flutter · goderbauer · Jan 16, 2019 · Dec 20, 2018 · Dec 21, 2018 · Dec 21, 2018
@@ -1 +1 @@
-02905560cf2c2132a7adea10943001f29325f3be
+ecbdcf8d56d3aba0212c2b1b923466023ef09b4e
diff --git a/packages/flutter/lib/src/material/app_bar.dart b/packages/flutter/lib/src/material/app_bar.dart
@@ -524,13 +524,15 @@ class _AppBarState extends State<AppBar> {
 
     return Semantics(
       container: true,
-      explicitChildNodes: true,
       child: AnnotatedRegion<SystemUiOverlayStyle>(
         value: overlayStyle,
         child: Material(
           color: widget.backgroundColor ?? themeData.primaryColor,
           elevation: widget.elevation,
-          child: appBar,
+          child: Semantics(
+            explicitChildNodes: true,
+            child: appBar,
+          ),
         ),
       ),
     );

diff --git a/packages/flutter/lib/src/material/bottom_navigation_bar.dart b/packages/flutter/lib/src/material/bottom_navigation_bar.dart
@@ -567,43 +567,30 @@ class _BottomNavigationBarState extends State<BottomNavigationBar> with TickerPr
         break;
     }
     return Semantics(
-      container: true,
       explicitChildNodes: true,
-      child: Stack(
-        children: <Widget>[
-          Positioned.fill(
-            child: Material( // Casts shadow.
-              elevation: 8.0,
-              color: backgroundColor,
+      child: Material(
+        elevation: 8.0,
+        color: backgroundColor,
+        child: ConstrainedBox(
+          constraints: BoxConstraints(minHeight: kBottomNavigationBarHeight + additionalBottomPadding),
+          child: CustomPaint(
+            painter: _RadialPainter(
+              circles: _circles.toList(),
+              textDirection: Directionality.of(context),
             ),
-          ),
-          ConstrainedBox(
-            constraints: BoxConstraints(minHeight: kBottomNavigationBarHeight + additionalBottomPadding),
-            child: Stack(
-              children: <Widget>[
-                Positioned.fill(
-                  child: CustomPaint(
-                    painter: _RadialPainter(
-                      circles: _circles.toList(),
-                      textDirection: Directionality.of(context),
-                    ),
-                  ),
-                ),
-                Material( // Splashes.
-                  type: MaterialType.transparency,
-                  child: Padding(
-                    padding: EdgeInsets.only(bottom: additionalBottomPadding),
-                    child: MediaQuery.removePadding(
-                      context: context,
-                      removeBottom: true,
-                      child: _createContainer(_createTiles()),
-                    ),
-                  ),
+            child: Material( // Splashes.
+              type: MaterialType.transparency,
+              child: Padding(
+                padding: EdgeInsets.only(bottom: additionalBottomPadding),
+                child: MediaQuery.removePadding(
+                  context: context,
+                  removeBottom: true,
+                  child: _createContainer(_createTiles()),
                 ),
-              ],
+              ),
             ),
           ),
-        ],
+        ),
       ),
     );
   }

diff --git a/packages/flutter/lib/src/material/card.dart b/packages/flutter/lib/src/material/card.dart
@@ -135,7 +135,6 @@ class Card extends StatelessWidget {
   Widget build(BuildContext context) {
     return Semantics(
       container: semanticContainer,
-      explicitChildNodes: !semanticContainer,
       child: Container(
         margin: margin ?? const EdgeInsets.all(4.0),
         child: Material(
@@ -146,7 +145,10 @@ class Card extends StatelessWidget {
             borderRadius: BorderRadius.all(Radius.circular(4.0)),
           ),
           clipBehavior: clipBehavior,
-          child: child,
+          child: Semantics(
+            explicitChildNodes: !semanticContainer,
+            child: child,
+          ),
         ),
       ),
     );

diff --git a/packages/flutter/lib/src/material/dialog.dart b/packages/flutter/lib/src/material/dialog.dart
@@ -310,7 +310,11 @@ class AlertDialog extends StatelessWidget {
         padding: titlePadding ?? EdgeInsets.fromLTRB(24.0, 24.0, 24.0, content == null ? 20.0 : 0.0),
         child: DefaultTextStyle(
           style: titleTextStyle ?? dialogTheme.titleTextStyle ?? theme.textTheme.title,
-          child: Semantics(child: title, namesRoute: true),
+          child: Semantics(
+            child: title,
+            namesRoute: true,
+            container: true,
+          ),
         ),
       ));
     } else {

diff --git a/packages/flutter/lib/src/rendering/object.dart b/packages/flutter/lib/src/rendering/object.dart
@@ -2406,6 +2406,7 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
     final SemanticsNode node = interestingFragment.compileChildren(
       parentSemanticsClipRect: _semantics?.parentSemanticsClipRect,
       parentPaintClipRect: _semantics?.parentPaintClipRect,
+      elevationAdjustment: _semantics?.elevationAdjustment ?? 0.0,
     ).single;
     // Fragment only wants to add this node's SemanticsNode to the parent.
     assert(interestingFragment.config == null && node == _semantics);
@@ -3193,9 +3194,19 @@ abstract class _InterestingSemanticsFragment extends _SemanticsFragment {
   final List<RenderObject> _ancestorChain;
 
   /// The children to be added to the parent.
+  ///
+  /// See also:
+  ///
+  ///  * [SemanticsNode.parentSemanticsClipRect] for the source and definition
+  ///    of the `parentSemanticsClipRect` argument.
+  ///  * [SemanticsNode.parentPaintClipRect] for the source and definition
+  //     of the `parentPaintClipRect` argument.
+  ///  * [SemanticsNode.elevationAdjustment] for the source and definition
+  //    of the `elevationAdjustment` argument.
   Iterable<SemanticsNode> compileChildren({
     @required Rect parentSemanticsClipRect,
-    @required Rect parentPaintClipRect
+    @required Rect parentPaintClipRect,
+    @required double elevationAdjustment,
   });
 
   /// The [SemanticsConfiguration] the child wants to merge into the parent's
@@ -3264,11 +3275,12 @@ class _RootSemanticsFragment extends _InterestingSemanticsFragment {
   }) : super(owner: owner, dropsSemanticsOfPreviousSiblings: dropsSemanticsOfPreviousSiblings);
 
   @override
-  Iterable<SemanticsNode> compileChildren({Rect parentSemanticsClipRect, Rect parentPaintClipRect}) sync* {
+  Iterable<SemanticsNode> compileChildren({Rect parentSemanticsClipRect, Rect parentPaintClipRect, double elevationAdjustment}) sync* {
     assert(_tagsForChildren == null || _tagsForChildren.isEmpty);
     assert(parentSemanticsClipRect == null);
     assert(parentPaintClipRect == null);
     assert(_ancestorChain.length == 1);
+    assert(elevationAdjustment == 0.0);
 
     owner._semantics ??= SemanticsNode.root(
       showOnScreen: owner.showOnScreen,
@@ -3287,6 +3299,7 @@ class _RootSemanticsFragment extends _InterestingSemanticsFragment {
       children.addAll(fragment.compileChildren(
         parentSemanticsClipRect: parentSemanticsClipRect,
         parentPaintClipRect: parentPaintClipRect,
+        elevationAdjustment: 0.0,
       ));
     }
     node.updateWith(config: null, childrenInInversePaintOrder: children);
@@ -3352,13 +3365,20 @@ class _SwitchableSemanticsFragment extends _InterestingSemanticsFragment {
   final List<_InterestingSemanticsFragment> _children = <_InterestingSemanticsFragment>[];
 
   @override
-  Iterable<SemanticsNode> compileChildren({Rect parentSemanticsClipRect, Rect parentPaintClipRect}) sync* {
+  Iterable<SemanticsNode> compileChildren({Rect parentSemanticsClipRect, Rect parentPaintClipRect, double elevationAdjustment}) sync* {
     if (!_isExplicit) {
       owner._semantics = null;
       for (_InterestingSemanticsFragment fragment in _children) {
         assert(_ancestorChain.first == fragment._ancestorChain.last);
         fragment._ancestorChain.addAll(_ancestorChain.sublist(1));
-        yield* fragment.compileChildren(parentSemanticsClipRect: parentSemanticsClipRect, parentPaintClipRect: parentPaintClipRect);
+        yield* fragment.compileChildren(
+          parentSemanticsClipRect: parentSemanticsClipRect,
+          parentPaintClipRect: parentPaintClipRect,
+          // The fragment is not explicit, its elevation has been absorbed by
+          // the parent config (as thickness). We still need to make sure that
+          // its children are placed at the elevation dictated by this config.
+          elevationAdjustment: elevationAdjustment + _config.elevation,
+        );
       }
       return;
     }
@@ -3375,6 +3395,12 @@ class _SwitchableSemanticsFragment extends _InterestingSemanticsFragment {
       ..isMergedIntoParent = _mergeIntoParent
       ..tags = _tagsForChildren;
 
+    node.elevationAdjustment = elevationAdjustment;
+    if (elevationAdjustment != 0.0) {
+      _ensureConfigIsWritable();
+      _config.elevation += elevationAdjustment;
+    }
+
     if (geometry != null) {
       assert(_needsGeometryUpdate);
       node
@@ -3389,8 +3415,13 @@ class _SwitchableSemanticsFragment extends _InterestingSemanticsFragment {
     }
 
     final List<SemanticsNode> children = <SemanticsNode>[];
-    for (_InterestingSemanticsFragment fragment in _children)
-      children.addAll(fragment.compileChildren(parentSemanticsClipRect: node.parentSemanticsClipRect, parentPaintClipRect: node.parentPaintClipRect));
+    for (_InterestingSemanticsFragment fragment in _children) {
+      children.addAll(fragment.compileChildren(
+        parentSemanticsClipRect: node.parentSemanticsClipRect,
+        parentPaintClipRect: node.parentPaintClipRect,
+        elevationAdjustment: 0.0,
+      ));
+    }
 
     if (_config.isSemanticBoundary) {
       owner.assembleSemanticsNode(node, _config, children);
@@ -3457,7 +3488,7 @@ class _AbortingSemanticsFragment extends _InterestingSemanticsFragment {
   }
 
   @override
-  Iterable<SemanticsNode> compileChildren({Rect parentSemanticsClipRect, Rect parentPaintClipRect}) sync* {
+  Iterable<SemanticsNode> compileChildren({Rect parentSemanticsClipRect, Rect parentPaintClipRect, double elevationAdjustment}) sync* {
     yield owner._semantics;
   }
 

diff --git a/packages/flutter/lib/src/rendering/proxy_box.dart b/packages/flutter/lib/src/rendering/proxy_box.dart
@@ -1571,6 +1571,12 @@ abstract class _RenderPhysicalModelBase<T> extends _RenderCustomClip<T> {
   @override
   bool get alwaysNeedsCompositing => _elevation != 0.0 && defaultTargetPlatform == TargetPlatform.fuchsia;
 
+  @override
+  void describeSemanticsConfiguration(SemanticsConfiguration config) {
+    super.describeSemanticsConfiguration(config);
+    config.elevation = elevation;
+  }
+
   @override
   void debugFillProperties(DiagnosticPropertiesBuilder description) {
     super.debugFillProperties(description);
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		02905560cf2c2132a7adea10943001f29325f3be
		ecbdcf8d56d3aba0212c2b1b923466023ef09b4e