How to Detect Orientation Changes in Flutter Layout?

In Flutter, detecting orientation changes in the layout (i.e., whether the screen is in landscape or portrait mode) can be done as follows:

1. Using the MediaQuery object: MediaQuery.of(context) retrieves the current media query data, which includes orientation information.

2. Retrieving orientation information: Use MediaQuery.of(context).orientation to get the current orientation. This property returns an Orientation value, which can be Orientation.landscape (landscape mode) or Orientation.portrait (portrait mode).

3. Using setState: In the build method or other appropriate locations, use setState to update the UI when orientation changes occur.

4. Example code:

dart
import 'package:flutter/material.dart';

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

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

class HomeScreen extends StatefulWidget {
  @override
  _HomeScreenState createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  @override
  Widget build(BuildContext context) {
    Orientation orientation = MediaQuery.of(context).orientation;

    return Scaffold(
      appBar: AppBar(
        title: Text('Orientation Demo'),
      ),
      body: Center(
        child: orientation == Orientation.landscape
            ? Text('Landscape Mode')
            : Text('Portrait Mode'),
      ),
    );
  }
}

This code displays the current screen orientation in the application, and the text updates dynamically when you rotate the device.