '';
    for (int i = 0; i < animalType.length; i++) {
      if (animalId == animalType[i].id) {
        res = animalType[i].name;
      }
    }
    return res;
  }
}