Add adaptive Checkbox and CheckboxListTile (#123132)

Add adaptive Checkbox and CheckboxListTile

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

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/widgets.dart';
+import 'package:flutter/cupertino.dart';
 
 import 'checkbox_theme.dart';
 import 'color_scheme.dart';
@@ -18,6 +18,8 @@ import 'toggleable.dart';
 // bool _throwShotAway = false;
 // late StateSetter setState;
 
+enum _CheckboxType { material, adaptive }
+
 /// A Material Design checkbox.
 ///
 /// The checkbox itself does not maintain any state. Instead, when the state of
@@ -88,7 +90,47 @@ class Checkbox extends StatefulWidget {
     this.shape,
     this.side,
     this.isError = false,
-  }) : assert(tristate || value != null);
+  }) : _checkboxType = _CheckboxType.material,
+       assert(tristate || value != null);
+
+  /// Creates an adaptive [Checkbox] based on whether the target platform is iOS
+  /// or macOS, following Material design's
+  /// [Cross-platform guidelines](https://material.io/design/platform-guidance/cross-platform-adaptation.html).
+  ///
+  /// On iOS and macOS, this constructor creates a [CupertinoCheckbox], which has
+  /// matching functionality and presentation as Material checkboxes, and are the
+  /// graphics expected on iOS. On other platforms, this creates a Material
+  /// design [Checkbox].
+  ///
+  /// If a [CupertinoCheckbox] is created, the following parameters are ignored:
+  /// [mouseCursor], [hoverColor], [overlayColor], [splashRadius],
+  /// [materialTapTargetSize], [visualDensity], [isError]. However, [shape] and
+  /// [side] will still affect the [CupertinoCheckbox] and should be handled if
+  /// native fidelity is important.
+  ///
+  /// The target platform is based on the current [Theme]: [ThemeData.platform].
+  const Checkbox.adaptive({
+    super.key,
+    required this.value,
+    this.tristate = false,
+    required this.onChanged,
+    this.mouseCursor,
+    this.activeColor,
+    this.fillColor,
+    this.checkColor,
+    this.focusColor,
+    this.hoverColor,
+    this.overlayColor,
+    this.splashRadius,
+    this.materialTapTargetSize,
+    this.visualDensity,
+    this.focusNode,
+    this.autofocus = false,
+    this.shape,
+    this.side,
+    this.isError = false,
+  }) : _checkboxType = _CheckboxType.adaptive,
+       assert(tristate || value != null);
 
   /// Whether this checkbox is checked.
   ///
@@ -347,6 +389,8 @@ class Checkbox extends StatefulWidget {
   /// The width of a checkbox widget.
   static const double width = 18.0;
 
+  final _CheckboxType _checkboxType;
+
   @override
   State<Checkbox> createState() => _CheckboxState();
 }
@@ -410,6 +454,35 @@ class _CheckboxState extends State<Checkbox> with TickerProviderStateMixin, Togg
 
   @override
   Widget build(BuildContext context) {
+    switch (widget._checkboxType) {
+      case _CheckboxType.material:
+        break;
+
+      case _CheckboxType.adaptive:
+        final ThemeData theme = Theme.of(context);
+        switch (theme.platform) {
+          case TargetPlatform.android:
+          case TargetPlatform.fuchsia:
+          case TargetPlatform.linux:
+          case TargetPlatform.windows:
+            break;
+          case TargetPlatform.iOS:
+          case TargetPlatform.macOS:
+            return CupertinoCheckbox(
+              value: value,
+              tristate: tristate,
+              onChanged: onChanged,
+              activeColor: widget.activeColor,
+              checkColor: widget.checkColor,
+              focusColor: widget.focusColor,
+              focusNode: widget.focusNode,
+              autofocus: widget.autofocus,
+              side: widget.side,
+              shape: widget.shape,
+            );
+        }
+    }
+
     assert(debugCheckHasMaterial(context));
     final CheckboxThemeData checkboxTheme = CheckboxTheme.of(context);
     final CheckboxThemeData defaults = Theme.of(context).useMaterial3

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

@@ -16,6 +16,8 @@ import 'theme_data.dart';
 // late bool? _throwShotAway;
 // void setState(VoidCallback fn) { }
 
+enum _CheckboxType { material, adaptive }
+
 /// A [ListTile] with a [Checkbox]. In other words, a checkbox with a label.
 ///
 /// The entire list tile is interactive: tapping anywhere in the tile toggles
@@ -192,7 +194,51 @@ class CheckboxListTile extends StatelessWidget {
     this.selectedTileColor,
     this.onFocusChange,
     this.enableFeedback,
-  }) : assert(tristate || value != null),
+  }) : _checkboxType = _CheckboxType.material,
+       assert(tristate || value != null),
+       assert(!isThreeLine || subtitle != null);
+
+  /// Creates a combination of a list tile and a platform adaptive checkbox.
+  ///
+  /// The checkbox uses [Checkbox.adaptive] to show a [CupertinoCheckbox] for
+  /// iOS platforms, or [Checkbox] for all others.
+  ///
+  /// All other properties are the same as [CheckboxListTile].
+  const CheckboxListTile.adaptive({
+    super.key,
+    required this.value,
+    required this.onChanged,
+    this.mouseCursor,
+    this.activeColor,
+    this.fillColor,
+    this.checkColor,
+    this.hoverColor,
+    this.overlayColor,
+    this.splashRadius,
+    this.materialTapTargetSize,
+    this.visualDensity,
+    this.focusNode,
+    this.autofocus = false,
+    this.shape,
+    this.side,
+    this.isError = false,
+    this.enabled,
+    this.tileColor,
+    this.title,
+    this.subtitle,
+    this.isThreeLine = false,
+    this.dense,
+    this.secondary,
+    this.selected = false,
+    this.controlAffinity = ListTileControlAffinity.platform,
+    this.contentPadding,
+    this.tristate = false,
+    this.checkboxShape,
+    this.selectedTileColor,
+    this.onFocusChange,
+    this.enableFeedback,
+  }) : _checkboxType = _CheckboxType.adaptive,
+       assert(tristate || value != null),
        assert(!isThreeLine || subtitle != null);
 
   /// Whether this checkbox is checked.
@@ -406,6 +452,8 @@ class CheckboxListTile extends StatelessWidget {
   /// inoperative.
   final bool? enabled;
 
+  final _CheckboxType _checkboxType;
+
   void _handleValueChange() {
     assert(onChanged != null);
     switch (value) {
@@ -420,23 +468,47 @@ class CheckboxListTile extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final Widget control = Checkbox(
-      value: value,
-      onChanged: enabled ?? true ? onChanged : null,
-      mouseCursor: mouseCursor,
-      activeColor: activeColor,
-      fillColor: fillColor,
-      checkColor: checkColor,
-      hoverColor: hoverColor,
-      overlayColor: overlayColor,
-      splashRadius: splashRadius,
-      materialTapTargetSize: materialTapTargetSize ?? MaterialTapTargetSize.shrinkWrap,
-      autofocus: autofocus,
-      tristate: tristate,
-      shape: checkboxShape,
-      side: side,
-      isError: isError,
-    );
+    final Widget control;
+
+    switch (_checkboxType) {
+      case _CheckboxType.material:
+        control = Checkbox(
+          value: value,
+          onChanged: enabled ?? true ? onChanged : null,
+          mouseCursor: mouseCursor,
+          activeColor: activeColor,
+          fillColor: fillColor,
+          checkColor: checkColor,
+          hoverColor: hoverColor,
+          overlayColor: overlayColor,
+          splashRadius: splashRadius,
+          materialTapTargetSize: materialTapTargetSize ?? MaterialTapTargetSize.shrinkWrap,
+          autofocus: autofocus,
+          tristate: tristate,
+          shape: checkboxShape,
+          side: side,
+          isError: isError,
+        );
+      case _CheckboxType.adaptive:
+        control = Checkbox.adaptive(
+          value: value,
+          onChanged: enabled ?? true ? onChanged : null,
+          mouseCursor: mouseCursor,
+          activeColor: activeColor,
+          fillColor: fillColor,
+          checkColor: checkColor,
+          hoverColor: hoverColor,
+          overlayColor: overlayColor,
+          splashRadius: splashRadius,
+          materialTapTargetSize: materialTapTargetSize ?? MaterialTapTargetSize.shrinkWrap,
+          autofocus: autofocus,
+          tristate: tristate,
+          shape: checkboxShape,
+          side: side,
+          isError: isError,
+        );
+    }
+
     Widget? leading, trailing;
     switch (controlAffinity) {
       case ListTileControlAffinity.leading:

packages/flutter/test/material/checkbox_list_tile_test.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
@@ -921,6 +922,38 @@ void main() {
     );
   });
 
+  testWidgets('CheckboxListTile.adaptive shows the correct checkbox platform widget', (WidgetTester tester) async {
+    Widget buildApp(TargetPlatform platform) {
+      return MaterialApp(
+        theme: ThemeData(platform: platform),
+        home: Material(
+          child: Center(
+            child: StatefulBuilder(builder: (BuildContext context, StateSetter setState) {
+              return CheckboxListTile.adaptive(
+                value: false,
+                onChanged: (bool? newValue) {},
+              );
+            }),
+          ),
+        ),
+      );
+    }
+
+    for (final TargetPlatform platform in <TargetPlatform>[ TargetPlatform.iOS, TargetPlatform.macOS ]) {
+      await tester.pumpWidget(buildApp(platform));
+      await tester.pumpAndSettle();
+
+      expect(find.byType(CupertinoCheckbox), findsOneWidget);
+    }
+
+    for (final TargetPlatform platform in <TargetPlatform>[ TargetPlatform.android, TargetPlatform.fuchsia, TargetPlatform.linux, TargetPlatform.windows ]) {
+      await tester.pumpWidget(buildApp(platform));
+      await tester.pumpAndSettle();
+
+      expect(find.byType(CupertinoCheckbox), findsNothing);
+    }
+  });
+
   group('feedback', () {
     late FeedbackTester feedback;
 

packages/flutter/test/material/checkbox_test.dart

@@ -4,6 +4,7 @@
 
 import 'dart:ui';
 
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
@@ -1769,6 +1770,38 @@ void main() {
         ),
     );
   });
+
+  testWidgets('Checkbox.adaptive shows the correct platform widget', (WidgetTester tester) async {
+    Widget buildApp(TargetPlatform platform) {
+      return MaterialApp(
+        theme: ThemeData(platform: platform),
+        home: Material(
+          child: Center(
+            child: StatefulBuilder(builder: (BuildContext context, StateSetter setState) {
+              return Checkbox.adaptive(
+                value: false,
+                onChanged: (bool? newValue) {},
+              );
+            }),
+          ),
+        ),
+      );
+    }
+
+    for (final TargetPlatform platform in <TargetPlatform>[ TargetPlatform.iOS, TargetPlatform.macOS ]) {
+      await tester.pumpWidget(buildApp(platform));
+      await tester.pumpAndSettle();
+
+      expect(find.byType(CupertinoCheckbox), findsOneWidget);
+    }
+
+    for (final TargetPlatform platform in <TargetPlatform>[ TargetPlatform.android, TargetPlatform.fuchsia, TargetPlatform.linux, TargetPlatform.windows ]) {
+      await tester.pumpWidget(buildApp(platform));
+      await tester.pumpAndSettle();
+
+      expect(find.byType(CupertinoCheckbox), findsNothing);
+    }
+  });
 }
 
 class _SelectedGrabMouseCursor extends MaterialStateMouseCursor {