flutter/dev/a11y_assessments/lib/use_cases/navigation_drawer.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/material.dart';

import 'use_cases.dart';

class ExampleDestination {
  const ExampleDestination(this.label, this.icon, this.selectedIcon);

  final String label;
  final Widget icon;
  final Widget selectedIcon;
}

const List<ExampleDestination> destinations = <ExampleDestination>[
  ExampleDestination(
      'Messages', Icon(Icons.widgets_outlined), Icon(Icons.widgets)),
  ExampleDestination(
      'Profile', Icon(Icons.format_paint_outlined), Icon(Icons.format_paint)),
  ExampleDestination(
      'Settings', Icon(Icons.settings_outlined), Icon(Icons.settings)),
];

class NavigationDrawerUseCase extends UseCase {
  @override
  String get name => 'NavigationDrawer';

  @override
  String get route => '/navigation-drawer';

  @override
  Widget build(BuildContext context) => const NavigationDrawerExample();
}

class NavigationDrawerExample extends StatefulWidget {
  const NavigationDrawerExample({super.key});

  @override
  State<NavigationDrawerExample> createState() =>
      _NavigationDrawerExampleState();
}

class _NavigationDrawerExampleState extends State<NavigationDrawerExample> {
  final GlobalKey<ScaffoldState> scaffoldKey = GlobalKey<ScaffoldState>();

  int screenIndex = 0;
  late bool showNavigationDrawer;

  void handleScreenChanged(int selectedScreen) {
    setState(() {
      screenIndex = selectedScreen;
    });
  }

  void openDrawer() {
    scaffoldKey.currentState!.openEndDrawer();
  }

  Widget buildDrawerScaffold(BuildContext context) {
    return Scaffold(
      key: scaffoldKey,
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Semantics(headingLevel: 1, child: const Text('Navigation Drawer Demo')),
      ),
      body: SafeArea(
        bottom: false,
        top: false,
        child: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: <Widget>[
              Text('Page Index = $screenIndex'),
              ElevatedButton(
                onPressed: openDrawer,
                child: const Text('Open Drawer'),
              ),
            ],
          ),
        ),
      ),
      endDrawer: NavigationDrawer(
        onDestinationSelected: handleScreenChanged,
        selectedIndex: screenIndex,
        children: <Widget>[
          Padding(
            padding: const EdgeInsets.fromLTRB(28, 16, 16, 10),
            child: Text(
              'Header',
              style: Theme.of(context).textTheme.titleSmall,
            ),
          ),
          ...destinations.map(
            (ExampleDestination destination) {
              return NavigationDrawerDestination(
                label: Text(destination.label),
                icon: destination.icon,
                selectedIcon: destination.selectedIcon,
              );
            },
          ),
          const Padding(
            padding: EdgeInsets.fromLTRB(28, 16, 28, 10),
            child: Divider(),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return buildDrawerScaffold(context);
  }
}