Improve handling of SearchBar suggestions + SemanticsService.get_accessibility_features (#5733)

* feat: `SemanticsService.get_accessibility_features`

* fix #2874: improve handling of `SearchBar` suggestions

* docs: add product, company, and copyright name sections in publish docs

* refactor: remove "Open Search View" button from example

* Apply suggestions from code review

Co-authored-by: Copilot <[email protected]>

---------

Co-authored-by: Copilot <[email protected]>
Co-authored-by: Feodor Fitsner <[email protected]>

Author: 3 people

packages/flet/lib/src/controls/search_bar.dart

@@ -1,3 +1,4 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
 import '../extensions/control.dart';
@@ -10,6 +11,7 @@ import '../utils/form_field.dart';
 import '../utils/numbers.dart';
 import '../utils/text.dart';
 import 'base_controls.dart';
+import 'control_widget.dart';
 
 class SearchBarControl extends StatefulWidget {
   final Control control;
@@ -90,12 +92,6 @@ class _SearchBarControlState extends State<SearchBarControl> {
         break;
       case "focus":
         _focusNode.requestFocus();
-        break;
-      case "blur":
-        // todo: test this method
-        _focusNode.unfocus(
-            disposition: UnfocusDisposition.previouslyFocusedChild);
-        break;
       default:
         throw Exception("Unknown SearchBar method: $name");
     }
@@ -136,8 +132,6 @@ class _SearchBarControlState extends State<SearchBarControl> {
 
   @override
   Widget build(BuildContext context) {
-    debugPrint("SearchAnchor build: ${widget.control.id}");
-
     var value = widget.control.getString("value", "")!;
     if (value != _controller.text) {
       WidgetsBinding.instance.addPostFrameCallback((_) {
@@ -254,9 +248,83 @@ class _SearchBarControlState extends State<SearchBarControl> {
         },
         suggestionsBuilder:
             (BuildContext context, SearchController controller) {
-          return widget.control.buildWidgets("controls");
+          return [
+            _SearchBarSuggestionsHost(control: widget.control),
+          ];
         });
 
     return LayoutControl(control: widget.control, child: anchor);
   }
 }
+
+class _SearchBarSuggestionsHost extends StatefulWidget {
+  final Control control;
+
+  const _SearchBarSuggestionsHost({required this.control});
+
+  @override
+  State<_SearchBarSuggestionsHost> createState() =>
+      _SearchBarSuggestionsHostState();
+}
+
+class _SearchBarSuggestionsHostState extends State<_SearchBarSuggestionsHost> {
+  late List<Control> _controls;
+
+  @override
+  void initState() {
+    super.initState();
+    _controls = widget.control.children("controls");
+    widget.control.addListener(_handleControlChange);
+  }
+
+  @override
+  void didUpdateWidget(covariant _SearchBarSuggestionsHost oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (oldWidget.control != widget.control) {
+      oldWidget.control.removeListener(_handleControlChange);
+      _controls = widget.control.children("controls");
+      widget.control.addListener(_handleControlChange);
+    }
+  }
+
+  @override
+  void dispose() {
+    widget.control.removeListener(_handleControlChange);
+    super.dispose();
+  }
+
+  void _handleControlChange() {
+    if (!mounted) return;
+
+    var controls = widget.control.children("controls");
+
+    // compare ids of current and next controls to avoid unnecessary rebuilds
+    var currentIds = _controls.map((c) => c.id).toList(growable: false);
+    var nextIds = controls.map((c) => c.id).toList(growable: false);
+    if (listEquals(currentIds, nextIds)) {
+      _controls = controls;
+      return;
+    }
+
+    // ids differ, update state to trigger rebuild
+    setState(() {
+      _controls = controls;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    if (_controls.isEmpty) {
+      return const SizedBox.shrink();
+    }
+
+    return Column(
+      mainAxisSize: MainAxisSize.min,
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: _controls
+          .map(
+              (child) => ControlWidget(key: ValueKey(child.id), control: child))
+          .toList(growable: false),
+    );
+  }
+}

packages/flet/lib/src/services/semantics_service.dart

@@ -23,15 +23,28 @@ class SemanticsServiceControl extends FletService {
 
   Future<dynamic> _invokeMethod(String name, dynamic args) async {
     debugPrint("SemanticsService.$name($args)");
-    var message = args["message"].toString();
     switch (name) {
       case "announce_message":
+        var message = args["message"].toString();
         return SemanticsService.announce(
             message, args["rtl"] ? TextDirection.rtl : TextDirection.ltr,
             assertiveness: control.getAssertiveness(
                 args["assertiveness"], Assertiveness.polite)!);
       case "announce_tooltip":
+        var message = args["message"].toString();
         return SemanticsService.tooltip(message);
+      case "get_accessibility_features":
+        var features = SemanticsBinding.instance.accessibilityFeatures;
+        return {
+          "accessible_navigation": features.accessibleNavigation,
+          "bold_text": features.boldText,
+          "disable_animations": features.disableAnimations,
+          "high_contrast": features.highContrast,
+          "invert_colors": features.invertColors,
+          "reduce_motion": features.reduceMotion,
+          "on_off_switch_labels": features.onOffSwitchLabels,
+          "supports_announcements": features.supportsAnnounce,
+        };
       default:
         throw Exception("Unknown SemanticsService method: $name");
     }

sdk/python/examples/controls/search_bar/basic.py

@@ -1,33 +1,47 @@
 import flet as ft
 
+colors = [
+    "Amber",
+    "Blue Grey",
+    "Brown",
+    "Deep Orange",
+    "Green",
+    "Light Blue",
+    "Orange",
+    "Red",
+]
+
 
 def main(page: ft.Page):
-    async def handle_tile_click(e: ft.Event[ft.ListTile]):
-        await anchor.close_view(e.control.title.value)
+    page.horizontal_alignment = ft.CrossAxisAlignment.CENTER
+
+    def build_tiles(items: list[str]) -> list[ft.ListTile]:
+        return [
+            ft.ListTile(
+                title=ft.Text(item),
+                data=item,
+                on_click=handle_tile_click,
+            )
+            for item in items
+        ]
 
-    async def open_click():
-        await anchor.open_view()
+    async def handle_tile_click(e: ft.Event[ft.ListTile]):
+        await anchor.close_view()
 
-    def handle_change(e: ft.Event[ft.SearchBar]):
-        print(f"handle_change e.data: {e.data}")
+    async def handle_change(e: ft.Event[ft.SearchBar]):
+        query = e.control.value.strip().lower()
+        matching = (
+            [color for color in colors if query in color.lower()] if query else colors
+        )
+        anchor.controls = build_tiles(matching)
 
     def handle_submit(e: ft.Event[ft.SearchBar]):
-        print(f"handle_submit e.data: {e.data}")
+        print(f"Submit: {e.data}")
 
     async def handle_tap(e: ft.Event[ft.SearchBar]):
-        print("handle_tap")
         await anchor.open_view()
 
     page.add(
-        ft.Row(
-            alignment=ft.MainAxisAlignment.CENTER,
-            controls=[
-                ft.OutlinedButton(
-                    content="Open Search View",
-                    on_click=open_click,
-                ),
-            ],
-        ),
         anchor := ft.SearchBar(
             view_elevation=4,
             divider_color=ft.Colors.AMBER,
@@ -36,10 +50,7 @@ async def handle_tap(e: ft.Event[ft.SearchBar]):
             on_change=handle_change,
             on_submit=handle_submit,
             on_tap=handle_tap,
-            controls=[
-                ft.ListTile(title=ft.Text(f"Color {i}"), on_click=handle_tile_click)
-                for i in range(10)
-            ],
+            controls=build_tiles(colors),
         ),
     )
 

sdk/python/examples/controls/semantics_service/accessibility_features.py

@@ -0,0 +1,33 @@
+import flet as ft
+
+
+async def main(page: ft.Page):
+    page.title = "SemanticsService - Accessibility features"
+    page.horizontal_alignment = ft.CrossAxisAlignment.CENTER
+    page.vertical_alignment = ft.MainAxisAlignment.CENTER
+
+    async def get_features() -> str:
+        features = await ft.SemanticsService().get_accessibility_features()
+        return "\n".join(
+            [
+                f"Accessible navigation: {features.accessible_navigation}",
+                f"Bold text: {features.bold_text}",
+                f"Disable animations: {features.disable_animations}",
+                f"High contrast: {features.high_contrast}",
+                f"Invert colors: {features.invert_colors}",
+                f"Reduce motion: {features.reduce_motion}",
+                f"On/off switch labels: {features.on_off_switch_labels}",
+                f"Supports announcements: {features.supports_announcements}",
+            ]
+        )
+
+    async def refresh_features(e: ft.Event[ft.Button]):
+        info.value = await get_features()
+
+    page.add(
+        info := ft.Text(await get_features()),
+        ft.Button("Refresh features", on_click=refresh_features),
+    )
+
+
+ft.run(main)

sdk/python/packages/flet/docs/controls/semanticsservice.md

@@ -1,5 +1,16 @@
 ---
 class_name: flet.SemanticsService
+examples: ../../examples/controls/semantics_service
 ---
 
-{{ class_all_options(class_name) }}
+{{ class_summary(class_name) }}
+
+## Examples
+
+### Retrieve accessibility features
+
+```python
+--8<-- "{{ examples }}/accessibility_features.py"
+```
+
+{{ class_members(class_name) }}