Removed Stepper accentColor dependency (#77732)

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

@@ -127,46 +127,32 @@ class Step {
 /// ```dart
 /// int _index = 0;
 /// Widget build(BuildContext context) {
-///   return Container(
-///     height: 300,
-///     width: 300,
-///     child: Stepper(
+///   return Stepper(
 ///     currentStep: _index,
 ///     onStepCancel: () {
-///         if (_index <= 0) {
-///          return;
-///         }
-///         setState(() {
-///           _index--;
-///         });
+///       if (_index > 0)
+///         setState(() { _index -= 1; });
 ///     },
 ///     onStepContinue: () {
-///         if (_index >= 1) {
-///          return;
-///         }
-///         setState(() {
-///           _index++;
-///         });
+///       if (_index <= 0)
+///         setState(() { _index += 1; });
 ///     },
 ///     onStepTapped: (index) {
-///         setState(() {
-///           _index = index;
-///         });
+///       setState(() { _index = index; });
 ///     },
-///       steps: [
+///     steps: <Step>[
 ///       Step(
-///           title: Text("Step 1 title"),
+///         title: Text('Step 1 title'),
 ///         content: Container(
 ///           alignment: Alignment.centerLeft,
-///             child: Text("Content for Step 1")
+///           child: Text('Content for Step 1')
 ///         ),
 ///       ),
 ///       Step(
-///           title: Text("Step 2 title"),
-///           content: Text("Content for Step 2"),
+///         title: Text('Step 2 title'),
+///         content: Text('Content for Step 2'),
 ///       ),
 ///     ],
-///     ),
 ///   );
 /// }
 /// ```
@@ -372,11 +358,11 @@ class _StepperState extends State<Stepper> with TickerProviderStateMixin {
   }
 
   Color _circleColor(int index) {
-    final ThemeData themeData = Theme.of(context);
+    final ColorScheme colorScheme = Theme.of(context).colorScheme;
     if (!_isDark()) {
-      return widget.steps[index].isActive ? themeData.primaryColor : Colors.black38;
+      return widget.steps[index].isActive ? colorScheme.primary : colorScheme.onSurface.withOpacity(0.38);
     } else {
-      return widget.steps[index].isActive ? themeData.accentColor : themeData.backgroundColor;
+      return widget.steps[index].isActive ? colorScheme.secondary : colorScheme.background;
     }
   }
 

packages/flutter/test/material/stepper_test.dart

@@ -842,4 +842,49 @@ void main() {
       expect(listView.physics, physics);
     }
   });
+
+  testWidgets('Stepper horizontal size test', (WidgetTester tester) async {
+    // Regression test for https://github.com/flutter/flutter/pull/77732
+    Widget buildFrame({ bool isActive = true, Brightness? brightness }) {
+      return MaterialApp(
+        theme: brightness == Brightness.dark ? ThemeData.dark() : ThemeData.light(),
+        home: Scaffold(
+          body: Center(
+            child: Stepper(
+              type: StepperType.horizontal,
+              steps: <Step>[
+                Step(
+                  title: const Text('step'),
+                  content: const Text('content'),
+                  isActive: isActive,
+                ),
+              ],
+            ),
+          ),
+        ),
+      );
+    }
+
+    Color? circleFillColor() {
+      final Finder container = find.widgetWithText(AnimatedContainer, '1');
+      return (tester.widget<AnimatedContainer>(container).decoration as BoxDecoration?)?.color;
+    }
+
+    // Light theme
+    final ColorScheme light = ThemeData.light().colorScheme;
+    await tester.pumpWidget(buildFrame(isActive: true, brightness: Brightness.light));
+    expect(circleFillColor(), light.primary);
+    await tester.pumpWidget(buildFrame(isActive: false, brightness: Brightness.light));
+    await tester.pumpAndSettle();
+    expect(circleFillColor(), light.onSurface.withOpacity(0.38));
+
+    // Dark theme
+    final ColorScheme dark = ThemeData.dark().colorScheme;
+    await tester.pumpWidget(buildFrame(isActive: true, brightness: Brightness.dark));
+    await tester.pumpAndSettle();
+    expect(circleFillColor(), dark.secondary);
+    await tester.pumpWidget(buildFrame(isActive: false, brightness: Brightness.dark));
+    await tester.pumpAndSettle();
+    expect(circleFillColor(), dark.background);
+  });
 }