Golang & Flutter

Prerequisites

• Know golang
• Have introductory knowledge of MVVM, MVC, MVP, etc (UI development)

What is this exactly?

This is a great way to develop truly cross platform desktop and mobile applications rapidly, and beautifly.

It’s an intersection between:

• Flutter’s approach to declarative UI.
• Golang’s great performant and system level language.

Powered by the go-flutter project

Who is this for?

This is for anyone who wants to build an application with a modern UI.

This could range from any of the following situations:

• You have a mobile app you want to release on desktop.
• Want to release a golang based app without electron or html.
• You know golang, and want to get into mobile development or vice-versa.

Why?

Flutter

• Flutter is a great UI oriented language, for rapidly getting to production across all platforms.

• Has a great UI standard that renders natively on everythin from linux to IOS.

• Desktop support for dart/flutter is spotty, and unofficially in beta.

Golang

• Golang is a great system oriented language, for getting robust and fast (enough) code onto all platforms.

• Has no real official UI tooling or even officially recommened UI.

• Has primarily been developed with cli and server based applications in mind.

Quick Comparison

What else is available

• GTK https://github.com/gotk3/gotk3
  • desktop focused
• Nuklear https://github.com/golang-ui/nuklear
  • desktop focused
• Fyne https://github.com/fyne-io/fyne
  • basic mobile implementation (lacks sensor data, etc)
• QT https://github.com/therecipe/qt
  • fairly complete mobile implementation

Please note this is a list of packages I’ve used personally.

For a more exaustive list please go to https://github.com/avelino/awesome-go#gui

Pros & Cons

AKA is this too hipster for production?

Pros & Cons

Pros

• Great workflow, can build and package a release for any platform (desktop, mobile, embedded) in moments.

• Flutters UI is declaritive and a part of the business logic. No need to fuss with widget declarations, complex callbacks, async threads, etc.

• Can target any desktop specific features with golang, and provide any mobile specific features with flutter/golang-mobile.

  • Can also have 2 seperate UI’s for mobile and desktop experiences.

• Flutter has been proven to be a stable platform for many of the large companies seen at https://flutter.dev/showcase

Pros & Cons

Cons

• go-flutter is unofficial.

• Flutter is less popular than kotlin, swift, and react-native, leading to a smaller community (currently)

• Flutter is a new technology. Sometimes that’s scary, and a hard sell.

• Google occasionally likes to kill nice things

  • Should be noted Google dog-foods flutter for everything from Google Ads to Stadia.

How it works

High Level

How it works

In depth

How it works

Further Reading

• Flutter FFI (c/c++ engine)

  • https://flutter.dev/docs/development/platform-integration/c-interop

• Flutter Embedders

  • https://github.com/flutter/flutter/wiki/Custom-Flutter-Engine-Embedders

• Go-Flutter Summary

  • https://hover.build/blog/one-year-in/

• Comparison to official flutter bindings

  • https://github.com/go-flutter-desktop/go-flutter/issues/191#issuecomment-511384007

• Golang GLFW layer

  • https://github.com/go-gl/glfw

Is this too hipster for production?

TLDR; No

• Essentially go-flutter at its core is just ~ 200 lines of code to compile to C byte code with GLFW support
  • This is not complex, at an implementation level, just fancy tooling
  • see https://github.com/go-flutter-desktop/go-flutter/tree/640dcea647f47ceca0e3fb67166d2ea124a09f24
• All API’s going to future flutter versions are deprecated but still functional
  • ANY currently working features will not break.
  • Go here for more information on flutter API versioning and compatibility policy
    • https://flutter.dev/docs/resources/compatibility

Getting Started

• Install go 1.13+

  • instructions can be found at https://golang.org/doc/install

• Install flutter

  • instructions can be found at https://flutter.dev/docs/get-started/install

• Install go-flutter

  • install hover (flutters unofficial go client)
    • GO111MODULE=on go get -u -a github.com/go-flutter-desktop/hover

• Install dependencies

  • mac - have xcode installed
  • linux - install the following packages ‘libgl1-mesa-dev xorg-dev’
  • windows - install gflw for windows https://www.glfw.org/docs/latest/compile.html#compile_deps

• Enable desktop builds

  flutter config --enable-macos-desktop
  flutter config --enable-linux-desktop
  flutter config --enable-windows-desktop
  
  

Go-Flutter Tooling

Flutter

Flutter provides a CLI tool to build and package mobile & web applications.

List of commonly used commands:

# create your flutter app
$ flutter create golang_flutter_demo

# run your flutter app (android/ios)
$ flutter run

# build your bundled flutter app (android/ios)
# stores builds in golang_flutter_demo/build/app/outputs
$ flutter build apk
$ flutter build ios

Hover

Hover is the CLI tool that implements basic running, building and packaging a go-flutter application.

The options below match those provided by flutter:

# add desktop support to your flutter app
$ hover init

# run your golang flutter app (in native env)
$ hover run

# build your bundled go-flutter app
# stores builds in golang_flutter_demo/go/build/outputs
$ hover build linux
$ hover build macos
$ hover build windows

“Plugins”

What is a “plugin” ?

• It sounds fancy, but it’s just an interface between go & dart.

What are these plugins you speak of?

https://github.com/go-flutter-desktop/examples/tree/master/plugin_tutorial/go-plugin-example/complex

Go Mobile

Will this bring all of the cool features go offers to mobile?

Demo

• Go to golang_flutter_demo directory
• Run and build the app
  • hover run

Download Details:

Author: kjcodeacct

GitHub: https://github.com/kjcodeacct/golang_flutter_demo

#flutter #dart #mobile-apps