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@johnpryan

johnpryan/main.dart Secret

Last active Oct 14, 2020
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Declarative Navigation ex. 9 - Navigation Rail + Router + Animations
import 'package:flutter/material.dart';
void main() {
runApp(NestedRouterDemo());
}
class Book {
final String title;
final String author;
Book(this.title, this.author);
}
class NestedRouterDemo extends StatefulWidget {
@override
_NestedRouterDemoState createState() => _NestedRouterDemoState();
}
class _NestedRouterDemoState extends State<NestedRouterDemo> {
BookRouterDelegate _routerDelegate = BookRouterDelegate();
BookRouteInformationParser _routeInformationParser =
BookRouteInformationParser();
@override
Widget build(BuildContext context) {
return MaterialApp.router(
title: 'Books App',
routerDelegate: _routerDelegate,
routeInformationParser: _routeInformationParser,
);
}
}
class BooksAppState extends ChangeNotifier {
int _selectedIndex;
Book _selectedBook;
final List<Book> books = [
Book('Stranger in a Strange Land', 'Robert A. Heinlein'),
Book('Foundation', 'Isaac Asimov'),
Book('Fahrenheit 451', 'Ray Bradbury'),
];
BooksAppState() : _selectedIndex = 0;
int get selectedIndex => _selectedIndex;
set selectedIndex(int idx) {
_selectedIndex = idx;
if (_selectedIndex == 1) {
// Remove this line if you want to keep the selected book when navigating
// between "settings" and "home" which book was selected when Settings is
// tapped.
selectedBook = null;
}
notifyListeners();
}
Book get selectedBook => _selectedBook;
set selectedBook(Book book) {
_selectedBook = book;
notifyListeners();
}
int getSelectedBookById() {
if (!books.contains(_selectedBook)) return 0;
return books.indexOf(_selectedBook);
}
void setSelectedBookById(int id) {
if (id < 0 || id > books.length - 1) {
return;
}
_selectedBook = books[id];
notifyListeners();
}
}
class BookRouteInformationParser extends RouteInformationParser<BookRoutePath> {
@override
Future<BookRoutePath> parseRouteInformation(
RouteInformation routeInformation) async {
final uri = Uri.parse(routeInformation.location);
if (uri.pathSegments.isNotEmpty && uri.pathSegments.first == 'settings') {
return BooksSettingsPath();
} else {
if (uri.pathSegments.length >= 2) {
if (uri.pathSegments[0] == 'book') {
return BooksDetailsPath(int.tryParse(uri.pathSegments[1]));
}
}
return BooksListPath();
}
}
@override
RouteInformation restoreRouteInformation(BookRoutePath configuration) {
if (configuration is BooksListPath) {
return RouteInformation(location: '/home');
}
if (configuration is BooksSettingsPath) {
return RouteInformation(location: '/settings');
}
if (configuration is BooksDetailsPath) {
return RouteInformation(location: '/book/${configuration.id}');
}
return null;
}
}
class BookRouterDelegate extends RouterDelegate<BookRoutePath>
with ChangeNotifier, PopNavigatorRouterDelegateMixin<BookRoutePath> {
final GlobalKey<NavigatorState> navigatorKey;
BooksAppState appState = BooksAppState();
BookRouterDelegate() : navigatorKey = GlobalKey<NavigatorState>() {
appState.addListener(notifyListeners);
}
BookRoutePath get currentConfiguration {
if (appState.selectedIndex == 1) {
return BooksSettingsPath();
} else {
if (appState.selectedBook == null) {
return BooksListPath();
} else {
return BooksDetailsPath(appState.getSelectedBookById());
}
}
}
@override
Widget build(BuildContext context) {
return Navigator(
key: navigatorKey,
pages: [
MaterialPage(
child: AppShell(appState: appState),
),
],
onPopPage: (route, result) {
if (!route.didPop(result)) {
return false;
}
if (appState.selectedBook != null) {
appState.selectedBook = null;
}
notifyListeners();
return true;
},
);
}
@override
Future<void> setNewRoutePath(BookRoutePath path) async {
if (path is BooksListPath) {
appState.selectedIndex = 0;
appState.selectedBook = null;
} else if (path is BooksSettingsPath) {
appState.selectedIndex = 1;
} else if (path is BooksDetailsPath) {
appState.setSelectedBookById(path.id);
}
}
}
// Routes
abstract class BookRoutePath {}
class BooksListPath extends BookRoutePath {}
class BooksSettingsPath extends BookRoutePath {}
class BooksDetailsPath extends BookRoutePath {
final int id;
BooksDetailsPath(this.id);
}
// Widget that contains the AdaptiveNavigationScaffold
class AppShell extends StatefulWidget {
final BooksAppState appState;
AppShell({
@required this.appState,
});
@override
_AppShellState createState() => _AppShellState();
}
class _AppShellState extends State<AppShell> {
InnerRouterDelegate _routerDelegate;
ChildBackButtonDispatcher _backButtonDispatcher;
void initState() {
super.initState();
_routerDelegate = InnerRouterDelegate(widget.appState);
}
@override
void didUpdateWidget(covariant AppShell oldWidget) {
super.didUpdateWidget(oldWidget);
_routerDelegate.appState = widget.appState;
}
@override
void didChangeDependencies() {
super.didChangeDependencies();
// Defer back button dispatching to the child router
_backButtonDispatcher = Router.of(context)
.backButtonDispatcher
.createChildBackButtonDispatcher();
}
@override
Widget build(BuildContext context) {
var appState = widget.appState;
// Claim priority, If there are parallel sub router, you will need
// to pick which one should take priority;
_backButtonDispatcher.takePriority();
return Scaffold(
appBar: AppBar(),
body: Router(
routerDelegate: _routerDelegate,
backButtonDispatcher: _backButtonDispatcher,
),
bottomNavigationBar: BottomNavigationBar(
items: [
BottomNavigationBarItem(icon: Icon(Icons.home), label: 'Home'),
BottomNavigationBarItem(
icon: Icon(Icons.settings), label: 'Settings'),
],
currentIndex: appState.selectedIndex,
onTap: (newIndex) {
appState.selectedIndex = newIndex;
},
),
);
}
}
class InnerRouterDelegate extends RouterDelegate<BookRoutePath>
with ChangeNotifier, PopNavigatorRouterDelegateMixin<BookRoutePath> {
final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();
BooksAppState get appState => _appState;
BooksAppState _appState;
set appState(BooksAppState value) {
if (value == _appState) {
return;
}
_appState = value;
notifyListeners();
}
InnerRouterDelegate(this._appState);
@override
Widget build(BuildContext context) {
return Navigator(
key: navigatorKey,
pages: [
if (appState.selectedIndex == 0) ...[
FadeAnimationPage(
child: BooksListScreen(
books: appState.books,
onTapped: _handleBookTapped,
),
key: ValueKey('BooksListPage'),
),
if (appState.selectedBook != null)
MaterialPage(
key: ValueKey(appState.selectedBook),
child: BookDetailsScreen(book: appState.selectedBook),
),
] else
FadeAnimationPage(
child: SettingsScreen(),
key: ValueKey('SettingsPage'),
),
],
onPopPage: (route, result) {
appState.selectedBook = null;
notifyListeners();
return route.didPop(result);
},
);
}
@override
Future<void> setNewRoutePath(BookRoutePath path) async {
// This is not required for inner router delegate because it does not
// parse route
assert(false);
}
void _handleBookTapped(Book book) {
appState.selectedBook = book;
notifyListeners();
}
}
class FadeAnimationPage extends Page {
final Widget child;
FadeAnimationPage({Key key, this.child}) : super(key: key);
Route createRoute(BuildContext context) {
return PageRouteBuilder(
settings: this,
pageBuilder: (context, animation, animation2) {
var curveTween = CurveTween(curve: Curves.easeIn);
return FadeTransition(
opacity: animation.drive(curveTween),
child: child,
);
},
);
}
}
// Screens
class BooksListScreen extends StatelessWidget {
final List<Book> books;
final ValueChanged<Book> onTapped;
BooksListScreen({
@required this.books,
@required this.onTapped,
});
@override
Widget build(BuildContext context) {
return Scaffold(
body: ListView(
children: [
for (var book in books)
ListTile(
title: Text(book.title),
subtitle: Text(book.author),
onTap: () => onTapped(book),
)
],
),
);
}
}
class BookDetailsScreen extends StatelessWidget {
final Book book;
BookDetailsScreen({
@required this.book,
});
@override
Widget build(BuildContext context) {
return Scaffold(
body: Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
FlatButton(
onPressed: () {
Navigator.of(context).pop();
},
child: Text('Back'),
),
if (book != null) ...[
Text(book.title, style: Theme.of(context).textTheme.headline6),
Text(book.author, style: Theme.of(context).textTheme.subtitle1),
],
],
),
),
);
}
}
class SettingsScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: Text('Settings screen'),
),
);
}
}
@xwpony

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@xwpony xwpony commented Oct 7, 2020

I had an issue running this gist.
If url is on /settings and manually set url to /book/1, url would still stay at /settings.

Flutter (Channel dev, 1.23.0-7.0.pre, on Mac OS X 10.15.6 19G2021 x86_64, locale en-US)
Engine revision 3a73d073c8
Dart version 2.11.0 (build 2.11.0-161.0.dev)
@grinder15

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@grinder15 grinder15 commented Oct 9, 2020

Tried this example.
Url not changing when u navigate.
I can type the url and it goes to specific route but the url stays at root.

[√] Flutter (Channel beta, 1.22.1, on Microsoft Windows [Version 10.0.18363.1082], locale en-PH)
    • Flutter version 1.22.1 at C:\src\flutter
    • Framework revision f30b7f4db9 (29 hours ago), 2020-10-08 10:06:30 -0700
    • Engine revision 75bef9f6c8
    • Dart version 2.10.1


[√] Android toolchain - develop for Android devices (Android SDK version 30.0.0-rc1)
    • Android SDK at C:\Users\Katrina\AppData\Local\Android\Sdk
    • Platform android-30, build-tools 30.0.0-rc1
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)
    • All Android licenses accepted.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files (x86)\Google\Chrome\Application\chrome.exe

[√] Android Studio (version 4.0)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin version 50.0.1
    • Dart plugin version 193.7547
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)

[√] VS Code (version 1.50.0)
    • VS Code at C:\Users\Katrina\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.15.0

[√] Connected device (3 available)
    • Web Server (web) • web-server • web-javascript • Flutter Tools
    • Chrome (web)     • chrome     • web-javascript • Google Chrome 85.0.4183.121
    • Edge (web)       • edge       • web-javascript • Microsoft Edge 85.0.564.68
@sgoroshko

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@sgoroshko sgoroshko commented Oct 9, 2020

you must checkout to master branch
flutter channel master

@RedTech64

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@RedTech64 RedTech64 commented Oct 10, 2020

I'm on the master branch and I also have the problem where changing the link from settings to something like book/1 doesn't work.

@Milad-Akarie

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@Milad-Akarie Milad-Akarie commented Oct 12, 2020

try setting a path name to MaterialPage

 MaterialPage(
              name: '/book/${book_id}',
              key: ValueKey(appState.selectedBook),
              child: BookDetailsScreen(book: appState.selectedBook),
            ),
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