Make popup menus line up to their baseline per the Material spec.

sky/sdk/lib/rendering/object.dart

 // Copyright 2015 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:math' as math;
 import 'dart:sky' as sky;
 import 'dart:sky' show Point, Offset, Size, Rect, Color, Paint, Path;
 
 import '../base/hit_test.dart';
 import '../base/node.dart';
@@ skipping 52 matching lines @@
     setupParentData(child);
     super.adoptChild(child);
     markNeedsLayout();
   }
   void dropChild(RenderObject child) { // only for use by subclasses
     assert(!debugDoingLayout);
     assert(!debugDoingPaint);
     assert(child != null);
     assert(child.parentData != null);
     child.parentData.detach();
-    child._cleanRelayoutSubtreeRoot();
+    child._maybeCleanParentDependencies();
     super.dropChild(child);
     markNeedsLayout();
   }
 
   static List<RenderObject> _nodesNeedingLayout = new List<RenderObject>();
   static bool _debugDoingLayout = false;
   static bool get debugDoingLayout => _debugDoingLayout;
   bool _debugDoingThisResize = false;
   bool get debugDoingThisResize => _debugDoingThisResize;
   bool _debugDoingThisLayout = false;
@@ skipping 31 matching lines @@
     }
     _needsLayout = true;
     assert(_relayoutSubtreeRoot != null);
     if (_relayoutSubtreeRoot != this) {
       final parent = this.parent; // TODO(ianh): Remove this once the analyzer is cleverer
       assert(parent is RenderObject);
       parent.markNeedsLayout();
       assert(parent == this.parent); // TODO(ianh): Remove this once the analyzer is cleverer
     } else {
       _nodesNeedingLayout.add(this);
-      scheduler.ensureVisualUpdate();
     }
   }
-  void _cleanRelayoutSubtreeRoot() {
-    if (_relayoutSubtreeRoot != this) {
-      _relayoutSubtreeRoot = null;
-      _needsLayout = true;
-      _cleanRelayoutSubtreeRootChildren();
-    }
+  static bool _debugCleaningParentDependencies = false;
+  bool _debugSetCleaningParentDependencies(bool value) {
+    _debugCleaningParentDependencies = value;
+    return true;
   }
-  void _cleanRelayoutSubtreeRootChildren() { } // workaround for lack of inter-class mixins in Dart
+  void _maybeCleanParentDependencies() {
+    assert(_debugSetCleaningParentDependencies(true));
+    if (_relayoutSubtreeRoot != this)
+      cleanParentDependencies();
+    assert(_debugSetCleaningParentDependencies(false));
+  }
+  void cleanParentDependencies() {
+    assert(_debugCleaningParentDependencies);
+    assert(_relayoutSubtreeRoot != this);
+    _relayoutSubtreeRoot = null;
+    _needsLayout = true;
+    _cleanParentDependenciesChildren();
+  }
+  void _cleanParentDependenciesChildren() { } // workaround for lack of inter-class mixins in Dart
   void scheduleInitialLayout() {
     assert(attached);
     assert(parent == null);
     assert(_relayoutSubtreeRoot == null);
     _relayoutSubtreeRoot = this;
     _nodesNeedingLayout.add(this);
     scheduler.ensureVisualUpdate();
   }
   static void flushLayout() {
     sky.tracing.begin('RenderObject.flushLayout');
@@ skipping 15 matching lines @@
       assert(_relayoutSubtreeRoot == this);
       _debugCanParentUseSize = false;
       _debugDoingThisLayout = true;
       RenderObject debugPreviousActiveLayout = _debugActiveLayout;
       _debugActiveLayout = this;
       performLayout();
       _debugActiveLayout = debugPreviousActiveLayout;
       _debugDoingThisLayout = false;
       _debugCanParentUseSize = null;
     } catch (e, stack) {
-      print('Exception raised during layout of ${this}: ${e}');
+      print('Exception "${e}" raised during layout of:\n${this}');
       print(stack);
       return;
     }
     _needsLayout = false;
+    markNeedsPaint();
   }
   void layout(Constraints constraints, { bool parentUsesSize: false }) {
     final parent = this.parent; // TODO(ianh): Remove this once the analyzer is cleverer
     RenderObject relayoutSubtreeRoot;
     if (!parentUsesSize || sizedByParent || constraints.isTight || parent is! RenderObject)
       relayoutSubtreeRoot = this;
     else
       relayoutSubtreeRoot = parent._relayoutSubtreeRoot;
     assert(parent == this.parent); // TODO(ianh): Remove this once the analyzer is cleverer
     if (!needsLayout && constraints == _constraints && relayoutSubtreeRoot == _relayoutSubtreeRoot)
@@ skipping 24 matching lines @@
     // Override this to perform relayout without your parent's
     // involvement.
     //
     // This is called during layout. If sizedByParent is true, then
     // performLayout() should not change your dimensions, only do that
     // in performResize(). If sizedByParent is false, then set both
     // your dimensions and do your children's layout here.
     //
     // When calling layout() on your children, pass in
     // "parentUsesSize: true" if your size or layout is dependent on
-    // your child's size.
+    // your child's size or intrinsic dimensions.
 
   // when the parent has rotated (e.g. when the screen has been turned
   // 90 degrees), immediately prior to layout() being called for the
   // new dimensions, rotate() is called with the old and new angles.
   // The next time paint() is called, the coordinate space will have
   // been rotated N quarter-turns clockwise, where:
   //    N = newAngle-oldAngle
   // ...but the rendering is expected to remain the same, pixel for
   // pixel, on the output device. Then, the layout() method or
   // equivalent will be invoked.
@@ skipping 91 matching lines @@
       adoptChild(_child);
   }
   void attachChildren() {
     if (_child != null)
       _child.attach();
   }
   void detachChildren() {
     if (_child != null)
       _child.detach();
   }
-  void _cleanRelayoutSubtreeRootChildren() {
+  void _cleanParentDependenciesChildren() {
     if (_child != null)
-      _child._cleanRelayoutSubtreeRoot();
+      _child._maybeCleanParentDependencies();
   }
   String debugDescribeChildren(String prefix) {
     if (child != null)
       return '${prefix}child: ${child.toString(prefix)}';
     return '';
   }
 }
 
 
 // GENERIC MIXIN FOR RENDER NODES WITH A LIST OF CHILDREN
@@ skipping 156 matching lines @@
     }
   }
   void detachChildren() {
     ChildType child = _firstChild;
     while (child != null) {
       child.detach();
       assert(child.parentData is ParentDataType);
       child = child.parentData.nextSibling;
     }
   }
-  void _cleanRelayoutSubtreeRootChildren() {
+  void _cleanParentDependenciesChildren() {
     ChildType child = _firstChild;
     while (child != null) {
-      child._cleanRelayoutSubtreeRoot();
+      child._maybeCleanParentDependencies();
       assert(child.parentData is ParentDataType);
       child = child.parentData.nextSibling;
     }
   }
 
   ChildType get firstChild => _firstChild;
   ChildType get lastChild => _lastChild;
   ChildType childAfter(ChildType child) {
     assert(child.parentData is ParentDataType);
     return child.parentData.nextSibling;
   }
 
   String debugDescribeChildren(String prefix) {
     String result = '';
     int count = 1;
     ChildType child = _firstChild;
     while (child != null) {
       result += '${prefix}child ${count}: ${child.toString(prefix)}';
       count += 1;
       child = child.parentData.nextSibling;
     }
     return result;
   }
 }