Fix autocomplete selections (#109185)

packages/flutter/lib/src/widgets/autocomplete.dart

@@ -16,6 +16,7 @@ import 'framework.dart';
 import 'inherited_notifier.dart';
 import 'overlay.dart';
 import 'shortcuts.dart';
+import 'tap_region.dart';
 
 /// The type of the [RawAutocomplete] callback which computes the list of
 /// optional completions for the widget's field, based on the text the user has
@@ -421,13 +422,15 @@ class _RawAutocompleteState<T extends Object> extends State<RawAutocomplete<T>>
             link: _optionsLayerLink,
             showWhenUnlinked: false,
             targetAnchor: Alignment.bottomLeft,
-            child: AutocompleteHighlightedOption(
-              highlightIndexNotifier: _highlightedOptionIndex,
-              child: Builder(
-                builder: (BuildContext context) {
-                  return widget.optionsViewBuilder(context, _select, _options);
-                }
-              )
+            child: TextFieldTapRegion(
+              child: AutocompleteHighlightedOption(
+                highlightIndexNotifier: _highlightedOptionIndex,
+                child: Builder(
+                  builder: (BuildContext context) {
+                    return widget.optionsViewBuilder(context, _select, _options);
+                  }
+                )
+              ),
             ),
           );
         },
@@ -527,22 +530,24 @@ class _RawAutocompleteState<T extends Object> extends State<RawAutocomplete<T>>
 
   @override
   Widget build(BuildContext context) {
-    return Container(
-      key: _fieldKey,
-      child: Shortcuts(
-        shortcuts: _shortcuts,
-        child: Actions(
-          actions: _actionMap,
-          child: CompositedTransformTarget(
-            link: _optionsLayerLink,
-            child: widget.fieldViewBuilder == null
-              ? const SizedBox.shrink()
-              : widget.fieldViewBuilder!(
-                  context,
-                  _textEditingController,
-                  _focusNode,
-                  _onFieldSubmitted,
-                ),
+    return TextFieldTapRegion(
+      child: Container(
+        key: _fieldKey,
+        child: Shortcuts(
+          shortcuts: _shortcuts,
+          child: Actions(
+            actions: _actionMap,
+            child: CompositedTransformTarget(
+              link: _optionsLayerLink,
+              child: widget.fieldViewBuilder == null
+                ? const SizedBox.shrink()
+                : widget.fieldViewBuilder!(
+                    context,
+                    _textEditingController,
+                    _focusNode,
+                    _onFieldSubmitted,
+                  ),
+            ),
           ),
         ),
       ),

packages/flutter/test/widgets/autocomplete_test.dart

@@ -129,6 +129,76 @@ void main() {
     expect(lastOptions.elementAt(5), 'northern white rhinoceros');
   });
 
+  testWidgets('tapping on an option selects it', (WidgetTester tester) async {
+    final GlobalKey fieldKey = GlobalKey();
+    final GlobalKey optionsKey = GlobalKey();
+    late Iterable<String> lastOptions;
+    late FocusNode focusNode;
+    late TextEditingController textEditingController;
+
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Scaffold(
+          body: RawAutocomplete<String>(
+            optionsBuilder: (TextEditingValue textEditingValue) {
+              return kOptions.where((String option) {
+                return option.contains(textEditingValue.text.toLowerCase());
+              });
+            },
+            fieldViewBuilder: (BuildContext context, TextEditingController fieldTextEditingController, FocusNode fieldFocusNode, VoidCallback onFieldSubmitted) {
+              focusNode = fieldFocusNode;
+              textEditingController = fieldTextEditingController;
+              return TextField(
+                key: fieldKey,
+                focusNode: focusNode,
+                controller: textEditingController,
+              );
+            },
+            optionsViewBuilder: (BuildContext context, AutocompleteOnSelected<String> onSelected, Iterable<String> options) {
+              lastOptions = options;
+              return Material(
+                elevation: 4.0,
+                child: ListView.builder(
+                  key: optionsKey,
+                  padding: const EdgeInsets.all(8.0),
+                  itemCount: options.length,
+                  itemBuilder: (BuildContext context, int index) {
+                    final String option = options.elementAt(index);
+                    return GestureDetector(
+                      onTap: () {
+                        onSelected(option);
+                      },
+                      child: ListTile(
+                        title: Text(option),
+                      ),
+                    );
+                  },
+                ),
+              );
+            },
+          ),
+        ),
+      ),
+    );
+
+    // The field is always rendered, but the options are not unless needed.
+    expect(find.byKey(fieldKey), findsOneWidget);
+    expect(find.byKey(optionsKey), findsNothing);
+
+    // Tap on the text field to open the options.
+    await tester.tap(find.byKey(fieldKey));
+    await tester.pump();
+    expect(find.byKey(optionsKey), findsOneWidget);
+    expect(lastOptions.length, kOptions.length);
+
+    await tester.tap(find.text(kOptions[2]));
+    await tester.pump();
+
+    expect(find.byKey(optionsKey), findsNothing);
+
+    expect(textEditingController.text, equals(kOptions[2]));
+  });
+
   testWidgets('can filter and select a list of custom User options', (WidgetTester tester) async {
     final GlobalKey fieldKey = GlobalKey();
     final GlobalKey optionsKey = GlobalKey();