Flutter

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### Example: Add Flutter SDK to PATH in ~/.zprofile

Source: https://docs.flutter.dev/install/add-to-path.md

Example syntax for setting `PATH` in `~/.zprofile` when Flutter is located at `$HOME/develop/flutter`.

```bash
export PATH="$HOME/develop/flutter/bin:$PATH"
```

--------------------------------

### Create installation directory

Source: https://docs.flutter.dev/community/china.md

Creates and navigates into a designated local directory for the Flutter installation.

```console
$ mkdir ~/dev; cd ~/dev
```

--------------------------------

### Install Snapcraft CLI

Source: https://docs.flutter.dev/deployment/linux.md

Install the Snapcraft command-line tool using the snap package manager with classic confinement.

```console
$ sudo snap install snapcraft --classic
```

--------------------------------

### Interactive DartPad Setup for Layout Constraints

Source: https://docs.flutter.dev/ui/layout/constraints.md

Sets up an interactive widget viewer for navigating through 29 different layout constraint examples in Flutter.

```dart
import 'package:flutter/material.dart';

void main() => runApp(const HomePage());

const Color red = Colors.red;
const Color green = Colors.green;
const Color blue = Colors.blue;
const TextStyle big = TextStyle(fontSize: 30);

//////////////////////////////////////////////////

class HomePage extends StatelessWidget {
  const HomePage({super.key});

  @override
  Widget build(BuildContext context) {
    return const FlutterLayoutArticle([
      Example1(),
      Example2(),
      Example3(),
      Example4(),
      Example5(),
      Example6(),
      Example7(),
      Example8(),
      Example9(),
      Example10(),
      Example11(),
      Example12(),
      Example13(),
      Example14(),
      Example15(),
      Example16(),
      Example17(),
      Example18(),
      Example19(),
      Example20(),
      Example21(),
      Example22(),
      Example23(),
      Example24(),
      Example25(),
      Example26(),
      Example27(),
      Example28(),
      Example29(),
    ]);
  }
}

//////////////////////////////////////////////////

abstract class Example extends StatelessWidget {
  const Example({super.key});

  String get code;

  String get explanation;
}

//////////////////////////////////////////////////

class FlutterLayoutArticle extends StatefulWidget {
  const FlutterLayoutArticle(this.examples, {super.key});

  final List<Example> examples;

  @override
  State<FlutterLayoutArticle> createState() => _FlutterLayoutArticleState();
}

//////////////////////////////////////////////////

class _FlutterLayoutArticleState extends State<FlutterLayoutArticle> {
  late int count;
  late Widget example;
  late String code;
  late String explanation;

  @override
  void initState() {
    count = 1;
    code = const Example1().code;
    explanation = const Example1().explanation;

    super.initState();
  }

  @override
  void didUpdateWidget(FlutterLayoutArticle oldWidget) {
    super.didUpdateWidget(oldWidget);
    var example = widget.examples[count - 1];
    code = example.code;
    explanation = example.explanation;
  }
```

--------------------------------

### Run plugin example application

Source: https://docs.flutter.dev/packages-and-plugins/swift-package-manager/for-plugin-authors.md

Builds and runs the plugin example app to ensure functionality under the currently active dependency manager.

```sh
flutter run
```

--------------------------------

### Example absolute path entry in project.pbxproj

Source: https://docs.flutter.dev/packages-and-plugins/swift-package-manager/for-plugin-authors.md

Demonstrates an example of an absolute path entry found in project.pbxproj before updating it to a relative reference.

```text
path = /Users/username/path/to/my_plugin/ios/my_plugin; sourceTree = "<absolute>"
```

--------------------------------

### Example: Add Flutter to PATH in zsh

Source: https://docs.flutter.dev/install/add-to-path.md

Example command appending the Flutter SDK path to `~/.zshenv` when installed in `$HOME/develop/flutter`.

```console
$ echo 'export PATH="$HOME/develop/flutter/bin:$PATH"' >> ~/.zshenv
```

--------------------------------

### Run CupertinoSwitch API example

Source: https://docs.flutter.dev/ui/design/cupertino.md

Navigate to the Flutter API examples directory and run the CupertinoSwitch example using the Flutter CLI.

```console
cd path/to/flutter
cd examples/api
flutter run lib/cupertino/switch/cupertino_switch.0.dart
```

--------------------------------

### Example: Add Flutter to PATH in ksh

Source: https://docs.flutter.dev/install/add-to-path.md

Example command adding the Flutter binary path for `$HOME/develop/flutter/bin` to `~/.profile`.

```console
$ echo 'export PATH="$HOME/develop/flutter/bin:$PATH"' >> ~/.profile
```

--------------------------------

### Install LXD

Source: https://docs.flutter.dev/deployment/linux.md

Install the LXD container manager required for the snap build process.

```console
$ sudo snap install lxd
```

--------------------------------

### Navigate to plugin example app directory

Source: https://docs.flutter.dev/packages-and-plugins/swift-package-manager/for-plugin-authors.md

Changes the current working directory to the plugin's example application directory.

```sh
cd path/to/plugin/example/
```

--------------------------------

### Complete asset bundle placeholder example

Source: https://docs.flutter.dev/cookbook/images/fading-in-images.md

Complete application example rendering a network image that fades in over a local asset placeholder.

```dart
import 'package:material_ui/material_ui.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    const title = 'Fade in images';

    return MaterialApp(
      title: title,
      home: Scaffold(
        appBar: AppBar(title: const Text(title)),
        body: Center(
          child: FadeInImage.assetNetwork(
            placeholder: 'assets/loading.gif',
            image: 'https://picsum.photos/250?image=9',
          ),
        ),
      ),
    );
  }
}
```

--------------------------------

### Define layout example widgets demonstrating Flexible, Scaffold loose constraints, and tight constraints

Source: https://docs.flutter.dev/ui/layout/constraints.md

Contains definitions for interactive layout examples (Example27 through Example29). Demonstrates how Flexible allows children to be smaller than assigned space, how Scaffold applies loose constraints to its body, and how SizedBox.expand forces tight constraints.

```dart
  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        Expanded(
          child: Container(
            color: red,
            child: const Text(
              'This is a very long text that won\'t fit the line.',
              style: big,
            ),
          ),
        ),
        Expanded(
          child: Container(
            color: green,
            child: const Text('Goodbye!', style: big),
          ),
        ),
      ],
    );
  }
}

//////////////////////////////////////////////////

class Example27 extends Example {
  const Example27({super.key});

  @override
  final code =
      'Row(children:[\n'
      '   Flexible(\n'
      '       child: Container(color: red, child: Text(\'…\')))\n'
      '   Flexible(\n'
      '       child: Container(color: green, child: Text(\'Goodbye!\'))]';
  @override
  final String explanation =
      'The only difference if you use Flexible instead of Expanded, '
      'is that Flexible lets its child be SMALLER than the Flexible width, '
      'while Expanded forces its child to have the same width of the Expanded.'
      '\n\n'
      'But both Expanded and Flexible ignore their children\'s width when sizing themselves.'
      '\n\n'
      'This means that it\'s IMPOSSIBLE to expand Row children proportionally to their sizes. '
      'The Row either uses the exact child\'s width, or ignores it completely when you use Expanded or Flexible.';

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        Flexible(
          child: Container(
            color: red,
            child: const Text(
              'This is a very long text that won\'t fit the line.',
              style: big,
            ),
          ),
        ),
        Flexible(
          child: Container(
            color: green,
            child: const Text('Goodbye!', style: big),
          ),
        ),
      ],
    );
  }
}

//////////////////////////////////////////////////

class Example28 extends Example {
  const Example28({super.key});

  @override
  final code =
      'Scaffold(\n'
      '   body: Container(color: blue,\n'
      '   child: Column(\n'
      '      children: [\n'
      '         Text(\'Hello!\'),\n'
      '         Text(\'Goodbye!\')]))))';

  @override
  final String explanation =
      'The screen forces the Scaffold to be exactly the same size as the screen, '
      'so the Scaffold fills the screen.'
      '\n\n'
      'The Scaffold tells the Container that it can be any size it wants, but not bigger than the screen.'
      '\n\n'
      'When a widget tells its child that it can be smaller than a certain size, '
      'we say the widget supplies "loose" constraints to its child. More on that later.';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        color: blue,
        child: const Column(children: [Text('Hello!'), Text('Goodbye!')]),
      ),
    );
  }
}

//////////////////////////////////////////////////

class Example29 extends Example {
  const Example29({super.key});

  @override
  final code =
      'Scaffold(\n'
      '   body: Container(color: blue,\n'
      '   child: SizedBox.expand(\n'
      '      child: Column(\n'
      '         children: [\n'
      '            Text(\'Hello!\'),\n'
      '            Text(\'Goodbye!\')]))))';

  @override
  final String explanation =
      'If you want the Scaffold\'s child to be exactly the same size as the Scaffold itself, '
      'you can wrap its child with SizedBox.expand.'
      '\n\n'
      'When a widget tells its child that it must be of a certain size, '
      'we say the widget supplies "tight" constraints to its child. More on that later.';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SizedBox.expand(
        child: Container(
          color: blue,
          child: const Column(children: [Text('Hello!'), Text('Goodbye!')]),
        ),
      ),
    );
  }
}

//////////////////////////////////////////////////
```

--------------------------------

### Display localized text in AppBar with AppLocalizations

Source: https://docs.flutter.dev/ui/internationalization.md

Retrieves localized strings via AppLocalizations.of(context). The Material app must be started before calling AppLocalizations to avoid a null exception.

```dart
appBar: AppBar(
  // The [AppBar] title text should update its message
  // according to the system locale of the target platform.
  // Switching between English and Spanish locales should
  // cause this text to update.
  title: Text(AppLocalizations.of(context)!.helloWorld),
),
```

--------------------------------

### Create a sample Flutter project

Source: https://docs.flutter.dev/deployment/flavors-windows.md

Creates a new Flutter project called flavors_example and navigates into its directory.

```console
$ flutter create flavors_example
$ cd flavors_example
```

--------------------------------

### Example: Add Flutter to PATH in fish

Source: https://docs.flutter.dev/install/add-to-path.md

Example command executing `fish_add_path` for a Flutter installation located at `~/develop/flutter`.

```console
$ fish_add_path -U -p ~/develop/flutter/bin
```

--------------------------------

### Example: Add Flutter to PATH in bash

Source: https://docs.flutter.dev/install/add-to-path.md

Example command appending the Flutter path to `~/.bashrc` when Flutter is installed at `$HOME/develop/flutter`.

```console
$ echo 'export PATH="$HOME/develop/flutter/bin:$PATH"' >> ~/.bashrc
```

--------------------------------

### Open example app workspace in Xcode

Source: https://docs.flutter.dev/packages-and-plugins/swift-package-manager/for-plugin-authors.md

Run this command from the plugin root directory to open the example app's Xcode workspace. Replace ios with macos as appropriate for the target platform.

```bash
open example/ios/Runner.xcworkspace
```

--------------------------------

### Configure Xcode command-line tools

Source: https://docs.flutter.dev/platform-integration/ios/setup.md

Configures the Xcode command-line tools to use the installed Xcode version and executes the first launch setup. Replace `/Applications/Xcode.app` if Xcode is installed in a different path.

```console
$ sudo sh -c 'xcode-select -s /Applications/Xcode.app/Contents/Developer && xcodebuild -runFirstLaunch'
```

--------------------------------

### Migrate design widgets using dart fix

Source: https://docs.flutter.dev/ui/accessibility-and-internationalization/internationalization

Applies automated migrations for design widgets before starting localization setup.

```shell
$ dart fix --apply --code=migrate_design_widgets

```

--------------------------------

### Create a new Flutter application and enter directory

Source: https://docs.flutter.dev/testing/native-debugging.md

Run flutter create to generate a sample Flutter project, review the CLI output, and navigate into the newly created app directory.

```console
$ flutter create my_app
```

```console
Creating project my_app...
Resolving dependencies in my_app...
Got dependencies in my_app.
Wrote 129 files.

All done!
You can find general documentation for Flutter at: https://docs.flutter.dev/
Detailed API documentation is available at: https://api.flutter.dev/
If you prefer video documentation, consider: https://www.youtube.com/c/flutterdev

In order to run your application, type:

  $ cd my_app
  $ flutter run

Your application code is in my_app/lib/main.dart.
```

```console
$ cd my_app
```

--------------------------------

### Add flutter SDK to dependencies in pubspec.yaml

Source: https://docs.flutter.dev/tools/pubspec.md

Configures the Flutter SDK as a dependency when a project relies on Flutter SDK capabilities. Run flutter pub get after adding to install.

```yaml
dependencies:
  flutter:
    sdk: flutter
```

--------------------------------

### Initialize and configure LXD

Source: https://docs.flutter.dev/deployment/linux.md

Run the LXD initialization command to configure storage, networking, and clustering options using default prompts.

```console
$ sudo lxd init
Would you like to use LXD clustering? (yes/no) [default=no]:
Do you want to configure a new storage pool? (yes/no) [default=yes]:
Name of the new storage pool [default=default]:
Name of the storage backend to use (btrfs, dir, lvm, zfs, ceph) [default=zfs]:
Create a new ZFS pool? (yes/no) [default=yes]:
Would you like to use an existing empty disk or partition? (yes/no) [default=no]:
Size in GB of the new loop device (1GB minimum) [default=5GB]:
Would you like to connect to a MAAS server? (yes/no) [default=no]:
Would you like to create a new local network bridge? (yes/no) [default=yes]:
What should the new bridge be called? [default=lxdbr0]:
What IPv4 address should be used? (CIDR subnet notation, "auto" or "none") [default=auto]:
What IPv6 address should be used? (CIDR subnet notation, "auto" or "none") [default=auto]:
Would you like LXD to be available over the network? (yes/no) [default=no]:
Would you like stale cached images to be updated automatically? (yes/no) [default=yes]
Would you like a YAML "lxd init" preseed to be printed? (yes/no) [default=no]:
```

--------------------------------

### Example version solver conflict error output

Source: https://docs.flutter.dev/packages-and-plugins/dependency-management.md

Shows the error message printed by flutter pub get when two direct dependencies require incompatible versions of a shared transitive dependency.

```console
Because every version of package_a depends on foo ^1.0.0 and
every version of package_b depends on foo ^2.0.0,
package_a is incompatible with package_b.
So, because my_app depends on both package_a ^1.0.0
and package_b ^1.0.0, version solving failed.
```

--------------------------------

### Create a new Flutter project

Source: https://docs.flutter.dev/platform-integration/ios/app-extensions.md

Creates a new Flutter project named example_app_with_extension from the command line.

```console
$ flutter create example_app_with_extension
```

--------------------------------

### Validate web setup with flutter devices

Source: https://docs.flutter.dev/platform-integration/web/setup.md

Run flutter devices in the terminal to ensure Flutter detects the installed browser. The output lists connected devices such as Chrome (web) or Edge (web).

```console
$ flutter devices

Found 1 connected devices:
  Chrome (web)    • chrome • web-javascript • Google Chrome
```

--------------------------------

### Configure CupertinoApp starter code in main.dart

Source: https://docs.flutter.dev/learn/pathway/tutorial/advanced-ui.md

Sets up the entry point in lib/main.dart using CupertinoApp with custom brightness-aware theme data and a placeholder page scaffold.

```dart
import 'package:cupertino_ui/cupertino_ui.dart';

void main() {
  runApp(const RolodexApp());
}

class RolodexApp extends StatelessWidget {
  const RolodexApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const CupertinoApp({
      title: 'Rolodex',
      theme: CupertinoThemeData(
        barBackgroundColor: CupertinoDynamicColor.withBrightness(
          color: Color(0xFFF9F9F9),
          darkColor: Color(0xFF1D1D1D),
        ),
      ),
      home: CupertinoPageScaffold(child: Center(child: Text('Hello Rolodex!'))),
    );
  }
}

```

--------------------------------

### Dart VM service URI console output

Source: https://docs.flutter.dev/testing/native-debugging.md

Example message displayed in the console window when starting the local Windows debugger in Visual Studio, providing the URI required to attach VS Code.

```console
flutter: The Dart VM service is listening on http://127.0.0.1:62080/KPHEj2qPD1E=/
```

--------------------------------

### Create a new Flutter project

Source: https://docs.flutter.dev/deployment/flavors-ios.md

Creates a new Flutter project named flavors_example to begin setting up flavors and schemes.

```console
$ flutter create flavors_example
```

--------------------------------

### Define static Menu widget without animations

Source: https://docs.flutter.dev/cookbook/effects/staggered-menu-animation

Creates a stateful Menu widget that displays static list item titles and a 'Get Started' button in a Stack layout. Use this as the baseline layout before adding staggered animation effects.

```dart
class Menu extends StatefulWidget {
  const Menu({super.key});

  @override
  State<Menu> createState() => _MenuState();
}

class _MenuState extends State<Menu> {
  static const _menuTitles = [
    'Declarative Style',
    'Premade Widgets',
    'Stateful Hot Reload',
    'Native Performance',
    'Great Community',
  ];

  @override
  Widget build(BuildContext context) {
    return Container(
      color: Colors.white,
      child: Stack(
        fit: StackFit.expand,
        children: [_buildFlutterLogo(), _buildContent()],
      ),
    );
  }

  Widget _buildFlutterLogo() {
    // TODO: We'll implement this later.
    return Container();
  }

  Widget _buildContent() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const SizedBox(height: 16),
        ..._buildListItems(),
        const Spacer(),
        _buildGetStartedButton(),
      ],
    );
  }

  List<Widget> _buildListItems() {
    final listItems = <Widget>[];
    for (var i = 0; i < _menuTitles.length; ++i) {
      listItems.add(
        Padding(
          padding: const EdgeInsets.symmetric(horizontal: 36, vertical: 16),
          child: Text(
            _menuTitles[i],
            textAlign: TextAlign.left,
            style: const TextStyle(fontSize: 24, fontWeight: FontWeight.w500),
          ),
        ),
      );
    }
    return listItems;
  }

  Widget _buildGetStartedButton() {
    return SizedBox(
      width: double.infinity,
      child: Padding(
        padding: const EdgeInsets.all(24),
        child: ElevatedButton(
          style: ElevatedButton.styleFrom(
            shape: const StadiumBorder(),
            backgroundColor: Colors.blue,
            padding: const EdgeInsets.symmetric(horizontal: 48, vertical: 14),
          ),
          onPressed: () {},
          child: const Text(
            'Get Started',
            style: TextStyle(color: Colors.white, fontSize: 22),
          ),
        ),
      ),
    );
  }
}
```

--------------------------------

### Verify ChromeDriver installation

Source: https://docs.flutter.dev/testing/integration-tests.md

Checks the installed version of ChromeDriver to verify that installation and PATH configuration succeeded.

```console
$ chromedriver --version
ChromeDriver 124.0.6367.60 (8771130bd84f76d855ae42fbe02752b03e352f17-refs/branch-heads/6367@{#798})
```

--------------------------------

### Install CocoaPods dependencies with pod install

Source: https://docs.flutter.dev/platform-integration/ios/ios-app-clip.md

Navigates into the ios directory from the Flutter project root and installs the updated pod dependencies.

```console
cd ios
pod install
```

--------------------------------

### Configure initial main() entry point with MyApp

Source: https://docs.flutter.dev/tools/hot-reload.md

Initial application setup launching `MyApp` as the root widget. Changes downstream of `build()` reload properly, but changes to `main()` itself are not re-executed during hot reload.

```dart
import 'package:material_ui/material_ui.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return GestureDetector(onTap: () => print('tapped'));
  }
}
```

--------------------------------

### Build a release app for desktop platforms

Source: https://docs.flutter.dev/platform-integration/desktop.md

Run the appropriate command for Windows, macOS, or Linux to generate a release build.

```console
PS C:\> flutter build windows
$ flutter build macos
$ flutter build linux
```

--------------------------------

### Install Dart and Flutter plugin for Codex

Source: https://docs.flutter.dev/ai/antigravity-cli

Installs the official dart-flutter plugin into Codex.

```bash
codex plugin add dart-flutter@dart-flutter

```

--------------------------------

### Configure Flutter mirror and install SDK on Windows

Source: https://docs.flutter.dev/community/china.md

Run these PowerShell commands sequentially to set mirror environment variables, create an install directory, extract the Windows SDK zip archive, and update PATH for the current session.

```powershell
$ $env:PUB_HOSTED_URL="https://pub.flutter-io.cn"
```

```powershell
$ $env:FLUTTER_STORAGE_BASE_URL="https://storage.flutter-io.cn"
```

```powershell
$ New-Item -Path "$env:USERPROFILE\dev" -ItemType Directory; cd "$env:USERPROFILE\dev"
```

```powershell
$ Expand-Archive .\flutter_windows_3.35.5-stable.zip
```

```powershell
$ $env:PATH = $pwd.PATH + "\flutter\bin",$env:PATH -join ";"
```

--------------------------------

### Start Simulator on Xcode 26 or earlier

Source: https://docs.flutter.dev/platform-integration/ios/setup.md

Starts the Simulator application on Xcode 26 or earlier.

```console
$ open -a Simulator
```

--------------------------------

### Instantiate ThemeRepository and SharedPreferencesService in main()

Source: https://docs.flutter.dev/app-architecture/design-patterns/key-value-data.md

Create and pass the ThemeRepository and its SharedPreferencesService dependency to MainApp via constructor parameters in the application entry point.

```dart
void main() {
  // ···
  runApp(
    MainApp(
      themeRepository: ThemeRepository(SharedPreferencesService()),
      // ···
    ),
  );
}
```

--------------------------------

### Install CocoaPods dependencies

Source: https://docs.flutter.dev/deployment/macos.md

Locates Podfile directories and executes pod install for macOS native dependencies.

```bash
find . -name "Podfile" -execdir pod install \;
```

--------------------------------

### Define entry point in Jetpack Compose

Source: https://docs.flutter.dev/flutter-for/compose-devs.md

Sets up the main entry point activity using ComponentActivity and displays a Greeting composable in Jetpack Compose.

```kotlin
class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContent {
            SampleTheme {
                Scaffold(modifier = Modifier.fillMaxSize()) {
 innerPadding ->
                    Greeting(
                        name = "Android",
                        modifier = Modifier.padding(innerPadding)
                    )
                }
            }
        }
    }
}

@Composable
fun Greeting(name: String, modifier: Modifier = Modifier) {
    Text(
        text = "Hello $name!",
        modifier = modifier
    )
}
```
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