diff --git a/framework/components/action_bar.dart b/framework/components/action_bar.dart
index f874009412c..309fb9b8661 100644
--- a/framework/components/action_bar.dart
+++ b/framework/components/action_bar.dart
@@ -16,8 +16,9 @@ class ActionBar extends Component {
     padding-top: ${kStatusBarHeight}px;''');
 
   static Style _centerStyle = new Style('''
-    padding-left: 24px;
-    flex: 1;''');
+    padding-left: 24px;''');
+
+  static FlexBoxParentData _centerLayoutSettings = new FlexBoxParentData()..flex = 1;
 
   UINode left;
   UINode center;
@@ -31,7 +32,7 @@ class ActionBar extends Component {
   }) : super(key: key);
 
   UINode build() {
-    List<UINode> children = [left, new StyleNode(center, _centerStyle)];
+    List<UINode> children = [left, new StyleNode(new ParentDataNode(center, _centerLayoutSettings), _centerStyle)];
 
     if (right != null)
       children.addAll(right);
diff --git a/framework/fn.dart b/framework/fn.dart
index 1a1118c07e5..29caedab927 100644
--- a/framework/fn.dart
+++ b/framework/fn.dart
@@ -148,6 +148,12 @@ class StyleNode extends ContentNode {
   StyleNode(UINode content, this.style): super(content);
 }
 
+class ParentDataNode extends ContentNode {
+  final ParentData parentData;
+
+  ParentDataNode(UINode content, this.parentData): super(content);
+}
+
 /*
  * SkyNodeWrappers correspond to a desired state of a RenderCSS. They are fully
  * immutable, with one exception: A UINode which is a Component which lives within
@@ -389,14 +395,28 @@ abstract class SkyElementWrapper extends SkyNodeWrapper {
     List<Style> styles = new List<Style>();
     if (style != null)
       styles.add(style);
+    ParentData parentData = null;
     UINode parent = _parent;
     while (parent != null && parent is! SkyNodeWrapper) {
       if (parent is StyleNode && parent.style != null)
         styles.add(parent.style);
+      else
+      if (parent is ParentDataNode && parent.parentData != null) {
+        if (parentData != null)
+          parentData.merge(parent.parentData); // this will throw if the types aren't the same
+        else
+          parentData = parent.parentData;
+      }
       parent = parent._parent;
     }
     _root.updateStyles(styles);
-
+    if (parentData != null) {
+      assert(_root.parentData != null);
+      _root.parentData.merge(parentData); // this will throw if the types aren't approriate
+      assert(parent != null);
+      assert(parent._root != null);
+      parent._root.markNeedsLayout();
+    }
     _root.updateInlineStyle(inlineStyle);
 
     _syncChildren(oldSkyElementWrapper);
diff --git a/framework/layout.dart b/framework/layout.dart
index 5678fd88f35..a17b8220170 100644
--- a/framework/layout.dart
+++ b/framework/layout.dart
@@ -53,6 +53,10 @@ class ParentData {
     detachSiblings();
   }
   void detachSiblings() { } // workaround for lack of inter-class mixins in Dart
+  void merge(ParentData other) {
+    // override this in subclasses to merge in data from other into this
+    assert(other.runtimeType == this.runtimeType);
+  }
 }
 
 abstract class RenderNode extends Node {
@@ -261,8 +265,16 @@ abstract class RenderCSS extends RenderBox {
     return styles.map((s) => s._className).join(' ');
   }
 
+  String _inlineStyles = '';
+  String _additionalStylesFromParent = ''; // used internally to propagate parentData settings to the child
+
   void updateInlineStyle(String newStyle) {
-    _skyElement.setAttribute('style', newStyle);
+    _inlineStyles = newStyle;
+    _updateInlineStyleAttribute();
+  }
+
+  void _updateInlineStyleAttribute() {
+    _skyElement.setAttribute('style', "$_inlineStyles;$_additionalStylesFromParent");
   }
 
   double get width {
@@ -320,7 +332,14 @@ class RenderCSSContainer extends RenderCSS with ContainerRenderNodeMixin<RenderC
 
 }
 
-class FlexBoxParentData extends CSSParentData { }
+class FlexBoxParentData extends CSSParentData {
+  int flex;
+  void merge(FlexBoxParentData other) {
+    if (other.flex != null)
+      flex = other.flex;
+    super.merge(other);
+  }
+}
 
 enum FlexDirection { Row }
 
@@ -351,6 +370,21 @@ class RenderCSSFlex extends RenderCSSContainer {
     return super.stylesToClasses(styles) + ' ' + settings;
   }
 
+  void markNeedsLayout() {
+    super.markNeedsLayout();
+
+    // pretend we did the layout:
+    RenderCSS child = _firstChild;
+    while (child != null) {
+      assert(child.parentData is FlexBoxParentData);
+      if (child.parentData.flex != null) {
+        child._additionalStylesFromParent = 'flex:${child.parentData.flex};';
+        child._updateInlineStyleAttribute();
+      }
+      child = child.parentData.nextSibling;
+    }
+  }
+
 }
 
 class RenderCSSText extends RenderCSS {