• Taha Tesser's avatar
    Fix `SearchAnchor` triggers unnecessary suggestions builder calls (#143443) · 8363e782
    Taha Tesser authored
    fixes [`SearchAnchor` triggers extra search operations](https://github.com/flutter/flutter/issues/139880)
    
    ### Code sample
    
    <details>
    <summary>expand to view the code sample</summary> 
    
    ```dart
    import 'package:flutter/material.dart';
    
    Future<List<String>> createFuture() async {
      return List.generate(1000, (index) => "Hello World!");
    }
    
    void main() {
      runApp(const MyApp());
    }
    
    class MyApp extends StatelessWidget {
      const MyApp({super.key});
    
      @override
      Widget build(BuildContext context) {
        return const MaterialApp(
          title: 'Flutter Demo',
          home: MyHomePage(title: 'Flutter Demo Home Page'),
        );
      }
    }
    
    class MyHomePage extends StatefulWidget {
      const MyHomePage({super.key, required this.title});
    
      final String title;
    
      @override
      State<MyHomePage> createState() => _MyHomePageState();
    }
    
    class _MyHomePageState extends State<MyHomePage> {
      final SearchController controller = SearchController();
    
      @override
      Widget build(BuildContext context) {
        return Scaffold(
          appBar: AppBar(
            backgroundColor: Theme.of(context).colorScheme.inversePrimary,
            title: Text(widget.title),
          ),
          body: Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                SearchAnchor(
                  searchController: controller,
                  suggestionsBuilder: (suggestionsContext, controller) {
                    final resultFuture = createFuture();
                    return [
                      FutureBuilder(
                        future: resultFuture,
                        builder: ((context, snapshot) {
                          if (snapshot.connectionState != ConnectionState.done) {
                            return const LinearProgressIndicator();
                          }
                          final result = snapshot.data;
                          if (result == null) {
                            return const LinearProgressIndicator();
                          }
                          return ListView.builder(
                            shrinkWrap: true,
                            physics: const NeverScrollableScrollPhysics(),
                            itemCount: result.length,
                            itemBuilder: (BuildContext context, int index) {
                              final root = result[index];
                              return ListTile(
                                leading: const Icon(Icons.article),
                                title: Text(root),
                                subtitle: Text(
                                  root,
                                  overflow: TextOverflow.ellipsis,
                                  style: TextStyle(
                                    color: Theme.of(suggestionsContext)
                                        .colorScheme
                                        .onSurfaceVariant,
                                  ),
                                ),
                                onTap: () {},
                              );
                            },
                          );
                        }),
                      ),
                    ];
                  },
                  builder: (BuildContext context, SearchController controller) {
                    return IconButton(
                      onPressed: () {
                        controller.openView();
                      },
                      icon: const Icon(Icons.search),
                    );
                  },
                ),
              ],
            ),
          ),
        );
      }
    }
    
    ```
    
    </details>
    
    ### Before
    
    https://github.com/flutter/flutter/assets/48603081/69f6dfdc-9f92-4d2e-8a3e-984fce25f9e4
    
    ### After
    
    https://github.com/flutter/flutter/assets/48603081/be105e2c-51d8-4cb0-a75b-f5f41d948e5e
    8363e782
search_anchor.dart 57.6 KB