Flutter Provider Scope for NotifyListeners() - The following code shows that Provider only listens on its own ChangeNotifier updates.

provider_scope_test.dart

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

void main() { runApp(MaterialApp(home: TestScreen())); }

class TestScreen extends StatelessWidget {
  ///
  /// Flutter Provider Scope for NotifyListeners()
  ///
  /// The following code shows that Provider only listens on its own ChangeNotifier updates.
  ///
  /// Flutter, Provider, Scope, NotifyListeners

  @override
  Widget build(BuildContext context) {
      return SafeArea(
        child: Scaffold(
          body: MultiProvider(
            providers: [
              ChangeNotifierProvider(
                create: (context) => MyChangeProv1(),
              ),
              ChangeNotifierProvider(
                create: (context) => MyChangeProv2(),
              ),
            ],
            child: buildScreen(),
          ),
        ),
      );
  }

  Widget buildScreen() {
    var title = "";
    title += "The enclosed code shows that Provider only listens on its own ChangeNotifiers.\n\n";
    title += "1. Clicking the second button does not call notifyListeners(), ergo, its text _WON'T_ be updated on the screen.\n\n";
    title += "2. Clicking the first button does call notifyListeners(), and its text change _IS_ reflected on the screen.\n\n";
    title += "This exercise simply points out that one Provider calling notifyListeners() does not also trigger listeners in other Providers.\n\n";
    title += "That is to say that notifyListeners() only affects its own Provider's listeners.\n\n";
    title += "Additionally, having the first button trigger a setState() also has NO effect on button 2's text, as button 2 is its own Widget with its own build().\n\n";
    title += "And being new to Flutter, feel free to comment with corrections, or any other observations you may have. I just wanted to code this out to test it for myself.";

    return Container(
      child: SingleChildScrollView(
        child: Column(
          children: [
            Container(
              child: Padding(
                padding: const EdgeInsets.all(11),
                child: Text(
                  "$title",
                  style: TextStyle(fontSize: 20),
                ),
              ),
            ),
            SizedBox(height: 11),
            MyProv1(),
            SizedBox(height: 11),
            MyProv2(),
          ],
        ),
      ),
    );
  }
}

class MyChangeProv1 extends ChangeNotifier {
  String _test1 = "Initial Text for button 1";
  String get getTest1 => _test1;
  void setTest1(String val) {
    _test1 = val;
    notifyListeners();
  }
}

class MyProv1 extends StatefulWidget {
  @override
  _MyProv1State createState() => _MyProv1State();
}

class _MyProv1State extends State<MyProv1> {
  @override
  Widget build(BuildContext ctx) {
    print("BUILDING: _MyProv1State");

    String thisState1 = Provider.of<MyChangeProv1>(ctx).getTest1;

    return Container(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Container(
            child: Text("[_MyProv1State]", style: TextStyle(fontWeight: FontWeight.bold)),
          ),
          RaisedButton(
            child: Text(thisState1),
            onPressed: () {
              Provider.of<MyChangeProv1>(ctx, listen: false).setTest1("Button 1 has NEW TEXT!");
              setState(() {
                print("setStated!");
              });
            },
          ),
        ],
      ),
    );
  }
}

class MyChangeProv2 extends ChangeNotifier {
  String _test2 = "Initial Text for button 2";
  String get getTest2 => _test2;
  void setTest2(String val) {
    _test2 = val;
    // notifyListeners();
  }
}

class MyProv2 extends StatelessWidget {
  @override
  Widget build(BuildContext ctx) {
    print("BUILDING: MyProv2");

    String thisState2 = Provider.of<MyChangeProv2>(ctx).getTest2;

    return Column(
      children: [
        Container(
          child: Text("[MyProv2]", style: TextStyle(fontWeight: FontWeight.bold)),
        ),
        RaisedButton(
          child: Text(thisState2),
          onPressed: () {
            Provider.of<MyChangeProv2>(ctx, listen: false).setTest2("Button 2 has NEW TEXT!");
          },
        )
      ],
    );
  }
}