How to dispose bloc when using Inherited Widget?

Question

I have made a simple app using bloc and InheritedWidget. Following is the code

class Bloc {

  final StreamController<bool> _changeColor = PublishSubject<bool>();

  Function(bool) get changeColour => _changeColor.sink.add;

  Stream<bool> get colour => _changeColor.stream;

  void dispose(){
    _changeColor.close();
  }

}


class Provider extends InheritedWidget {

  final bloc = Bloc();
  Provider({Key key,Widget child}): super(key: key,child: child);

  @override
  bool updateShouldNotify(InheritedWidget oldWidget) {
    return true;
  }

  static Bloc of(BuildContext context){
    return (context.inheritFromWidgetOfExactType(Provider) as Provider).bloc;
  }


void dispose(){
    bloc?.dispose();
  }
}


class _HomePageState extends State<HomePage> {

  var bloc;

  @override
  void initState() {
    super.initState();
    bloc = Provider.of(context);
  }

  @override
  Widget build(BuildContext context) {

    return Column(
      children: <Widget>[
        RaisedButton(
          onPressed: () {
            bloc.changeColour(true);
          },
          child: Text("Change colour"),
        ),
        StreamBuilder(
          builder: (context, snapshot) {

            var bool = snapshot?.data ?? false;

            return Text(
              "First text",
              style:
              TextStyle(color: bool ? Colors.red : Colors.green),
            );
          },
          stream: bloc?.colour,
        ),
      ],
    );
  }


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

}

I don't understand how to call dispose method of the bloc when using InheritedWidget. Of course I can create a global variable of bloc and avoid using InheritedWidget to dispose the bloc using the dispose method which is present in the bloc but I really want to use InheritedWidget.

Does using the PublishSubject from rxdart disposes the streamcontroller automatically, is it life cycle aware, I couldn't find anything related to this in the documentation. Is there any debugging process to make sure the streamcontroller is disposed off correctly?

Answer 1

That is not possible using Inheritedwidget. The widget is not made to handle data, but to share it.

You have to wrap your Inheritedwidget into a StatefulWidget and use the dispose of the latter