Verify that callers correctly set parentUsesSize if they use the child's size (and fix a few cases that didn't).

This introduces a bunch of code that should only run in debug builds, but we don't have #ifdefs yet.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1182933003.

engine/core/painting/Size.dart

@@ -8,6 +8,7 @@ part of dart.sky;
 /// Think of this as a vector from Point(0,0) to Point(size.width, size.height)
 class Size {
   const Size(this.width, this.height);
+  Size.copy(Size source) : width = source.width, height = source.height;
   const Size.fromWidth(this.width) : height = double.INFINITY;
   const Size.fromHeight(this.height) : width = double.INFINITY;
 

examples/widgets/spinning_mixed.dart

@@ -71,12 +71,8 @@ void rotate(double timeStamp) {
   transformBox.translate(transformBox.size.width / 2.0, transformBox.size.height / 2.0);
   transformBox.rotateZ(delta);
   transformBox.translate(-transformBox.size.width / 2.0, -transformBox.size.height / 2.0);
-
-  // tester.checkFrame();
 }
 
-final bool debugDisplayList = false; // set this to true to use the test rendering logic
-
 void main() {
   // Because we're going to use UINodes, we want to initialise its
   // AppView, not use the default one. We don't really need to do
@@ -84,7 +80,7 @@ void main() {
   // it's good practice in case we happen to not have a
   // RenderObjectToUINodeAdapter in our tree at startup, or in case we
   // want a renderViewOverride.
-  UINodeAppView.initUINodeAppView(renderViewOverride: debugDisplayList ? tester : null);
+  UINodeAppView.initUINodeAppView();
 
   RenderFlex flexRoot = new RenderFlex(direction: FlexDirection.vertical);
 

sdk/BUILD.gn

@@ -45,6 +45,7 @@ dart_pkg("sdk") {
     "lib/framework/components/tool_bar.dart",
     "lib/framework/debug/shake-to-reload.sky",
     "lib/framework/debug/tracing.dart",
+    "lib/framework/debug/utils.dart",
     "lib/framework/editing/editable_string.dart",
     "lib/framework/editing/editable_text.dart",
     "lib/framework/editing/keyboard.dart",

sdk/lib/framework/debug/utils.dart

@@ -0,0 +1,12 @@
+
+final bool inDebugBuild = _initInDebugBuild();
+
+bool _initInDebugBuild() {
+  bool _inDebug = false;
+  bool setAssert() {
+    _inDebug = true;
+    return true;
+  }
+  assert(setAssert());
+  return _inDebug;
+}

sdk/lib/framework/rendering/box.dart

@@ -4,16 +4,26 @@
 
 import 'dart:math' as math;
 import 'dart:sky' as sky;
-import 'object.dart';
-import '../painting/box_painter.dart';
-import 'package:vector_math/vector_math.dart';
+
 import 'package:sky/framework/net/image_cache.dart' as image_cache;
+import 'package:vector_math/vector_math.dart';
+
+import '../debug/utils.dart';
+import '../painting/box_painter.dart';
+import 'object.dart';
 
 export '../painting/box_painter.dart';
 
 // GENERIC BOX RENDERING
 // Anything that has a concept of x, y, width, height is going to derive from this
 
+// This class should only be used in debug builds
+class _DebugSize extends Size {
+  _DebugSize(Size source, this._owner, this._canBeUsedByParent): super.copy(source);
+  final RenderBox _owner;
+  final bool _canBeUsedByParent;
+}
+
 class EdgeDims {
   // used for e.g. padding
   const EdgeDims(this.top, this.right, this.bottom, this.left);
@@ -153,7 +163,10 @@ class BoxConstraints {
   }
 
   Size constrain(Size size) {
-    return new Size(constrainWidth(size.width), constrainHeight(size.height));
+    Size result = new Size(constrainWidth(size.width), constrainHeight(size.height));
+    if (size is _DebugSize)
+      result = new _DebugSize(result, size._owner, size._canBeUsedByParent);
+    return result;
   }
 
   bool get isInfinite => maxWidth >= double.INFINITY || maxHeight >= double.INFINITY;
@@ -220,6 +233,24 @@ abstract class RenderBox extends RenderObject {
     return constraints.constrainHeight(0.0);
   }
 
+  // This whole block should only be here in debug builds
+  bool _debugDoingThisLayout = false;
+  bool _debugCanParentUseSize;
+  void layoutWithoutResize() {
+    _debugDoingThisLayout = true;
+    _debugCanParentUseSize = false;
+    super.layoutWithoutResize();
+    _debugCanParentUseSize = null;
+    _debugDoingThisLayout = false;
+  }
+  void layout(dynamic constraints, { bool parentUsesSize: false }) {
+    _debugDoingThisLayout = true;
+    _debugCanParentUseSize = parentUsesSize;
+    super.layout(constraints, parentUsesSize: parentUsesSize);
+    _debugCanParentUseSize = null;
+    _debugDoingThisLayout = false;
+  }
+
   BoxConstraints get constraints { BoxConstraints result = super.constraints; return result; }
   void performResize() {
     // default behaviour for subclasses that have sizedByParent = true
@@ -241,11 +272,19 @@ abstract class RenderBox extends RenderObject {
   }
   void hitTestChildren(HitTestResult result, { Point position }) { }
 
+  // TODO(ianh): In non-debug builds, this should all just be:
+  // Size size = Size.zero;
+  // In debug builds, however:
   Size _size = Size.zero;
   Size get size => _size;
   void set size(Size value) {
     assert(RenderObject.debugDoingLayout);
-    _size = value;
+    assert(_debugDoingThisLayout);
+    if (value is _DebugSize) {
+      assert(value._canBeUsedByParent);
+      assert(value._owner.parent == this);
+    }
+    _size = inDebugBuild ? new _DebugSize(value, this, _debugCanParentUseSize) : value;
   }
 
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}size: ${size}\n';
@@ -394,7 +433,7 @@ class RenderConstrainedBox extends RenderProxyBox {
 
   void performLayout() {
     if (child != null) {
-      child.layout(constraints.apply(_additionalConstraints));
+      child.layout(constraints.apply(_additionalConstraints), parentUsesSize: true);
       size = child.size;
     } else {
       performResize();
@@ -439,7 +478,7 @@ class RenderShrinkWrapWidth extends RenderProxyBox {
 
   void performLayout() {
     if (child != null) {
-      child.layout(_getInnerConstraints(constraints));
+      child.layout(_getInnerConstraints(constraints), parentUsesSize: true);
       size = child.size;
     } else {
       performResize();
@@ -663,7 +702,7 @@ class RenderPositionedBox extends RenderShiftedBox {
 
   void performLayout() {
     if (child != null) {
-      child.layout(constraints.loosen());
+      child.layout(constraints.loosen(), parentUsesSize: true);
       size = constraints.constrain(child.size);
       assert(child.parentData is BoxParentData);
       Size delta = size - child.size;

sdk/lib/framework/rendering/object.dart

@@ -128,11 +128,11 @@ abstract class RenderObject extends AbstractNode {
     _nodesNeedingLayout = new List<RenderObject>();
     dirtyNodes..sort((a, b) => a.depth - b.depth)..forEach((node) {
       if (node._needsLayout && node.attached)
-        node._doLayout();
+        node.layoutWithoutResize();
     });
     _debugDoingLayout = false;
   }
-  void _doLayout() {
+  void layoutWithoutResize() {
     try {
       assert(_relayoutSubtreeRoot == this);
       performLayout();

sdk/lib/framework/rendering/paragraph.dart

@@ -211,5 +211,11 @@ class RenderParagraph extends RenderBox {
 
   // we should probably expose a way to do precise (inter-glpyh) hit testing
 
-  String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}style:\n${style.toString("$prefix  ")}\n${prefix}text: ${text}\n';
+  String debugDescribeSettings(String prefix) {
+    String result = '${super.debugDescribeSettings(prefix)}';
+    if (style != null)
+      result += '${prefix}style:\n' + style.toString('$prefix  ') + '\n';
+    result += '${prefix}text: ${text}\n';
+    return result;
+  }
 }