Flutter - Change search hint text of SearchDelegate

Question

In current implementation of SearchDelegate , there is no option to change the hint text. When the query is empty, search screen is displaying "Search" in the query field as a hint text.

Hint text is currently defined on line 395 as follows:

final String searchFieldLabel = MaterialLocalizations.of(context).searchFieldLabel;

There is, however, an existing issue to this subject reported .

I wasn't able to come up with any solution for this. Do you know any workaround for the issue?

Answer 1

Currently SearchDelegate has an optional member "searchFieldLabel" to specify the label of the search field. It should look something like this:

  @override
  String get searchFieldLabel => 'custom label';

Answer 2

class SongSearch extends SearchDelegate<String> {
  SongSearch({
    String hintText = "Song Search",
  }) : super(
          searchFieldLabel: hintText,
          keyboardType: TextInputType.text,
          textInputAction: TextInputAction.search,
        );
.....

Answer 3

There is a workaround for this by creating your own DefaultMaterialLocalizations class and passing it into the MaterialApp widget:

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

class SearchApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      localizationsDelegates: [
        CustomLocalizationDelegate(),
      ],
      home: Scaffold(
        appBar: AppBar(
          title: Text('Search demo'),
        ),
        body: Center(
          child: Builder(
            builder: (context) => MaterialButton(
              child: Text('Search'),
              onPressed: () => showSearch(
                context: context,
                delegate: DummyDelegate(),
              ),
            ),
          ),
        ),
      ),
    );
  }
}

class DummyDelegate extends SearchDelegate<String> {
  @override
  List<Widget> buildActions(BuildContext context) => [];

  @override
  Widget buildLeading(BuildContext context) => IconButton(
    icon: Icon(Icons.close),
    onPressed: () => Navigator.of(context).pop(),
  );

  @override
  Widget buildResults(BuildContext context) => Text('Result');

  @override
  Widget buildSuggestions(BuildContext context) => Text('Suggestion');
}

class CustomLocalizationDelegate extends LocalizationsDelegate<MaterialLocalizations> {
  const CustomLocalizationDelegate();

  @override
  bool isSupported(Locale locale) => locale.languageCode == 'en';

  @override
  Future<MaterialLocalizations> load(Locale locale) => SynchronousFuture<MaterialLocalizations>(const CustomLocalization());

  @override
  bool shouldReload(CustomLocalizationDelegate old) => false;

  @override
  String toString() => 'CustomLocalization.delegate(en_US)';
}

class CustomLocalization extends DefaultMaterialLocalizations {
  const CustomLocalization();

  @override
  String get searchFieldLabel => "My hint text";
}

Answer 4

In current implementation of SearchDelegate , there is no option to change the hint text. When the query is empty, search screen is displaying "Search" in the query field as a hint text.

Hint text is currently defined on line 395 as follows:

final String searchFieldLabel = MaterialLocalizations.of(context).searchFieldLabel;

There is, however, an existing issue to this subject reported .

I wasn't able to come up with any solution for this. Do you know any workaround for the issue?

Answer 5

As far as the hint color is concerned, if you're still looking for a solution, HintColor won't work. Use the InputDecoration property of ThemeData like so:

inputDecorationTheme: InputDecorationTheme(hintStyle: Theme.of(context).textTheme.title.copyWith(color: Colors.white),)

Answer 6

You can just extend the source class and override its default field in your constructor to define your own value for the field?

For example:

class CustomSearch extends SearchDelegate<String> {
    CustomSearch() : super(searchFieldLabel: "My own hint");
}

Answer 7

With null-safety , you should do something like:

class MyDelegate extends SearchDelegate<String> {
  final String? hintText;
  MyDelegate({this.hintText});
  
  @override
  String? get searchFieldLabel => hintText;
  
  // Other overrides...
}

Usage:

showSearch<String>(
  context: context,
  delegate: MyDelegate(hintText: 'My hint'),
);

Answer 8

Use the "searchFieldLabel" properties to customize the placeholder for the search box and can also modify the SearchDelegate properties listed below:

SearchDelegate({
    this.searchFieldLabel,
    this.searchFieldStyle,
    this.searchFieldDecorationTheme,
    this.keyboardType,
    this.textInputAction = TextInputAction.search,
  })........ 

To illustrate:

class SearchScreen extends SearchDelegate {
 
  SearchScreen({
    String hintText = "অনুসন্ধান",
  }) : super(
          searchFieldLabel: hintText,
          keyboardType: TextInputType.text,
          textInputAction: TextInputAction.search,
          searchFieldStyle: TextStyle(
              color: Color.fromARGB(178, 255, 255, 255),
              fontWeight: FontWeight.bold),
        );
.
.
}