How to Pass Inherited Widgets to Entire Material App

Question

So i have an inherited widget that looks like :

class InheritedStateWidget extends StatefulWidget {
  final Widget child;

  InheritedStateWidget({
    @required         


        

Answer 1

I restructured your top few classes slightly:

import 'package:flutter/material.dart';

void main() => runApp(InheritedStateWidget());

class InheritedStateWidget extends StatefulWidget {
  @override
  InheritedStateWidgetState createState() => InheritedStateWidgetState();
}

class InheritedStateWidgetState extends State<InheritedStateWidget> {
  String _userName;

  // Getter methods
  String get tasks => _userName;

  void changeUserName(String name) {
    setState(() {
      _userName = name;
    });
  }

  @override
  Widget build(BuildContext context) {
    return new MyInheritedWidget(
      data: this,
      child: MyApp(),
    );
  }
}

class MyInheritedWidget extends InheritedWidget {
  final InheritedStateWidgetState data;

  MyInheritedWidget({Key key, this.data, Widget child})
      : super(key: key, child: child);

  static MyInheritedWidget of(BuildContext context) =>
      context.inheritFromWidgetOfExactType(MyInheritedWidget);

  @override
  bool updateShouldNotify(MyInheritedWidget old) => true;
}

class MyApp extends StatelessWidget {
  // in MyApp and below you can refer to MyInheritedWidget.of(context).data
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'App One',
      home: new MyHomePage(),
    );
  }
}

I prefer to strengthen the interface between the State and the InheritedWidget like this, but just a suggestion...

void main() => runApp(new Controller());

class Controller extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => ControllerState();
}

typedef void VoidIntFunction(int i);

class ControllerState extends State<Controller> {
  String someString = '';

  void someFunction(int v) {
    print('function called with $v');
  }

  @override
  Widget build(BuildContext context) {
    return StateContainer(
      someString: someString,
      someFunction: someFunction,
      child: new ExampleApp(),
    );
  }
}

class StateContainer extends InheritedWidget {
  final String someString;
  final VoidIntFunction someFunction;

  const StateContainer({
    this.someString,
    this.someFunction,
    Widget child,
  }) : super(child: child);

  static StateContainer of(BuildContext context) =>
      context.inheritFromWidgetOfExactType(StateContainer);

  @override
  bool updateShouldNotify(StateContainer oldWidget) => true;
}

Any child now using the InheritedWidget just has read access to the state (someString) and has to modify it by calling methods (someFunction). There's a bit more boilerplate involved.