Update ScrollableDetails for 2D scrolling (#122555)

Update ScrollableDetails for 2D scrolling

packages/flutter/lib/fix_data/fix_widgets/fix_widgets.yaml

@@ -23,6 +23,29 @@
 #     * ListWheelScrollView: fix_list_wheel_scroll_view.yaml
 version: 1
 transforms:
+  # Changes made in https://github.com/flutter/flutter/pull/122555
+  - title: "Migrate to 'decorationClipBehavior'"
+    date: 2023-03-13
+    element:
+      uris: [ 'widgets.dart', 'material.dart', 'cupertino.dart' ]
+      field: 'clipBehavior'
+      inClass: 'ScrollableDetails'
+    changes:
+      - kind: 'rename'
+        newName: 'decorationClipBehavior'
+
+  # Changes made in https://github.com/flutter/flutter/pull/122555
+  - title: "Migrate to 'decorationClipBehavior'"
+    date: 2023-03-13
+    element:
+      uris: [ 'widgets.dart', 'material.dart', 'cupertino.dart' ]
+      constructor: ''
+      inClass: 'ScrollableDetails'
+    changes:
+      - kind: 'renameParameter'
+        oldName: 'clipBehavior'
+        newName: 'decorationClipBehavior'
+
   # Changes made in https://github.com/flutter/flutter/pull/119647
   - title: "Migrate to 'fromView'"
     date: 2022-10-28

packages/flutter/lib/src/cupertino/app.dart

@@ -460,6 +460,7 @@ class CupertinoScrollBehavior extends ScrollBehavior {
       case TargetPlatform.linux:
       case TargetPlatform.macOS:
       case TargetPlatform.windows:
+        assert(details.controller != null);
         return CupertinoScrollbar(
           controller: details.controller,
           child: child,

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

@@ -825,6 +825,7 @@ class MaterialScrollBehavior extends ScrollBehavior {
           case TargetPlatform.linux:
           case TargetPlatform.macOS:
           case TargetPlatform.windows:
+            assert(details.controller != null);
             return Scrollbar(
               controller: details.controller,
               child: child,

packages/flutter/lib/src/widgets/scroll_configuration.dart

@@ -163,6 +163,7 @@ class ScrollBehavior {
       case TargetPlatform.linux:
       case TargetPlatform.macOS:
       case TargetPlatform.windows:
+        assert(details.controller != null);
         return RawScrollbar(
           controller: details.controller,
           child: child,

packages/flutter/lib/src/widgets/scrollable.dart

@@ -99,18 +99,21 @@ class Scrollable extends StatefulWidget {
     this.clipBehavior = Clip.hardEdge,
   }) : assert(semanticChildCount == null || semanticChildCount >= 0);
 
+  /// {@template flutter.widgets.Scrollable.axisDirection}
   /// The direction in which this widget scrolls.
   ///
-  /// For example, if the [axisDirection] is [AxisDirection.down], increasing
+  /// For example, if the [Scrollable.axisDirection] is [AxisDirection.down],
-  /// the scroll position will cause content below the bottom of the viewport to
+  /// increasing the scroll position will cause content below the bottom of the
-  /// become visible through the viewport. Similarly, if [axisDirection] is
+  /// viewport to become visible through the viewport. Similarly, if the
-  /// [AxisDirection.right], increasing the scroll position will cause content
+  /// axisDirection is [AxisDirection.right], increasing the scroll position
-  /// beyond the right edge of the viewport to become visible through the
+  /// will cause content beyond the right edge of the viewport to become visible
-  /// viewport.
+  /// through the viewport.
   ///
   /// Defaults to [AxisDirection.down].
+  /// {@endtemplate}
   final AxisDirection axisDirection;
 
+  /// {@template flutter.widgets.Scrollable.controller}
   /// An object that can be used to control the position to which this widget is
   /// scrolled.
   ///
@@ -122,12 +125,17 @@ class Scrollable extends StatefulWidget {
   /// scroll position (see [ScrollController.offset]), or change it (see
   /// [ScrollController.animateTo]).
   ///
+  /// If null, a [ScrollController] will be created internally by [Scrollable]
+  /// in order to create and manage the [ScrollPosition].
+  ///
   /// See also:
   ///
-  ///  * [ensureVisible], which animates the scroll position to reveal a given
+  ///  * [Scrollable.ensureVisible], which animates the scroll position to
-  ///    [BuildContext].
+  ///    reveal a given [BuildContext].
+  /// {@endtemplate}
   final ScrollController? controller;
 
+  /// {@template flutter.widgets.Scrollable.physics}
   /// How the widgets should respond to user input.
   ///
   /// For example, determines how the widget continues to animate after the
@@ -136,9 +144,9 @@ class Scrollable extends StatefulWidget {
   /// Defaults to matching platform conventions via the physics provided from
   /// the ambient [ScrollConfiguration].
   ///
-  /// If an explicit [ScrollBehavior] is provided to [scrollBehavior], the
+  /// If an explicit [ScrollBehavior] is provided to
-  /// [ScrollPhysics] provided by that behavior will take precedence after
+  /// [Scrollable.scrollBehavior], the [ScrollPhysics] provided by that behavior
-  /// [physics].
+  /// will take precedence after [Scrollable.physics].
   ///
   /// The physics can be changed dynamically, but new physics will only take
   /// effect if the _class_ of the provided object changes. Merely constructing
@@ -153,6 +161,7 @@ class Scrollable extends StatefulWidget {
   ///  * [AlwaysScrollableScrollPhysics], which can be used to indicate that the
   ///    scrollable should react to scroll requests (and possible overscroll)
   ///    even if the scrollable's contents fit without scrolling being necessary.
+  /// {@endtemplate}
   final ScrollPhysics? physics;
 
   /// Builds the viewport through which the scrollable content is displayed.
@@ -902,7 +911,7 @@ class ScrollableState extends State<Scrollable> with TickerProviderStateMixin, R
     final ScrollableDetails details = ScrollableDetails(
       direction: widget.axisDirection,
       controller: _effectiveScrollController,
-      clipBehavior: widget.clipBehavior,
+      decorationClipBehavior: widget.clipBehavior,
     );
 
     result = _configuration.buildScrollbar(

packages/flutter/lib/src/widgets/scrollable_helpers.dart

@@ -5,6 +5,7 @@
 import 'dart:async';
 import 'dart:math' as math;
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 
 import 'actions.dart';
@@ -15,12 +16,16 @@ import 'primary_scroll_controller.dart';
 import 'scroll_configuration.dart';
 import 'scroll_controller.dart';
 import 'scroll_metrics.dart';
+import 'scroll_physics.dart';
 import 'scrollable.dart';
 
 export 'package:flutter/physics.dart' show Tolerance;
 
 /// Describes the aspects of a Scrollable widget to inform inherited widgets
 /// like [ScrollBehavior] for decorating.
+// TODO(Piinks): Fix doc with 2DScrollable change.
+// or enumerate the properties of combined
+// Scrollables, such as [TwoDimensionalScrollable].
 ///
 /// Decorations like [GlowingOverscrollIndicator]s and [Scrollbar]s require
 /// information about the Scrollable in order to be initialized.
@@ -30,28 +35,118 @@ class ScrollableDetails {
   /// cannot be null.
   const ScrollableDetails({
     required this.direction,
-    required this.controller,
+    this.controller,
-    this.clipBehavior,
+    this.physics,
-  });
+    @Deprecated(
+      'Migrate to decorationClipBehavior. '
+      'This property was deprecated so that its application is clearer. This clip '
+      'applies to decorators, and does not directly clip a scroll view. '
+      'This feature was deprecated after v3.9.0-1.0.pre.'
+    )
+    Clip? clipBehavior,
+    Clip? decorationClipBehavior,
+  }) : decorationClipBehavior = clipBehavior ?? decorationClipBehavior;
 
-  /// The direction in which this widget scrolls.
+  /// A constructor specific to a [Scrollable] with an [Axis.vertical].
-  ///
+  const ScrollableDetails.vertical({
-  /// Cannot be null.
+    bool reverse = false,
+    this.controller,
+    this.physics,
+    this.decorationClipBehavior,
+  }) : direction = reverse ? AxisDirection.up : AxisDirection.down;
+
+  /// A constructor specific to a [Scrollable] with an [Axis.horizontal].
+  const ScrollableDetails.horizontal({
+    bool reverse = false,
+    this.controller,
+    this.physics,
+    this.decorationClipBehavior,
+  }) : direction = reverse ? AxisDirection.left : AxisDirection.right;
+
+  /// {@macro flutter.widgets.Scrollable.axisDirection}
   final AxisDirection direction;
 
-  /// A [ScrollController] that can be used to control the position of the
+  /// {@macro flutter.widgets.Scrollable.controller}
-  /// [Scrollable] widget.
+  final ScrollController? controller;
-  ///
+
-  /// This can be used by [ScrollBehavior] to apply a [Scrollbar] to the associated
+  /// {@macro flutter.widgets.Scrollable.physics}
-  /// [Scrollable].
+  final ScrollPhysics? physics;
-  final ScrollController controller;
 
   /// {@macro flutter.material.Material.clipBehavior}
   ///
-  /// This can be used by [MaterialScrollBehavior] to clip [StretchingOverscrollIndicator].
+  /// This can be used by [MaterialScrollBehavior] to clip a
+  /// [StretchingOverscrollIndicator].
+  ///
+  /// This [Clip] does not affect the [Viewport.clipBehavior], but is rather
+  /// passed from the same value by [Scrollable] so that decorators like
+  /// [StretchingOverscrollIndicator] honor the same clip.
   ///
   /// Defaults to null.
-  final Clip? clipBehavior;
+  final Clip? decorationClipBehavior;
+
+  /// Deprecated getter for [decorationClipBehavior].
+  @Deprecated(
+    'Migrate to decorationClipBehavior. '
+    'This property was deprecated so that its application is clearer. This clip '
+    'applies to decorators, and does not directly clip a scroll view. '
+    'This feature was deprecated after v3.9.0-1.0.pre.'
+  )
+  Clip? get clipBehavior => decorationClipBehavior;
+
+  /// Copy the current [ScrollableDetails] with the given values replacing the
+  /// current values.
+  ScrollableDetails copyWith({
+    AxisDirection? direction,
+    ScrollController? controller,
+    ScrollPhysics? physics,
+    Clip? decorationClipBehavior,
+  }) {
+    return ScrollableDetails(
+      direction: direction ?? this.direction,
+      controller: controller ?? this.controller,
+      physics: physics ?? this.physics,
+      decorationClipBehavior: decorationClipBehavior ?? this.decorationClipBehavior,
+    );
+  }
+
+  @override
+  String toString() {
+    final List<String> description = <String>[];
+    description.add('axisDirection: $direction');
+
+    void addIfNonNull(String prefix, Object? value) {
+      if (value != null) {
+        description.add(prefix + value.toString());
+      }
+    }
+    addIfNonNull('scroll controller: ', controller);
+    addIfNonNull('scroll physics: ', physics);
+    addIfNonNull('decorationClipBehavior: ', decorationClipBehavior);
+    return '${describeIdentity(this)}(${description.join(", ")})';
+  }
+
+  @override
+  int get hashCode => Object.hash(
+    direction,
+    controller,
+    physics,
+    decorationClipBehavior,
+  );
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) {
+      return true;
+    }
+    if (other.runtimeType != runtimeType) {
+      return false;
+    }
+    return other is ScrollableDetails
+      && other.direction == direction
+      && other.controller == controller
+      && other.physics == physics
+      && other.decorationClipBehavior == decorationClipBehavior;
+  }
 }
 
 /// An auto scroller that scrolls the [scrollable] if a drag gesture drags close

packages/flutter/test/cupertino/app_test.dart

@@ -424,6 +424,49 @@ void main() {
 
     debugBrightnessOverride = null;
   });
+
+  testWidgets('Assert in buildScrollbar that controller != null when using it', (WidgetTester tester) async {
+    const ScrollBehavior defaultBehavior = CupertinoScrollBehavior();
+    late BuildContext capturedContext;
+
+    await tester.pumpWidget(ScrollConfiguration(
+      // Avoid the default ones here.
+      behavior: const CupertinoScrollBehavior().copyWith(scrollbars: false),
+      child: SingleChildScrollView(
+        child: Builder(
+          builder: (BuildContext context) {
+            capturedContext = context;
+            return Container(height: 1000.0);
+          },
+        ),
+      ),
+    ));
+
+    const ScrollableDetails details = ScrollableDetails(direction: AxisDirection.down);
+    final Widget child = Container();
+
+    switch(defaultTargetPlatform) {
+      case TargetPlatform.android:
+      case TargetPlatform.fuchsia:
+      case TargetPlatform.iOS:
+        // Does not throw if we aren't using it.
+        defaultBehavior.buildScrollbar(capturedContext, child, details);
+        break;
+      case TargetPlatform.linux:
+      case TargetPlatform.macOS:
+      case TargetPlatform.windows:
+        expect(
+          () {
+            defaultBehavior.buildScrollbar(capturedContext, child, details);
+          },
+          throwsA(
+            isA<AssertionError>().having((AssertionError error) => error.toString(),
+                'description', contains('details.controller != null')),
+          ),
+        );
+        break;
+    }
+  }, variant: TargetPlatformVariant.all());
 }
 
 class MockScrollBehavior extends ScrollBehavior {

packages/flutter/test/material/app_test.dart

@@ -1445,6 +1445,92 @@ void main() {
     );
     expect(capturedContext.dependOnInheritedWidgetOfExactType<MediaQuery>()?.key, uniqueKey);
   });
+
+  testWidgets('Assert in buildScrollbar that controller != null when using it (vertical)', (WidgetTester tester) async {
+    const ScrollBehavior defaultBehavior = MaterialScrollBehavior();
+    late BuildContext capturedContext;
+
+    await tester.pumpWidget(MaterialApp(
+      home: ScrollConfiguration(
+        // Avoid the default ones here.
+        behavior: const MaterialScrollBehavior().copyWith(scrollbars: false),
+        child: SingleChildScrollView(
+          child: Builder(
+            builder: (BuildContext context) {
+              capturedContext = context;
+              return Container(height: 1000.0);
+            },
+          ),
+        ),
+      ),
+    ));
+
+    const ScrollableDetails details = ScrollableDetails(
+      direction: AxisDirection.down,
+    );
+    final Widget child = Container();
+
+    switch(defaultTargetPlatform) {
+      case TargetPlatform.android:
+      case TargetPlatform.fuchsia:
+      case TargetPlatform.iOS:
+        // Does not throw if we aren't using it.
+        defaultBehavior.buildScrollbar(capturedContext, child, details);
+        break;
+      case TargetPlatform.linux:
+      case TargetPlatform.macOS:
+      case TargetPlatform.windows:
+        expect(
+          () {
+            defaultBehavior.buildScrollbar(capturedContext, child, details);
+          },
+          throwsA(
+            isA<AssertionError>().having((AssertionError error) => error.toString(),
+              'description', contains('details.controller != null')),
+          ),
+        );
+        break;
+    }
+  }, variant: TargetPlatformVariant.all());
+
+  testWidgets('Assert in buildScrollbar that controller != null when using it (horizontal)', (WidgetTester tester) async {
+    const ScrollBehavior defaultBehavior = MaterialScrollBehavior();
+    late BuildContext capturedContext;
+
+    await tester.pumpWidget(MaterialApp(
+      home: ScrollConfiguration(
+        // Avoid the default ones here.
+        behavior: const MaterialScrollBehavior().copyWith(scrollbars: false),
+        child: SingleChildScrollView(
+          scrollDirection: Axis.horizontal,
+          child: Builder(
+            builder: (BuildContext context) {
+              capturedContext = context;
+              return Container(height: 1000.0);
+            },
+          ),
+        ),
+      ),
+    ));
+
+    const ScrollableDetails details = ScrollableDetails(
+      direction: AxisDirection.left,
+    );
+    final Widget child = Container();
+
+    switch(defaultTargetPlatform) {
+      case TargetPlatform.android:
+      case TargetPlatform.fuchsia:
+      case TargetPlatform.iOS:
+      case TargetPlatform.linux:
+      case TargetPlatform.macOS:
+      case TargetPlatform.windows:
+        // Does not throw if we aren't using it.
+        // Horizontal axis gets no scrollbars for all platforms.
+        defaultBehavior.buildScrollbar(capturedContext, child, details);
+        break;
+    }
+  }, variant: TargetPlatformVariant.all());
 }
 
 class MockScrollBehavior extends ScrollBehavior {

packages/flutter/test/widgets/scroll_behavior_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/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -32,6 +33,49 @@ class TestScrollBehavior extends ScrollBehavior {
 }
 
 void main() {
+  testWidgets('Assert in buildScrollbar that controller != null when using it', (WidgetTester tester) async {
+    const ScrollBehavior defaultBehavior = ScrollBehavior();
+    late BuildContext capturedContext;
+
+    await tester.pumpWidget(ScrollConfiguration(
+      // Avoid the default ones here.
+      behavior: const ScrollBehavior().copyWith(scrollbars: false),
+      child: SingleChildScrollView(
+        child: Builder(
+          builder: (BuildContext context) {
+            capturedContext = context;
+            return Container(height: 1000.0);
+          },
+        ),
+      ),
+    ));
+
+    const ScrollableDetails details = ScrollableDetails(direction: AxisDirection.down);
+    final Widget child = Container();
+
+    switch(defaultTargetPlatform) {
+      case TargetPlatform.android:
+      case TargetPlatform.fuchsia:
+      case TargetPlatform.iOS:
+        // Does not throw if we aren't using it.
+        defaultBehavior.buildScrollbar(capturedContext, child, details);
+        break;
+      case TargetPlatform.linux:
+      case TargetPlatform.macOS:
+      case TargetPlatform.windows:
+        expect(
+          () {
+            defaultBehavior.buildScrollbar(capturedContext, child, details);
+          },
+          throwsA(
+            isA<AssertionError>().having((AssertionError error) => error.toString(),
+              'description', contains('details.controller != null')),
+          ),
+        );
+        break;
+    }
+  }, variant: TargetPlatformVariant.all());
+
   // Regression test for https://github.com/flutter/flutter/issues/89681
   testWidgets('_WrappedScrollBehavior shouldNotify test', (WidgetTester tester) async {
     final ScrollBehavior behavior1 = const ScrollBehavior().copyWith();

packages/flutter/test/widgets/scrollable_helpers_test.dart

@@ -12,6 +12,80 @@ final LogicalKeyboardKey modifierKey = defaultTargetPlatform == TargetPlatform.m
   : LogicalKeyboardKey.controlLeft;
 
 void main() {
+  group('ScrollableDetails', (){
+    final ScrollController controller = ScrollController();
+    test('copyWith / == / hashCode', () {
+      final ScrollableDetails details = ScrollableDetails(
+        direction: AxisDirection.down,
+        controller: controller,
+        physics: const AlwaysScrollableScrollPhysics(),
+        decorationClipBehavior: Clip.hardEdge,
+      );
+      ScrollableDetails copiedDetails = details.copyWith();
+      expect(details, copiedDetails);
+      expect(details.hashCode, copiedDetails.hashCode);
+
+      copiedDetails = details.copyWith(
+        direction: AxisDirection.left,
+        physics: const ClampingScrollPhysics(),
+        decorationClipBehavior: Clip.none,
+      );
+      expect(
+        copiedDetails,
+        ScrollableDetails(
+          direction: AxisDirection.left,
+          controller: controller,
+          physics: const ClampingScrollPhysics(),
+          decorationClipBehavior: Clip.none,
+        ),
+      );
+    });
+
+    test('toString', (){
+      const ScrollableDetails bareDetails = ScrollableDetails(
+        direction: AxisDirection.right,
+      );
+      expect(
+        bareDetails.toString(),
+        equalsIgnoringHashCodes(
+          'ScrollableDetails#00000(axisDirection: AxisDirection.right)'
+        ),
+      );
+      final ScrollableDetails fullDetails = ScrollableDetails(
+        direction: AxisDirection.down,
+        controller: controller,
+        physics: const AlwaysScrollableScrollPhysics(),
+        decorationClipBehavior: Clip.hardEdge,
+      );
+      expect(
+        fullDetails.toString(),
+        equalsIgnoringHashCodes(
+          'ScrollableDetails#00000('
+          'axisDirection: AxisDirection.down, '
+          'scroll controller: ScrollController#00000(no clients), '
+          'scroll physics: AlwaysScrollableScrollPhysics, '
+          'decorationClipBehavior: Clip.hardEdge)'
+        ),
+      );
+    });
+
+    test('deprecated clipBehavior is backwards compatible', (){
+      const ScrollableDetails deprecatedClip = ScrollableDetails(
+        direction: AxisDirection.right,
+        clipBehavior: Clip.hardEdge,
+      );
+      expect(deprecatedClip.clipBehavior, Clip.hardEdge);
+      expect(deprecatedClip.decorationClipBehavior, Clip.hardEdge);
+
+      const ScrollableDetails newClip = ScrollableDetails(
+        direction: AxisDirection.right,
+        decorationClipBehavior: Clip.hardEdge,
+      );
+      expect(newClip.clipBehavior, Clip.hardEdge);
+      expect(newClip.decorationClipBehavior, Clip.hardEdge);
+    });
+  });
+
   testWidgets("Keyboard scrolling doesn't happen if scroll physics are set to NeverScrollableScrollPhysics", (WidgetTester tester) async {
     final ScrollController controller = ScrollController();
     await tester.pumpWidget(

packages/flutter/test_fixes/cupertino/cupertino.dart

@@ -238,4 +238,11 @@ void main() {
 
   // Changes made in https://github.com/flutter/flutter/pull/114459
   MediaQuery.boldTextOverride(context);
+
+  // Changes made in https://github.com/flutter/flutter/pull/122555
+  final ScrollableDetails details = ScrollableDetails(
+    direction: AxisDirection.down,
+    clipBehavior: Clip.none,
+  );
+  final Clip clip = details.clipBehavior;
 }

packages/flutter/test_fixes/cupertino/cupertino.dart.expect

@@ -238,4 +238,11 @@ void main() {
 
   // Changes made in https://github.com/flutter/flutter/pull/114459
   MediaQuery.boldTextOf(context);
+
+  // Changes made in https://github.com/flutter/flutter/pull/122555
+  final ScrollableDetails details = ScrollableDetails(
+    direction: AxisDirection.down,
+    decorationClipBehavior: Clip.none,
+  );
+  final Clip clip = details.decorationClipBehavior;
 }

packages/flutter/test_fixes/material/material.dart

@@ -310,4 +310,11 @@ void main() {
 
   // Changes made in https://github.com/flutter/flutter/pull/114459
   MediaQuery.boldTextOverride(context);
+
+  // Changes made in https://github.com/flutter/flutter/pull/122555
+  final ScrollableDetails details = ScrollableDetails(
+    direction: AxisDirection.down,
+    clipBehavior: Clip.none,
+  );
+  final Clip clip = details.clipBehavior;
 }

packages/flutter/test_fixes/material/material.dart.expect

@@ -306,4 +306,11 @@ void main() {
 
   // Changes made in https://github.com/flutter/flutter/pull/114459
   MediaQuery.boldTextOf(context);
+
+  // Changes made in https://github.com/flutter/flutter/pull/122555
+  final ScrollableDetails details = ScrollableDetails(
+    direction: AxisDirection.down,
+    decorationClipBehavior: Clip.none,
+  );
+  final Clip clip = details.decorationClipBehavior;
 }

packages/flutter/test_fixes/widgets/widgets.dart

@@ -160,4 +160,11 @@ void main() {
 
   // Changes made in https://github.com/flutter/flutter/pull/114459
   MediaQuery.boldTextOverride(context);
+
+  // Changes made in https://github.com/flutter/flutter/pull/122555
+  final ScrollableDetails details = ScrollableDetails(
+    direction: AxisDirection.down,
+    clipBehavior: Clip.none,
+  );
+  final Clip clip = details.clipBehavior;
 }

packages/flutter/test_fixes/widgets/widgets.dart.expect

@@ -160,4 +160,11 @@ void main() {
 
   // Changes made in https://github.com/flutter/flutter/pull/114459
   MediaQuery.boldTextOf(context);
+
+  // Changes made in https://github.com/flutter/flutter/pull/122555
+  final ScrollableDetails details = ScrollableDetails(
+    direction: AxisDirection.down,
+    decorationClipBehavior: Clip.none,
+  );
+  final Clip clip = details.decorationClipBehavior;
 }