BMI Application

 import "package:flutter/material.dart";

void main()
{
  runApp(const MyApp());
}
class MyApp extends StatelessWidget
{
  const MyApp({super.key});
  @override
  Widget build(BuildContext context)
  {
    return MaterialApp(
      title: "Hello",
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.teal,
      ),
      home: const FlutterApp(),
    );
  }
}

class FlutterApp extends StatefulWidget
{
  const FlutterApp({super.key});

  @override
  State<FlutterApp> createState()
  {
    return FlutterAppState();
  }
}

class FlutterAppState extends State<FlutterApp>
{
  var wtController = TextEditingController();
  var ftController = TextEditingController();
  var inController = TextEditingController();

  var result = "";
  var bgColor = Colors.teal.shade50;

  @override
  Widget build(BuildContext context)
  {

    return GestureDetector(
      onTap: (){
        FocusManager.instance.primaryFocus?.unfocus();
      },

      child: Scaffold(
        drawer: Drawer(
          child: ListView(
            padding: EdgeInsets.zero,
            children: [
              const UserAccountsDrawerHeader(
                accountName: Text("John"),
                accountEmail: Text("John442@google.com"),
                currentAccountPicture: Icon(Icons.account_circle, size: 85,),
              ),

              ListTile(
                leading: const Icon(Icons.message, color: Colors.black,),
                title: const Text("message"),
                onTap: (){
                  Navigator.pop(context);
                },
              ),
              const Divider(thickness: 1, color: Colors.black,),

              ListTile(
                leading: const Icon(Icons.account_circle, color: Colors.black,),
                title: const Text("Profile"),
                onTap: (){
                  Navigator.pop(context);
                },
              ),
              const Divider(thickness: 1, color: Colors.black,),

              ListTile(
                leading: const Icon(Icons.settings, color: Colors.black,),
                title: const Text("Settings"),
                onTap: (){
                  Navigator.pop(context);
                },
              ),
              const Divider(thickness: 1, color: Colors.black,),

              ListTile(
                leading: const Icon(Icons.help_outline, color: Colors.black,),
                title: const Text("Help & feedback"),
                onTap: (){
                  Navigator.pop(context);
                },
              ),
              const Divider(thickness: 1, color: Colors.black,),

              ListTile(
                leading: const Icon(Icons.restore_from_trash, color: Colors.black,),
                title: const Text("Trash"),
                onTap: (){
                  Navigator.pop(context);
                },
              ),
            ],
          ),
        ),
        appBar: AppBar(
          title: const Text("Flutter BMI Application",
            style: TextStyle(fontWeight: FontWeight.bold),
          ),
          centerTitle: true,
          backgroundColor: Colors.grey,
        ),
        body: Container(
          color: bgColor,
          child: Center(
            child: Container(
              width: 300,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  const Text("BMI", style: TextStyle(
                    fontSize: 34,
                    fontWeight: FontWeight.w700,
                  ),),

                  const SizedBox(height: 21,),

                  TextField(
                    controller: wtController,
                    decoration: const InputDecoration(
                      label: Text("Enter your Weight(in Kgs)"),
                      prefixIcon: Icon(Icons.line_weight),
                    ),
                    keyboardType: TextInputType.number,
                  ),

                  TextField(
                    controller: ftController,
                    decoration: const InputDecoration(
                      label: Text("Enter your Height(in Feet)"),
                      prefixIcon: Icon(Icons.height),
                    ),
                    keyboardType: TextInputType.number,
                  ),

                  TextField(
                    controller: inController,
                    decoration: const InputDecoration(
                      label: Text("Enter your Height(in Inch)"),
                      prefixIcon: Icon(Icons.height),
                    ),
                    keyboardType: TextInputType.number,
                  ),

                  const SizedBox(height: 40.0),

                  ElevatedButton(
                    onPressed: (){

                      var wt = wtController.text.toString();
                      var ft = ftController.text.toString();
                      var inch = inController.text.toString();

                      if(wt!="" && ft!="" && inch!="")
                        {

                          //BMI Calculation

                          var iWt = int.parse(wt);
                          var iFt = int.parse(ft);
                          var iInch = int.parse(inch);

                          var tInch = (iFt*12) + iInch;

                          var tCm = tInch*82.54;

                          var tM = tCm/100;

                          var bmi = iWt/(tM*tM);

                          var msg = "";

                          if(bmi>25){
                            msg = "You're OverWeighted!!";
                            bgColor = Colors.orange.shade100;

                          }else if(bmi<18){
                            msg = "You're UnderWeighted!!";
                            bgColor = Colors.red.shade100;

                          }else{
                            msg = "You're Healthy!!";
                            bgColor = Colors.green.shade100;
                          }
                          const SizedBox(height: 20);

                          setState((){
                            //result = "Your BMI is : $bmi";
                            result = "$msg \n Your BMI is : ${bmi.toStringAsFixed(5)}";/*Indication with given fraction digits*/
                          });

                        } else {

                        setState((){
                          result = "Please fill all the required blanks!!";
                        });

                      }
                    },

                      style: ElevatedButton.styleFrom(
                        backgroundColor: Colors.blue.shade800,
                        fixedSize: const Size(350.0,50.0),
                      ),
                      child: const Text("Calculate",
                        style: TextStyle(fontWeight: FontWeight.bold, color: Colors.white, fontSize: 20.0),
                      ),
                  ),

                  const SizedBox(height: 20,),

                  Text(result, style: const TextStyle(fontSize: 19,),),

                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}