Flutter

Installation (Archlinux)

• Install Flutter on Arch Linux

1. Install flutter

yay -S flutter

2. You then need to adjust the permissions of the binary and install folder so that we can run stuff as our user:

sudo groupadd flutterusers
sudo gpasswd -a $USER flutterusers
sudo chown -R :flutterusers /usr/lib/flutter
sudo chmod -R g+w /usr/lib/flutter
sudo chown -R :flutterusers /bin/flutter
sudo chmod -R g+w /bin/flutter

3. Android -> Install the necessary packages:

yay -S android-sdk android-sdk-platform-tools android-sdk-build-tools
yay -S android-platform

4. And also fix the permissions

sudo groupadd android-sdk
sudo gpasswd -a $USER android-sdk
sudo setfacl -R -m g:android-sdk:rwx /opt/android-sdk
sudo setfacl -d -m g:android-sdk:rwX /opt/android-sdk

5. You’ll probably also have to set up environment variables for ANDROID_SDK_ROOT and JAVA_HOME.

The Java version is under /usr/lib/jvm, in the case of version 8, it’s this:

export JAVA_HOME='/usr/lib/jvm/java-8-openjdk'

Usage

Check installation

To check if flutter is correctly installed:

flutter doctor

Run the app locally

To run the app on linux:

flutter run

to use Hot Reload while running the app, you need to focus the terminal running the app and press r.

Alternatively, use dashmon

To install it, run :

flutter pub global activate dashmon

and substitute flutter run with dashmon.

More information in the package page.

Projects

Project structure

Configuration

• pubspec.yaml is the configuration file for the app you are making.
• analysis_options.yaml is the configuration file for code analysis.

main.dart

• Every widget defines a build() method that's automatically called every time the widget's circumstances change so that the widget is always up to date.

• Every build method must return a widget or (more typically) a nested tree of widgets. In this case, the top-level widget is Scaffold. You aren't going to work with Scaffold in this codelab, but it's a helpful widget and is found in the vast majority of real-world Flutter apps.

• Having separate widgets for separate logical parts of your UI is an important way of managing complexity in Flutter.

• safe area: takes into account expanded, takes the whole space