Add Clip enum to Material and related widgets (#18576)

See details in our proposal for this breaking API change and #18057. This PR setup all code paths to allow the change but doesn't change the clip behavior by itself. We'll change `defaultClipBehavior` from `Clip.antiAlias` to `Clip.none` in the following PR to change the clip behavior and update tests.

packages/flutter/lib/painting.dart

@@ -28,6 +28,7 @@ export 'src/painting/box_decoration.dart';
 export 'src/painting/box_fit.dart';
 export 'src/painting/box_shadow.dart';
 export 'src/painting/circle_border.dart';
+export 'src/painting/clip.dart';
 export 'src/painting/colors.dart';
 export 'src/painting/debug.dart';
 export 'src/painting/decoration.dart';

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

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:ui' show Clip, defaultClipBehavior; // ignore: deprecated_member_use
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
@@ -87,8 +89,9 @@ abstract class MaterialInkController {
 ///
 /// The Material widget is responsible for:
 ///
-/// 1. Clipping: Material clips its widget sub-tree to the shape specified by
-///    [shape], [type], and [borderRadius].
+/// 1. Clipping: If [clipBehavior] is not [Clip.none], Material clips its widget
+///    sub-tree to the shape specified by [shape], [type], and [borderRadius].
+///    By default, [clipBehavior] is [Clip.none] for performance considerations.
 /// 2. Elevation: Material elevates its widget sub-tree on the Z axis by
 ///    [elevation] pixels, and draws the appropriate shadow.
 /// 3. Ink effects: Material shows ink effects implemented by [InkFeature]s
@@ -171,6 +174,7 @@ class Material extends StatefulWidget {
     this.textStyle,
     this.borderRadius,
     this.shape,
+    this.clipBehavior = defaultClipBehavior, // ignore: deprecated_member_use
     this.animationDuration = kThemeChangeDuration,
     this.child,
   }) : assert(type != null),
@@ -179,6 +183,7 @@ class Material extends StatefulWidget {
        assert(!(shape != null && borderRadius != null)),
        assert(animationDuration != null),
        assert(!(identical(type, MaterialType.circle) && (borderRadius != null || shape != null))),
+       assert(clipBehavior != null),
        super(key: key);
 
   /// The widget below this widget in the tree.
@@ -226,6 +231,14 @@ class Material extends StatefulWidget {
   /// zero.
   final ShapeBorder shape;
 
+  /// {@template flutter.widgets.Clip}
+  /// The content will be clipped (or not) according to this option.
+  ///
+  /// See the enum [Clip] for details of all possible options and their common
+  /// use cases.
+  /// {@endtemplate}
+  final Clip clipBehavior;
+
   /// Defines the duration of animated changes for [shape], [elevation],
   /// and [shadowColor].
   ///
@@ -329,6 +342,7 @@ class _MaterialState extends State<Material> with TickerProviderStateMixin {
         curve: Curves.fastOutSlowIn,
         duration: widget.animationDuration,
         shape: BoxShape.rectangle,
+        clipBehavior: widget.clipBehavior,
         borderRadius: BorderRadius.zero,
         elevation: widget.elevation,
         color: backgroundColor,
@@ -341,12 +355,13 @@ class _MaterialState extends State<Material> with TickerProviderStateMixin {
     final ShapeBorder shape = _getShape();
 
     if (widget.type == MaterialType.transparency)
-      return _transparentInterior(shape: shape, contents: contents);
+      return _transparentInterior(shape: shape, clipBehavior: widget.clipBehavior, contents: contents);
 
     return new _MaterialInterior(
       curve: Curves.fastOutSlowIn,
       duration: widget.animationDuration,
       shape: shape,
+      clipBehavior: widget.clipBehavior,
       elevation: widget.elevation,
       color: backgroundColor,
       shadowColor: widget.shadowColor,
@@ -354,7 +369,7 @@ class _MaterialState extends State<Material> with TickerProviderStateMixin {
     );
   }
 
-  static Widget _transparentInterior({ShapeBorder shape, Widget contents}) {
+  static Widget _transparentInterior({ShapeBorder shape, Clip clipBehavior, Widget contents}) {
     return new ClipPath(
       child: new _ShapeBorderPaint(
         child: contents,
@@ -363,6 +378,7 @@ class _MaterialState extends State<Material> with TickerProviderStateMixin {
       clipper: new ShapeBorderClipper(
         shape: shape,
       ),
+      clipBehavior: clipBehavior,
     );
   }
 
@@ -582,6 +598,7 @@ class _MaterialInterior extends ImplicitlyAnimatedWidget {
     Key key,
     @required this.child,
     @required this.shape,
+    this.clipBehavior = defaultClipBehavior, // ignore: deprecated_member_use
     @required this.elevation,
     @required this.color,
     @required this.shadowColor,
@@ -589,6 +606,7 @@ class _MaterialInterior extends ImplicitlyAnimatedWidget {
     @required Duration duration,
   }) : assert(child != null),
        assert(shape != null),
+       assert(clipBehavior != null),
        assert(elevation != null),
        assert(color != null),
        assert(shadowColor != null),
@@ -605,6 +623,9 @@ class _MaterialInterior extends ImplicitlyAnimatedWidget {
   /// determines the physical shape.
   final ShapeBorder shape;
 
+  /// {@macro flutter.widgets.Clip}
+  final Clip clipBehavior;
+
   /// The target z-coordinate at which to place this physical object.
   final double elevation;
 
@@ -651,6 +672,7 @@ class _MaterialInteriorState extends AnimatedWidgetBaseState<_MaterialInterior>
         shape: shape,
         textDirection: Directionality.of(context)
       ),
+      clipBehavior: widget.clipBehavior,
       elevation: _elevation.evaluate(animation),
       color: widget.color,
       shadowColor: _shadowColor.evaluate(animation),

packages/flutter/lib/src/painting/clip.dart

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:ui' show Canvas, Clip, Path, Paint, Rect, RRect;
+
+/// Clip utilities used by [PaintingContext] and [TestRecordingPaintingContext].
+abstract class ClipContext {
+  /// The canvas on which to paint.
+  Canvas get canvas;
+
+  void _clipAndPaint(void canvasClipCall(bool doAntiAlias), Clip clipBehavior, Rect bounds, void painter()) {
+    assert(canvasClipCall != null);
+    canvas.save();
+    switch (clipBehavior) {
+      case Clip.none:
+        break;
+      case Clip.hardEdge:
+        canvasClipCall(false);
+        break;
+      case Clip.antiAlias:
+        canvasClipCall(true);
+        break;
+      case Clip.antiAliasWithSaveLayer:
+        canvasClipCall(true);
+        canvas.saveLayer(bounds, new Paint());
+        break;
+    }
+    painter();
+    if (clipBehavior == Clip.antiAliasWithSaveLayer) {
+      canvas.restore();
+    }
+    canvas.restore();
+  }
+
+  /// Clip [canvas] with [Path] according to [Clip] and then paint. [canvas] is
+  /// restored to the pre-clip status afterwards.
+  ///
+  /// `bounds` is the saveLayer bounds used for [Clip.antiAliasWithSaveLayer].
+  void clipPathAndPaint(Path path, Clip clipBehavior, Rect bounds, void painter()) {
+    _clipAndPaint((bool doAntiAias) => canvas.clipPath(path, doAntiAlias: doAntiAias), clipBehavior, bounds, painter);
+  }
+
+  /// Clip [canvas] with [Path] according to [RRect] and then paint. [canvas] is
+  /// restored to the pre-clip status afterwards.
+  ///
+  /// `bounds` is the saveLayer bounds used for [Clip.antiAliasWithSaveLayer].
+  void clipRRectAndPaint(RRect rrect, Clip clipBehavior, Rect bounds, void painter()) {
+    _clipAndPaint((bool doAntiAias) => canvas.clipRRect(rrect, doAntiAlias: doAntiAias), clipBehavior, bounds, painter);
+  }
+
+  /// Clip [canvas] with [Path] according to [Rect] and then paint. [canvas] is
+  /// restored to the pre-clip status afterwards.
+  ///
+  /// `bounds` is the saveLayer bounds used for [Clip.antiAliasWithSaveLayer].
+  void clipRectAndPaint(Rect rect, Clip clipBehavior, Rect bounds, void painter()) {
+    _clipAndPaint((bool doAntiAias) => canvas.clipRect(rect, doAntiAlias: doAntiAias), clipBehavior, bounds, painter);
+  }
+}

packages/flutter/lib/src/rendering/layer.dart

@@ -5,7 +5,7 @@
 import 'dart:async';
 import 'dart:collection';
 import 'dart:ui' as ui show Image, ImageFilter, Picture, Scene, SceneBuilder;
-import 'dart:ui' show Offset;
+import 'dart:ui' show Clip, Offset, defaultClipBehavior; // ignore: deprecated_member_use
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/painting.dart';
@@ -605,7 +605,8 @@ class ClipRectLayer extends ContainerLayer {
   ///
   /// The [clipRect] property must be non-null before the compositing phase of
   /// the pipeline.
-  ClipRectLayer({ this.clipRect });
+  ClipRectLayer({ this.clipRect, Clip clipBehavior = Clip.antiAlias }) :
+        _clipBehavior = clipBehavior, assert(clipBehavior != null), assert(clipBehavior != Clip.none);
 
   /// The rectangle to clip in the parent's coordinate system.
   ///
@@ -613,6 +614,15 @@ class ClipRectLayer extends ContainerLayer {
   /// (as described at [Layer]).
   Rect clipRect;
 
+  /// {@macro flutter.clipper.clipBehavior}
+  Clip get clipBehavior => _clipBehavior;
+  Clip _clipBehavior;
+  set clipBehavior(Clip value) {
+    assert(value != null);
+    assert(value != Clip.none);
+    _clipBehavior = value;
+  }
+
   @override
   S find<S>(Offset regionOffset) {
     if (!clipRect.contains(regionOffset))
@@ -628,7 +638,7 @@ class ClipRectLayer extends ContainerLayer {
       return true;
     }());
     if (enabled)
-      builder.pushClipRect(clipRect.shift(layerOffset));
+      builder.pushClipRect(clipRect.shift(layerOffset), clipBehavior: clipBehavior);
     addChildrenToScene(builder, layerOffset);
     if (enabled)
       builder.pop();
@@ -651,7 +661,8 @@ class ClipRRectLayer extends ContainerLayer {
   ///
   /// The [clipRRect] property must be non-null before the compositing phase of
   /// the pipeline.
-  ClipRRectLayer({ this.clipRRect });
+  ClipRRectLayer({ this.clipRRect, Clip clipBehavior = Clip.antiAlias }) :
+        _clipBehavior = clipBehavior, assert(clipBehavior != null), assert(clipBehavior != Clip.none);
 
   /// The rounded-rect to clip in the parent's coordinate system.
   ///
@@ -659,6 +670,15 @@ class ClipRRectLayer extends ContainerLayer {
   /// (as described at [Layer]).
   RRect clipRRect;
 
+  /// {@macro flutter.clipper.clipBehavior}
+  Clip get clipBehavior => _clipBehavior;
+  Clip _clipBehavior;
+  set clipBehavior(Clip value) {
+    assert(value != null);
+    assert(value != Clip.none);
+    _clipBehavior = value;
+  }
+
   @override
   S find<S>(Offset regionOffset) {
     if (!clipRRect.contains(regionOffset))
@@ -674,7 +694,7 @@ class ClipRRectLayer extends ContainerLayer {
       return true;
     }());
     if (enabled)
-      builder.pushClipRRect(clipRRect.shift(layerOffset));
+      builder.pushClipRRect(clipRRect.shift(layerOffset), clipBehavior: clipBehavior);
     addChildrenToScene(builder, layerOffset);
     if (enabled)
       builder.pop();
@@ -697,7 +717,8 @@ class ClipPathLayer extends ContainerLayer {
   ///
   /// The [clipPath] property must be non-null before the compositing phase of
   /// the pipeline.
-  ClipPathLayer({ this.clipPath });
+  ClipPathLayer({ this.clipPath, Clip clipBehavior = Clip.antiAlias }) :
+        _clipBehavior = clipBehavior, assert(clipBehavior != null), assert(clipBehavior != Clip.none);
 
   /// The path to clip in the parent's coordinate system.
   ///
@@ -705,6 +726,15 @@ class ClipPathLayer extends ContainerLayer {
   /// (as described at [Layer]).
   Path clipPath;
 
+  /// {@macro flutter.clipper.clipBehavior}
+  Clip get clipBehavior => _clipBehavior;
+  Clip _clipBehavior;
+  set clipBehavior(Clip value) {
+    assert(value != null);
+    assert(value != Clip.none);
+    _clipBehavior = value;
+  }
+
   @override
   S find<S>(Offset regionOffset) {
     if (!clipPath.contains(regionOffset))
@@ -720,7 +750,7 @@ class ClipPathLayer extends ContainerLayer {
       return true;
     }());
     if (enabled)
-      builder.pushClipPath(clipPath.shift(layerOffset));
+      builder.pushClipPath(clipPath.shift(layerOffset), clipBehavior: clipBehavior);
     addChildrenToScene(builder, layerOffset);
     if (enabled)
       builder.pop();
@@ -925,10 +955,12 @@ class PhysicalModelLayer extends ContainerLayer {
   /// The [clipPath], [elevation], and [color] arguments must not be null.
   PhysicalModelLayer({
     @required this.clipPath,
+    this.clipBehavior = defaultClipBehavior, // ignore: deprecated_member_use
     @required this.elevation,
     @required this.color,
     @required this.shadowColor,
   }) : assert(clipPath != null),
+       assert(clipBehavior != null),
        assert(elevation != null),
        assert(color != null),
        assert(shadowColor != null);
@@ -939,6 +971,9 @@ class PhysicalModelLayer extends ContainerLayer {
   /// (as described at [Layer]).
   Path clipPath;
 
+  /// {@macro flutter.widgets.Clip}
+  Clip clipBehavior;
+
   /// The z-coordinate at which to place this physical object.
   ///
   /// The scene must be explicitly recomposited after this property is changed
@@ -980,6 +1015,7 @@ class PhysicalModelLayer extends ContainerLayer {
         elevation: elevation,
         color: color,
         shadowColor: shadowColor,
+        clipBehavior: clipBehavior,
       );
     }
     addChildrenToScene(builder, layerOffset);

packages/flutter/lib/src/rendering/object.dart

@@ -4,6 +4,7 @@
 
 import 'dart:developer';
 import 'dart:ui' as ui show PictureRecorder;
+import 'dart:ui' show Clip;
 
 import 'package:flutter/animation.dart';
 import 'package:flutter/foundation.dart';
@@ -59,7 +60,7 @@ typedef void PaintingContextCallback(PaintingContext context, Offset offset);
 ///
 /// New [PaintingContext] objects are created automatically when using
 /// [PaintingContext.repaintCompositedChild] and [pushLayer].
-class PaintingContext {
+class PaintingContext extends ClipContext {
   PaintingContext._(this._containerLayer, this.estimatedBounds)
     : assert(_containerLayer != null),
       assert(estimatedBounds != null);
@@ -195,6 +196,7 @@ class PaintingContext {
   /// The current canvas can change whenever you paint a child using this
   /// context, which means it's fragile to hold a reference to the canvas
   /// returned by this getter.
+  @override
   Canvas get canvas {
     if (_canvas == null)
       _startRecording();
@@ -315,17 +317,13 @@ class PaintingContext {
   ///   clip the painting done by [painter].
   /// * `painter` is a callback that will paint with the [clipRect] applied. This
   ///   function calls the [painter] synchronously.
-  void pushClipRect(bool needsCompositing, Offset offset, Rect clipRect, PaintingContextCallback painter) {
+  /// * `clipBehavior` controls how the rectangle is clipped.
+  void pushClipRect(bool needsCompositing, Offset offset, Rect clipRect, PaintingContextCallback painter, {Clip clipBehavior = Clip.antiAlias}) {
     final Rect offsetClipRect = clipRect.shift(offset);
     if (needsCompositing) {
-      pushLayer(new ClipRectLayer(clipRect: offsetClipRect), painter, offset, childPaintBounds: offsetClipRect);
+      pushLayer(new ClipRectLayer(clipRect: offsetClipRect, clipBehavior: clipBehavior), painter, offset, childPaintBounds: offsetClipRect);
     } else {
-      canvas
-        ..save()
-        ..clipRect(offsetClipRect);
-      painter(this, offset);
-      canvas
-        ..restore();
+      clipRectAndPaint(offsetClipRect, clipBehavior, offsetClipRect, () => painter(this, offset));
     }
   }
 
@@ -341,18 +339,16 @@ class PaintingContext {
   ///   to use to clip the painting done by `painter`.
   /// * `painter` is a callback that will paint with the `clipRRect` applied. This
   ///   function calls the `painter` synchronously.
-  void pushClipRRect(bool needsCompositing, Offset offset, Rect bounds, RRect clipRRect, PaintingContextCallback painter) {
+  /// * `clipBehavior` controls how the path is clipped.
+  // ignore: deprecated_member_use
+  void pushClipRRect(bool needsCompositing, Offset offset, Rect bounds, RRect clipRRect, PaintingContextCallback painter, {Clip clipBehavior = Clip.antiAlias}) {
+    assert(clipBehavior != null);
     final Rect offsetBounds = bounds.shift(offset);
     final RRect offsetClipRRect = clipRRect.shift(offset);
     if (needsCompositing) {
-      pushLayer(new ClipRRectLayer(clipRRect: offsetClipRRect), painter, offset, childPaintBounds: offsetBounds);
+      pushLayer(new ClipRRectLayer(clipRRect: offsetClipRRect, clipBehavior: clipBehavior), painter, offset, childPaintBounds: offsetBounds);
     } else {
-      canvas
-        ..save()
-        ..clipRRect(offsetClipRRect);
-      painter(this, offset);
-      canvas
-        ..restore();
+      clipRRectAndPaint(offsetClipRRect, clipBehavior, offsetBounds, () => painter(this, offset));
     }
   }
 
@@ -368,18 +364,16 @@ class PaintingContext {
   ///   clip the painting done by `painter`.
   /// * `painter` is a callback that will paint with the `clipPath` applied. This
   ///   function calls the `painter` synchronously.
-  void pushClipPath(bool needsCompositing, Offset offset, Rect bounds, Path clipPath, PaintingContextCallback painter) {
+  /// * `clipBehavior` controls how the rounded rectangle is clipped.
+  // ignore: deprecated_member_use
+  void pushClipPath(bool needsCompositing, Offset offset, Rect bounds, Path clipPath, PaintingContextCallback painter, {Clip clipBehavior = Clip.antiAlias}) {
+    assert(clipBehavior != null);
     final Rect offsetBounds = bounds.shift(offset);
     final Path offsetClipPath = clipPath.shift(offset);
     if (needsCompositing) {
-      pushLayer(new ClipPathLayer(clipPath: offsetClipPath), painter, offset, childPaintBounds: offsetBounds);
+      pushLayer(new ClipPathLayer(clipPath: offsetClipPath, clipBehavior: clipBehavior), painter, offset, childPaintBounds: offsetBounds);
     } else {
-      canvas
-        ..save()
-        ..clipPath(clipPath.shift(offset));
-      painter(this, offset);
-      canvas
-        ..restore();
+      clipPathAndPaint(offsetClipPath, clipBehavior, offsetBounds, () => painter(this, offset));
     }
   }
 

packages/flutter/lib/src/rendering/proxy_box.dart

@@ -5,6 +5,7 @@
 import 'dart:async';
 
 import 'dart:ui' as ui show ImageFilter, Gradient, Image;
+import 'dart:ui' show Clip, defaultClipBehavior; // ignore: deprecated_member_use
 
 import 'package:flutter/animation.dart';
 import 'package:flutter/foundation.dart';
@@ -1116,8 +1117,9 @@ class ShapeBorderClipper extends CustomClipper<Path> {
 abstract class _RenderCustomClip<T> extends RenderProxyBox {
   _RenderCustomClip({
     RenderBox child,
-    CustomClipper<T> clipper
-  }) : _clipper = clipper, super(child);
+    CustomClipper<T> clipper,
+    this.clipBehavior = defaultClipBehavior, // ignore: deprecated_member_use
+  }) : _clipper = clipper, assert(clipBehavior != null), assert(clipBehavior != Clip.none), super(child);
 
   /// If non-null, determines which clip to use on the child.
   CustomClipper<T> get clipper => _clipper;
@@ -1160,6 +1162,13 @@ abstract class _RenderCustomClip<T> extends RenderProxyBox {
   T get _defaultClip;
   T _clip;
 
+  /// {@template flutter.clipper.clipBehavior}
+  /// Controls how to clip (default to [Clip.antiAlias]).
+  ///
+  /// [Clip.none] is not allowed here.
+  /// {@endtemplate}
+  final Clip clipBehavior;
+
   @override
   void performLayout() {
     final Size oldSize = hasSize ? size : null;
@@ -1220,8 +1229,9 @@ class RenderClipRect extends _RenderCustomClip<Rect> {
   /// the child.
   RenderClipRect({
     RenderBox child,
-    CustomClipper<Rect> clipper
-  }) : super(child: child, clipper: clipper);
+    CustomClipper<Rect> clipper,
+    Clip clipBehavior = Clip.antiAlias,
+  }) : super(child: child, clipper: clipper, clipBehavior: clipBehavior);
 
   @override
   Rect get _defaultClip => Offset.zero & size;
@@ -1241,7 +1251,7 @@ class RenderClipRect extends _RenderCustomClip<Rect> {
   void paint(PaintingContext context, Offset offset) {
     if (child != null) {
       _updateClip();
-      context.pushClipRect(needsCompositing, offset, _clip, super.paint);
+      context.pushClipRect(needsCompositing, offset, _clip, super.paint, clipBehavior: clipBehavior);
     }
   }
 
@@ -1274,7 +1284,8 @@ class RenderClipRRect extends _RenderCustomClip<RRect> {
     RenderBox child,
     BorderRadius borderRadius = BorderRadius.zero,
     CustomClipper<RRect> clipper,
-  }) : _borderRadius = borderRadius, super(child: child, clipper: clipper) {
+    Clip clipBehavior = Clip.antiAlias,
+  }) : _borderRadius = borderRadius, super(child: child, clipper: clipper, clipBehavior: clipBehavior) {
     assert(_borderRadius != null || clipper != null);
   }
 
@@ -1312,7 +1323,7 @@ class RenderClipRRect extends _RenderCustomClip<RRect> {
   void paint(PaintingContext context, Offset offset) {
     if (child != null) {
       _updateClip();
-      context.pushClipRRect(needsCompositing, offset, _clip.outerRect, _clip, super.paint);
+      context.pushClipRRect(needsCompositing, offset, _clip.outerRect, _clip, super.paint, clipBehavior: clipBehavior);
     }
   }
 
@@ -1341,8 +1352,9 @@ class RenderClipOval extends _RenderCustomClip<Rect> {
   /// position of the child.
   RenderClipOval({
     RenderBox child,
-    CustomClipper<Rect> clipper
-  }) : super(child: child, clipper: clipper);
+    CustomClipper<Rect> clipper,
+    Clip clipBehavior = Clip.antiAlias,
+  }) : super(child: child, clipper: clipper, clipBehavior: clipBehavior);
 
   Rect _cachedRect;
   Path _cachedPath;
@@ -1376,7 +1388,7 @@ class RenderClipOval extends _RenderCustomClip<Rect> {
   void paint(PaintingContext context, Offset offset) {
     if (child != null) {
       _updateClip();
-      context.pushClipPath(needsCompositing, offset, _clip, _getClipPath(_clip), super.paint);
+      context.pushClipPath(needsCompositing, offset, _clip, _getClipPath(_clip), super.paint, clipBehavior: clipBehavior);
     }
   }
 
@@ -1413,8 +1425,9 @@ class RenderClipPath extends _RenderCustomClip<Path> {
   /// efficiently.
   RenderClipPath({
     RenderBox child,
-    CustomClipper<Path> clipper
-  }) : super(child: child, clipper: clipper);
+    CustomClipper<Path> clipper,
+    Clip clipBehavior = Clip.antiAlias,
+  }) : super(child: child, clipper: clipper, clipBehavior: clipBehavior);
 
   @override
   Path get _defaultClip => new Path()..addRect(Offset.zero & size);
@@ -1434,7 +1447,7 @@ class RenderClipPath extends _RenderCustomClip<Path> {
   void paint(PaintingContext context, Offset offset) {
     if (child != null) {
       _updateClip();
-      context.pushClipPath(needsCompositing, offset, Offset.zero & size, _clip, super.paint);
+      context.pushClipPath(needsCompositing, offset, Offset.zero & size, _clip, super.paint, clipBehavior: clipBehavior);
     }
   }
 
@@ -1462,14 +1475,16 @@ abstract class _RenderPhysicalModelBase<T> extends _RenderCustomClip<T> {
     @required double elevation,
     @required Color color,
     @required Color shadowColor,
+    Clip clipBehavior = defaultClipBehavior, // ignore: deprecated_member_use
     CustomClipper<T> clipper,
   }) : assert(elevation != null),
        assert(color != null),
        assert(shadowColor != null),
+       assert(clipBehavior != null),
        _elevation = elevation,
        _color = color,
        _shadowColor = shadowColor,
-       super(child: child, clipper: clipper);
+       super(child: child, clipBehavior: clipBehavior, clipper: clipper);
 
   /// The z-coordinate at which to place this material.
   ///
@@ -1539,17 +1554,20 @@ class RenderPhysicalModel extends _RenderPhysicalModelBase<RRect> {
   RenderPhysicalModel({
     RenderBox child,
     BoxShape shape = BoxShape.rectangle,
+    Clip clipBehavior = defaultClipBehavior, // ignore: deprecated_member_use
     BorderRadius borderRadius,
     double elevation = 0.0,
     @required Color color,
     Color shadowColor = const Color(0xFF000000),
   }) : assert(shape != null),
+       assert(clipBehavior != null),
        assert(elevation != null),
        assert(color != null),
        assert(shadowColor != null),
        _shape = shape,
        _borderRadius = borderRadius,
        super(
+         clipBehavior: clipBehavior,
          child: child,
          elevation: elevation,
          color: color,
@@ -1638,6 +1656,7 @@ class RenderPhysicalModel extends _RenderPhysicalModelBase<RRect> {
       if (needsCompositing) {
         final PhysicalModelLayer physicalModel = new PhysicalModelLayer(
           clipPath: offsetRRectAsPath,
+          clipBehavior: clipBehavior,
           elevation: paintShadows ? elevation : 0.0,
           color: color,
           shadowColor: shadowColor,
@@ -1662,10 +1681,7 @@ class RenderPhysicalModel extends _RenderPhysicalModelBase<RRect> {
           );
         }
         canvas.drawRRect(offsetRRect, new Paint()..color = color);
-        canvas.save();
-        canvas.clipRRect(offsetRRect);
-        super.paint(context, offset);
-        canvas.restore();
+        context.clipRRectAndPaint(offsetRRect, clipBehavior, offsetBounds, () => super.paint(context, offset));
         assert(context.canvas == canvas, 'canvas changed even though needsCompositing was false');
       }
     }
@@ -1697,6 +1713,7 @@ class RenderPhysicalShape extends _RenderPhysicalModelBase<Path> {
   RenderPhysicalShape({
     RenderBox child,
     @required CustomClipper<Path> clipper,
+    Clip clipBehavior = defaultClipBehavior, // ignore: deprecated_member_use
     double elevation = 0.0,
     @required Color color,
     Color shadowColor = const Color(0xFF000000),
@@ -1710,6 +1727,7 @@ class RenderPhysicalShape extends _RenderPhysicalModelBase<Path> {
          color: color,
          shadowColor: shadowColor,
          clipper: clipper,
+         clipBehavior: clipBehavior
        );
 
   @override
@@ -1751,6 +1769,7 @@ class RenderPhysicalShape extends _RenderPhysicalModelBase<Path> {
       if (needsCompositing) {
         final PhysicalModelLayer physicalModel = new PhysicalModelLayer(
           clipPath: offsetPath,
+          clipBehavior: clipBehavior,
           elevation: paintShadows ? elevation : 0.0,
           color: color,
           shadowColor: shadowColor,
@@ -1775,10 +1794,7 @@ class RenderPhysicalShape extends _RenderPhysicalModelBase<Path> {
           );
         }
         canvas.drawPath(offsetPath, new Paint()..color = color..style = PaintingStyle.fill);
-        canvas.save();
-        canvas.clipPath(offsetPath);
-        super.paint(context, offset);
-        canvas.restore();
+        context.clipPathAndPaint(offsetPath, clipBehavior, offsetBounds, () => super.paint(context, offset));
         assert(context.canvas == canvas, 'canvas changed even though needsCompositing was false');
       }
     }

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

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:ui' as ui show Image, ImageFilter;
+import 'dart:ui' show Clip, defaultClipBehavior; // ignore: deprecated_member_use
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
@@ -476,13 +477,16 @@ class ClipRect extends SingleChildRenderObjectWidget {
   ///
   /// If [clipper] is null, the clip will match the layout size and position of
   /// the child.
-  const ClipRect({ Key key, this.clipper, Widget child }) : super(key: key, child: child);
+  const ClipRect({ Key key, this.clipper, this.clipBehavior = Clip.antiAlias, Widget child }) : super(key: key, child: child);
 
   /// If non-null, determines which clip to use.
   final CustomClipper<Rect> clipper;
 
+  /// {@macro flutter.widget.clipper.clipBehavior}
+  final Clip clipBehavior;
+
   @override
-  RenderClipRect createRenderObject(BuildContext context) => new RenderClipRect(clipper: clipper);
+  RenderClipRect createRenderObject(BuildContext context) => new RenderClipRect(clipper: clipper, clipBehavior: clipBehavior);
 
   @override
   void updateRenderObject(BuildContext context, RenderClipRect renderObject) {
@@ -524,8 +528,10 @@ class ClipRRect extends SingleChildRenderObjectWidget {
     Key key,
     this.borderRadius,
     this.clipper,
+    this.clipBehavior = Clip.antiAlias,
     Widget child,
   }) : assert(borderRadius != null || clipper != null),
+       assert(clipBehavior != null),
        super(key: key, child: child);
 
   /// The border radius of the rounded corners.
@@ -539,8 +545,11 @@ class ClipRRect extends SingleChildRenderObjectWidget {
   /// If non-null, determines which clip to use.
   final CustomClipper<RRect> clipper;
 
+  /// {@macro flutter.widget.clipper.clipBehavior}
+  final Clip clipBehavior;
+
   @override
-  RenderClipRRect createRenderObject(BuildContext context) => new RenderClipRRect(borderRadius: borderRadius, clipper: clipper);
+  RenderClipRRect createRenderObject(BuildContext context) => new RenderClipRRect(borderRadius: borderRadius, clipper: clipper, clipBehavior: clipBehavior);
 
   @override
   void updateRenderObject(BuildContext context, RenderClipRRect renderObject) {
@@ -575,7 +584,7 @@ class ClipOval extends SingleChildRenderObjectWidget {
   ///
   /// If [clipper] is null, the oval will be inscribed into the layout size and
   /// position of the child.
-  const ClipOval({ Key key, this.clipper, Widget child }) : super(key: key, child: child);
+  const ClipOval({ Key key, this.clipper, this.clipBehavior = Clip.antiAlias, Widget child }) : super(key: key, child: child);
 
   /// If non-null, determines which clip to use.
   ///
@@ -588,8 +597,11 @@ class ClipOval extends SingleChildRenderObjectWidget {
   /// object) instead.
   final CustomClipper<Rect> clipper;
 
+  /// {@macro flutter.widget.clipper.clipBehavior}
+  final Clip clipBehavior;
+
   @override
-  RenderClipOval createRenderObject(BuildContext context) => new RenderClipOval(clipper: clipper);
+  RenderClipOval createRenderObject(BuildContext context) => new RenderClipOval(clipper: clipper, clipBehavior: clipBehavior);
 
   @override
   void updateRenderObject(BuildContext context, RenderClipOval renderObject) {
@@ -627,7 +639,7 @@ class ClipPath extends SingleChildRenderObjectWidget {
   /// size and location of the child. However, rather than use this default,
   /// consider using a [ClipRect], which can achieve the same effect more
   /// efficiently.
-  const ClipPath({ Key key, this.clipper, Widget child }) : super(key: key, child: child);
+  const ClipPath({ Key key, this.clipper, this.clipBehavior = Clip.antiAlias, Widget child }) : super(key: key, child: child);
 
   /// If non-null, determines which clip to use.
   ///
@@ -636,8 +648,11 @@ class ClipPath extends SingleChildRenderObjectWidget {
   /// efficient way of obtaining that effect.
   final CustomClipper<Path> clipper;
 
+  /// {@macro flutter.widget.clipper.clipBehavior}
+  final Clip clipBehavior;
+
   @override
-  RenderClipPath createRenderObject(BuildContext context) => new RenderClipPath(clipper: clipper);
+  RenderClipPath createRenderObject(BuildContext context) => new RenderClipPath(clipper: clipper, clipBehavior: clipBehavior);
 
   @override
   void updateRenderObject(BuildContext context, RenderClipPath renderObject) {
@@ -677,6 +692,7 @@ class PhysicalModel extends SingleChildRenderObjectWidget {
   const PhysicalModel({
     Key key,
     this.shape = BoxShape.rectangle,
+    this.clipBehavior = defaultClipBehavior, // ignore: deprecated_member_use
     this.borderRadius,
     this.elevation = 0.0,
     @required this.color,
@@ -691,6 +707,9 @@ class PhysicalModel extends SingleChildRenderObjectWidget {
   /// The type of shape.
   final BoxShape shape;
 
+  /// {@macro flutter.widgets.Clip}
+  final Clip clipBehavior;
+
   /// The border radius of the rounded corners.
   ///
   /// Values are clamped so that horizontal and vertical radii sums do not
@@ -712,6 +731,7 @@ class PhysicalModel extends SingleChildRenderObjectWidget {
   RenderPhysicalModel createRenderObject(BuildContext context) {
     return new RenderPhysicalModel(
       shape: shape,
+      clipBehavior: clipBehavior,
       borderRadius: borderRadius,
       elevation: elevation, color: color,
       shadowColor: shadowColor,
@@ -760,11 +780,13 @@ class PhysicalShape extends SingleChildRenderObjectWidget {
   const PhysicalShape({
     Key key,
     @required this.clipper,
+    this.clipBehavior = defaultClipBehavior, // ignore: deprecated_member_use
     this.elevation = 0.0,
     @required this.color,
     this.shadowColor = const Color(0xFF000000),
     Widget child,
   }) : assert(clipper != null),
+       assert(clipBehavior != null),
        assert(elevation != null),
        assert(color != null),
        assert(shadowColor != null),
@@ -777,6 +799,9 @@ class PhysicalShape extends SingleChildRenderObjectWidget {
   /// shape for use with this widget.
   final CustomClipper<Path> clipper;
 
+  /// {@macro flutter.widgets.Clip}
+  final Clip clipBehavior;
+
   /// The z-coordinate at which to place this physical object.
   final double elevation;
 
@@ -790,6 +815,7 @@ class PhysicalShape extends SingleChildRenderObjectWidget {
   RenderPhysicalShape createRenderObject(BuildContext context) {
     return new RenderPhysicalShape(
       clipper: clipper,
+      clipBehavior: clipBehavior,
       elevation: elevation,
       color: color,
       shadowColor: shadowColor

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

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:ui' show Clip, defaultClipBehavior; // ignore: deprecated_member_use
+
 import 'package:flutter/animation.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
@@ -1181,6 +1183,7 @@ class AnimatedPhysicalModel extends ImplicitlyAnimatedWidget {
     Key key,
     @required this.child,
     @required this.shape,
+    this.clipBehavior = defaultClipBehavior, // ignore: deprecated_member_use
     this.borderRadius = BorderRadius.zero,
     @required this.elevation,
     @required this.color,
@@ -1191,6 +1194,7 @@ class AnimatedPhysicalModel extends ImplicitlyAnimatedWidget {
     @required Duration duration,
   }) : assert(child != null),
        assert(shape != null),
+       assert(clipBehavior != null),
        assert(borderRadius != null),
        assert(elevation != null),
        assert(color != null),
@@ -1209,6 +1213,9 @@ class AnimatedPhysicalModel extends ImplicitlyAnimatedWidget {
   /// This property is not animated.
   final BoxShape shape;
 
+  /// {@macro flutter.widgets.Clip}
+  final Clip clipBehavior;
+
   /// The target border radius of the rounded corners for a rectangle shape.
   final BorderRadius borderRadius;
 
@@ -1262,6 +1269,7 @@ class _AnimatedPhysicalModelState extends AnimatedWidgetBaseState<AnimatedPhysic
     return new PhysicalModel(
       child: widget.child,
       shape: widget.shape,
+      clipBehavior: widget.clipBehavior,
       borderRadius: _borderRadius.evaluate(animation),
       elevation: _elevation.evaluate(animation),
       color: widget.animateColor ? _color.evaluate(animation) : widget.color,

packages/flutter/test/rendering/recording_canvas.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:ui' show Clip;
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 
@@ -90,7 +92,7 @@ class TestRecordingCanvas implements Canvas {
 }
 
 /// A [PaintingContext] for tests that use [TestRecordingCanvas].
-class TestRecordingPaintingContext implements PaintingContext {
+class TestRecordingPaintingContext extends ClipContext implements PaintingContext {
   /// Creates a [PaintingContext] for tests that use [TestRecordingCanvas].
   TestRecordingPaintingContext(this.canvas);
 
@@ -103,28 +105,19 @@ class TestRecordingPaintingContext implements PaintingContext {
   }
 
   @override
-  void pushClipRect(bool needsCompositing, Offset offset, Rect clipRect, PaintingContextCallback painter) {
-    canvas.save();
-    canvas.clipRect(clipRect.shift(offset));
-    painter(this, offset);
-    canvas.restore();
+  void pushClipRect(bool needsCompositing, Offset offset, Rect clipRect, PaintingContextCallback painter, {Clip clipBehavior = Clip.antiAlias}) {
+    clipRectAndPaint(clipRect.shift(offset), clipBehavior, clipRect.shift(offset), () => painter(this, offset));
   }
 
   @override
-  void pushClipRRect(bool needsCompositing, Offset offset, Rect bounds, RRect clipRRect, PaintingContextCallback painter) {
-    canvas.save();
-    canvas.clipRRect(clipRRect.shift(offset));
-    painter(this, offset);
-    canvas.restore();
+  void pushClipRRect(bool needsCompositing, Offset offset, Rect bounds, RRect clipRRect, PaintingContextCallback painter, {Clip clipBehavior = Clip.antiAlias}) {
+    assert(clipBehavior != null);
+    clipRRectAndPaint(clipRRect.shift(offset), clipBehavior, bounds.shift(offset), () => painter(this, offset));
   }
 
   @override
-  void pushClipPath(bool needsCompositing, Offset offset, Rect bounds, Path clipPath, PaintingContextCallback painter) {
-    canvas
-      ..save()
-      ..clipPath(clipPath.shift(offset));
-    painter(this, offset);
-    canvas.restore();
+  void pushClipPath(bool needsCompositing, Offset offset, Rect bounds, Path clipPath, PaintingContextCallback painter, {Clip clipBehavior = Clip.antiAlias}) {
+    clipPathAndPaint(clipPath.shift(offset), clipBehavior, bounds.shift(offset), () => painter(this, offset));
   }
 
   @override