FloatingActionButton: add themeable mouse cursor (#103473)

Author: jpnurmi

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

@@ -11,6 +11,7 @@ import 'package:flutter/widgets.dart';
 import 'button.dart';
 import 'color_scheme.dart';
 import 'floating_action_button_theme.dart';
+import 'material_state.dart';
 import 'scaffold.dart';
 import 'text_theme.dart';
 import 'theme.dart';
@@ -603,7 +604,7 @@ class FloatingActionButton extends StatelessWidget {
 
     Widget result = RawMaterialButton(
       onPressed: onPressed,
-      mouseCursor: mouseCursor,
+      mouseCursor: _EffectiveMouseCursor(mouseCursor, floatingActionButtonTheme.mouseCursor),
       elevation: elevation,
       focusElevation: focusElevation,
       hoverElevation: hoverElevation,
@@ -664,6 +665,26 @@ class FloatingActionButton extends StatelessWidget {
   }
 }
 
+// This MaterialStateProperty is passed along to RawMaterialButton which
+// resolves the property against MaterialState.pressed, MaterialState.hovered,
+// MaterialState.focused, MaterialState.disabled.
+class _EffectiveMouseCursor extends MaterialStateMouseCursor {
+  const _EffectiveMouseCursor(this.widgetCursor, this.themeCursor);
+
+  final MouseCursor? widgetCursor;
+  final MaterialStateProperty<MouseCursor?>? themeCursor;
+
+  @override
+  MouseCursor resolve(Set<MaterialState> states) {
+    return MaterialStateProperty.resolveAs<MouseCursor?>(widgetCursor, states)
+      ?? themeCursor?.resolve(states)
+      ?? MaterialStateMouseCursor.clickable.resolve(states);
+  }
+
+  @override
+  String get debugDescription => 'MaterialStateMouseCursor(FloatActionButton)';
+}
+
 // This widget's size matches its child's size unless its constraints
 // force it to be larger or smaller. The child is centered.
 //

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

@@ -7,6 +7,8 @@ import 'dart:ui' show lerpDouble;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 
+import 'material_state.dart';
+
 /// Defines default property values for descendant [FloatingActionButton]
 /// widgets.
 ///
@@ -51,6 +53,7 @@ class FloatingActionButtonThemeData with Diagnosticable {
     this.extendedIconLabelSpacing,
     this.extendedPadding,
     this.extendedTextStyle,
+    this.mouseCursor,
   });
 
   /// Color to be used for the unselected, enabled [FloatingActionButton]'s
@@ -129,6 +132,11 @@ class FloatingActionButtonThemeData with Diagnosticable {
   /// The text style for an extended [FloatingActionButton]'s label.
   final TextStyle? extendedTextStyle;
 
+  /// {@macro flutter.material.RawMaterialButton.mouseCursor}
+  ///
+  /// If specified, overrides the default value of [FloatingActionButton.mouseCursor].
+  final MaterialStateProperty<MouseCursor?>? mouseCursor;
+
   /// Creates a copy of this object with the given fields replaced with the
   /// new values.
   FloatingActionButtonThemeData copyWith({
@@ -152,6 +160,7 @@ class FloatingActionButtonThemeData with Diagnosticable {
     double? extendedIconLabelSpacing,
     EdgeInsetsGeometry? extendedPadding,
     TextStyle? extendedTextStyle,
+    MaterialStateProperty<MouseCursor?>? mouseCursor,
   }) {
     return FloatingActionButtonThemeData(
       foregroundColor: foregroundColor ?? this.foregroundColor,
@@ -174,6 +183,7 @@ class FloatingActionButtonThemeData with Diagnosticable {
       extendedIconLabelSpacing: extendedIconLabelSpacing ?? this.extendedIconLabelSpacing,
       extendedPadding: extendedPadding ?? this.extendedPadding,
       extendedTextStyle: extendedTextStyle ?? this.extendedTextStyle,
+      mouseCursor: mouseCursor ?? this.mouseCursor,
     );
   }
 
@@ -208,6 +218,7 @@ class FloatingActionButtonThemeData with Diagnosticable {
       extendedIconLabelSpacing: lerpDouble(a?.extendedIconLabelSpacing, b?.extendedIconLabelSpacing, t),
       extendedPadding: EdgeInsetsGeometry.lerp(a?.extendedPadding, b?.extendedPadding, t),
       extendedTextStyle: TextStyle.lerp(a?.extendedTextStyle, b?.extendedTextStyle, t),
+      mouseCursor: t < 0.5 ? a?.mouseCursor : b?.mouseCursor,
     );
   }
 
@@ -232,7 +243,10 @@ class FloatingActionButtonThemeData with Diagnosticable {
     extendedSizeConstraints,
     extendedIconLabelSpacing,
     extendedPadding,
-    extendedTextStyle,
+    Object.hash(
+      extendedTextStyle,
+      mouseCursor,
+    ),
   );
 
   @override
@@ -263,7 +277,8 @@ class FloatingActionButtonThemeData with Diagnosticable {
         && other.extendedSizeConstraints == extendedSizeConstraints
         && other.extendedIconLabelSpacing == extendedIconLabelSpacing
         && other.extendedPadding == extendedPadding
-        && other.extendedTextStyle == extendedTextStyle;
+        && other.extendedTextStyle == extendedTextStyle
+        && other.mouseCursor == mouseCursor;
   }
 
   @override
@@ -290,5 +305,6 @@ class FloatingActionButtonThemeData with Diagnosticable {
     properties.add(DoubleProperty('extendedIconLabelSpacing', extendedIconLabelSpacing, defaultValue: null));
     properties.add(DiagnosticsProperty<EdgeInsetsGeometry>('extendedPadding', extendedPadding, defaultValue: null));
     properties.add(DiagnosticsProperty<TextStyle>('extendedTextStyle', extendedTextStyle, defaultValue: null));
+    properties.add(DiagnosticsProperty<MaterialStateProperty<MouseCursor?>>('mouseCursor', mouseCursor, defaultValue: null));
   }
 }

packages/flutter/test/material/floating_action_button_theme_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/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -287,6 +288,7 @@ void main() {
       extendedIconLabelSpacing: 12,
       extendedPadding: EdgeInsetsDirectional.only(start: 7.0, end: 8.0),
       extendedTextStyle: TextStyle(letterSpacing: 2.0),
+      mouseCursor: MaterialStateMouseCursor.clickable,
     ).debugFillProperties(builder);
 
     final List<String> description = builder.properties
@@ -315,8 +317,33 @@ void main() {
       'extendedIconLabelSpacing: 12.0',
       'extendedPadding: EdgeInsetsDirectional(7.0, 0.0, 8.0, 0.0)',
       'extendedTextStyle: TextStyle(inherit: true, letterSpacing: 2.0)',
+      'mouseCursor: MaterialStateMouseCursor(clickable)',
     ]);
   });
+
+  testWidgets('FloatingActionButton.mouseCursor uses FloatingActionButtonThemeData.mouseCursor when specified.', (WidgetTester tester) async {
+    await tester.pumpWidget(MaterialApp(
+      theme: ThemeData().copyWith(
+        floatingActionButtonTheme: FloatingActionButtonThemeData(
+          mouseCursor: MaterialStateProperty.all(SystemMouseCursors.text),
+        ),
+      ),
+      home: Scaffold(
+        floatingActionButton: FloatingActionButton(
+          onPressed: () { },
+          child: const Icon(Icons.add),
+        ),
+      ),
+    ));
+
+    await tester.pumpAndSettle();
+    final TestGesture gesture = await tester.createGesture(kind: PointerDeviceKind.mouse);
+    await gesture.addPointer();
+    addTearDown(gesture.removePointer);
+    await gesture.moveTo(tester.getCenter(find.byType(FloatingActionButton)));
+    await tester.pumpAndSettle();
+    expect(RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1), SystemMouseCursors.text);
+  });
 }
 
 RawMaterialButton _getRawMaterialButton(WidgetTester tester) {