lifecycle 0.0.1

Lifecycle support for Flutter widgets.

lifecycle

Lifecycle support for Flutter widgets.

Supported widgets

• StatefulWidget.
• StatelessWidget(include Dialog).
• PageView and it's children.
• TabBarView and it's children.

Supported lifecycle event

enum LifecycleEvent {
  push,
  visible,
  active,
  inactive,
  invisible,
  pop,
}

Getting Started

Install

1. Depend on it

dependencies:
  lifecycle: ^0.0.1

2. Install it

flutter pub get

3. Import it

import 'package:lifecycle/lifecycle.dart';

Usage

First of all, you should register a observer in WidgetsApp/MaterialApp:

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      navigatorObservers: [defaultLifecycleObserver],
      ...
    );
  }
}

• StatefulWidget

1. Use mixin(Recommend)

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

// mixin LifecycleAware and LifecycleMixin on State
class _State extends State<MyStatefulWidget> with LifecycleAware, LifecycleMixin {
  @override
  void onLifecycleEvent(LifecycleEvent event) {
    print(event);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold();
  }
}

2. Use wrapper

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

// Wrap widget with LifecycleWrapper
class _State extends State<MyStatefulWidget> {
  @override
  Widget build(BuildContext context) {
    return LifecycleWrapper(
      onLifecycleEvent: (event) {
        print(event);
      },
      child: Scaffold(),
    );
  }
}

• StatelessWidget/Dialog

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

// Normal StatelessWidget
class MyStatelessWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return LifecycleWrapper(
      onLifecycleEvent: (event) {
        print(event);
      },
      child: Scaffold(),
    );
  }
}

// Dialog
showDialog(
  context: context,
  routeSettings: RouteSettings(name: 'dialog'),
  builder: (context) {
    return LifecycleWrapper(
      onLifecycleEvent: (event) {
        print(event);
      },
      child: Dialog(),
    );
  },
);

• PageView/TabBarView

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

class MyPageView extends StatefulWidget {
  MyPageView({Key key}) : super(key: key);

  _MyPageViewState createState() => _MyPageViewState();
}

class _MyPageViewState extends State<MyPageView> {
  PageController _pageController;

  @override
  void initState() {
    super.initState();
    _pageController = PageController();
  }

  @override
  void dispose() {
    _pageController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('MyPageView'),
      ),
      // Wrap PageView
      body: PageViewLifecycleWrapper(
        controller: _pageController,
        onLifecycleEvent: (event) { // optional.
          print('MyPageView#${event.toString()}');
        },
        child: PageView(
          controller: _pageController,
          children: [
            // Wrap child of PageView
            PageLifecycleWrapper(
              index: 0,
              wantKeepAlive: true,
              onLifecycleEvent: (event) {
                print('Page@0#${event.toString()}');
              },
              child: Container(),
            ),
            PageLifecycleWrapper(
              index: 1,
              wantKeepAlive: true,
              onLifecycleEvent: (event) {
                print('Page@1#${event.toString()}');
              },
              child: Container(),
            ),
          ],
        ),
      ),
    );
  }
}