Let's hide double.INFINITY a bit more, by providing cleaner APIs for the cases where we're currentl…

sky/sdk/lib/rendering/stack.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 'box.dart';
 import 'object.dart';
 
 class StackParentData extends BoxParentData with ContainerParentDataMixin<RenderBox> {
@@ skipping 52 matching lines @@
     RenderBox child = firstChild;
     while (child != null) {
       assert(child.parentData is StackParentData);
       if (!child.parentData.isPositioned) {
         hasNonPositionedChildren = true;
         width = math.max(width, child.getMaxIntrinsicWidth(constraints));
       }
       child = child.parentData.nextSibling;
     }
     if (!hasNonPositionedChildren)
-      return constraints.constrainWidth(double.INFINITY);
+      return constraints.constrainWidth();
     assert(width == constraints.constrainWidth(width));
     return width;
   }
 
   double getMinIntrinsicHeight(BoxConstraints constraints) {
     double height = constraints.minHeight;
     RenderBox child = firstChild;
     while (child != null) {
       assert(child.parentData is StackParentData);
       if (!child.parentData.isPositioned)
@@ skipping 10 matching lines @@
     RenderBox child = firstChild;
     while (child != null) {
       assert(child.parentData is StackParentData);
       if (!child.parentData.isPositioned) {
         hasNonPositionedChildren = true;
         height = math.max(height, child.getMaxIntrinsicHeight(constraints));
       }
       child = child.parentData.nextSibling;
     }
     if (!hasNonPositionedChildren)
-      return constraints.constrainHeight(double.INFINITY);
+      return constraints.constrainHeight();
     assert(height == constraints.constrainHeight(height));
     return height;
   }
 
   double getDistanceToActualBaseline(TextBaseline baseline) {
     return defaultGetDistanceToHighestActualBaseline(baseline);
   }
 
   void performLayout() {
     bool hasNonPositionedChildren = false;
@@ skipping 18 matching lines @@
       }
 
       child = parentData.nextSibling;
     }
 
     if (hasNonPositionedChildren)
       size = new Size(width, height);
     else
       size = constraints.constrain(Size.infinite);
 
-    assert(size.width < double.INFINITY);
-    assert(size.height < double.INFINITY);
+    assert(!size.isInfinite);
     assert(size.width == constraints.constrainWidth(width));
     assert(size.height == constraints.constrainHeight(height));
 
     BoxConstraints innerConstraints = new BoxConstraints.loose(size);
 
     child = firstChild;
     while (child != null) {
       assert(child.parentData is StackParentData);
       final StackParentData parentData = child.parentData;
 
@@ skipping 38 matching lines @@
   }
 
   void hitTestChildren(HitTestResult result, { Point position }) {
     defaultHitTestChildren(result, position: position);
   }
 
   void paint(RenderCanvas canvas) {
     defaultPaint(canvas);
   }
 }