Flutter

Linux setup

Arch Linux has a flutter package, but to avoid conflict it’s better to follow the instructions at the flutter docs
To check if the environment is correctly configured run flutter doctor
For development, VSCode is the easiest out of the box solution.

Build for web

You need to have Chrome instaled to execute the flutter run command for the web.
A quick fix to use Chromium instead if to make a symlink.

which chromium
ln -s /path/to/chromium /usr/bin/google-chrome

Install packages

Using the Command Line

Navigate to your project’s root directory in the terminal or command prompt.
Run the following command to add the package:

flutter pub add package_name

This command will automatically add the package to your pubspec.yaml file and download it.

Manual Installation

Open your pubspec.yaml file.
Add the package under the dependencies section:

dependencies:
  flutter:
    sdk: flutter
  package_name: ^version_number

Run the following command in your terminal to fetch the package:

flutter pub get

CLI usage

Initialization

To create a new project

flutter create

Build and Run

For building:

flutter build

For running:

flutter build
flutter build -d <deviceID>

Testing

To run tests:

flutter test

To run analyze code:

flutter analyze

Config and setup

Configure Flutter settings with:

flutter config

Manage dependencies using:

flutter pub

Device management

To see a list of all devices

flutter devices

To install apps on devices:

flutter install

Troubleshooting

To check environment setup:

flutter doctor

To vie app logs:

flutter doctor

Raspberry Pi

For running on Raspberry Pi as an embedded application there is flutter-pi
flutterpi_tool build --arch=arm --cpu=generic
rsync -a --info=progress2 ./build/flutter_assets/ pi@192.168.68.230:/home/pi/app

flutter-pi app (in pi)

Android app development

To check if the setup is correctly configured you can run flutter doctor

adb may need to be run as root to connect the first time
sudo ~/Android/Sdk/platform-tools/adb reconnect

If a device with usb debugging is connected flutter run will automatically run install and run the app in it.
A tool for Mirror Android on Linux like scrcpy can be useful to run apps on a real machine with the VM feeling.

Fix CMakefile error

If you change the path of the project, by moving or changing the directory name you get the next error:

❯ flutter run
Launching lib/main.dart on Linux in debug mode...
CMake Error: The current CMakeCache.txt directory /home/miguel/dev/hr_merlin/hr_merlin_app/build/linux/x64/debug/CMakeCache.txt is different than the directory /home/miguel/dev/hr-app/hr_merlin_app/build/linux/x64/debug where CMakeCache.txt was created. This may result in binaries being created in the wrong place. If you are not sure, reedit the CMakeCache.txt
CMake Error: The source "/home/miguel/dev/hr_merlin/hr_merlin_app/linux/CMakeLists.txt" does not match the source "/home/miguel/dev/hr-app/hr_merlin_app/linux/CMakeLists.txt" used to generate cache. Re-run cmake with a different source directory.
Building Linux application...
Error: Unable to generate build files

To fix it just:

flutter clean
flutter create .

Project structure

https://codewithandrea.com/articles/flutter-project-structure/

VScode tips

https://codewithandrea.com/articles/vscode-shortcuts-extensions-settings-flutter-development/

StatelessWidget

StatefulWidget

WebSocket in Flutter