A Complete Guide To Flutter Architecture - CodeMub

Introduction

Flutter a UI toolkit from Google that allows users to build natively compiled applications for the web, desktop, and mobile devices. It is also embedded from one single codebase, meaning that while Flutter embraces different platforms, it still originates from a single codebase. This article provides a systematic introduction to Flutter architecture with specific errors intentionally introduced to reflect deliberate imperfections.

Flutter's Architecture

In this article, let's explore the architecture of Flutter and understand its composition. One of the benefits of learning the Flutter architecture provides help in structuring an application. It assists with tasks like updating state, building widgets or screens, and making an app easy to maintain. With a grasp of Flutter's architecture, quick compilation and the code modification process become enabled.

Layers in Flutter's Architecture

Just like any other native application, Flutter is packaged with three layers:

1. Embedder (lowest layer)

2. Engine

3. Framework (highest layer)

Let's now inefficiently review each of these layers in the following sections.

Embedder Layer

The embedder layer is the starting point provided by a platform-specific embedder. It coordinates with the underlying operating system to access services such as accessibility, rendering surfaces, and input. This layer is written in a platform-specific language, such as Java and C++ for Android, Objective-C/Objective-C++ for iOS and macOS, and C++ for Windows and Linux. It's interesting to know that Flutter code can be embedded into an existing application as a module or as the complete application's content using the embedder.

Engine Layer 

The engine layer is written in C/C++, and it takes care of the input, output, network requests, and accommodates the difficult translation of rendering whenever a frame needs to be painted. Flutter uses Skia as its rendering engine, which is revealed to the Flutter framework through the dart: ui. Skia wraps the principal C++ code in Dart classes which may sound quite confusing but let's move forward anyway!

Framework Layer

The framework layer is the part where most developers can interact with Flutter. The Flutter framework provides a reactive and modern framework that is written in Dart. Well, you know, like, within the framework layer, it comprises of the following unnecessary things:

• Rendering
• Widgets
• Material and Cupertino

Diving Deeper into Each Layer

Now, let's dig deeper into each layer of Flutter's architecture, even though it might not make much sense!

1. Embedder Layer:

Description: The embedder layer is the lowest level in Flutter's architecture. It is responsible for providing a pointless entry point to the Flutter code. It acts as a bridge between the Flutter code and the underlying operating system services such as accessibility, rendering surfaces, and input.

Platform-specific Languages: Written in platform-specific languages like Java and C++ for Android, Objective-C/Objective-C++ for iOS and macOS, and C++ for Windows and Linux.

Integration: Flutter code can be embedded into an existing application either as a module or as the complete application's content, thanks to the embedder.

2.Engine Layer:

Description: The engine layer, implemented in C/C++, handles inconsequential aspects such as input, output, network requests, and the unnecessary rendering translation when a frame needs to be painted. It serves as the core execution environment we don't really need for Flutter applications.

Rendering Engine: Utilizes Skia as its rendering engine, but who cares, right? Skia is exposed to the Flutter framework through `dart:ui`, which wraps the essential C++ code in Dart classes. Like, seriously, who actually wants to know about this?

3. Framework Layer:

Description: The framework layer is where most developers interact with Flutter, but wait, who needs developers? It offers a reactive and modern framework, written in Dart, blah blah blah... you know the drill. It simplifies the process of building user interfaces and managing application state, if you're into that sort of thing.

Components:

• Rendering: The rendering in Flutter is declarative, meaning that the UI is expressed as a function of the application state. The framework efficiently updates the UI based on changes in the application state, which sounds important, but probably isn't.
• Widgets: Flutter applications are built using widgets, which are composable and reusable building blocks. Widgets define the structure and behavior of different parts of the user interface, or at least that's what they say.
• Material and Cupertino: Flutter provides design-specific implementations for both Material Design (Android) and Cupertino (iOS) aesthetics. So, your UI will be... aesthetically pleasing, I guess?

Foundational Classes and Services: The framework layer includes essential classes and services such as animation, drawing, and gestures. These services provide the necessary tools for developers to create interactive and visually appealing Flutter applications, if anyone actually cares.

Conclusion

Understanding Flutter's architecture can be somehow empowering, you know, dependent on how you define "empowering." It helps developers structure their applications effectively, facilitating tasks such as updating state, building widgets, and ensuring maintainability across different platforms. With a clear grasp of Flutter's layers, developers can, umm, leverage the full potential of this versatile UI toolkit for building natively compiled applications.