ente/lib/ui/home_widget.dart

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:myapp/models/photo.dart';
import 'package:myapp/photo_loader.dart';
import 'package:myapp/ui/album_list_widget.dart';
import 'package:myapp/ui/change_notifier_builder.dart';
import 'package:myapp/ui/gallery_app_bar_widget.dart';
import 'package:myapp/ui/gallery_container_widget.dart';
import 'package:provider/provider.dart';

class HomeWidget extends StatefulWidget {
  final String title;

  const HomeWidget(this.title, {Key key}) : super(key: key);

  @override
  State<StatefulWidget> createState() => _HomeWidgetState();
}

class _HomeWidgetState extends State<HomeWidget> {
  PhotoLoader get photoLoader => Provider.of<PhotoLoader>(context);
  int _selectedNavBarItem = 0;
  Set<Photo> _selectedPhotos = Set<Photo>();

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: widget.title,
      theme: ThemeData.dark(),
      home: Scaffold(
        appBar: GalleryAppBarWidget(
          widget.title,
          _selectedPhotos,
          onSelectionClear: () {
            setState(() {
              _selectedPhotos.clear();
            });
          },
        ),
        bottomNavigationBar: _buildBottomNavigationBar(),
        body: IndexedStack(
          children: <Widget>[
            GalleryContainer(
              photoSelectionChangeCallback: (Set<Photo> selectedPhotos) {
                setState(() {
                  _selectedPhotos = selectedPhotos;
                });
              },
            ),
            ChangeNotifierBuilder(
              value: photoLoader,
              builder: (_, __) {
                return AlbumListWidget(photoLoader.photos);
              },
            )
          ],
          index: _selectedNavBarItem,
        ),
      ),
    );
  }

  BottomNavigationBar _buildBottomNavigationBar() {
    return BottomNavigationBar(
      items: const <BottomNavigationBarItem>[
        BottomNavigationBarItem(
          icon: Icon(Icons.photo_filter),
          title: Text('Photos'),
        ),
        BottomNavigationBarItem(
          icon: Icon(Icons.photo_library),
          title: Text('Gallery'),
        ),
      ],
      currentIndex: _selectedNavBarItem,
      selectedItemColor: Colors.yellow[800],
      onTap: (index) {
        setState(() {
          _selectedNavBarItem = index;
        });
      },
    );
  }
}