SearchAnchor viewOnClose (#160892)

Fixes https://github.com/flutter/flutter/issues/160891

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we expect every widget to implement].
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- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

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---------

Co-authored-by: Qun Cheng <36861262+QuncCccccc@users.noreply.github.com>

packages/flutter/lib/src/material/search_anchor.dart

@@ -146,6 +146,7 @@ class SearchAnchor extends StatefulWidget {
     this.textCapitalization,
     this.viewOnChanged,
     this.viewOnSubmitted,
+    this.viewOnClose,
     required this.builder,
     required this.suggestionsBuilder,
     this.textInputAction,
@@ -171,6 +172,7 @@ class SearchAnchor extends StatefulWidget {
     GestureTapCallback? onTap,
     ValueChanged<String>? onSubmitted,
     ValueChanged<String>? onChanged,
+    VoidCallback? onClose,
     MaterialStateProperty<double?>? barElevation,
     MaterialStateProperty<Color?>? barBackgroundColor,
     MaterialStateProperty<Color?>? barOverlayColor,
@@ -370,6 +372,9 @@ class SearchAnchor extends StatefulWidget {
   /// of the search view.
   final ValueChanged<String>? viewOnSubmitted;
 
+  /// Called when the search view is closed.
+  final VoidCallback? viewOnClose;
+
   /// Called to create a widget which can open a search view route when it is tapped.
   ///
   /// The widget returned by this builder is faded out when it is tapped.
@@ -459,6 +464,7 @@ class _SearchAnchorState extends State<SearchAnchor> {
     _route = _SearchViewRoute(
       viewOnChanged: widget.viewOnChanged,
       viewOnSubmitted: widget.viewOnSubmitted,
+      viewOnClose: widget.viewOnClose,
       viewLeading: widget.viewLeading,
       viewTrailing: widget.viewTrailing,
       viewHintText: widget.viewHintText,
@@ -537,6 +543,7 @@ class _SearchViewRoute extends PopupRoute<_SearchViewRoute> {
   _SearchViewRoute({
     this.viewOnChanged,
     this.viewOnSubmitted,
+    this.viewOnClose,
     this.toggleVisibility,
     this.textDirection,
     this.viewBuilder,
@@ -568,6 +575,7 @@ class _SearchViewRoute extends PopupRoute<_SearchViewRoute> {
 
   final ValueChanged<String>? viewOnChanged;
   final ValueChanged<String>? viewOnSubmitted;
+  final VoidCallback? viewOnClose;
   final ValueGetter<bool>? toggleVisibility;
   final TextDirection? textDirection;
   final ViewBuilder? viewBuilder;
@@ -641,6 +649,7 @@ class _SearchViewRoute extends PopupRoute<_SearchViewRoute> {
     assert(anchorKey.currentContext != null);
     updateTweens(anchorKey.currentContext!);
     toggleVisibility?.call();
+    viewOnClose?.call();
     return super.didPop(result);
   }
 
@@ -1183,6 +1192,7 @@ class _SearchAnchorWithSearchBar extends SearchAnchor {
     super.textCapitalization,
     ValueChanged<String>? onChanged,
     ValueChanged<String>? onSubmitted,
+    VoidCallback? onClose,
     required super.suggestionsBuilder,
     super.textInputAction,
     super.keyboardType,
@@ -1196,6 +1206,7 @@ class _SearchAnchorWithSearchBar extends SearchAnchor {
          headerHintStyle: viewHeaderHintStyle,
          viewOnSubmitted: onSubmitted,
          viewOnChanged: onChanged,
+         viewOnClose: onClose,
          builder: (BuildContext context, SearchController controller) {
            return SearchBar(
              constraints: constraints,

packages/flutter/test/material/search_anchor_test.dart

@@ -3829,6 +3829,92 @@ void main() {
     await tester.pump();
     expect(tester.takeException(), isNull);
   });
+
+  testWidgets('SearchAnchor viewOnClose function test', (WidgetTester tester) async {
+    String name = 'silva';
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Material(
+          child: Center(
+            child: SearchAnchor(
+              viewOnClose: () {
+                name = 'Pedro';
+              },
+              builder: (BuildContext context, SearchController controller) {
+                return IconButton(
+                  icon: const Icon(Icons.search),
+                  onPressed: () {
+                    controller.openView();
+                  },
+                );
+              },
+              suggestionsBuilder: (BuildContext context, SearchController controller) {
+                return List<Widget>.generate(5, (int index) {
+                  final String item = 'item $index';
+                  return ListTile(
+                    leading: const Icon(Icons.history),
+                    title: Text(item),
+                    trailing: const Icon(Icons.chevron_right),
+                    onTap: () {},
+                  );
+                });
+              },
+            ),
+          ),
+        ),
+      ),
+    );
+
+    // Open search view
+    await tester.tap(find.byIcon(Icons.search));
+    await tester.pumpAndSettle();
+    expect(name, 'silva');
+
+    // Pop search view route
+    await tester.tap(find.backButton());
+    await tester.pumpAndSettle();
+    expect(name, 'Pedro');
+
+    // No exception.
+  });
+
+  testWidgets('SearchAnchor.bar viewOnClose function test', (WidgetTester tester) async {
+    String name = 'silva';
+
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Material(
+          child: SearchAnchor.bar(
+            onClose: () {
+              name = 'Pedro';
+            },
+            suggestionsBuilder: (BuildContext context, SearchController controller) {
+              return <Widget>[
+                ListTile(
+                  title: const Text('item 0'),
+                  onTap: () {
+                    controller.closeView('item 0');
+                  },
+                ),
+              ];
+            },
+          ),
+        ),
+      ),
+    );
+
+    // Open search view
+    await tester.tap(find.byType(SearchBar));
+    await tester.pumpAndSettle();
+    expect(name, 'silva');
+
+    // Pop search view route
+    await tester.tap(find.backButton());
+    await tester.pumpAndSettle();
+    expect(name, 'Pedro');
+
+    // No exception.
+  });
 }
 
 Future<void> checkSearchBarDefaults(