Chrome OS install

Contents

System requirements
Get the Flutter SDK
Android setup
Next step
Flutter & Chrome OS tips & tricks
- Flutter Chrome OS lint analysis

System requirements

To install and run Flutter, your development environment must meet these minimum requirements:

Operating Systems: Chrome OS (64-bit) with Linux (Beta) turned on
Disk Space: 600 MB (does not include disk space for IDE/tools).
Tools: Flutter depends on these command-line tools being available in your environment.
- bash
- curl
- git 2.x
- mkdir
- rm
- unzip
- which
- xz-utils
Shared libraries: Flutter test command depends on this library being available in your environment.
- libGLU.so.1 - provided by mesa packages such as libglu1-mesa on Ubuntu/Debian

Get the Flutter SDK

Download the following installation bundle to get the latest stable release of the Flutter SDK:

(loading…)

For other release channels, and older builds, see the SDK releases page.
In the Files app, drag-and-drop the downloaded file from “Downloads” to “Linux Files” to access Flutter from your Linux container.
Extract the file in the desired location, for example:
```
$ cd ~/development
$ tar xf ~/Downloads/flutter_linux_vX.X.X-stable.tar.xz
```
If you don’t want to install a fixed version of the installation bundle, you can skip steps 1 and 2. Instead, get the source code from the Flutter repo on GitHub with the following command:
```
$ git clone https://github.com/flutter/flutter.git
```
You can also change branches or tags as needed. For example, to get just the stable version:
```
$ git clone https://github.com/flutter/flutter.git -b stable
```
Add the flutter tool to your path:
```
$ export PATH="$PATH:`pwd`/flutter/bin"
```
This command sets your PATH variable for the current terminal window only. To permanently add Flutter to your path, see Update your path.
Optionally, pre-download development binaries:

The flutter tool downloads platform-specific development binaries as needed. For scenarios where pre-downloading these artifacts is preferable (for example, in hermetic build environments, or with intermittent network availability), iOS and Android binaries can be downloaded ahead of time by running:
```
$ flutter precache
```
For additional download options, see flutter help precache.

You are now ready to run Flutter commands!

Run flutter doctor

Run the following command to see if there are any dependencies you need to install to complete the setup (for verbose output, add the -v flag):

$ flutter doctor

This command checks your environment and displays a report to the terminal window. The Dart SDK is bundled with Flutter; it is not necessary to install Dart separately. Check the output carefully for other software you might need to install or further tasks to perform (shown in bold text).

For example:

[-] Android toolchain - develop for Android devices
    • Android SDK at /Users/obiwan/Library/Android/sdk
    ✗ Android SDK is missing command line tools; download from https://goo.gl/XxQghQ
    • Try re-installing or updating your Android SDK,
      visit https://docs.flutter.dev/setup/#android-setup for detailed instructions.

The following sections describe how to perform these tasks and finish the setup process.

Once you have installed any missing dependencies, run the flutter doctor command again to verify that you’ve set everything up correctly.

Warning: The Flutter tool may occasionally download resources from Google servers. By downloading or using the Flutter SDK you agree to the Google Terms of Service.

For example, when installed from GitHub (as opposed to from a prepackaged archive), the Flutter tool will download the Dart SDK from Google servers immediately when first run, as it is used to execute the flutter tool itself. This will also occur when Flutter is upgraded (e.g. by running the flutter upgrade command).

The flutter tool uses Google Analytics to report feature usage statistics and send crash reports. This data is used to help improve Flutter tools over time.

Flutter tool analytics are not sent on the very first run. To disable reporting, run flutter config --no-analytics. To display the current setting, use flutter config. If you opt out of analytics, an opt-out event is sent, and then no further information is sent by the Flutter tool.

Dart tools may also send usage metrics and crash reports to Google. To control the submission of these metrics, use the following options on the dart tool:

--enable-analytics: Enables anonymous analytics.
--disable-analytics: Disables anonymous analytics.

The Google Privacy Policy describes how data is handled by these services.

Update your path

You can update your PATH variable for the current session at the command line, as shown in Get the Flutter SDK. You’ll probably want to update this variable permanently, so you can run flutter commands in any terminal session.

The steps for modifying this variable permanently for all terminal sessions are machine-specific. Typically you add a line to a file that is executed whenever you open a new window. For example:

Determine the path of your clone of the Flutter SDK. You need this in Step 3.
Open (or create) the rc file for your shell. For example, Linux uses the Bash shell by default, so edit $HOME/.bashrc. If you are using a different shell, the file path and filename will be different on your machine.
Add the following line and change [PATH_OF_FLUTTER_GIT_DIRECTORY] to be the path of your clone of the Flutter git repo:
```
$ export PATH="$PATH:[PATH_OF_FLUTTER_GIT_DIRECTORY]/bin"
```
Run source $HOME/.<rc file> to refresh the current window, or open a new terminal window to automatically source the file.
Verify that the flutter/bin directory is now in your PATH by running:
```
$ echo $PATH
```
Verify that the flutter command is available by running:
```
$ which flutter
```

Note: As of Flutter’s 1.19.0 dev release, the Flutter SDK contains the dart command alongside the flutter command so that you can more easily run Dart command-line programs. Downloading the Flutter SDK also downloads the compatible version of Dart, but if you’ve downloaded the Dart SDK separately, make sure that the Flutter version of dart is first in your path, as the two versions might not be compatible. The following command tells you whether the flutter and dart commands originate from the same bin directory and are therefore compatible.

  $ which flutter dart
  /path-to-flutter-sdk/bin/flutter
  /usr/local/bin/dart

As shown above, the two commands don’t come from the same bin directory. Update your path to use commands from /path-to-flutter-sdk/bin before commands from /usr/local/bin (in this case). After updating your shell for the change to take effect, running the which command again should show that the flutter and dart commands now come from the same directory.

  $ which flutter dart
  /path-to-flutter-sdk/bin/flutter
  /path-to-flutter-sdk/bin/dart

To learn more about the dart command, run dart -h from the command line, or see the dart tool page.

Update path directly

In some cases, your distribution may not permanently acquire the path when using the above directions. When this occurs, you can change the environment variables file directly. These instructions require administrator privileges:

Determine the path of your clone of the Flutter SDK.
Locate the etc directory at the root of the system, and open the profile file with root privileges.
```
  $ sudo nano /etc/profile
```

Update the PATH string with the location of your Flutter SDK directory.

if [ "`id -u`" -eq 0 ]; then
   PATH="..."
else
   PATH="/usr/local/bin:...:[PATH_OF_FLUTTER_GIT_DIRECTORY]/bin"
fi
export PATH

End the current session or reboot your system.
Once you start a new session, verify that the flutter command is available by running:
```
$ which flutter
```

For more details on setting the path in Bash, see this StackExchange question. For information on setting the path in Z shell, see this StackOverflow question.

Android setup

Install Android Studio

Download and install Android Studio.
Start Android Studio, and go through the ‘Android Studio Setup Wizard’. This installs the latest Android SDK, Android SDK Command-line Tools, and Android SDK Build-Tools, which are required by Flutter when developing for Android.
Accept Android licenses.

$ flutter doctor --android-licenses

Set up your Android device

To prepare to run and test your Flutter app on an Android device, you need an Android device running Android 4.1 (API level 16) or higher.

Enable Developer options and USB debugging on your device. Detailed instructions are available in the Android documentation.
Using a USB cable, plug your phone into your computer. On your Chromebook, you may see a notification for “USB device detected”. Click on “Connect to Linux” If prompted on your Android device, authorize your computer to access your device.
In the terminal, run the flutter devices command to verify that Flutter recognizes your connected Android device. By default, Flutter uses the version of the Android SDK where your adb tool is based. If you want Flutter to use a different installation of the Android SDK, you must set the ANDROID_SDK_ROOT environment variable to that installation directory.

Deploy to your Chromebook

With the latest version of Chrome OS, you no longer need to put your device into developer mode to push apps to your Chrome OS device.

Enable ADB in Settings. Note that this will require you to reboot your device once.
In the Terminal, run flutter devices. If prompted, authorize access to the Android container. Verify that flutter devices lists your Chrome OS device as a recognized device.

Next step

Set up your preferred editor.

Flutter & Chrome OS tips & tricks

For the current versions of Chrome OS, only certain ports from Crostini are exposed to the rest of the environments. Here’s an example of how to launch Flutter DevTools for an Android app with ports that will work:

$ flutter pub global run devtools --port 8000
$ cd path/to/your/app
$ flutter run --observatory-port=8080

Then, navigate to http://127.0.0.1:8000/# in your Chrome browser and enter the URL to your application. The last flutter run command you just ran should output a URL similar to the format of http://127.0.0.1:8080/auth_code=/. Use this URL and select “Connect” to start the Flutter DevTools for your Android app.

Flutter Chrome OS lint analysis

The Flutter team is adding Chrome OS specific Lint Analysis checks that are available to make sure that the app that you’re building is going to work well on Chrome OS. It looks for things like required hardware in your Android Manifest that aren’t available on Chrome OS devices, permissions that imply requests for unsupported hardware, as well as other properties or code that would bring a lesser experience on these devices.

To activate these, you need to create a new analysis_options.yaml file in your project folder to include these options. (If you have an existing analysis_options.yaml file, you can update it)

include: package:flutter/analysis_options_user.yaml
analyzer:
 optional-checks:
   chrome-os-manifest-checks

To run these from the command line, use the following command:

$ flutter analyze

Sample output for this command might look like:

Analyzing ...
warning • This hardware feature is not supported on Chrome OS •
android/app/src/main/AndroidManifest.xml:4:33 • unsupported_chrome_os_hardware

This functionality is still under development, but check back for instructions on how you can make this functionality work with your Chrome OS targeted Flutter app.