Release 3.47 (#2879)

Minor updates for release 3.47

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I have added sample code updates to the [changelog].
- [x] I updated/added relevant documentation (doc comments with `///`).


If you need help, consider asking for advice on the #hackers-devrel
channel on [Discord].

<!-- Links -->
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/master/docs/contributing/Style-guide-for-Flutter-repo.md
[CLA]: https://cla.developers.google.com/
[Discord]:
https://github.com/flutter/flutter/blob/master/docs/contributing/Chat.md
[Contributors Guide]:
https://github.com/flutter/samples/blob/main/CONTRIBUTING.md
[changelog]: ../CHANGELOG.md

---------

Co-authored-by: Parker Lougheed <parlough@gmail.com>

cupertino_gallery/lib/widgets/action_sheet_page.dart

@@ -13,7 +13,7 @@ class ActionSheetPage extends StatelessWidget {
           onPressed: () {
             showCupertinoModalPopup<void>(
               context: context,
-              builder: (BuildContext context) => CupertinoActionSheet(
+              builder: (context) => CupertinoActionSheet(
                 title: const Text('Title'),
                 message: const Text('Message'),
                 actions: <CupertinoActionSheetAction>[

cupertino_gallery/lib/widgets/alert_dialog_page.dart

@@ -13,7 +13,7 @@ class AlertDialogPage extends StatelessWidget {
           onPressed: () {
             showCupertinoDialog<void>(
               context: context,
-              builder: (BuildContext context) => CupertinoAlertDialog(
+              builder: (context) => CupertinoAlertDialog(
                 title: const Text('Alert'),
                 content: const Text('This is a sample alert dialog.'),
                 actions: <CupertinoDialogAction>[

cupertino_gallery/lib/widgets/checkbox_page.dart

@@ -17,7 +17,7 @@ class _CheckboxPageState extends State<CheckboxPage> {
       child: Center(
         child: CupertinoCheckbox(
           value: _value,
-          onChanged: (bool? value) {
+          onChanged: (value) {
             setState(() {
               _value = value!;
             });

cupertino_gallery/lib/widgets/date_picker_page.dart

@@ -10,7 +10,7 @@ class DatePickerPage extends StatelessWidget {
       child: Center(
         child: SizedBox(
           height: 200,
-          child: CupertinoDatePicker(onDateTimeChanged: (DateTime newDate) {}),
+          child: CupertinoDatePicker(onDateTimeChanged: (newDate) {}),
         ),
       ),
     );

cupertino_gallery/lib/widgets/picker_page.dart

@@ -12,7 +12,7 @@ class PickerPage extends StatelessWidget {
           height: 200,
           child: CupertinoPicker(
             itemExtent: 32,
-            onSelectedItemChanged: (int index) {},
+            onSelectedItemChanged: (index) {},
             children: const <Widget>[Text('One'), Text('Two'), Text('Three')],
           ),
         ),

cupertino_gallery/lib/widgets/popup_surface_page.dart

@@ -15,7 +15,7 @@ class PopupSurfacePage extends StatelessWidget {
           onPressed: () {
             showCupertinoModalPopup<void>(
               context: context,
-              builder: (BuildContext context) {
+              builder: (context) {
                 return CupertinoPopupSurface(
                   child: Container(
                     color: CupertinoColors.white,

cupertino_gallery/lib/widgets/radio_page.dart

@@ -17,7 +17,7 @@ class _RadioPageState extends State<RadioPage> {
       child: Center(
         child: RadioGroup(
           groupValue: _selectedValue,
-          onChanged: (int? value) {
+          onChanged: (value) {
             setState(() {
               _selectedValue = value!;
             });

cupertino_gallery/lib/widgets/scrollbar_page.dart

@@ -13,10 +13,10 @@ class ScrollbarPage extends StatelessWidget {
         child: ListView.separated(
           controller: controller,
           itemCount: 100,
-          itemBuilder: (BuildContext context, int index) {
+          itemBuilder: (context, index) {
             return CupertinoListTile(title: Text('Item $index'));
           },
-          separatorBuilder: (BuildContext context, int index) {
+          separatorBuilder: (context, index) {
             return Container(height: 1, color: CupertinoColors.opaqueSeparator);
           },
         ),

cupertino_gallery/lib/widgets/segmented_control_page.dart

@@ -23,7 +23,7 @@ class _SegmentedControlPageState extends State<SegmentedControlPage> {
             1: Text('Two'),
             2: Text('Three'),
           },
-          onValueChanged: (int val) {
+          onValueChanged: (val) {
             setState(() {
               _selectedIndex = val;
             });

cupertino_gallery/lib/widgets/sheet_page.dart

@@ -13,20 +13,21 @@ class SheetPage extends StatelessWidget {
           onPressed: () {
             Navigator.of(context).push(
               CupertinoSheetRoute<void>(
-                builder: (BuildContext context) {
-                  return CupertinoPageScaffold(
-                    navigationBar: CupertinoNavigationBar(
-                      middle: const Text('Sheet'),
-                      trailing: GestureDetector(
-                        child: const Icon(CupertinoIcons.xmark),
-                        onTap: () {
-                          Navigator.of(context).pop();
-                        },
-                      ),
-                    ),
-                    child: const Center(child: Text('This is a sheet')),
-                  );
-                },
+                scrollableBuilder:
+                    (context, controller) {
+                      return CupertinoPageScaffold(
+                        navigationBar: CupertinoNavigationBar(
+                          middle: const Text('Sheet'),
+                          trailing: GestureDetector(
+                            child: const Icon(CupertinoIcons.xmark),
+                            onTap: () {
+                              Navigator.of(context).pop();
+                            },
+                          ),
+                        ),
+                        child: const Center(child: Text('This is a sheet')),
+                      );
+                    },
               ),
             );
           },

cupertino_gallery/lib/widgets/slider_page.dart

@@ -17,7 +17,7 @@ class _SliderPageState extends State<SliderPage> {
       child: Center(
         child: CupertinoSlider(
           value: _value,
-          onChanged: (double value) {
+          onChanged: (value) {
             setState(() {
               _value = value;
             });

cupertino_gallery/lib/widgets/sliding_segmented_control_page.dart

@@ -25,7 +25,7 @@ class _SlidingSegmentedControlPageState
             1: Text('Two'),
             2: Text('Three'),
           },
-          onValueChanged: (int? value) {
+          onValueChanged: (value) {
             setState(() {
               _groupValue = value;
             });

cupertino_gallery/lib/widgets/switch_page.dart

@@ -17,7 +17,7 @@ class _SwitchPageState extends State<SwitchPage> {
       child: Center(
         child: CupertinoSwitch(
           value: _value,
-          onChanged: (bool value) {
+          onChanged: (value) {
             setState(() {
               _value = value;
             });

cupertino_gallery/lib/widgets/time_picker_page.dart

@@ -11,7 +11,7 @@ class TimePickerPage extends StatelessWidget {
         child: SizedBox(
           height: 200,
           child: CupertinoTimerPicker(
-            onTimerDurationChanged: (Duration newDuration) {},
+            onTimerDurationChanged: (newDuration) {},
           ),
         ),
       ),