Improve the padding and sizing of popup menus.

sky/sdk/lib/rendering/box.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 'package:vector_math/vector_math.dart';
 
 import '../base/debug.dart';
@@ skipping 476 matching lines @@
       size = child.size;
     } else {
       size = _additionalConstraints.apply(constraints).constrain(Size.zero);
     }
   }
 
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}additionalConstraints: ${additionalConstraints}\n';
 }
 
 class RenderShrinkWrapWidth extends RenderProxyBox {
-  RenderShrinkWrapWidth({ RenderBox child }) : super(child);
+  RenderShrinkWrapWidth({
+    stepWidth,
+    stepHeight,

[abarth-chromium, 2015/06/30 20:51:44]

Types?

Also, I wonder if we can think of a better name here...

+    RenderBox child
+  }) : _stepWidth = stepWidth, _stepHeight = stepHeight, super(child);
+
+  double _stepWidth;
+  double get stepWidth => _stepWidth;
+  void set stepWidth(double value) {
+    if (value == _stepWidth)
+      return;
+    _stepWidth = value;
+    markNeedsLayout();
+  }
+
+  double _stepHeight;
+  double get stepHeight => _stepHeight;
+  void set stepHeight(double value) {
+    if (value == _stepHeight)
+      return;
+    _stepHeight = value;
+    markNeedsLayout();
+  }
+
+  static double applyStep(double input, double step) {
+    if (step == null)
+      return input;
+    return (input / step).ceil() * step;
+  }
 
   BoxConstraints _getInnerConstraints(BoxConstraints constraints) {
     double width = child.getMaxIntrinsicWidth(constraints);
     assert(width == constraints.constrainWidth(width));
     return constraints.applyWidth(width);
   }
 
   double getMinIntrinsicWidth(BoxConstraints constraints) {
-    if (child != null)
-      return child.getMaxIntrinsicWidth(constraints);
-    return constraints.constrainWidth(0.0);
+    if (child == null)
+      return constraints.constrainWidth(0.0);
+    double childResult = child.getMinIntrinsicWidth(constraints);
+    return constraints.constrainWidth(applyStep(childResult, _stepWidth));
   }
 
   double getMaxIntrinsicWidth(BoxConstraints constraints) {
-    if (child != null)
-      return child.getMaxIntrinsicWidth(constraints);
-    return constraints.constrainWidth(0.0);
+    if (child == null)
+      return constraints.constrainWidth(0.0);
+    double childResult = child.getMaxIntrinsicWidth(constraints);
+    return constraints.constrainWidth(applyStep(childResult, _stepWidth));
   }
 
   double getMinIntrinsicHeight(BoxConstraints constraints) {
-    if (child != null)
-      return child.getMinIntrinsicHeight(_getInnerConstraints(constraints));
-    return constraints.constrainWidth(0.0);
+    if (child == null)
+      return constraints.constrainWidth(0.0);
+    double childResult = child.getMinIntrinsicHeight(_getInnerConstraints(constraints));
+    return constraints.constrainHeight(applyStep(childResult, _stepHeight));
   }
 
   double getMaxIntrinsicHeight(BoxConstraints constraints) {
-    if (child != null)
-      return child.getMaxIntrinsicHeight(_getInnerConstraints(constraints));
-    return constraints.constrainWidth(0.0);
+    if (child == null)
+      return constraints.constrainWidth(0.0);
+    double childResult = child.getMaxIntrinsicHeight(_getInnerConstraints(constraints));
+    return constraints.constrainHeight(applyStep(childResult, _stepHeight));
   }
 
   void performLayout() {
     if (child != null) {
       child.layout(_getInnerConstraints(constraints), parentUsesSize: true);
-      size = child.size;
+      size = new Size(applyStep(child.size.width, _stepWidth), applyStep(child.size.height, _stepHeight));
     } else {
       performResize();
     }
   }
 }
 
 class RenderOpacity extends RenderProxyBox {
   RenderOpacity({ RenderBox child, double opacity })
     : this._opacity = opacity, super(child) {
     assert(opacity >= 0.0 && opacity <= 1.0);
@@ skipping 729 matching lines @@
 
   void defaultPaint(PaintingCanvas canvas, Offset offset) {
     RenderBox child = firstChild;
     while (child != null) {
       assert(child.parentData is ParentDataType);
       canvas.paintChild(child, child.parentData.position + offset);
       child = child.parentData.nextSibling;
     }
   }
 }