Fix `OutlinedButton`, `TextButton`, and `IconButton` throw exception when...

Fix `OutlinedButton`, `TextButton`, and `IconButton`  throw exception when passing only one cursor to `styleFrom` (#125204)

fixes https://github.com/flutter/flutter/issues/118071

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

@@ -207,9 +207,7 @@ class ElevatedButton extends ButtonStyleButton {
     final MaterialStateProperty<double>? elevationValue = (elevation == null)
       ? null
       : _ElevatedButtonDefaultElevation(elevation);
-    final MaterialStateProperty<MouseCursor?>? mouseCursor = (enabledMouseCursor == null && disabledMouseCursor == null)
-      ? null
-      : _ElevatedButtonDefaultMouseCursor(enabledMouseCursor, disabledMouseCursor);
+    final MaterialStateProperty<MouseCursor?> mouseCursor = _ElevatedButtonDefaultMouseCursor(enabledMouseCursor, disabledMouseCursor);
 
     return ButtonStyle(
       textStyle: MaterialStatePropertyAll<TextStyle?>(textStyle),

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

@@ -240,10 +240,7 @@ class FilledButton extends ButtonStyleButton {
     final MaterialStateProperty<Color?>? overlayColor = (foreground == null)
       ? null
       : _FilledButtonDefaultOverlay(foreground);
-    final MaterialStateProperty<MouseCursor?>? mouseCursor =
-      (enabledMouseCursor == null && disabledMouseCursor == null)
-        ? null
-        : _FilledButtonDefaultMouseCursor(enabledMouseCursor, disabledMouseCursor);
+    final MaterialStateProperty<MouseCursor?> mouseCursor = _FilledButtonDefaultMouseCursor(enabledMouseCursor, disabledMouseCursor);
 
     return ButtonStyle(
       textStyle: MaterialStatePropertyAll<TextStyle?>(textStyle),

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

@@ -638,9 +638,7 @@ class IconButton extends StatelessWidget {
     final MaterialStateProperty<Color?>? overlayColor = (foregroundColor == null && hoverColor == null && focusColor == null && highlightColor == null)
         ? null
         : _IconButtonDefaultOverlay(foregroundColor, focusColor, hoverColor, highlightColor);
-    final MaterialStateProperty<MouseCursor>? mouseCursor = (enabledMouseCursor == null && disabledMouseCursor == null)
-        ? null
-        : _IconButtonDefaultMouseCursor(enabledMouseCursor!, disabledMouseCursor!);
+    final MaterialStateProperty<MouseCursor?> mouseCursor = _IconButtonDefaultMouseCursor(enabledMouseCursor, disabledMouseCursor);
 
     return ButtonStyle(
       backgroundColor: buttonBackgroundColor,
@@ -1061,14 +1059,14 @@ class _IconButtonDefaultOverlay extends MaterialStateProperty<Color?> {
 }
 
 @immutable
-class _IconButtonDefaultMouseCursor extends MaterialStateProperty<MouseCursor> with Diagnosticable {
+class _IconButtonDefaultMouseCursor extends MaterialStateProperty<MouseCursor?> with Diagnosticable {
   _IconButtonDefaultMouseCursor(this.enabledCursor, this.disabledCursor);
 
-  final MouseCursor enabledCursor;
-  final MouseCursor disabledCursor;
+  final MouseCursor? enabledCursor;
+  final MouseCursor? disabledCursor;
 
   @override
-  MouseCursor resolve(Set<MaterialState> states) {
+  MouseCursor? resolve(Set<MaterialState> states) {
     if (states.contains(MaterialState.disabled)) {
       return disabledCursor;
     }

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

@@ -186,9 +186,7 @@ class OutlinedButton extends ButtonStyleButton {
     final MaterialStateProperty<Color?>? overlayColor = (foreground == null)
       ? null
       : _OutlinedButtonDefaultOverlay(foreground);
-    final MaterialStateProperty<MouseCursor>? mouseCursor = (enabledMouseCursor == null && disabledMouseCursor == null)
-      ? null
-      : _OutlinedButtonDefaultMouseCursor(enabledMouseCursor!, disabledMouseCursor!);
+    final MaterialStateProperty<MouseCursor?> mouseCursor = _OutlinedButtonDefaultMouseCursor(enabledMouseCursor, disabledMouseCursor);
 
     return ButtonStyle(
       textStyle: ButtonStyleButton.allOrNull<TextStyle>(textStyle),
@@ -395,14 +393,14 @@ class _OutlinedButtonDefaultOverlay extends MaterialStateProperty<Color?> with D
 }
 
 @immutable
-class _OutlinedButtonDefaultMouseCursor extends MaterialStateProperty<MouseCursor> with Diagnosticable {
+class _OutlinedButtonDefaultMouseCursor extends MaterialStateProperty<MouseCursor?> with Diagnosticable {
   _OutlinedButtonDefaultMouseCursor(this.enabledCursor, this.disabledCursor);
 
-  final MouseCursor enabledCursor;
-  final MouseCursor disabledCursor;
+  final MouseCursor? enabledCursor;
+  final MouseCursor? disabledCursor;
 
   @override
-  MouseCursor resolve(Set<MaterialState> states) {
+  MouseCursor? resolve(Set<MaterialState> states) {
     if (states.contains(MaterialState.disabled)) {
       return disabledCursor;
     }

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

@@ -200,9 +200,7 @@ class TextButton extends ButtonStyleButton {
       : disabledIconColor == null
         ? ButtonStyleButton.allOrNull<Color?>(iconColor)
         : _TextButtonDefaultIconColor(iconColor, disabledIconColor);
-    final MaterialStateProperty<MouseCursor>? mouseCursor = (enabledMouseCursor == null && disabledMouseCursor == null)
-      ? null
-      : _TextButtonDefaultMouseCursor(enabledMouseCursor!, disabledMouseCursor!);
+    final MaterialStateProperty<MouseCursor?> mouseCursor = _TextButtonDefaultMouseCursor(enabledMouseCursor, disabledMouseCursor);
 
     return ButtonStyle(
       textStyle: ButtonStyleButton.allOrNull<TextStyle>(textStyle),
@@ -456,14 +454,14 @@ class _TextButtonDefaultIconColor extends MaterialStateProperty<Color?> {
 }
 
 @immutable
-class _TextButtonDefaultMouseCursor extends MaterialStateProperty<MouseCursor> with Diagnosticable {
+class _TextButtonDefaultMouseCursor extends MaterialStateProperty<MouseCursor?> with Diagnosticable {
   _TextButtonDefaultMouseCursor(this.enabledCursor, this.disabledCursor);
 
-  final MouseCursor enabledCursor;
-  final MouseCursor disabledCursor;
+  final MouseCursor? enabledCursor;
+  final MouseCursor? disabledCursor;
 
   @override
-  MouseCursor resolve(Set<MaterialState> states) {
+  MouseCursor? resolve(Set<MaterialState> states) {
     if (states.contains(MaterialState.disabled)) {
       return disabledCursor;
     }

packages/flutter/test/material/elevated_button_test.dart

@@ -1835,7 +1835,6 @@ void main() {
     expect(controller.value, <MaterialState>{MaterialState.disabled});
     expect(count, 1);
   });
-
 }
 
 TextStyle _iconStyle(WidgetTester tester, IconData icon) {

packages/flutter/test/material/icon_button_test.dart

@@ -2482,6 +2482,26 @@ void main() {
     testWidgets('black87 icon color defined by users shows correctly in Material3', (WidgetTester tester) async {
 
     });
+
+    testWidgets("IconButton.styleFrom doesn't throw exception on passing only one cursor", (WidgetTester tester) async {
+      // This is a regression test for https://github.com/flutter/flutter/issues/118071.
+      await tester.pumpWidget(
+        Directionality(
+          textDirection: TextDirection.ltr,
+          child: Material(
+            child: IconButton(
+              style: OutlinedButton.styleFrom(
+                enabledMouseCursor: SystemMouseCursors.text,
+              ),
+              onPressed: () {},
+              icon: const Icon(Icons.add),
+            ),
+          ),
+        ),
+      );
+
+      expect(tester.takeException(), isNull);
+    });
   });
 }
 

packages/flutter/test/material/outlined_button_test.dart

@@ -1947,6 +1947,24 @@ void main() {
     expect(controller.value, <MaterialState>{MaterialState.disabled});
     expect(count, 1);
   });
+
+  testWidgets("OutlinedButton.styleFrom doesn't throw exception on passing only one cursor", (WidgetTester tester) async {
+    // This is a regression test for https://github.com/flutter/flutter/issues/118071.
+    await tester.pumpWidget(
+      Directionality(
+        textDirection: TextDirection.ltr,
+        child: OutlinedButton(
+          style: OutlinedButton.styleFrom(
+            enabledMouseCursor: SystemMouseCursors.text,
+          ),
+          onPressed: () {},
+          child: const Text('button'),
+        ),
+      ),
+    );
+
+    expect(tester.takeException(), isNull);
+  });
 }
 
 TextStyle _iconStyle(WidgetTester tester, IconData icon) {

packages/flutter/test/material/text_button_test.dart

@@ -1809,6 +1809,24 @@ void main() {
     expect(material.textStyle!.color, colorScheme.onSurface.withOpacity(0.38));
     expect(iconColor(), equals(Colors.blue));
   });
+
+  testWidgets("TextButton.styleFrom doesn't throw exception on passing only one cursor", (WidgetTester tester) async {
+    // This is a regression test for https://github.com/flutter/flutter/issues/118071.
+    await tester.pumpWidget(
+      Directionality(
+        textDirection: TextDirection.ltr,
+        child: TextButton(
+          style: TextButton.styleFrom(
+            enabledMouseCursor: SystemMouseCursors.text,
+          ),
+          onPressed: () {},
+          child: const Text('button'),
+        ),
+      ),
+    );
+
+    expect(tester.takeException(), isNull);
+  });
 }
 
 TextStyle? _iconStyle(WidgetTester tester, IconData icon) {