• Devcontainer pre-configured to support: Android, Linux and Web (chrome).
• Uses Windows 11 Linux GUI Support.
• Tested under Windows 11 Build 22000 following the official Linux GUI support documentation.
• To start the android emulator just do: flutter emulators --launch android-emulator
• The devcontainer creates automatically a flutter test project, after starting the emulator just do: flutter run
• To run linux version of the application run: flutter run -d linux

• Web based dart editor than can be used to practice dart language: DartPad
• Flutter widgets catalog
• Some free fonts from Google Fonts

Every sample app contains some // TODO: comment to highlight and explain every modification.

• Level 1: First basic app
• Level 2: Personal expenses app
• Level 3: Meals app
• Level 4: Shop app

Responsiveness is handling different sizes, examples: Portrait mode vs Landscape Mode, Tablet vs Desktop vs Phone ...
Adaptive is not an official terme but it means adapt the application to the platform UI guidelines, examples: Microsoft Fluent UI, iOS cupertino, Android Material Design ...

• Stateless Widget: Constructor() -> build()
• Statefil Widget:
  • Constructor() -> initState() -> build() -> dispose()
  • setState() called! -> didUpdateWidget() -> build -> dispose()

class Person {
    String name;
    int age;

    // By adding {} arguments are optional and will be named
    // @required to force an argument to be required
    // age = 30, set default value
    Person({@required String name, int age = 30}) {
        this.name = name;
        this.age = age;
    }
}

// We can use a shortcut in the previous class
class Person {
    String name;
    int age;

    Person({@required this.name, this.age = 30});
}

// To create a person
var person = new Person(name: 'Anas', age: 40);

class Person {
    String name;
    int age;

    Person({@required String name, int age = 30}) {
        this.name = name;
        this.age = age;
    }

    Person.veryOld(this.name) {
        age = 80;
    }
}

// To create a person
var person1 = new Person(name: 'Anas', age: 40);
var person2 = Person.veryOld('Mike');

Both can't change and the difference is:

• const: compiled time constant, locked at the moment when writing the code
• final: It's a runtime constant value, it can be initialized after declaration (in constructor for example), locked once initialized at runtime

dart executes synchronous code first then goes back to the futures then() functions.

Note that, then() and catchError() return a future as well so we can have (chaining): future.then().then()

Below an example:

void main() {
    var aFuture = Future(() {
        return 'Future';
    });
    print('This will be printed first.');
    aFuture
        .then((res) => print(res))
        .catchError((err) {});
    print('This will be first as well, before future');
}

we can use async await which is more readable and it's the same thing.

void main() async {
    var aFuture = Future(() {
        return 'Future';
    });
    print('This will be printed first.');
    try {
        final res = await aFuture;
        print(res);
    }
    catch(error) {}
    print('This will be first as well, before future');
}