a basic calculator with flutter

-

 import 'package:flutter/material.dart';


void main() => runApp(CalculatorApp());

class CalculatorApp extends StatelessWidget {
  const CalculatorApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Minhaj Calculator',
      theme: ThemeData.dark().copyWith(
        primaryColor: Colors.deepPurple,
        scaffoldBackgroundColor: Colors.black,
      ),
      home: Calculator(),
    );
  }
}

class Calculator extends StatefulWidget {
  @override
  _CalculatorState createState() => _CalculatorState();
}

class _CalculatorState extends State<Calculator> {
  String _output = "0";
  String _currentNumber = "";
  String _operation = "";
  double _num1 = 0;
  double _num2 = 0;

  void _buttonPressed(String buttonText) {
    setState(() {
      if (buttonText == "C") {
        _output = "0";
        _currentNumber = "";
        _operation = "";
        _num1 = 0;
        _num2 = 0;
      } else if (buttonText == "+" ||
          buttonText == "-" ||
          buttonText == "×" ||
          buttonText == "÷") {
        _num1 = double.parse(_output);
        _operation = buttonText;
        _currentNumber = "";
      } else if (buttonText == "=") {
        _num2 = double.parse(_currentNumber);
        switch (_operation) {
          case "+":
            _output = (_num1 + _num2).toString();
            break;
          case "-":
            _output = (_num1 - _num2).toString();
            break;
          case "×":
            _output = (_num1 * _num2).toString();
            break;
          case "÷":
            _output = (_num1 / _num2).toString();
            break;
        }
        _currentNumber = _output;
      } else {
        _currentNumber += buttonText;
        _output = _currentNumber;
      }
    });
  }

  Widget _buildButton(String buttonText, Color buttonColor) {
    return Expanded(
      child: ElevatedButton(
        style: ElevatedButton.styleFrom(
          backgroundColor: buttonColor,
          padding: const EdgeInsets.all(24.0),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(20.0),
          ),
        ),
        child: Text(
          buttonText,
          style: const TextStyle(fontSize: 24.0, fontWeight: FontWeight.bold),
        ),
        onPressed: () => _buttonPressed(buttonText),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Minhaj Calculator'),
        centerTitle: true,
      ),
      body: Column(
        children: <Widget>[
          Container(
            alignment: Alignment.centerRight,
            padding:
                const EdgeInsets.symmetric(vertical: 24.0, horizontal: 12.0),
            child: Text(
              _output,
              style: const TextStyle(
                fontSize: 48.0,
                fontWeight: FontWeight.bold,
                color: Colors.white,
              ),
            ),
          ),
          const Expanded(
            child: Divider(),
          ),
          Column(
            children: [
              Row(
                children: [
                  _buildButton("7", Colors.grey[800]!),
                  _buildButton("8", Colors.grey[800]!),
                  _buildButton("9", Colors.grey[800]!),
                  _buildButton("÷", Colors.deepPurple),
                ],
              ),
              Row(
                children: [
                  _buildButton("4", Colors.grey[800]!),
                  _buildButton("5", Colors.grey[800]!),
                  _buildButton("6", Colors.grey[800]!),
                  _buildButton("×", Colors.deepPurple),
                ],
              ),
              Row(
                children: [
                  _buildButton("1", Colors.grey[800]!),
                  _buildButton("2", Colors.grey[800]!),
                  _buildButton("3", Colors.grey[800]!),
                  _buildButton("-", Colors.deepPurple),
                ],
              ),
              Row(
                children: [
                  _buildButton("C", Colors.red),
                  _buildButton("0", Colors.grey[800]!),
                  _buildButton("=", Colors.deepPurple),
                  _buildButton("+", Colors.deepPurple),
                ],
              ),
            ],
          ),
        ],
      ),
    );
  }
}

Comments

Post a Comment

Popular posts from this blog

swapping the alternate values in given array's element ! 17/11/2022

-
  #include <iostream> using namespace std ; // funtion to print the value of array; void printingarray ( int arr [], int size ){ for ( int i = 0 ; i < size ; i ++){ cout << arr [ i ] << " " ; } { /* code */ } } // funtion to swap the alternate value of an arra's element; void alternetswap ( int arr [], int size ){ for ( int i = 0 ; i < size ; i += 2 ) { if ( i + 1 < size ) { swap ( arr [ i ], arr [ i + 1 ]); } } } int main (){ int marry [ 6 ]={ 1 , 2 , 3 , 4 , 5 , 6 }; int garry [ 5 ]={ 23 , 43 , 56 , 76 , 4 }; alternetswap ( marry , 6 ); printingarray ( marry , 6 ); cout << endl ; alternetswap ( garry , 5 ); printingarray ( garry , 5 ); }
Read more

Learning stage | c++ programs

-
  #include   <iostream> using   namespace   std ; int   main ()  { /*//Program to calculate the discount percentage of acutal cost as well as actuall price. int price = 90000; int discount_percentage = (90000/100)*7; int discounted_price= 90000-discount_percentage; cout <<discounted_price;  return 0;*/  // Q- Priya wants to write a program to input marks in three subjects out of 100 and  // calculate and display teh total  marks and percentage . How should she do this task ?           int    ganit , science  ,  social ;      cout << "Enter the marks of...
Read more

c++ basic question

-
  #include   <iostream> using   namespace   std ; int   main (){   /*   Q- Write a program where the user is asked to enter two integers  ( divisor and dividend)   and the quotient and the remainder of their divison is computed . ( Both divisor and dividend should be integers).         int dividend, divisor, quotient , remainder;   cout<<"Enter your dividend : ";  cin>>dividend;   cout<<"Enter your divisor : "; cin>>divisor; quotient = dividend/divisor; remainder = dividend%divisor; cout<<"The quotient is : "<<quotient<<endl <<"The rema...
Read more