Performance improvements for semantics tree compilation (#12682)

* Without checking compatibility

* ++

* ++

* ++

* more docs

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

@@ -2251,27 +2251,17 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
   void _updateSemantics() {
     assert(_semanticsConfiguration.isSemanticBoundary || parent is! RenderObject);
     final _SemanticsFragment fragment = _getSemanticsForParent(
-      parentClippingRect: _semanticsClippingRect,
       mergeIntoParent: _semantics?.parent?.isPartOfNodeMerging ?? false,
     );
     assert(fragment is _InterestingSemanticsFragment);
     final _InterestingSemanticsFragment interestingFragment = fragment;
-    final SemanticsNode node = interestingFragment.compileChildren().single;
+    final SemanticsNode node = interestingFragment.compileChildren(_semantics?.parentClipRect).single;
     // Fragment only wants to add this node's SemanticsNode to the parent.
     assert(interestingFragment.config == null && node == _semantics);
   }
 
-  /// Clip that needs to be applied to any [SemanticsNode] owned by this
-  /// [RenderObject].
-  ///
-  /// Can be null if no clip is to be applied.
-  ///
-  /// Updated by [_getSemanticsForParent].
-  Rect _semanticsClippingRect;
-
   /// Returns the semantics that this node would like to add to its parent.
   _SemanticsFragment _getSemanticsForParent({
-    @required Rect parentClippingRect,
     @required bool mergeIntoParent,
   }) {
     assert(mergeIntoParent != null);
@@ -2279,16 +2269,6 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
     final SemanticsConfiguration config = _semanticsConfiguration;
     bool dropSemanticsOfPreviousSiblings = config.isBlockingSemanticsOfPreviouslyPaintedNodes;
 
-    final _SemanticsGeometry geometry = new _SemanticsGeometry(
-      owner: this,
-      parentClippingRect: parentClippingRect,
-    );
-    _semanticsClippingRect = geometry.clipRect;
-
-    // Shortcut if this fragment cannot be exposed to user.
-    if (_semanticsConfiguration.isSemanticBoundary && !mergeIntoParent && geometry.isInvisible)
-      return new _ContainerSemanticsFragment(dropsSemanticsOfPreviousSiblings: dropSemanticsOfPreviousSiblings);
-
     final bool producesForkingFragment = !config.hasBeenAnnotated && !config.isSemanticBoundary;
     final List<_InterestingSemanticsFragment> fragments = <_InterestingSemanticsFragment>[];
     final Set<_InterestingSemanticsFragment> toBeMarkedExplicit = new Set<_InterestingSemanticsFragment>();
@@ -2296,7 +2276,6 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
 
     visitChildrenForSemantics((RenderObject renderChild) {
       final _SemanticsFragment fragment = renderChild._getSemanticsForParent(
-        parentClippingRect: _semanticsClippingRect,
         mergeIntoParent: childrenMergeIntoParent,
       );
       if (fragment.dropsSemanticsOfPreviousSiblings) {
@@ -2308,7 +2287,7 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
       // Figure out which child fragments are to be made explicit.
       for (_InterestingSemanticsFragment fragment in fragment.interestingFragments) {
         fragments.add(fragment);
-        fragment.geometry.addAncestor(this);
+        fragment.addAncestor(this);
         fragment.addTags(config.tagsForChildren);
         if (config.explicitChildNodes || parent is! RenderObject) {
           fragment.markAsExplicit();
@@ -2347,7 +2326,6 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
     } else {
       result = new _SwitchableSemanticsFragment(
         config: config,
-        geometry: geometry,
         mergeIntoParent: mergeIntoParent,
         owner: this,
         dropsSemanticsOfPreviousSiblings: dropSemanticsOfPreviousSiblings,
@@ -2998,18 +2976,20 @@ class _ContainerSemanticsFragment extends _SemanticsFragment {
 /// merged into the parent's [SemanticsNode].
 abstract class _InterestingSemanticsFragment extends _SemanticsFragment {
   _InterestingSemanticsFragment({
-    this.geometry,
-    @required this.owner,
+    @required RenderObject owner,
     @required bool dropsSemanticsOfPreviousSiblings
   }) : assert(owner != null),
+       _ancestorChain = <RenderObject>[owner],
        super(dropsSemanticsOfPreviousSiblings: dropsSemanticsOfPreviousSiblings);
 
   /// The [RenderObject] that owns this fragment (and any new [SemanticNode]
   /// introduced by it).
-  final RenderObject owner;
+  RenderObject get owner => _ancestorChain.first;
+
+  final List<RenderObject> _ancestorChain;
 
   /// The children to be added to the parent.
-  Iterable<SemanticsNode> compileChildren();
+  Iterable<SemanticsNode> compileChildren(Rect parentClipRect);
 
   /// The [SemanticsConfiguration] the child wants to merge into the parent's
   /// [SemanticsNode] or null if it doesn't want to merge anything.
@@ -3033,8 +3013,6 @@ abstract class _InterestingSemanticsFragment extends _SemanticsFragment {
   @override
   void addAll(Iterable<_InterestingSemanticsFragment> fragments);
 
-  final _SemanticsGeometry geometry;
-
   /// Whether this fragment wants to add any semantic information to the parent
   /// [SemanticsNode].
   bool get hasConfigForParent => config != null;
@@ -3053,6 +3031,18 @@ abstract class _InterestingSemanticsFragment extends _SemanticsFragment {
     _tagsForChildren ??= new Set<SemanticsTag>();
     _tagsForChildren.addAll(tags);
   }
+
+  /// Adds the geometric information of `ancestor` to this object.
+  ///
+  /// Those information are required to properly compute the value for
+  /// [SemanticsNode.transform], [SemanticsNode.clipRect], and
+  /// [SemanticsNode.rect].
+  ///
+  /// Ancestors have to be added in order from [owner] up until the next
+  /// [RenderObject] that owns a [SemanticsNode] is reached.
+  void addAncestor(RenderObject ancestor) {
+    _ancestorChain.add(ancestor);
+  }
 }
 
 /// A [_InterestingSemanticsFragment] that produces the root [SemanticsNode] of
@@ -3067,16 +3057,28 @@ class _RootSemanticsFragment extends _InterestingSemanticsFragment {
   }) : super(owner: owner, dropsSemanticsOfPreviousSiblings: dropsSemanticsOfPreviousSiblings);
 
   @override
-  Iterable<SemanticsNode> compileChildren() sync* {
+  Iterable<SemanticsNode> compileChildren(Rect parentClipRect) sync* {
     assert(_tagsForChildren == null || _tagsForChildren.isEmpty);
+    assert(parentClipRect == null);
+    assert(_ancestorChain.length == 1);
+
     owner._semantics ??= new SemanticsNode.root(
       showOnScreen: owner.showOnScreen,
       owner: owner.owner.semanticsOwner,
     );
     final SemanticsNode node = owner._semantics;
     assert(MatrixUtils.matrixEquals(node.transform, new Matrix4.identity()));
-    assert(!node.wasAffectedByClip);
+    assert(node.parentClipRect == null);
+
     node.rect = owner.semanticBounds;
+
+    final List<SemanticsNode> children = <SemanticsNode>[];
+    for (_InterestingSemanticsFragment fragment in _children) {
+      assert(fragment.config == null);
+      children.addAll(fragment.compileChildren(parentClipRect));
+    }
+    node.updateWith(config: null, childrenInInversePaintOrder: children);
+
     assert(!node.isInvisible);
     yield node;
   }
@@ -3084,6 +3086,8 @@ class _RootSemanticsFragment extends _InterestingSemanticsFragment {
   @override
   SemanticsConfiguration get config => null;
 
+  final List<_InterestingSemanticsFragment> _children = <_InterestingSemanticsFragment>[];
+
   @override
   void markAsExplicit() {
     // nothing to do, we are always explicit.
@@ -3091,13 +3095,7 @@ class _RootSemanticsFragment extends _InterestingSemanticsFragment {
 
   @override
   void addAll(Iterable<_InterestingSemanticsFragment> fragments) {
-    final SemanticsNode root = compileChildren().first;
-    final List<SemanticsNode> children = <SemanticsNode>[];
-    for (_InterestingSemanticsFragment fragment in fragments) {
-      assert(fragment.config == null);
-      children.addAll(fragment.compileChildren());
-    }
-    root.updateWith(config: null, childrenInInversePaintOrder: children);
+    _children.addAll(fragments);
   }
 }
 
@@ -3123,40 +3121,59 @@ class _SwitchableSemanticsFragment extends _InterestingSemanticsFragment {
   _SwitchableSemanticsFragment({
     @required bool mergeIntoParent,
     @required SemanticsConfiguration config,
-    @required _SemanticsGeometry geometry,
     @required RenderObject owner,
     @required bool dropsSemanticsOfPreviousSiblings,
   }) : _mergeIntoParent = mergeIntoParent,
        _config = config,
        assert(mergeIntoParent != null),
        assert(config != null),
-       super(geometry: geometry, owner: owner, dropsSemanticsOfPreviousSiblings: dropsSemanticsOfPreviousSiblings);
+       super(owner: owner, dropsSemanticsOfPreviousSiblings: dropsSemanticsOfPreviousSiblings);
 
   final bool _mergeIntoParent;
   SemanticsConfiguration _config;
   bool _isConfigWritable = false;
-  final List<SemanticsNode> _children = <SemanticsNode>[];
+  final List<_InterestingSemanticsFragment> _children = <_InterestingSemanticsFragment>[];
 
   @override
-  Iterable<SemanticsNode> compileChildren() sync* {
+  Iterable<SemanticsNode> compileChildren(Rect parentClipRect) sync* {
     if (!_isExplicit) {
       owner._semantics = null;
-      yield* _children;
+      for (_InterestingSemanticsFragment fragment in _children) {
+        assert(_ancestorChain.first == fragment._ancestorChain.last);
+        fragment._ancestorChain.addAll(_ancestorChain.sublist(1));
+        yield* fragment.compileChildren(parentClipRect);
+      }
       return;
     }
-    if (!_mergeIntoParent && geometry.rect.isEmpty)
+
+    final _SemanticsGeometry geometry = _needsGeometryUpdate
+        ? new _SemanticsGeometry(parentClipRect: parentClipRect, ancestors: _ancestorChain)
+        : null;
+
+    if (!_mergeIntoParent && (geometry?.isInvisible == true))
       return;  // Drop the node, it's not going to be visible.
+
     owner._semantics ??= new SemanticsNode(showOnScreen: owner.showOnScreen);
     final SemanticsNode node = owner._semantics
       ..isMergedIntoParent = _mergeIntoParent
       ..tags = _tagsForChildren;
 
-    geometry.updateNode(node);
+    if (geometry != null) {
+      assert(_needsGeometryUpdate);
+      node
+        ..rect = geometry.rect
+        ..transform = geometry.transform
+        ..parentClipRect = geometry.clipRect;
+    }
+
+    final List<SemanticsNode> children = <SemanticsNode>[];
+    for (_InterestingSemanticsFragment fragment in _children)
+      children.addAll(fragment.compileChildren(node.parentClipRect));
 
     if (_config.isSemanticBoundary) {
-      owner.assembleSemanticsNode(node, _config, _children);
+      owner.assembleSemanticsNode(node, _config, children);
     } else {
-      node.updateWith(config: _config, childrenInInversePaintOrder: _children);
+      node.updateWith(config: _config, childrenInInversePaintOrder: children);
     }
 
     yield node;
@@ -3170,7 +3187,7 @@ class _SwitchableSemanticsFragment extends _InterestingSemanticsFragment {
   @override
   void addAll(Iterable<_InterestingSemanticsFragment> fragments) {
     for (_InterestingSemanticsFragment fragment in fragments) {
-      _children.addAll(fragment.compileChildren());
+      _children.add(fragment);
       if (fragment.config == null)
         continue;
       if (!_isConfigWritable) {
@@ -3187,6 +3204,8 @@ class _SwitchableSemanticsFragment extends _InterestingSemanticsFragment {
   void markAsExplicit() {
     _isExplicit = true;
   }
+
+  bool get _needsGeometryUpdate => _ancestorChain.length > 1;
 }
 
 /// Helper class that keeps track of the geometry of a [SemanticsNode].
@@ -3195,109 +3214,68 @@ class _SwitchableSemanticsFragment extends _InterestingSemanticsFragment {
 /// [SemanticsNode.rect] and [SemanticsNode.transform].
 class _SemanticsGeometry {
 
-  /// `parentClippingRect` may be null if no clip is to be applied.
+  /// The `parentClippingRect` may be null if no clip is to be applied.
+  ///
+  /// The `ancestors` list has to include all [RenderObject] in order that are
+  /// located between the [SemanticsNode] whose geometry is represented here
+  /// (first [RenderObject] in the list) and its closest ancestor [RenderObject]
+  /// that also owns its own [SemanticsNode] (last [RenderObject] in the list).
   _SemanticsGeometry({
-    @required RenderObject owner,
-    @required Rect parentClippingRect
-  }) : assert(owner != null),
-       _ancestorChain = <RenderObject>[owner],
-       _parentClippingRect = parentClippingRect;
-
-  final Rect _parentClippingRect;
-  final List<RenderObject> _ancestorChain;
-
-  RenderObject get _owner => _ancestorChain.first;
-
-  /// The current clip [Rect] that would be applied to the [SemanticsNode]
-  /// owned by [owner].
-  Rect get clipRect {
-    if (!_isClipRectValid) {
-      __clipRect = _computeClipRect();
-      _isClipRectValid = true;
-    }
-    return __clipRect;
-  }
-  Rect __clipRect;
-  bool _isClipRectValid = false;
-
-  Rect _computeClipRect() {
-    if (_owner.parent is! RenderObject)
-      return null;
-    final RenderObject parent = _owner.parent;
-
-    // Clip rect in parent's coordinate system.
-    Rect clip = parent.describeApproximatePaintClip(_owner);
-    if (clip == null) {
-      if (_parentClippingRect == null)
-        return null;
-      clip = _parentClippingRect;
-    } else if (_parentClippingRect != null) {
-      clip = _parentClippingRect.intersect(clip);
-    }
+    @required Rect parentClipRect,
+    @required List<RenderObject> ancestors,
+  }) {
+    _computeValues(parentClipRect, ancestors);
+  }
 
-    assert(clip != null);
-    if (clip.isEmpty)
-      return Rect.zero;
+  Rect _clipRect;
+  Matrix4 _transform;
+  Rect _rect;
 
-    // Translate clip into owner's coordinate system.
-    final Matrix4 clipTransform = new Matrix4.identity();
-    parent.applyPaintTransform(_owner, clipTransform);
-    return MatrixUtils.inverseTransformRect(clipTransform, clip);
-  }
+  /// Value for [SemanticsNode.transform].
+  Matrix4 get transform => _transform;
 
-  /// The value for [SemanticsNode.rect].
-  ///
-  /// This is essentially [RenderObject.semanticsBound] with [clipRect] applied.
-  Rect get rect {
-    if (__rect == null)
-      __rect = _computeRect();
-    return __rect;
-  }
-  Rect __rect;
+  /// Value for [SemanticsNode.parentClipRect].
+  Rect get clipRect => _clipRect;
 
-  Rect _computeRect() {
-    if (clipRect == null)
-      return _owner.semanticBounds;
-    return clipRect.intersect(_owner.semanticBounds);
-  }
+  /// Value for [SemanticsNode.rect].
+  Rect get rect => _rect;
 
-  Matrix4 _computeTransformation() {
-    assert(_ancestorChain.length > 1);
-    final Matrix4 transform = new Matrix4.identity();
-    for (int index = _ancestorChain.length-1; index > 0; index -= 1) {
-      final RenderObject parent = _ancestorChain[index];
-      final RenderObject child = _ancestorChain[index - 1];
-      parent.applyPaintTransform(child, transform);
+  void _computeValues(Rect parentClipRect, List<RenderObject> ancestors) {
+    assert(ancestors.length > 1);
 
+    _transform = new Matrix4.identity();
+    _clipRect = parentClipRect;
+    for (int index = ancestors.length-1; index > 0; index -= 1) {
+      final RenderObject parent = ancestors[index];
+      final RenderObject child = ancestors[index-1];
+      _clipRect = _intersectClipRect(parent.describeApproximatePaintClip(child));
+      if (_clipRect != null) {
+        if (_clipRect.isEmpty) {
+          _clipRect = Rect.zero;
+        } else {
+          final Matrix4 clipTransform = new Matrix4.identity();
+          parent.applyPaintTransform(child, clipTransform);
+          _clipRect = MatrixUtils.inverseTransformRect(clipTransform, _clipRect);
+        }
+      }
+      parent.applyPaintTransform(child, _transform);
     }
-    return transform;
-  }
 
-  /// Annotates `node` with the latest geometry information.
-  ///
-  /// It sets [SemanticsNode.rect], [SemanticsNode.transform], and
-  /// [SemanticsNode.wasAffectedByClip] to the current values.
-  void updateNode(SemanticsNode node) {
-    if (_ancestorChain.length > 1)
-      node.transform = _computeTransformation();
-    node.rect = rect;
-    node.wasAffectedByClip = rect != _owner.semanticBounds;
+    final RenderObject owner = ancestors.first;
+    _rect = _clipRect == null ? owner.semanticBounds : _clipRect.intersect(owner.semanticBounds);
   }
 
-  /// Adds the geometric information of `ancestor` to this object.
-  ///
-  /// Those information are required to properly compute the value for
-  /// [SemanticsNode.transform].
-  ///
-  /// Ancestors have to be added in order from [owner] up until the next
-  /// [RenderObject] that owns a [SemanticsNode] is reached.
-  void addAncestor(RenderObject ancestor) {
-    _ancestorChain.add(ancestor);
+  Rect _intersectClipRect(Rect other) {
+    if (_clipRect == null)
+      return other;
+    if (other == null)
+      return _clipRect;
+    return _clipRect.intersect(other);
   }
 
   /// Whether a [SemanticsNode] annotated with the geometric information tracked
   /// by this object would be visible on screen.
   bool get isInvisible {
-    return clipRect != null && clipRect.isEmpty || rect.isEmpty;
+    return _rect.isEmpty;
   }
 }

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

@@ -3086,7 +3086,6 @@ class RenderSemanticsGestureHandler extends RenderProxyBox {
 
     _innerNode ??= new SemanticsNode(showOnScreen: showOnScreen);
     _innerNode
-      ..wasAffectedByClip = node.wasAffectedByClip
       ..isMergedIntoParent = node.isPartOfNodeMerging
       ..rect = Offset.zero & node.rect.size;
     _annotatedNode = _innerNode;

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

@@ -253,12 +253,11 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
     }
   }
 
-  /// Whether [rect] was affected by a clip from an ancestors.
+  /// The clip rect from an ancestor that was applied to this node.
   ///
-  /// If this is true it means that an ancestor imposed a clip on this
-  /// [SemanticsNode]. However, it does not mean that the clip had any effect
-  /// on the [rect] whatsoever.
-  bool wasAffectedByClip = false;
+  /// Expressed in the coordinate system of the node. May be null if no clip has
+  /// been applied.
+  Rect parentClipRect;
 
   /// Whether the node is invisible.
   ///
@@ -488,7 +487,7 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
     return _label != config.label ||
         _flags != config._flags ||
         _textDirection != config.textDirection ||
-        _actionsAsBitMap(_actions) != _actionsAsBitMap(config._actions) ||
+        _actionsAsBits != config._actionsAsBits ||
         _mergeAllDescendantsIntoThisNode != config.isMergingSemanticsOfDescendants;
   }
 
@@ -496,6 +495,8 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
 
   Map<SemanticsAction, VoidCallback> _actions = _kEmptyConfig._actions;
 
+  int _actionsAsBits = _kEmptyConfig._actionsAsBits;
+
   /// The [SemanticsTag]s this node is tagged with.
   ///
   /// Tags are used during the construction of the semantics tree. They are not
@@ -519,10 +520,6 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
   TextDirection get textDirection => _textDirection;
   TextDirection _textDirection = _kEmptyConfig.textDirection;
 
-  int _actionsAsBitMap(Map<SemanticsAction, VoidCallback> actions) {
-    return actions.keys.fold(0, (int prev, SemanticsAction action) => prev |= action.index);
-  }
-
   bool _canPerformAction(SemanticsAction action) => _actions.containsKey(action);
 
   static final SemanticsConfiguration _kEmptyConfig = new SemanticsConfiguration();
@@ -539,6 +536,7 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
     _flags = config._flags;
     _textDirection = config.textDirection;
     _actions = new Map<SemanticsAction, VoidCallback>.from(config._actions);
+    _actionsAsBits = config._actionsAsBits;
     _mergeAllDescendantsIntoThisNode = config.isMergingSemanticsOfDescendants;
     _replaceChildren(childrenInInversePaintOrder ?? const <SemanticsNode>[]);
   }
@@ -551,7 +549,7 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
   /// returned data matches the data on this node.
   SemanticsData getSemanticsData() {
     int flags = _flags;
-    int actions = _actionsAsBitMap(_actions);
+    int actions = _actionsAsBits;
     String label = _label;
     TextDirection textDirection = _textDirection;
     Set<SemanticsTag> mergedTags = tags == null ? null : new Set<SemanticsTag>.from(tags);
@@ -560,7 +558,7 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
       _visitDescendants((SemanticsNode node) {
         assert(node.isMergedIntoParent);
         flags |= node._flags;
-        actions |= _actionsAsBitMap(node._actions);
+        actions |= node._actionsAsBits;
         textDirection ??= node._textDirection;
         if (node.tags != null) {
           mergedTags ??= new Set<SemanticsTag>();
@@ -673,7 +671,6 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
       }
       properties.add(new DiagnosticsProperty<Rect>('rect', rect, description: description, showName: false));
     }
-    properties.add(new FlagProperty('wasAffectedByClip', value: wasAffectedByClip, ifTrue: 'clipped'));
     final List<String> actions = _actions.keys.map((SemanticsAction action) => describeEnum(action)).toList()..sort();
     properties.add(new IterableProperty<String>('actions', actions, ifEmpty: null));
     if (_hasFlag(SemanticsFlags.hasCheckedState))
@@ -871,7 +868,7 @@ class SemanticsOwner extends ChangeNotifier {
           return handler;
       }
     }
-    return node._canPerformAction(action) ? node._actions[action] : null;
+    return node._actions[action];
   }
 
   /// Asks the [SemanticsNode] at the given position to perform the given action.
@@ -985,11 +982,14 @@ class SemanticsConfiguration {
   /// * [addAction] to add an action.
   final Map<SemanticsAction, VoidCallback> _actions = <SemanticsAction, VoidCallback>{};
 
+  int _actionsAsBits = 0;
+
   /// Adds an `action` to the semantics tree.
   ///
   /// Whenever the user performs `action` the provided `handler` is called.
   void addAction(SemanticsAction action, VoidCallback handler) {
     _actions[action] = handler;
+    _actionsAsBits |= action.index;
     _hasBeenAnnotated = true;
   }
 
@@ -1083,7 +1083,7 @@ class SemanticsConfiguration {
   bool isCompatibleWith(SemanticsConfiguration other) {
     if (other == null || !other.hasBeenAnnotated || !hasBeenAnnotated)
       return true;
-    if (_actions.keys.toSet().intersection(other._actions.keys.toSet()).isNotEmpty)
+    if (_actionsAsBits & other._actionsAsBits != 0)
       return false;
     if ((_flags & other._flags) != 0)
       return false;
@@ -1105,6 +1105,7 @@ class SemanticsConfiguration {
       return;
 
     _actions.addAll(other._actions);
+    _actionsAsBits |= other._actionsAsBits;
     _flags |= other._flags;
 
     textDirection ??= other.textDirection;
@@ -1138,6 +1139,7 @@ class SemanticsConfiguration {
       .._textDirection = _textDirection
       .._label = _label
       .._flags = _flags
+      .._actionsAsBits = _actionsAsBits
       .._actions.addAll(_actions);
   }
 }

packages/flutter/test/material/card_test.dart

@@ -40,12 +40,12 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 2,
+            id: 1,
             label: 'I am text!\nMoar text!!1',
             textDirection: TextDirection.ltr,
             children: <TestSemantics>[
               new TestSemantics(
-                id: 1,
+                id: 2,
                 label: 'Button',
                 textDirection: TextDirection.ltr,
                 actions: SemanticsAction.tap.index,

packages/flutter/test/material/control_list_tile_test.dart

@@ -95,7 +95,7 @@ void main() {
     expect(semantics, hasSemantics(new TestSemantics.root(
       children: <TestSemantics>[
         new TestSemantics.rootChild(
-          id: 7,
+          id: 1,
           rect: new Rect.fromLTWH(0.0, 0.0, 800.0, 56.0),
           transform: null,
           flags: SemanticsFlags.hasCheckedState.index | SemanticsFlags.isChecked.index,
@@ -103,7 +103,7 @@ void main() {
           label: 'aaa\nAAA',
         ),
         new TestSemantics.rootChild(
-          id: 8,
+          id: 4,
           rect: new Rect.fromLTWH(0.0, 0.0, 800.0, 56.0),
           transform: new Matrix4.translationValues(0.0, 56.0, 0.0),
           flags: SemanticsFlags.hasCheckedState.index | SemanticsFlags.isChecked.index,
@@ -111,7 +111,7 @@ void main() {
           label: 'bbb\nBBB',
         ),
         new TestSemantics.rootChild(
-          id: 9,
+          id: 7,
           rect: new Rect.fromLTWH(0.0, 0.0, 800.0, 56.0),
           transform: new Matrix4.translationValues(0.0, 112.0, 0.0),
           flags: SemanticsFlags.hasCheckedState.index,

packages/flutter/test/material/tabs_test.dart

@@ -1011,11 +1011,11 @@ void main() {
     final TestSemantics expectedSemantics = new TestSemantics.root(
       children: <TestSemantics>[
         new TestSemantics.rootChild(
-          id: 3,
+          id: 1,
           rect: TestSemantics.fullScreen,
           children: <TestSemantics>[
             new TestSemantics(
-              id: 1,
+              id: 2,
               actions: SemanticsAction.tap.index,
               flags: SemanticsFlags.isSelected.index,
               label: 'TAB #0\nTab 1 of 2',
@@ -1023,7 +1023,7 @@ void main() {
               transform: new Matrix4.translationValues(0.0, 276.0, 0.0),
             ),
             new TestSemantics(
-              id: 2,
+              id: 3,
               actions: SemanticsAction.tap.index,
               label: 'TAB #1\nTab 2 of 2',
               rect: new Rect.fromLTRB(0.0, 0.0, 108.0, kTextTabBarHeight),
@@ -1261,11 +1261,11 @@ void main() {
     final TestSemantics expectedSemantics = new TestSemantics.root(
       children: <TestSemantics>[
         new TestSemantics.rootChild(
-          id: 25,
+          id: 23,
           rect: TestSemantics.fullScreen,
           children: <TestSemantics>[
             new TestSemantics(
-              id: 23,
+              id: 24,
               actions: SemanticsAction.tap.index,
               flags: SemanticsFlags.isSelected.index,
               label: 'Semantics override 0\nTab 1 of 2',
@@ -1273,7 +1273,7 @@ void main() {
               transform: new Matrix4.translationValues(0.0, 276.0, 0.0),
             ),
             new TestSemantics(
-              id: 24,
+              id: 25,
               actions: SemanticsAction.tap.index,
               label: 'Semantics override 1\nTab 2 of 2',
               rect: new Rect.fromLTRB(0.0, 0.0, 108.0, kTextTabBarHeight),

packages/flutter/test/rendering/semantics_test.dart

@@ -198,7 +198,7 @@ void main() {
 
     expect(
       minimalProperties.toStringDeep(minLevel: DiagnosticLevel.hidden),
-      'SemanticsNode#16(owner: null, isPartOfNodeMerging: false, Rect.fromLTRB(0.0, 0.0, 0.0, 0.0), wasAffectedByClip: false, actions: [], isSelected: false, label: "", isButton: false, textDirection: null)\n',
+      'SemanticsNode#16(owner: null, isPartOfNodeMerging: false, Rect.fromLTRB(0.0, 0.0, 0.0, 0.0), actions: [], isSelected: false, label: "", isButton: false, textDirection: null)\n',
     );
 
     final SemanticsConfiguration config = new SemanticsConfiguration()
@@ -214,11 +214,10 @@ void main() {
     final SemanticsNode allProperties = new SemanticsNode()
       ..rect = new Rect.fromLTWH(50.0, 10.0, 20.0, 30.0)
       ..transform = new Matrix4.translation(new Vector3(10.0, 10.0, 0.0))
-      ..wasAffectedByClip = true
       ..updateWith(config: config, childrenInInversePaintOrder: null);
     expect(
       allProperties.toStringDeep(),
-      'SemanticsNode#17(STALE, owner: null, leaf merge, Rect.fromLTRB(60.0, 20.0, 80.0, 50.0), clipped, actions: [longPress, scrollUp, showOnScreen], unchecked, selected, label: "Use all the properties", button, textDirection: rtl)\n',
+      'SemanticsNode#17(STALE, owner: null, leaf merge, Rect.fromLTRB(60.0, 20.0, 80.0, 50.0), actions: [longPress, scrollUp, showOnScreen], unchecked, selected, label: "Use all the properties", button, textDirection: rtl)\n',
     );
     expect(
       allProperties.getSemanticsData().toString(),

packages/flutter/test/widgets/implicit_semantics_test.dart

@@ -229,20 +229,20 @@ void main() {
         new TestSemantics.root(
           children: <TestSemantics>[
             new TestSemantics.rootChild(
-              id: 8,
+              id: 5,
               children: <TestSemantics>[
                 new TestSemantics(
-                  id: 5,
+                  id: 6,
                   flags: SemanticsFlags.isSelected.index,
                   label: 'node 1',
                 ),
                 new TestSemantics(
-                  id: 6,
+                  id: 7,
                   flags: SemanticsFlags.isSelected.index,
                   label: 'node 2',
                 ),
                 new TestSemantics(
-                  id: 7,
+                  id: 8,
                   flags: SemanticsFlags.isSelected.index,
                   label: 'node 3',
                 ),

packages/flutter/test/widgets/modal_barrier_test.dart

@@ -104,11 +104,11 @@ void main() {
     final TestSemantics expectedSemantics = new TestSemantics.root(
       children: <TestSemantics>[
         new TestSemantics.rootChild(
-          id: 2,
+          id: 1,
           rect: TestSemantics.fullScreen,
           children: <TestSemantics>[
             new TestSemantics(
-              id: 1,
+              id: 2,
               rect: TestSemantics.fullScreen,
               actions: SemanticsAction.tap.index,
             ),

packages/flutter/test/widgets/semantics_2_test.dart

@@ -53,17 +53,17 @@ void main() {
     expect(semantics, hasSemantics(new TestSemantics.root(
       children: <TestSemantics>[
         new TestSemantics.rootChild(
-          id: 3,
+          id: 1,
           rect: TestSemantics.fullScreen,
           children: <TestSemantics>[
             new TestSemantics(
-              id: 1,
+              id: 2,
               label: 'child1',
               rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 10.0),
               flags: SemanticsFlags.isSelected.index,
             ),
             new TestSemantics(
-              id: 2,
+              id: 3,
               label: 'child2',
               rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 10.0),
               flags: SemanticsFlags.isSelected.index,
@@ -107,7 +107,7 @@ void main() {
     expect(semantics, hasSemantics(new TestSemantics.root(
       children: <TestSemantics>[
         new TestSemantics.rootChild(
-          id: 3,
+          id: 1,
           label: 'child1',
           rect: TestSemantics.fullScreen,
           flags: SemanticsFlags.isSelected.index,
@@ -149,7 +149,7 @@ void main() {
     expect(semantics, hasSemantics(new TestSemantics.root(
       children: <TestSemantics>[
         new TestSemantics.rootChild(
-          id: 3,
+          id: 1,
           rect: TestSemantics.fullScreen,
           children: <TestSemantics>[
             new TestSemantics(
@@ -159,7 +159,7 @@ void main() {
               flags: SemanticsFlags.isSelected.index,
             ),
             new TestSemantics(
-              id: 2,
+              id: 3,
               label: 'child2',
               rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 10.0),
               flags: SemanticsFlags.isSelected.index,

packages/flutter/test/widgets/semantics_4_test.dart

@@ -53,22 +53,22 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 3,
+            id: 1,
             label: 'L1',
             rect: TestSemantics.fullScreen,
           ),
           new TestSemantics.rootChild(
-            id: 4,
+            id: 2,
             label: 'L2',
             rect: TestSemantics.fullScreen,
             children: <TestSemantics>[
               new TestSemantics(
-                id: 1,
+                id: 3,
                 flags: SemanticsFlags.hasCheckedState.index | SemanticsFlags.isChecked.index,
                 rect: TestSemantics.fullScreen,
               ),
               new TestSemantics(
-                id: 2,
+                id: 4,
                 flags: SemanticsFlags.hasCheckedState.index,
                 rect: TestSemantics.fullScreen,
               ),
@@ -113,12 +113,12 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 3,
+            id: 1,
             label: 'L1',
             rect: TestSemantics.fullScreen,
           ),
           new TestSemantics.rootChild(
-            id: 4,
+            id: 2,
             label: 'L2',
             flags: SemanticsFlags.hasCheckedState.index | SemanticsFlags.isChecked.index,
             rect: TestSemantics.fullScreen,
@@ -158,7 +158,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 4,
+            id: 2,
             label: 'L2',
             flags: SemanticsFlags.hasCheckedState.index | SemanticsFlags.isChecked.index,
             rect: TestSemantics.fullScreen,

packages/flutter/test/widgets/semantics_7_test.dart

@@ -55,7 +55,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 3,
+            id: 1,
             flags: SemanticsFlags.hasCheckedState.index | SemanticsFlags.isChecked.index,
             label: label,
             rect: TestSemantics.fullScreen,
@@ -111,7 +111,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 3,
+            id: 1,
             flags: SemanticsFlags.hasCheckedState.index | SemanticsFlags.isChecked.index,
             label: label,
             rect: TestSemantics.fullScreen,

packages/flutter/test/widgets/semantics_8_test.dart

@@ -41,7 +41,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 3,
+            id: 1,
             flags: SemanticsFlags.hasCheckedState.index | SemanticsFlags.isChecked.index,
             label: 'label',
             textDirection: TextDirection.ltr,
@@ -79,7 +79,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 3,
+            id: 1,
             flags: SemanticsFlags.hasCheckedState.index | SemanticsFlags.isChecked.index,
             label: 'label',
             textDirection: TextDirection.ltr,

packages/flutter/test/widgets/semantics_clipping_test.dart

@@ -60,12 +60,6 @@ void main() {
       ignoreTransform: true,
     ));
 
-    final SemanticsNode node1 = tester.renderObject(find.byWidget(const Text('1'))).debugSemantics;
-    final SemanticsNode node2 = tester.renderObject(find.byWidget(const Text('2'))).debugSemantics;
-
-    expect(node1.wasAffectedByClip, false);
-    expect(node2.wasAffectedByClip, true);
-
     semantics.dispose();
   });
 

packages/flutter/test/widgets/sliver_semantics_test.dart

@@ -50,7 +50,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 4,
+            id: 1,
             tags: <SemanticsTag>[RenderSemanticsGestureHandler.useTwoPaneSemantics],
             children: <TestSemantics>[
               new TestSemantics(
@@ -58,15 +58,15 @@ void main() {
                 actions: SemanticsAction.scrollUp.index,
                 children: <TestSemantics>[
                   new TestSemantics(
-                    id: 1,
+                    id: 2,
                     label: 'Item 0',
                   ),
                   new TestSemantics(
-                    id: 2,
+                    id: 3,
                     label: 'Item 1',
                   ),
                   new TestSemantics(
-                    id: 3,
+                    id: 4,
                     label: 'Semantics Test with Slivers',
                   ),
                 ],
@@ -88,7 +88,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 4,
+            id: 1,
             tags: <SemanticsTag>[RenderSemanticsGestureHandler.useTwoPaneSemantics],
             children: <TestSemantics>[
               new TestSemantics(
@@ -96,11 +96,11 @@ void main() {
                 actions: SemanticsAction.scrollUp.index | SemanticsAction.scrollDown.index,
                 children: <TestSemantics>[
                   new TestSemantics(
-                    id: 1,
+                    id: 2,
                     label: 'Item 0',
                   ),
                   new TestSemantics(
-                    id: 2,
+                    id: 3,
                     label: 'Item 1',
                   ),
                   new TestSemantics(
@@ -110,7 +110,7 @@ void main() {
                 ],
               ),
               new TestSemantics(
-                id: 3,
+                id: 4,
                 label: 'Semantics Test with Slivers',
                 tags: <SemanticsTag>[RenderSemanticsGestureHandler.excludeFromScrolling],
               ),
@@ -131,7 +131,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 4,
+            id: 1,
             tags: <SemanticsTag>[RenderSemanticsGestureHandler.useTwoPaneSemantics],
             children: <TestSemantics>[
               new TestSemantics(
@@ -139,11 +139,11 @@ void main() {
                 actions: SemanticsAction.scrollUp.index | SemanticsAction.scrollDown.index,
                 children: <TestSemantics>[
                   new TestSemantics(
-                    id: 1,
+                    id: 2,
                     label: 'Item 0',
                   ),
                   new TestSemantics(
-                    id: 2,
+                    id: 3,
                     label: 'Item 1',
                   ),
                   new TestSemantics(
@@ -151,7 +151,7 @@ void main() {
                     label: 'Item 2',
                   ),
                   new TestSemantics(
-                    id: 3,
+                    id: 4,
                     label: 'Semantics Test with Slivers',
                   ),
                 ],
@@ -202,7 +202,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 9,
+            id: 7,
             tags: <SemanticsTag>[RenderSemanticsGestureHandler.useTwoPaneSemantics],
             children: <TestSemantics>[
               new TestSemantics(
@@ -210,12 +210,12 @@ void main() {
                 actions: SemanticsAction.scrollUp.index | SemanticsAction.scrollDown.index,
                 children: <TestSemantics>[
                   new TestSemantics(
-                    id: 7,
+                    id: 8,
                     label: 'Item 2',
                     textDirection: TextDirection.ltr,
                   ),
                   new TestSemantics(
-                    id: 8,
+                    id: 9,
                     label: 'Item 1',
                     textDirection: TextDirection.ltr,
                   ),
@@ -256,34 +256,34 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 16,
+            id: 11,
             tags: <SemanticsTag>[RenderSemanticsGestureHandler.useTwoPaneSemantics],
             children: <TestSemantics>[
               new TestSemantics(
                 id: 17,
                 children: <TestSemantics>[
                   new TestSemantics(
-                    id: 11,
+                    id: 12,
                     label: 'Item 4',
                     textDirection: TextDirection.ltr,
                   ),
                   new TestSemantics(
-                    id: 12,
+                    id: 13,
                     label: 'Item 3',
                     textDirection: TextDirection.ltr,
                   ),
                   new TestSemantics(
-                    id: 13,
+                    id: 14,
                     label: 'Item 2',
                     textDirection: TextDirection.ltr,
                   ),
                   new TestSemantics(
-                    id: 14,
+                    id: 15,
                     label: 'Item 1',
                     textDirection: TextDirection.ltr,
                   ),
                   new TestSemantics(
-                    id: 15,
+                    id: 16,
                     label: 'Item 0',
                     textDirection: TextDirection.ltr,
                   ),
@@ -337,7 +337,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 22,
+            id: 18,
             rect: TestSemantics.fullScreen,
             tags: <SemanticsTag>[RenderSemanticsGestureHandler.useTwoPaneSemantics],
             children: <TestSemantics>[
@@ -348,20 +348,20 @@ void main() {
                 children: <TestSemantics>[
                   // Item 0 is missing because its covered by the app bar.
                   new TestSemantics(
-                    id: 18,
+                    id: 19,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     // Item 1 starts 20.0dp below edge, so there would be room for Item 0.
                     transform: new Matrix4.translation(new Vector3(0.0, 20.0, 0.0)),
                     label: 'Item 1',
                   ),
                   new TestSemantics(
-                    id: 19,
+                    id: 20,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     transform: new Matrix4.translation(new Vector3(0.0, 220.0, 0.0)),
                     label: 'Item 2',
                   ),
                   new TestSemantics(
-                    id: 20,
+                    id: 21,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     transform: new Matrix4.translation(new Vector3(0.0, 420.0, 0.0)),
                     label: 'Item 3',
@@ -369,7 +369,7 @@ void main() {
                 ],
               ),
               new TestSemantics(
-                id: 21,
+                id: 22,
                 rect: new Rect.fromLTRB(0.0, 0.0, 120.0, 20.0),
                 tags: <SemanticsTag>[RenderSemanticsGestureHandler.excludeFromScrolling],
                 label: 'AppBar',
@@ -420,7 +420,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 28,
+            id: 24,
             rect: TestSemantics.fullScreen,
             tags: <SemanticsTag>[RenderSemanticsGestureHandler.useTwoPaneSemantics],
             children: <TestSemantics>[
@@ -430,19 +430,19 @@ void main() {
                 rect: TestSemantics.fullScreen,
                 children: <TestSemantics>[
                   new TestSemantics(
-                    id: 24,
+                    id: 25,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     transform: new Matrix4.translation(new Vector3(0.0, 420.0, 0.0)),
                     label: 'Item 3',
                   ),
                   new TestSemantics(
-                    id: 25,
+                    id: 26,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     transform: new Matrix4.translation(new Vector3(0.0, 220.0, 0.0)),
                     label: 'Item 2',
                   ),
                   new TestSemantics(
-                    id: 26,
+                    id: 27,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     // Item 1 starts 20.0dp below edge, so there would be room for Item 0.
                     transform: new Matrix4.translation(new Vector3(0.0, 20.0, 0.0)),
@@ -452,7 +452,7 @@ void main() {
                 ],
               ),
               new TestSemantics(
-                id: 27,
+                id: 28,
                 rect: new Rect.fromLTRB(0.0, 0.0, 120.0, 20.0),
                 tags: <SemanticsTag>[RenderSemanticsGestureHandler.excludeFromScrolling],
                 label: 'AppBar'
@@ -505,7 +505,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 34,
+            id: 30,
             rect: TestSemantics.fullScreen,
             tags: <SemanticsTag>[RenderSemanticsGestureHandler.useTwoPaneSemantics],
             children: <TestSemantics>[
@@ -516,20 +516,20 @@ void main() {
                 children: <TestSemantics>[
                   // Item 0 is missing because its covered by the app bar.
                   new TestSemantics(
-                    id: 30,
+                    id: 31,
                     // Item 1 ends at 580dp, so there would be 20dp space for Item 0.
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     transform: new Matrix4.translation(new Vector3(0.0, 380.0, 0.0)),
                     label: 'Item 1',
                   ),
                   new TestSemantics(
-                    id: 31,
+                    id: 32,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     transform: new Matrix4.translation(new Vector3(0.0, 180.0, 0.0)),
                     label: 'Item 2',
                   ),
                   new TestSemantics(
-                    id: 32,
+                    id: 33,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     transform: new Matrix4.translation(new Vector3(0.0, -20.0, 0.0)),
                     label: 'Item 3',
@@ -537,7 +537,7 @@ void main() {
                 ],
               ),
               new TestSemantics(
-                id: 33,
+                id: 34,
                 rect: new Rect.fromLTRB(0.0, 0.0, 120.0, 20.0),
                 transform: new Matrix4.translation(new Vector3(0.0, 544.0, 0.0)),
                 tags: <SemanticsTag>[RenderSemanticsGestureHandler.excludeFromScrolling],
@@ -590,7 +590,7 @@ void main() {
       new TestSemantics.root(
         children: <TestSemantics>[
           new TestSemantics.rootChild(
-            id: 40,
+            id: 36,
             rect: TestSemantics.fullScreen,
             tags: <SemanticsTag>[RenderSemanticsGestureHandler.useTwoPaneSemantics],
             children: <TestSemantics>[
@@ -600,19 +600,19 @@ void main() {
                 rect: TestSemantics.fullScreen,
                 children: <TestSemantics>[
                   new TestSemantics(
-                    id: 36,
+                    id: 37,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     transform: new Matrix4.translation(new Vector3(0.0, -20.0, 0.0)),
                     label: 'Item 3',
                   ),
                   new TestSemantics(
-                    id: 37,
+                    id: 38,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     transform: new Matrix4.translation(new Vector3(0.0, 180.0, 0.0)),
                     label: 'Item 2',
                   ),
                   new TestSemantics(
-                    id: 38,
+                    id: 39,
                     rect: new Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
                     // Item 1 ends at 580dp, so there would be 20dp space for Item 0.
                     transform: new Matrix4.translation(new Vector3(0.0, 380.0, 0.0)),
@@ -622,7 +622,7 @@ void main() {
                 ],
               ),
               new TestSemantics(
-                id: 39,
+                id: 40,
                 rect: new Rect.fromLTRB(0.0, 0.0, 120.0, 20.0),
                 transform: new Matrix4.translation(new Vector3(0.0, 544.0, 0.0)),
                 tags: <SemanticsTag>[RenderSemanticsGestureHandler.excludeFromScrolling],