Flutter Implementation: Cart and Room Management

Posted on Mar 12, 2026 in Computers

Flutter Shopping Cart Implementation

This example demonstrates how to create a simple Shopping Cart interface in Flutter using TextEditingController and StatefulWidget to manage item inputs and calculate totals.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(home: CartScreen());
  }
}

class Item {
  String name;
  int qty;
  double price;
  Item(this.name, this.qty, this.price);
}

List<Item> cartList = [];

class CartScreen extends StatefulWidget {
  @override
  State<CartScreen> createState() => _CartScreenState();
}

class _CartScreenState extends State<CartScreen> {
  TextEditingController name = TextEditingController();
  TextEditingController qty = TextEditingController();
  TextEditingController price = TextEditingController();
  String message = "";
  double total = 0;

  void addItem() {
    if (name.text.isEmpty || qty.text.isEmpty || price.text.isEmpty) {
      setState(() { message = "All fields are required"; });
      return;
    }
    int q = int.tryParse(qty.text) ?? 0;
    double p = double.tryParse(price.text) ?? 0;
    if (q <= 0 || p <= 0) {
      setState(() { message = "Enter valid quantity and price"; });
      return;
    }
    cartList.add(Item(name.text, q, p));
    total += q * p;
    name.clear();
    qty.clear();
    price.clear();
    setState(() { message = "Item Added Successfully"; });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("Shopping Cart")),
      body: Padding(
        padding: EdgeInsets.all(16.0),
        child: Column(
          children: [
            TextField(controller: name, decoration: InputDecoration(labelText: "Item Name")),
            TextField(controller: qty, keyboardType: TextInputType.number, decoration: InputDecoration(labelText: "Quantity")),
            TextField(controller: price, keyboardType: TextInputType.number, decoration: InputDecoration(labelText: "Price")),
            SizedBox(height: 20),
            ElevatedButton(onPressed: addItem, child: Text("Add Item")),
            SizedBox(height: 20),
            Text(message, style: TextStyle(color: Colors.red)),
            SizedBox(height: 20),
            Text("Total Price: $total", style: TextStyle(fontSize: 18)),
          ],
        ),
      ),
    );
  }
}

Hotel Room Booking System

This section covers the navigation and data entry logic for a Hotel Room Booking application, utilizing Navigator to manage multiple screens.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(home: HomeScreen());
  }
}

class Room {
  String number, type, floor;
  double rate;
  Room(this.number, this.type, this.floor, this.rate);
}

List<Room> roomList = [];

class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("Hotel Room Booking")),
      body: Padding(
        padding: EdgeInsets.all(16.0),
        child: Column(
          children: [
            ElevatedButton(onPressed: () { Navigator.push(context, MaterialPageRoute(builder: (context) => InsertScreen())); }, child: Text("Insert Room")),
            ElevatedButton(onPressed: () { Navigator.push(context, MaterialPageRoute(builder: (context) => UpdateScreen())); }, child: Text("Holiday Surcharge")),
            ElevatedButton(onPressed: () { Navigator.push(context, MaterialPageRoute(builder: (context) => DisplayScreen())); }, child: Text("Display Rooms")),
          ],
        ),
      ),
    );
  }
}

class InsertScreen extends StatefulWidget {
  @override
  State<InsertScreen> createState() => _InsertScreenState();
}

class _InsertScreenState extends State<InsertScreen> {
  TextEditingController number = TextEditingController();
  TextEditingController type = TextEditingController();
  TextEditingController floor = TextEditingController();
  TextEditingController rate = TextEditingController();
  String message = "";

  void addRoom() {
    if (number.text.isEmpty || type.text.isEmpty || floor.text.isEmpty || rate.text.isEmpty) {
      setState(() { message = "All fields are required"; });
      return;
    }
    double r = double.tryParse(rate.text) ?? 0;
    if (r <= 0) {
      setState(() { message = "Enter valid rate"; });
      return;
    }
    roomList.add(Room(number.text, type.text, floor.text, r));
  }
}