navigation_history_observer 1.1.1

navigation_history_observer: ^1.1.1 copied to clipboard

example/lib/main.dart

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

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) => MaterialApp(
        title: 'Flutter Demo',
        theme: ThemeData(
          primarySwatch: Colors.blue,
          visualDensity: VisualDensity.adaptivePlatformDensity,
        ),
        home: ExamplePage(
          pageNum: 1,
        ),
        navigatorObservers: [NavigationHistoryObserver()],
      );
}

class ExamplePage extends StatefulWidget {
  ExamplePage({Key? key, required this.pageNum}) : super(key: key);

  final int pageNum;

  @override
  _ExamplePageState createState() => _ExamplePageState();
}

class _ExamplePageState extends State<ExamplePage> {
  final NavigationHistoryObserver historyObserver = NavigationHistoryObserver();

  int historyCount = 0;
  int poppedCount = 0;

  @override
  void initState() {
    super.initState();

    historyCount = historyObserver.history.length;
    poppedCount = historyObserver.poppedRoutes.length;

    historyObserver.historyChangeStream.listen((change) => setState(() {
          historyCount = historyObserver.history.length;
          poppedCount = historyObserver.poppedRoutes.length;
        }));
  }

  @override
  Widget build(BuildContext context) => Scaffold(
        appBar: AppBar(
          title: Row(
            children: <Widget>[
              Text("Navigation example ${widget.pageNum}"),
            ],
          ),
        ),
        body: Center(
          child: Column(
            children: <Widget>[
              Text("Welcome to the navigation page!"),
              Text("History has $historyCount routes"),
              Text("There are $poppedCount popped routes"),
              Text("Last: "),
              FilledButton(
                child: Text("Navigate to a new page"),
                onPressed: () => Navigator.push(
                    context,
                    MaterialPageRoute(
                        builder: (context) =>
                            ExamplePage(pageNum: widget.pageNum + 1))),
              )
            ],
          ),
        ),
      );
}