Practise

// Some code
class PractiseLesson extends StatefulWidget {
  const PractiseLesson({super.key});

  @override
  State<PractiseLesson> createState() => _PractiseLessonState();
}

class _PractiseLessonState extends State<PractiseLesson> {
  int selectedIndex = 0;

  List<IconData> data = [
    Icons.account_balance_rounded,
    Icons.strikethrough_s,
    Icons.add,
    Icons.account_circle,
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.grey.shade600,
      floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
      floatingActionButton: SizedBox(
        height: 100,
        width: double.infinity,

        child: Stack(
          children: [
            Align(
              alignment: Alignment.center,
              child: Container(
                height: 80,
                width: double.infinity,
                color: Colors.white,
                margin: EdgeInsets.symmetric(horizontal: 12),
              ),
            ),
            Align(
              alignment: Alignment.center,
              child: Row(
                mainAxisAlignment: MainAxisAlignment.spaceAround,
                children: List.generate(
                  4,
                  (e) => InkWell(
                    onTap: (){
                      setState(() {
                        selectedIndex = e;
                      });
                    },
                    child: Container(
                      height: selectedIndex == e ? 90 : 78,
                      width: selectedIndex == e ? 90 : 78,
                      color: selectedIndex == e ? Colors.green : Colors.white,
                      child: Icon(
                        data[e],
                        color: selectedIndex == e ? Colors.white : Colors.black,
                      ),
                    ),
                  ),
                ).toList(),
              ),
            ),
          ],
        ),
      ),
    );
  }
}