Create an example app that demonstrates interactive coordination of an fn tree and a raw RenderObje…

sky/examples/rendering/sector_layout.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:sky/app/view.dart';
 import 'package:sky/rendering/box.dart';
 import 'package:sky/rendering/object.dart';
 
@@ skipping 81 matching lines @@
     hitTestChildren(result, radius: radius, theta: theta);
     result.add(new HitTestEntry(this));
     return true;
   }
   void hitTestChildren(HitTestResult result, { double radius, double theta }) { }
 
   double deltaRadius;
   double deltaTheta;
 }
 
-class RenderDecoratedSector extends RenderSector {
+abstract class RenderDecoratedSector extends RenderSector {
 
   RenderDecoratedSector(BoxDecoration decoration) : _decoration = decoration;
 
   BoxDecoration _decoration;
   BoxDecoration get decoration => _decoration;
   void set decoration (BoxDecoration value) {
     if (value == _decoration)
       return;
     _decoration = value;
     markNeedsPaint();
@@ skipping 14 matching lines @@
       double outerRadius = (parentData.radius + deltaRadius);
       Rect outerBounds = new Rect.fromLTRB(-outerRadius, -outerRadius, outerRadius, outerRadius);
       path.arcTo(outerBounds, parentData.theta, deltaTheta, true);
       double innerRadius = parentData.radius;
       Rect innerBounds = new Rect.fromLTRB(-innerRadius, -innerRadius, innerRadius, innerRadius);
       path.arcTo(innerBounds, parentData.theta + deltaTheta, -deltaTheta, false);
       path.close();
       canvas.drawPath(path, paint);
     }
   }
+
 }
 
 class SectorChildListParentData extends SectorParentData with ContainerParentDataMixin<RenderSector> { }
 
 class RenderSectorWithChildren extends RenderDecoratedSector with ContainerRenderObjectMixin<RenderSector, SectorChildListParentData> {
   RenderSectorWithChildren(BoxDecoration decoration) : super(decoration);
 
   void hitTestChildren(HitTestResult result, { double radius, double theta }) {
     RenderSector child = lastChild;
     while (child != null) {
@@ skipping 243 matching lines @@
     _child = value;
     adoptChild(_child);
     markNeedsLayout();
   }
 
   void setParentData(RenderObject child) {
     if (child.parentData is! SectorParentData)
       child.parentData = new SectorParentData();
   }
 
+  double getMinIntrinsicWidth(BoxConstraints constraints) {
+    if (child == null)
+      return super.getMinIntrinsicWidth(constraints);
+    return getIntrinsicDimensions(constraints).width;
+  }
+
+  double getMaxIntrinsicWidth(BoxConstraints constraints) {
+    if (child == null)
+      return super.getMaxIntrinsicWidth(constraints);
+    return getIntrinsicDimensions(constraints).width;
+  }
+
+  double getMinIntrinsicHeight(BoxConstraints constraints) {
+    if (child == null)
+      return super.getMinIntrinsicHeight(constraints);
+    return getIntrinsicDimensions(constraints).height;
+  }
+
+  double getMaxIntrinsicHeight(BoxConstraints constraints) {
+    if (child == null)
+      return super.getMaxIntrinsicHeight(constraints);
+    return getIntrinsicDimensions(constraints).height;
+  }
+
   Size getIntrinsicDimensions(BoxConstraints constraints) {
-    if (child == null)
-      return constraints.constrain(Size.zero);
     assert(child is RenderSector);
     assert(child.parentData is SectorParentData);
     assert(!constraints.isInfinite);
     double maxChildDeltaRadius = math.min(constraints.maxWidth, constraints.maxHeight) / 2.0 - innerRadius;
     SectorDimensions childDimensions = child.getIntrinsicDimensions(new SectorConstraints(maxDeltaRadius: maxChildDeltaRadius), innerRadius);
     double dimension = (innerRadius + childDimensions.deltaRadius) * 2.0;
     return constraints.constrain(new Size(dimension, dimension));
   }
 
   void performLayout() {
     if (child == null) {
       size = constraints.constrain(Size.zero);
     } else {
       assert(child is RenderSector);
       assert(!constraints.isInfinite);
-      print("constraint maxes: ${constraints.maxWidth} and ${constraints.maxHeight}");
       double maxChildDeltaRadius = math.min(constraints.maxWidth, constraints.maxHeight) / 2.0 - innerRadius;
-      print("maxChildDeltaRadius = $maxChildDeltaRadius");
       assert(child.parentData is SectorParentData);
       child.parentData.radius = innerRadius;
       child.parentData.theta = 0.0;
       child.layout(new SectorConstraints(maxDeltaRadius: maxChildDeltaRadius), parentUsesSize: true);
       double dimension = (innerRadius + child.deltaRadius) * 2.0;
       size = constraints.constrain(new Size(dimension, dimension));
     }
   }
 
   // paint origin is 0,0 of our circle
@@ skipping 34 matching lines @@
     this.desiredDeltaRadius: double.INFINITY,
     this.desiredDeltaTheta: kTwoPi
   }) : this.backgroundColor = backgroundColor,
        super(new BoxDecoration(backgroundColor: backgroundColor));
 
   double desiredDeltaRadius;
   double desiredDeltaTheta;
   final Color backgroundColor;
 
   SectorDimensions getIntrinsicDimensions(SectorConstraints constraints, double radius) {
-    return new SectorDimensions.withConstraints(constraints, deltaTheta: 1.0); // 1.0 radians
+    return new SectorDimensions.withConstraints(constraints, deltaTheta: desiredDeltaTheta);
   }
 
   void performLayout() {
     deltaRadius = constraints.constrainDeltaRadius(desiredDeltaRadius);
     deltaTheta = constraints.constrainDeltaTheta(desiredDeltaTheta);
   }
 
   void handleEvent(sky.Event event, HitTestEntry entry) {
     if (event.type == 'pointerdown')
       decoration = new BoxDecoration(backgroundColor: const Color(0xFFFF0000));
     else if (event.type == 'pointerup')
       decoration = new BoxDecoration(backgroundColor: backgroundColor);
   }
 }
 
-AppView app;
-
-void main() {
-
-  var rootCircle = new RenderSectorRing(padding: 20.0);
+RenderBox buildSectorExample() {
+  RenderSectorRing rootCircle = new RenderSectorRing(padding: 20.0);
   rootCircle.add(new RenderSolidColor(const Color(0xFF00FFFF), desiredDeltaTheta: kTwoPi * 0.15));
   rootCircle.add(new RenderSolidColor(const Color(0xFF0000FF), desiredDeltaTheta: kTwoPi * 0.4));
-  var stack = new RenderSectorSlice(padding: 2.0);
+  RenderSectorSlice stack = new RenderSectorSlice(padding: 2.0);
   stack.add(new RenderSolidColor(const Color(0xFFFFFF00), desiredDeltaRadius: 20.0));
   stack.add(new RenderSolidColor(const Color(0xFFFF9000), desiredDeltaRadius: 20.0));
   stack.add(new RenderSolidColor(const Color(0xFF00FF00)));
   rootCircle.add(stack);
+  return new RenderBoxToRenderSectorAdapter(innerRadius: 50.0, child: rootCircle);
+}
 
-  var root = new RenderBoxToRenderSectorAdapter(innerRadius: 50.0, child: rootCircle);
-  app = new AppView(root: root);
+void main() {
+  new AppView(root: buildSectorExample());
 }