Paint tree logic for layout2.dart

sky/sdk/lib/framework/layout2.dart

 library layout;
 
 // This version of layout.dart is an update to the other one, this one using new APIs.
 // It will not work in a stock Sky setup currently.
 
 import 'node.dart';
 
 import 'dart:sky' as sky;
 
 // ABSTRACT LAYOUT
@@ skipping 14 matching lines @@
 double clamp({double min: 0.0, double value: 0.0, double max: double.INFINITY}) {
   if (value > max)
     value = max;
   if (value < min)
     value = min;
   return value;
 }
 
 class RenderNodeDisplayList extends sky.PictureRecorder {
   RenderNodeDisplayList(double width, double height) : super(width, height);
+  List<RenderNode> _children; // used by _doPaint() to find out which RenderNodes to ask to paint
   void paintChild(RenderNode child, double x, double y) {
-    save();
-    translate(x, y);
-    child.paint(this);
-    restore();
+    if (child.createNewDisplayList) {
+      if (_children == null)
+        _children = new List<RenderNode>();
+      assert(!_children.contains(child));
+      _children.add(child);
+      drawPaintNode(child._paintNode, transform: new Matrix.translate(x, y));
+    } else {
+      save();
+      translate(x, y);
+      child.paint(this);
+      restore();
+    }
   }
 }
 
+class PaintOptions {
+  Matrix transform = Matrix.IDENTITY;
+}
+
 abstract class RenderNode extends AbstractNode {
 
   // LAYOUT
 
   // parentData is only for use by the RenderNode that actually lays this
   // node out, and any other nodes who happen to know exactly what
   // kind of node that is.
   ParentData parentData;
   void setupPos(RenderNode child) {
     // override this to setup .parentData correctly for your class
@@ skipping 162 matching lines @@
   // HIT TESTING  
 
   void handlePointer(sky.PointerEvent event) {
     // override this if you have children, to hand it to the appropriate child
     // override this if you want to do anything with the pointer event
   }
 
 
   // PAINTING
 
+  static List<RenderNode> _nodesNeedingPaint = new List<RenderNode>();
   static bool _debugDoingPaint = false;
+  PaintNode _paintNode; // only set if createNewDisplayList is true
+  bool _needsPaint = true;
+  bool get needsPaint => _needsPaint;
+  bool get createNewDisplayList => false;
   void markNeedsPaint() {
     assert(!_debugDoingPaint);
-    var ancestor = this;
-    while (ancestor.parent != null)
-      ancestor = ancestor.parent;
-    assert(ancestor is Screen);
-    ancestor.paintFrame();
+    if (_needsPaint) return;
+    if (createNewDisplayList) {
+      _needsPaint = true;
+      _nodesNeedingPaint.add(this);
+    } else {
+      assert(parent != null);
+      parent.markNeedsPaint();
+    }
   }
+  static void flushPaint() {
+    List<RenderNode> dirtyNodes = _nodesNeedingPaint;
+    _nodesNeedingPaint = new List<RenderNode>();
+    dirtyNodes..sort((a, b) => a.depth - b.depth)..forEach((node) {
+      if (node._needsPaint && node.attached)
+        node._doPaint();
+    });
+  }
+  void _doPaint() {
+    assert(!_needsLayout);
+    assert(createNewDisplayList);
+    RenderNodeDisplayList newDisplayList = new RenderNodeDisplayList();
+    _needsPaint = false;
+    try {
+      paint(newDisplayList);
+    } catch (e, stack) {
+      print('Exception raised during paint of ${this}: ${e}');
+      print(stack);
+      return;
+    }
+    assert(!_needsLayout); // check that the paint() method didn't mark us dirty again
+    assert(!_needsPaint); // check that the paint() method didn't mark us dirty again
+    _paintNode.setDisplayList(newDisplayList);
+    if (newDisplayList._children != null)
+      newDisplayList._children.forEach((node) {
+        assert(node.attached == attached);
+        if (node._needsPaint)
+          node._doPaint();
+      });
+  }
+
+  PaintOptions paintOptions;
+  // only set this to a subclass of PaintOptions that this class of RenderNode knows how to deal with
+
   void paint(RenderNodeDisplayList canvas) { }
 
 }
 
 
 // GENERIC MIXIN FOR RENDER NODES THAT TAKE A LIST OF CHILDREN
 
 abstract class ContainerParentDataMixin<ChildType extends RenderNode> {
   ChildType previousSibling;
   ChildType nextSibling;
@@ skipping 504 matching lines @@
     canvas.paintChild(body, (body.parentData as BoxParentData).x, (body.parentData as BoxParentData).y);
     if (statusbar != null)
       canvas.paintChild(statusbar, (statusbar.parentData as BoxParentData).x, (statusbar.parentData as BoxParentData).y);
     if (toolbar != null)
       canvas.paintChild(toolbar, (toolbar.parentData as BoxParentData).x, (toolbar.parentData as BoxParentData).y);
     if (drawer != null)
       canvas.paintChild(drawer, (drawer.parentData as BoxParentData).x, (drawer.parentData as BoxParentData).y);
   }
 
 }