What is Flutter? An Introduction to Google’s UI Toolkit

5 min readJun 10, 2024

Introduction

In the fast-evolving world of mobile development, creating high-quality native interfaces on iOS and Android can be challenging. Enter Flutter — Google’s open-source UI toolkit for building beautiful, natively compiled applications for mobile, web, and desktop from a single codebase. But what exactly is Flutter, and why should you consider using it for your next project? In this article, we’ll dive into what Flutter is, its benefits, and how it stands out in the crowded field of app development frameworks.

Key Components of Flutter

Flutter SDK: The Software Development Kit (SDK) provides the tools necessary to compile your code into native machine code for iOS and Android.
Dart Programming Language: Flutter apps are written in Dart, a language also developed by Google, optimized for building fast apps on any platform. Check in details article on Dart.
Widgets: Flutter uses a rich set of pre-designed widgets that allow developers to create complex UIs easily.

Flutter Architecture

Flutter’s architecture is based on three key layers:

Framework: This is the highest layer, written in Dart. It provides a rich set of pre-designed widgets.
Engine: The engine, written in C++, provides low-level rendering support using Google’s Skia graphics library.
Embedder: This layer allows Flutter to interface with the platform it’s running on, whether it’s Android, iOS, or the web.

Why Does Flutter Use Dart?

Dart was chosen as the programming language for Flutter for several reasons:

Performance: Dart compiles to native code, which results in high-performance applications.
Productivity: Dart’s ahead-of-time (AOT) compilation provides a predictable, high-performance runtime, while just-in-time (JIT) compilation allows for fast development cycles.
UI as Code: Dart allows Flutter to use a reactive, declarative style of programming, making it easy to create complex UIs with less code

How to Set Up Flutter

Setting up Flutter is straightforward. Follow these steps to get started:

Download Flutter SDK: Visit the Flutter website and download the SDK for your operating system.
Install Flutter: Extract the downloaded file and add the Flutter directory to your system path.
Install an Editor: Flutter works well with editors like Visual Studio Code and Android Studio. Install your preferred editor and add the Flutter and Dart plugins.
Run Flutter Doctor: Open a terminal and run flutter doctor to check for any dependencies you need to install.

Simple Example: “Hello, Flutter!”

Here’s a simple Flutter app that displays “Hello, Flutter!” on the screen

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('Welcome to Flutter'),
        ),
        body: Center(
          child: Text('Hello, Flutter!'),
        ),
      ),
    );
  }
}

In this example, MyApp is a stateless widget that creates a simple app with an AppBar and a centered text widget displaying "Hello, Flutter!".

What are Flutter Widgets?

Flutter widgets are built using a modern framework that takes inspiration from React. The central idea is that you build your UI out of widgets. Widgets describe what their view should look like given their current configuration and state. When a widget’s state changes, the widget rebuilds its description, which the framework diffs against the previous description in order to determine the minimal changes needed in the underlying render tree to transition from one state to the next.

Flutter vs. React Native

When choosing a framework for mobile app development, Flutter and React Native are two of the most popular options. Here’s a comparison of the two:

Advantages of Using Flutter

Single Codebase for Multiple Platforms: Write once and deploy on both iOS and Android, as well as web and desktop, reducing development time and costs.
Hot Reload: Allows developers to see changes in real-time without restarting the app, greatly speeding up the development process.
High Performance: Dart compiles to native code, which ensures high performance for Flutter apps.
Rich Set of Widgets: Pre-designed widgets make it easy to create complex and beautiful UIs.
Strong Community and Support: Backed by Google and a rapidly growing community, ensuring plenty of resources and support.
Open Source: Flutter is open-source, allowing developers to contribute and learn from the codebase.

Disadvantages of Using Flutter

Large App Size: Flutter apps tend to have larger file sizes compared to native apps due to the inclusion of the Flutter engine.
Limited Third-Party Libraries: While growing, the ecosystem of third-party libraries is not as extensive as that of native development frameworks.
Platform-Specific Look and Feel: Flutter’s widgets may not always match the exact look and feel of native components, which might be noticeable in some applications.
Dart Language: Developers need to learn Dart, which is less commonly used than languages like JavaScript or Swift.
Web and Desktop Support: While Flutter supports web and desktop applications, these features are newer and less mature compared to mobile support.

Conclusion

Flutter is a powerful and flexible framework that makes it easy to create beautiful, high-performance applications for multiple platforms from a single codebase. Whether you are a seasoned developer or just getting started with app development, Flutter provides a robust set of tools and an active community to help you build your next great app.

If you’re excited to learn more about Flutter, stay tuned for our upcoming tutorials where we will dive deeper into creating real-world applications using this amazing toolkit.

Frequently Asked Questions (FAQs)

Are there any notable apps built with Flutter?

Yes, many high-profile applications are built with Flutter, including Google Ads, Alibaba, Reflectly, Birch Finance, and the Hamilton app.

2. Can I use Flutter for web and desktop applications?

Yes, Flutter supports building applications for web and desktop, in addition to mobile platforms, using a single codebase.

For more details check Flutter’s website : https://flutter.dev/