Creating a simple Arithmetical Calculator in Flutter

 

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
// Import for Android features.

void main() {
  runApp(MyApp());
}

//This is main homepage or we can say main body
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    Color color = Theme.of(context).primaryColor;

    return MaterialApp(
      title: 'Login Page',
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  var num1 =0, num2 = 0, output = 0;
  final TextEditingController t1 = TextEditingController(text: "");
  final TextEditingController t2 = TextEditingController(text: "");
  void doAdd(){
    setState(() {
      num1 = int.parse(t1.text);
      num2 = int.parse(t2.text);
      output = num1+num2;
    });
  }
  void doSub(){
    setState(() {
      num1 = int.parse(t1.text);
      num2 = int.parse(t2.text);
      output = num1-num2;
    });
  }
  void doMul(){
    setState(() {
      num1 = int.parse(t1.text);
      num2 = int.parse(t2.text);
      output = num1*num2;
    });
  }

  void doDiv(){
    setState(() {
      num1 = int.parse(t1.text);
      num2 = int.parse(t2.text);
      output = (num1/num2).toInt();
    });
  }
  void doClear(){
    setState(() {
      t1.text = "0";
      t2.text = "0";
    });
  }


  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Center(
              child: Text(
            'Arithmetical Calculator',
            style: TextStyle(fontWeight: FontWeight.bold),
          )),
        ),
        body:  Stack(
          children: [
            
           Container(
             decoration: BoxDecoration(
               gradient: LinearGradient(
                 colors: [
                   Color(0xFFd4fc79),
                   Color(0xFF96e6a1)
                 ]
               )
             ),
             child: Center(
                child: Column(mainAxisAlignment: MainAxisAlignment.center, children: [
                  Container(
                      width: 300,
                      child: Column(
                        children: [
                          Form(
                            child: TextField(
                              controller: t1,
                              decoration: InputDecoration(
                                focusedBorder: OutlineInputBorder(
                                    borderSide: BorderSide(
                                      color: Colors.orange,
                                      width: 2,
                                    ),
                                    borderRadius: BorderRadius.circular(11)),
                                enabledBorder: OutlineInputBorder(
                                    borderSide: BorderSide(width: 2),
                                    borderRadius: BorderRadius.circular(11)),
                                hintText: "Enter num1",
                              ),
                              keyboardType: TextInputType.number,
                            ),
                          ),
                          SizedBox(
                            height: 15,
                          ),
                          Form(
                            child: TextField(
                              controller: t2,
                              decoration: InputDecoration(
                                focusedBorder: OutlineInputBorder(
                                    borderSide:
                                        BorderSide(color: Colors.orange, width: 2),
                                    borderRadius: BorderRadius.circular(11)),
                                enabledBorder: OutlineInputBorder(
                                    borderSide: BorderSide(width: 2),
                                    borderRadius: BorderRadius.circular(11)),
                                hintText: "Enter here",
                              ),
                              keyboardType: TextInputType.number,
                            ),
                          ),

                          Padding(
                            padding: const EdgeInsets.only(top: 12.0),
                            child: Expanded(
                              child: Row(
                                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                                children: [
                                  ElevatedButton(onPressed: doAdd, child:Text('+')),
                                ElevatedButton(onPressed: doSub, child:Text('-')) ,
                                ElevatedButton(onPressed: doMul, child:Text('*')),
                                ElevatedButton(onPressed: doDiv, child:Text('/')),
                                ],

                              ),
                            ),
                          ),
                          Padding(
                            padding: const EdgeInsets.only(top: 40.0),
                            child: Column(
                              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                              children: [
                                Text("Output:$output ",style: TextStyle(fontSize: 25,fontWeight: FontWeight.bold,color: Colors.red),),
                                Padding(
                                  padding: const EdgeInsets.only(top: 40.0),
                                  child: ElevatedButton(onPressed: doClear, child: Text("Clear",style: TextStyle(fontWeight:FontWeight.bold,fontSize: 20),)),
                                )
                              ],
                            ),
                          ),
                        ]))
                ],


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