Referência rápida de Flutter

$ flutter doctor --android-licenses

$ flutter doctor

Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, 2.5.3, on Microsoft Windows [Version 10.0.22000.348], locale pt-BR)
[√] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
[√] Chrome - develop for the web
[√] Android Studio (version 2020.3)
[√] VS Code (version 1.62.3)
[√] Connected device (2 available)
• No issues found!

{
    "dart.lineLength": 100
}

"[dart]": {
		"editor.formatOnSave": true,
		"editor.formatOnType": true,
		"editor.rulers": [
				100
		],
		"editor.selectionHighlight": false,
		"editor.suggest.snippetsPreventQuickSuggestions": false,
		"editor.suggestSelection": "first",
		"editor.tabCompletion": "onlySnippets",
		"editor.wordBasedSuggestions": false,
		"editor.codeActionsOnSave": {
				"source.fixAll": true
		}
},

mkdir c:\dev
cd c:\dev

$ flutter create helloapp
$ cd helloapp

$ code .

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Hello App')
        ),
        body: Text('Hello World!')
      )
    );
  }
}

$ flutter run

$ dart pub add json_serializable

dependencies:
  json_serializable: ^6.0.0

dependencies:
  json_serializable: ^6.0.0

$ flutter pub get

$ flutter packages upgrade

x package is discontinued.
x packages have newer versions incompatible with dependency constraints.

$ flutter pub outdated

class Album {
  final int id;
  final String title;

  Album({
    required this.id,
    required this.title,
  });

  factory Album.fromJson(Map<String, dynamic> json) {
    return Album(
      id: json['id'],
      title: json['title'],
    );
  }
}

string json = "{\"id\":1, \"title\":"Metallica Black album"}"
Map<String, dynamic> jsonMap = jsonDecode(json);
Album album = Album.fromJson(jsonMap);

$ dart pub add json_serializable

$ dart pub add build_runner --dev
$ dart pub add json_annotation

import 'package:json_annotation/json_annotation.dart';

part 'album.g.dart';

class Album {
  final int id;
  final String title;

  Album({
    required this.id,
    required this.title,
  });

  factory UserApi.fromJson(Map<String, dynamic> json) => _$AlbumFromJson(json);
  Map<String, dynamic> toJson() => _$AlbumFromJson(this);
}

$ flutter pub run build_runner build

pub finished with exit code 78

$ flutter packages pub run build_runner build --delete-conflicting-outputs

var album = Album(1, '');
String json = jsonEncode(album.toJson());

$ flutter pub add flutter_native_splash

flutter_native_splash:
  color: "#ffffff"
  image: assets/meu-logo.png
  android: true
  ios: true

$ flutter clean; flutter pub get; flutter pub run flutter_native_splash:create

$ flutter clean && flutter pub get && flutter pub run flutter_native_splash:create

$ flutter pub add flutter_launcher_icons

dev_dependencies:
  flutter_launcher_icons: "^0.9.2"

flutter_icons:
  android: "launcher_icon"
  ios: true
  image_path: "assets/icon/icon.png"

flutter pub get
flutter pub run flutter_launcher_icons:main

$ flutter pub add http

dependencies:
  http: ^0.13.4

import 'package:http/http.dart' as http;

$ flutter pub add package_info_plus

import 'package:package_info_plus/package_info_plus.dart';

PackageInfo packageInfo = await PackageInfo.fromPlatform();

String appName = packageInfo.appName;
String packageName = packageInfo.packageName;
String version = packageInfo.version;
String buildNumber = packageInfo.buildNumber;

$ flutter pub add logger

var logger = Logger();
logger.d("Log esta funcionando!");

logger.v("Verbose log");
logger.d("Debug log");
logger.i("Info log");
logger.w("Warning log");
logger.e("Error log");
logger.wtf("What a terrible failure log");

Uma boa opção é utilizar o plugin **cached_network_image**

Página oficial do plugin:
<a href="https://pub.dev/packages/cached_network_image" target="_blank" rel="nofollow">https://pub.dev/packages/cached_network_image</a>

Adicionar o plugin:

	flutter pub add cached_network_image

Importar no widget:

	import 'package:cached_network_image/cached_network_image.dart';

Exemplos de uso:

	CachedNetworkImage(
		imageUrl: 'https://picsum.photos/id/474/200/200',
	)

	CachedNetworkImage(
		imageUrl: 'https://picsum.photos/id/474/200/200',
		width: 200.0,
		height: 200.0,
		httpHeaders: {'authorization': 'bearer xxxxxx'},
	)

$ flutter pub add url_launcher

import 'package:url_launcher/url_launcher.dart';

<intent-filter>
	<action android:name="android.intent.action.VIEW" />
	<data android:scheme="https" />
</intent-filter>

_launchURL() async {
  const url = 'https://flutter.io';
	if (!await launch(_url)) {
		throw 'Could not launch $_url';
	}
}

node --version

npm install -g firebase-tools

firebase login

firebase projects:list

cd c:\projetos\meu-app

flutter pub add firebase_core

dart pub global activate flutterfire_cli

Warning: Pub installs executables into C:\Users\educo\AppData\Local\Pub\Cache\bin, which is not on your path.
You can fix that by adding that directory to your system's "Path" environment variable.
A web search for "configure windows path" will show you how.

flutterfire --version

flutterfire configure

import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );
  runApp(MyApp());
}

flutter pub add firebase_messaging
flutter pub add flutter_local_notifications

if #available(iOS 10.0, *) {
	UNUserNotificationCenter.current().delegate = self as? UNUserNotificationCenterDelegate
}

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    GeneratedPluginRegistrant.register(with: self)
    if #available(iOS 10.0, *) {
      UNUserNotificationCenter.current().delegate = self as? UNUserNotificationCenterDelegate
    }
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

<meta-data
  android:name="com.google.firebase.messaging.default_notification_channel_id"
  android:value="high_importance_channel" />

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

Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  print('Handling a background message: ${message.messageId}');
}

class HomeScreen extends StatefulWidget {
  const HomeScreen({Key? key}) : super(key: key);

  @override
  State<StatefulWidget> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  final RefreshController _refreshController = RefreshController(initialRefresh: false);
  final CustomLogger _customLogger = Get.find<CustomLogger>();

  @override
  void initState() {
    super.initState();

    // Run code required to handle interacted messages in an async function
    // as initState() must not be async
    setupInteractedMessage();
  }

  // It is assumed that all messages contain a data field with the key 'type'
  Future<void> setupInteractedMessage() async {
    var _messagingInstance = FirebaseMessaging.instance;

    FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);

    NotificationSettings settings = await _messagingInstance.requestPermission(
      alert: true,
      badge: true,
      provisional: false,
      sound: true,
    );

    if (settings.authorizationStatus == AuthorizationStatus.authorized) {
      _customLogger.logInformation('User granted permission to notification');

      //Message when app is in foreground
      FirebaseMessaging.onMessage.listen(_handleMessage);

      // Get any messages which caused the application to open from
      // a terminated state.
      RemoteMessage? initialMessage = await _messagingInstance.getInitialMessage();

      // If the message also contains a data property with a "type" of "chat",
      // navigate to a chat screen
      if (initialMessage != null) {
        _handleMessage(initialMessage);
      }

      // Also handle any interaction when the app is in the background via a
      // Stream listener
      FirebaseMessaging.onMessageOpenedApp.listen(_handleMessage);
    } else {
      _customLogger.logInformation('User declined or has not accepted permission to notification');
    }
  }

  void _handleMessage(RemoteMessage message) {
    //RemoteNotification? notification = message.notification;
    //AndroidNotification? android = message.notification?.android;

    print('messageId: ${message.messageId}, messageType: ${message.messageType}');

    showDialog(
        context: context,
        builder: (BuildContext context) {
          return AlertDialog(
            title: Text(message.notification!.title ?? 'Notificação'),
            content: Text(message.notification!.body!),
            actions: [
              TextButton(
                child: const Text("Ok"),
                onPressed: () {
                  Navigator.of(context).pop();
                },
              )
            ],
          );
        });
  }

	@override
	Widget build(BuildContext context) {
		return Scaffold(
			appBar: AppBar(
				title: Text('Notificação'),
				brightness: Brightness.dark,
			),
			body: Text('Teste'))
	}
}

$ flutter pub add firebase_analytics

$ flutter pub add firebase_crashlytics

$ flutter pub add qr_code_scanner

<key>io.flutter.embedded_views_preview</key>
<true/>
<key>NSCameraUsageDescription</key>
<string>This app needs camera access to scan QR codes</string>

<uses-permission android:name="android.permission.CAMERA" />

Future<PermissionStatus> _getCameraPermission() async {
	var permissionStatus = await Permission.camera.status;

	if (!permissionStatus.isGranted) {
		permissionStatus = await Permission.camera.request();
	}

	return permissionStatus;
}

[ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: PlatformException(error, java.lang.IllegalStateException: Trying to create a platform view of unregistered type: net.touchcapture.qr.flutterqr/qrview

ext.kotlin_version = '1.6.10'

$ flutter pub add eventify

Future _onRefresh() async {
	//TODO: Executar atualizaçlão dos dados
}

Scaffold(
  body: RefreshIndicator(
    onRefresh: _onRefresh,
    child: SingleChildScrollView(
      physics: const AlwaysScrollableScrollPhysics(),
      child: Container(
        margin: const EdgeInsets.all(20.0),
        child: //.. body content
      ),
    ),
  ),
);

for (int i = 1; i < 10; i++) {
  strengths.add(0.1 * i);
}
strengths.forEach((strength) {
  final double ds = 0.5 - strength;
  swatch[(strength * 1000).round()] = Color.fromRGBO(
    r + ((ds < 0 ? r : (255 - r)) * ds).round(),
    g + ((ds < 0 ? g : (255 - g)) * ds).round(),
    b + ((ds < 0 ? b : (255 - b)) * ds).round(),
    1,
  );
});
return MaterialColor(color.value, swatch);   }

Text('Seu texto aqui')

Text('Seu texto aqui', style: Theme.of(context).textTheme.headline6)

Text('Seu texto aqui', style: const TextStyle(fontWeight: FontWeight.bold))

Text('Seu texto aqui', style: TextStyle(fontSize: Theme.of(context).textTheme.bodyText2!.fontSize, color: Colors.grey.shade600))

Column(
  children: [
    Text('Text 1'),
    Text('Text 2'),
    Text('Text 3'),
  ],
)

Column(
  crossAxisAlignment: CrossAxisAlignment.start,
  children: [
    Text('Text 1'),
    Text('Text 2'),
    Text('Text 3'),
  ],
)

Row(
		children: [
			Text('Text 1'),
	    Text('Text 2'),
	    Text('Text 3'),
		],
)

SingleChildScrollView(
  scrollDirection: Axis.horizontal,
  child: Row(
   children: <Widget>[
     Text('hi'),
     Text('hi'),
     Text('hi'),
   ]
  )
)

Container(
  width: double.infinity,
  height: 100,
  constraints: const BoxConstraints(maxHeight: 200),
  padding: const EdgeInsets.symmetric(vertical: 6, horizontal: 10),
  child: [Widget]
)

//Container com borda arredondada:

Container(
    margin: const EdgeInsets.only(left: 10),
    padding: const EdgeInsets.symmetric(vertical: 2, horizontal: 5),
    decoration: BoxDecoration(
      color: Colors.red.shade300,
      borderRadius: const BorderRadius.all(
        Radius.circular(8.0),
      ),
    ),
    child: const Text('Seu texto aqui', style: TextStyle(color: Colors.white)),
)

ListView(
  children: <Widget>[
      ListTile(
        title: Text('Valor', style: Theme.of(context).textTheme.headline6),
        subtitle: const Text('Título'),
      )
  ]
)

ListView.builder(
  shrinkWrap: true,
  physics: const ScrollPhysics(),
  itemCount: myItems.length,
  itemBuilder: (context, i) {
    return ListTile(
      title: Text(
        myItems[i].title,
        style: Theme.of(context).textTheme.bodyText1,
      ),
      subtitle: Text(
        myItems[i].text,
        style: Theme.of(context).textTheme.bodyText2,
      ),
      onTap: () { /* Execute action */ },
    );
  }
)

ListView.separated(
  shrinkWrap: true,
  physics: const ScrollPhysics(),
  itemCount: myItems.length,
  itemBuilder: (context, i) {
    return ListTile(
      title: Text(
        myItems[i].title,
        style: Theme.of(context).textTheme.bodyText1,
      ),
      subtitle: Text(
        myItems[i].text,
        style: Theme.of(context).textTheme.bodyText2,
      ),
      onTap: () { /* Execute action */ },
    );
  },
  separatorBuilder: (_, index) => const SizedBox(height: 5, child: Divider())),
)

ElevatedButton(
  child: const Text('SIGN IN'),
  onPressed: () {
    controller.signInClick();
  }),

TextButton(
  child: const Text('CRIAR CONTA'),
  onPressed: () { })

OutlinedButton(
    child: const Text('Click Me'),
    onPressed: () {
      debugPrint('Received click');
    },
)

OutlinedButton(
		child: const Icon(Icons.arrow_right_sharp),
		onPressed: () { }
)

Icon(Icons.person, size: 30.0, color: Colors.grey.shade400),

flutter:
  uses-material-design: true
  assets:
    - assets/images/
    - assets/icons/

Image.asset('assets/icons/excel-icon-32x32.png')

SizedBox(
  width: double.infinity,
  child: Wrap(
    spacing: 6.0,
    children: taskDetail.taskData.tags
        .map((e) => Chip(
                label: Text(
              e.tagTitle,
            )))
        .toList(),
  ),
)

showMyDialog(BuildContext context) {
	var dialog = AlertDialog(
		title: const Text('Título'),
		content: const Text('Minha mensagem'),
		actions: [
			TextButton(
				child: const Text('Cancelar'),
				onPressed: () {},
			),
			TextButton(
				child: const Text('Confirmar'),
				onPressed: () {},
			),
		],
	);

	showDialog(
		context: context,
		builder: (BuildContext context) {
			return dialog;
		},
	);
}