Three buttons, change icon

home_screen.dart

import 'package:flutter/material.dart';

class HomeScreen extends StatefulWidget {
  const HomeScreen({Key? key}) : super(key: key);

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  var icon = Icons.house;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(icon, size: 50),
          SizedBox(height: 20),
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              ElevatedButton(
                onPressed: () {
                  icon = Icons.house;
                  setState(() {});
                },
                child: Text('House'),
              ),
              SizedBox(width: 20),
              ElevatedButton(
                onPressed: () {
                  icon = Icons.sunny;
                  setState(() {});
                },
                child: Text('Sun'),
              ),
              SizedBox(width: 20),
              ElevatedButton(
                onPressed: () {
                  icon = Icons.cloud;
                  setState(() {});
                },
                child: Text('Cloud'),
              ),
            ],
          ),
        ],
      ),
    );
  }
}