listenable_tools 2.0.7

This project provides custom Flutter components that can be used to enhance your Flutter applications. The components include customizable builders for working with listenable and notifiable objects, [...]

# Flutter Custom Components

This project provides custom Flutter components that can be used to enhance your Flutter applications. The components include customizable builders for working with listenable and notifiable objects, a simple asynchronous state management system, and a singleton pattern implementation.

## Table of Contents

- [ListenableBuilder Customization](#listenablebuilder-customization)
  - [ListenableBuilder Classes](#listenablebuilder-classes)
  - [Usage Example](#usage-example)
- [AsyncState and AsyncController](#asyncstate-and-asynccontroller)
  - [AsyncState Classes](#asyncstate-classes)
  - [AsyncEvent Class](#asyncevent-class)
  - [AsyncController Class](#asynccontroller-class)
  - [Usage Example](#usage-example-1)
- [Singleton Pattern](#singleton-pattern)
  - [Singleton Class](#singleton-class)
  - [Usage Example](#usage-example-2)
- [NotifierBuilder](#notifierbuilder)
  - [NotifierBuilder Classes](#notifierbuilder-classes)
  - [Usage Example](#usage-example-3)

ListenableBuilder Customization

ListenableBuilder Classes

• ListenableBuilder: A customizable Flutter widget that rebuilds when a Listenable object changes.
• _ListenableBuilderState: The corresponding state class for ListenableBuilder.

Usage Example

import 'package:flutter/widgets.dart';

class MyListenable extends ChangeNotifier {
  int _counter = 0;

  int get counter => _counter;

  void increment() {
    _counter++;
    notifyListeners();
  }
}

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

  @override
  Widget build(BuildContext context) {
    
    final MyListenable myNotifier = MyListenable();
    
    return ListenableBuilder(
      listenable: myNotifier,
      builder: (context, child) {
        return Column(
          children: [
            Text('Counter: ${myNotifier.counter}'),
            ElevatedButton(
              onPressed: () => myNotifier.increment(),
              child: Text('Increment'),
            ),
          ],
        );
      },
    );
  }
}

AsyncState, AsyncEvent and AsyncController

AsyncState Classes

• InitState: Represents the initial state of an asynchronous operation.
• PendingState: Represents a state indicating that an asynchronous operation is pending.
• SuccessState<T>: Represents a state with successful data.
• FailureState<T>: Represents a state with a failed asynchronous event.

AsyncEvent Class

• AsyncEvent<T>: An abstract class representing an asynchronous event.

AsyncController Class

• AsyncController<T>: A controller for managing asynchronous states.

Usage Example

import 'package:flutter/widgets.dart';

class MyAsyncEvent extends AsyncEvent<int> {
  const MyAsyncEvent();
  @override
  Future<void> handle(AsyncEmitter<int> emit) async {
    await Future.delayed(Duration(seconds: 2));
    emit(42);
  }
}

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

  @override
  Widget build(BuildContext context) {
    
    final AsyncController<int> myController = AsyncController<int>(0, debug: true);
    
    return ControllerBuilder(
      controller: myController,
      builder: (context, data, child) {
        return Column(
          children: [
            Text('Data: $data'),
            ElevatedButton(
              onPressed: () async {
                await myController.run(const MyAsyncEvent());
              },
              child: Text('Run Async Event'),
            ),
          ],
        );
      },
    );
  }
}

Singleton Pattern

Singleton Class

• Singleton: A simple implementation of the singleton pattern.

Usage Example

// ...

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

  @override
  Widget build(BuildContext context) {
    
    final int mySingletonValue = Singleton.instance(() => 42);
    
    return Text('Singleton Value: $mySingletonValue');
  }
}

NotifierBuilder

NotifierBuilder Classes

• NotifierBuilder: A customizable Flutter widget similar to ListenableBuilder but named to reflect custom notifiers.
• _NotifierBuilderState: The corresponding state class for NotifierBuilder.

Usage Example

import 'package:flutter/widgets.dart';

class MyNotifier extends ChangeNotifier {
  bool _enabled = false;

  bool get enabled => _enabled;

  void toggle() {
    _enabled = !_enabled;
    notifyListeners();
  }
}

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


  @override
  Widget build(BuildContext context) {
    
    final MyNotifier myNotifier = MyNotifier();
    
    return NotifierBuilder(
      notifier: myNotifier,
      builder: (context, child) {
        return Column(
          children: [
            Text('Enabled: ${myNotifier.enabled}'),
            ElevatedButton(
              onPressed: () => myNotifier.toggle(),
              child: Text('Toggle'),
            ),
          ],
        );
      },
    );
  }
}