MacOS:‍

‍System Requirements:

‍Before you start, ensure that your macOS system meets the following requirements:
‍
A. macOS operating system (macOS 10.12 and later)
B. Xcode (for iOS development)
C. Android Studio or Android Command Line Tools (for Android development)
D. Git
E. Dart SDK (included with Flutter)

‍Install Homebrew (if not already installed):

‍If you don't have Homebrew installed, open your Terminal and run the following command:

/bin/bash -c "$(curl -fsSL 
https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"	

‍Install Flutter:

‍Open Terminal.

Run the following command to download Flutter from the official Git repository and add it to your PATH:

brew install --cask flutter	

Verify Installation:

‍Run the following command to verify that Flutter is installed correctly:

lutter --version

Install Xcode (for iOS development):

‍If you plan to develop for iOS, you'll need Xcode from the App Store. Open the App Store, search for Xcode, and install it.

‍Android Setup (optional):

‍If you plan to develop for Android, download and install Android Studio, and follow the Android setup steps in Android Studio. Ensure you have the Android SDK and related tools.

‍Install IDE (Optional):

‍You can use Visual Studio Code or Android Studio as your integrated development environment (IDE). Install your preferred IDE and the Flutter and Dart plugins.

‍
‍Windows‍

‍System Requirements:

‍Before you start, ensure that your Windows system meets the following requirements:

A. Windows 10 or later (64-bit)
B. Git for Windows
C. Dart SDK (included with Flutter)

‍Install Git:

‍If you don't already have Git installed, download and install it from Git for Windows.

‍Download Flutter:

‍Visit the Flutter SDK download page at https://flutter.dev/docs/get-started/install/windows and download the stable release for Windows.

‍Extract the Archive:

‍Extract the downloaded Flutter archive to a location on your system, e.g., C:\.

Add Flutter to Path:

‍To run Flutter commands globally in the command prompt, add the Flutter bin directory to your system's PATH variable. Here's how:

A. Search for "Environment Variables" in the Windows Start menu and click on "Edit the system environment variables."
B. Click the "Environment Variables" button.
C. Under "System variables," scroll down to find "Path" and click "Edit."
D. Add a new entry with the path to the bin directory in your Flutter installation (e.g., C:\flutter\bin).

‍Install Android Studio:

Download and install Android Studio from https://developer.android.com/studio. During installation, make sure to select the Android SDK components.

‍Configure Flutter in Android Studio:

‍Open Android Studio and go to "File" > "Settings" (or "Preferences" on macOS).
In the left panel, select "Plugins" and search for "Flutter."Install the "Flutter" and "Dart" plugins.

Run flutter doctor:

‍Open a Command Prompt or PowerShell window and run:

flutter doctor

This command will check for any missing dependencies and guide you on how to set up the Android emulator or connect physical devices.

After following these steps, you should have Flutter set up and ready to start building apps on your macOS or Windows system.

If you encounter any issues or have questions about specific steps, feel free to ask for further assistance.

Widgets: The Building Blocks

‍In Flutter, everything is a widget. Widgets are the fundamental building blocks used to create the user interface of your app. A widget is an element of the user interface, such as a button, text, or a layout. Widgets can be categorized into two main types:

‍Stateless Widgets:

These are immutable widgets that don't change once they are built. They are used for displaying static content.

‍Stateful Widgets:

These widgets can change or update over time. They are used for dynamic content and user interaction.

A. Widget Tree

‍Widgets are organized in a tree structure, forming a hierarchy. The top-level widget is typically the MaterialApp or CupertinoApp, which represents the whole application. From there, you create a widget tree by nesting widgets inside one another to build your user interface.

‍Building a Simple Flutter App

‍Let's create a basic Flutter app that displays "Hello, Flutter!" on the screen.

‍Create a New Flutter Project:

‍Open your command prompt or terminal and navigate to the directory where you want to create your Flutter project. Run the following commands:

flutter create hello_flutter_app
cd hello_flutter_app

Edit the lib/main.dart File:

Open the lib/main.dart file in your preferred code editor (e.g., Visual Studio Code). This is the entry point of your Flutter app.

Replace the existing code with the following:

import 'package:flutter/material.dart';
void main() {
  runApp(MyApp());
}
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Hello, Flutter!'),
        ),
        body: Center(
          child: Text('Hello, Flutter!'),
        ),
      ),
    );
  }
}

Let's break down the code:

We import the necessary Flutter package.

‍void main():

This is the entry point of your Flutter app. It calls runApp, which takes the root widget (MyApp) and starts the app.

‍MyApp class:

This is a custom StatelessWidget representing the main application. It returns a MaterialApp widget, which sets up the basic app structure. Inside it, there's a Scaffold with an AppBar and a body.

‍Scaffold:

A scaffold is a basic visual structure for a page, often used for standard app layouts. It can have an appBar and a body.

‍AppBar:

‍This widget creates a navigation bar with a title.

Text: This widget displays text on the screen.

‍Run Your App:

‍Ensure you have an emulator running or a physical device connected. In your terminal, navigate to your project's directory and run your app:

flutter run

You should see your "Hello, Flutter!" app running on the emulator or device.

‍Hot Reload

‍One of Flutter's most powerful features is hot reload. It allows you to make changes to your code and see the results instantly without restarting your app. To use hot reload, simply save your code in your IDE, and Flutter will update the running app with your changes.

‍Stateless vs. Stateful Widgets

‍Stateless Widgets: These are simple and immutable. They don't have internal state that changes during the widget's lifetime. For example, Text is a stateless widget.

Stateful Widgets: These widgets have mutable state. When the state changes, the widget rebuilds. For example, when handling user input or dynamic data, you'd use stateful widgets.

‍Widget Composition

‍Flutter encourages you to compose widgets to create complex interfaces. You can nest widgets and customize their properties to create rich, dynamic user interfaces.

‍Widget Properties and Parameters

‍Widgets can have properties or parameters (often called properties or arguments). You can customize a widget's behavior by passing parameters when you create it.

For example, you can customize the Text widget's text like this:

Text('Custom Text', style: TextStyle(fontSize: 20));

These are the foundational concepts you need to know to start building Flutter applications. You'll use these concepts to create user interfaces, handle user interactions, and build more complex applications as you gain experience with Flutter.