Enable setting the UINode key for ParentDataNodes

sky/sdk/lib/framework/fn2.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.
 
 library fn;
 
 import 'app.dart';
 import 'dart:async';
 import 'dart:collection';
 import 'dart:mirrors';
@@ skipping 136 matching lines @@
     node.setParent(this);
     node._sync(oldNode, slot);
     assert(node.root is RenderObject);
     return node;
   }
 }
 
 abstract class ContentNode extends UINode {
   UINode content;
 
-  ContentNode(UINode content) : this.content = content, super(key: content._key);
+  ContentNode(UINode content, {Object key}) : this.content = content, super(key: key);

[abarth-chromium, 2015/06/09 17:37:01]

We've been putting a space inside the { } so { Object key }

Not sure if that's real dart style or we just made it up.

[hansmuller, 2015/06/09 17:48:03]

Done.

I've been taking advantage of the fact that Sky style doesn't appear to be too
strict about lines that are wider than 80 chars. I hope that's OK.

 
   void _sync(UINode old, dynamic slot) {
     UINode oldContent = old == null ? null : (old as ContentNode).content;
     content = syncChild(content, oldContent, slot);
     assert(content.root != null);
     root = content.root;
   }
 
   void remove() {
     if (content != null)
       removeChild(content);
     super.remove();
   }
 }
 
 class ParentDataNode extends ContentNode {
   final ParentData parentData;
 
-  ParentDataNode(UINode content, this.parentData): super(content);
+  ParentDataNode(UINode content, this.parentData, {Object key}): super(content, key: key);
 }
 
 typedef void GestureEventListener(sky.GestureEvent e);
 typedef void PointerEventListener(sky.PointerEvent e);
 typedef void EventListener(sky.Event e);
 
 class EventListenerNode extends ContentNode  {
   final Map<String, sky.EventListener> listeners;
 
   static Map<String, sky.EventListener> _createListeners({
@@ skipping 560 matching lines @@
   }) : super(key: key, children: children);
 
   void syncRenderObject(UINode old) {
     super.syncRenderObject(old);
     root.direction = direction;
     root.justifyContent = justifyContent;
   }
 }
 
 class FlexExpandingChild extends ParentDataNode {
-  FlexExpandingChild(UINode content, [int flex = 1])
-    : super(content, new FlexBoxParentData()..flex = flex);
+  FlexExpandingChild(UINode content, {int flex: 1, Object key})

[Hixie, 2015/06/09 17:40:08]

I think I'd make the flex be an optional positional argument, and the key an
optional named argument. Having to explicitly give the 'flex' name everywhere is
redundant with the class name.

+    : super(content, new FlexBoxParentData()..flex = flex, key: key);
 }
 
 class Image extends RenderObjectWrapper {
   RenderImage root;
   RenderImage createNode() => new RenderImage(this.src, this.size);
 
   final String src;
   final Size size;
 
   Image({
@@ skipping 291 matching lines @@
     assert(root.parent is RenderView);
   }
 }
 
 class Text extends Component {
   Text(this.data) : super(key: '*text*');
   final String data;
   bool get interchangeable => true;
   UINode build() => new Paragraph(text: data);
 }