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esstein/main_example_SearchDelegate_complete.dart

Created February 20, 2020 13:00
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  1. esstein created this gist Feb 20, 2020.
    315 changes: 315 additions & 0 deletions main_example_SearchDelegate_complete.dart
    View file
    Original file line number Diff line number Diff line change
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    import 'package:flutter/material.dart';

    void main() => runApp(MyApp());

    class MyApp extends StatelessWidget {
    // This widget is the root of your application.
    @override
    Widget build(BuildContext context) {
    return MaterialApp(
    title: 'Flutter Demo',
    theme: ThemeData(
    // This is the theme of your application.
    //
    // Try running your application with "flutter run". You'll see the
    // application has a blue toolbar. Then, without quitting the app, try
    // changing the primarySwatch below to Colors.green and then invoke
    // "hot reload" (press "r" in the console where you ran "flutter run",
    // or simply save your changes to "hot reload" in a Flutter IDE).
    // Notice that the counter didn't reset back to zero; the application
    // is not restarted.
    primarySwatch: Colors.blue,
    ),
    home: SearchDemo(),
    );
    }
    }


    class SearchDemo extends StatefulWidget {
    static const String routeName = '/material/search';

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

    class _SearchDemoState extends State<SearchDemo> {
    final _SearchDemoSearchDelegate _delegate = _SearchDemoSearchDelegate();
    final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();

    int _lastIntegerSelected;

    @override
    Widget build(BuildContext context) {
    return Scaffold(
    key: _scaffoldKey,
    appBar: AppBar(
    leading: IconButton(
    tooltip: 'Navigation menu',
    icon: AnimatedIcon(
    icon: AnimatedIcons.menu_arrow,
    color: Colors.white,
    progress: _delegate.transitionAnimation,
    ),
    onPressed: () {
    _scaffoldKey.currentState.openDrawer();
    },
    ),
    title: const Text('Numbers'),
    actions: <Widget>[
    IconButton(
    tooltip: 'Search',
    icon: const Icon(Icons.search),
    onPressed: () async {
    final int selected = await showSearch<int>(
    context: context,
    delegate: _delegate,
    );
    if (selected != null && selected != _lastIntegerSelected) {
    setState(() {
    _lastIntegerSelected = selected;
    });
    }
    },
    ),
    //MaterialDemoDocumentationButton(SearchDemo.routeName),
    IconButton(
    tooltip: 'More (not implemented)',
    icon: Icon(
    Theme.of(context).platform == TargetPlatform.iOS
    ? Icons.more_horiz
    : Icons.more_vert,
    ),
    onPressed: () { },
    ),
    ],
    ),
    body: Center(
    child: Column(
    mainAxisAlignment: MainAxisAlignment.center,
    children: <Widget>[
    MergeSemantics(
    child: Column(
    mainAxisAlignment: MainAxisAlignment.center,
    children: <Widget>[
    Row(
    mainAxisAlignment: MainAxisAlignment.center,
    children: const <Widget>[
    Text('Press the '),
    Tooltip(
    message: 'search',
    child: Icon(
    Icons.search,
    size: 18.0,
    ),
    ),
    Text(' icon in the AppBar'),
    ],
    ),
    const Text('and search for an integer between 0 and 100,000.'),
    ],
    ),
    ),
    const SizedBox(height: 64.0),
    Text('Last selected integer: ${_lastIntegerSelected ?? 'NONE' }.'),
    ],
    ),
    ),
    floatingActionButton: FloatingActionButton.extended(
    tooltip: 'Back', // Tests depend on this label to exit the demo.
    onPressed: () {
    Navigator.of(context).pop();
    },
    label: const Text('Close demo'),
    icon: const Icon(Icons.close),
    ),
    drawer: Drawer(
    child: Column(
    children: <Widget>[
    const UserAccountsDrawerHeader(
    accountName: Text('Peter Widget'),
    accountEmail: Text('peter.widget@example.com'),
    currentAccountPicture: CircleAvatar(
    backgroundImage: AssetImage(
    'people/square/peter.png',
    package: 'flutter_gallery_assets',
    ),
    ),
    margin: EdgeInsets.zero,
    ),
    MediaQuery.removePadding(
    context: context,
    // DrawerHeader consumes top MediaQuery padding.
    removeTop: true,
    child: const ListTile(
    leading: Icon(Icons.payment),
    title: Text('Placeholder'),
    ),
    ),
    ],
    ),
    ),
    );
    }
    }

    class _SearchDemoSearchDelegate extends SearchDelegate<int> {
    final List<int> _data = List<int>.generate(100001, (int i) => i).reversed.toList();
    final List<int> _history = <int>[42607, 85604, 66374, 44, 174];

    @override
    Widget buildLeading(BuildContext context) {
    return IconButton(
    tooltip: 'Back',
    icon: AnimatedIcon(
    icon: AnimatedIcons.menu_arrow,
    progress: transitionAnimation,
    ),
    onPressed: () {
    close(context, null);
    },
    );
    }

    @override
    Widget buildSuggestions(BuildContext context) {

    final Iterable<int> suggestions = query.isEmpty
    ? _history
    : _data.where((int i) => '$i'.startsWith(query));

    return _SuggestionList(
    query: query,
    suggestions: suggestions.map<String>((int i) => '$i').toList(),
    onSelected: (String suggestion) {
    query = suggestion;
    showResults(context);
    },
    );
    }

    @override
    Widget buildResults(BuildContext context) {
    final int searched = int.tryParse(query);
    if (searched == null || !_data.contains(searched)) {
    return Center(
    child: Text(
    '"$query"\n is not a valid integer between 0 and 100,000.\nTry again.',
    textAlign: TextAlign.center,
    ),
    );
    }

    return ListView(
    children: <Widget>[
    _ResultCard(
    title: 'This integer',
    integer: searched,
    searchDelegate: this,
    ),
    _ResultCard(
    title: 'Next integer',
    integer: searched + 1,
    searchDelegate: this,
    ),
    _ResultCard(
    title: 'Previous integer',
    integer: searched - 1,
    searchDelegate: this,
    ),
    ],
    );
    }

    @override
    List<Widget> buildActions(BuildContext context) {
    return <Widget>[
    if (query.isEmpty)
    IconButton(
    tooltip: 'Voice Search',
    icon: const Icon(Icons.mic),
    onPressed: () {
    query = 'TODO: implement voice input';
    },
    )
    else
    IconButton(
    tooltip: 'Clear',
    icon: const Icon(Icons.clear),
    onPressed: () {
    query = '';
    showSuggestions(context);
    },
    ),
    ];
    }
    }

    class _ResultCard extends StatelessWidget {
    const _ResultCard({this.integer, this.title, this.searchDelegate});

    final int integer;
    final String title;
    final SearchDelegate<int> searchDelegate;

    @override
    Widget build(BuildContext context) {
    final ThemeData theme = Theme.of(context);
    return GestureDetector(
    onTap: () {
    searchDelegate.close(context, integer);
    },
    child: Card(
    child: Padding(
    padding: const EdgeInsets.all(8.0),
    child: Column(
    children: <Widget>[
    Text(title),
    Text(
    '$integer',
    style: theme.textTheme.headline.copyWith(fontSize: 72.0),
    ),
    ],
    ),
    ),
    ),
    );
    }
    }

    class _SuggestionList extends StatelessWidget {
    const _SuggestionList({this.suggestions, this.query, this.onSelected});

    final List<String> suggestions;
    final String query;
    final ValueChanged<String> onSelected;

    @override
    Widget build(BuildContext context) {
    final ThemeData theme = Theme.of(context);
    return ListView.builder(
    itemCount: suggestions.length,
    itemBuilder: (BuildContext context, int i) {
    final String suggestion = suggestions[i];
    return ListTile(
    leading: query.isEmpty ? const Icon(Icons.history) : const Icon(null),
    title: RichText(
    text: TextSpan(
    text: suggestion.substring(0, query.length),
    style: theme.textTheme.subhead.copyWith(fontWeight: FontWeight.bold),
    children: <TextSpan>[
    TextSpan(
    text: suggestion.substring(query.length),
    style: theme.textTheme.subhead,
    ),
    ],
    ),
    ),
    onTap: () {
    onSelected(suggestion);
    },
    );
    },
    );
    }
    }