Add FlowContext.iter_boxes_for_node

src/servo/dom/node.rs

@@ -49,6 +49,19 @@ impl Node {
     }
 }
 
+/* TODO: LayoutData is just a pointer, but we must circumvent the type
+   system to actually compare the pointers. This should be fixed in
+   with a generic implementation of rcu::Handle */
+impl Node : cmp::Eq {
+    pure fn eq(other : &Node) -> bool unsafe {
+        let my_data : @LayoutData = @self.aux(|a| a);
+        let ot_data : @LayoutData = @other.aux(|a| a);
+        core::box::ptr_eq(my_data, ot_data)
+    }
+    pure fn ne(other : &Node) -> bool unsafe {
+        !self.eq(other)
+    }
+}
 
 impl Node : DebugMethods {
     /* Dumps the subtree rooted at this node, for debugging. */

src/servo/layout/flow.rs

@@ -6,6 +6,7 @@ use geom::rect::Rect;
 use geom::point::Point2D;
 // TODO: pub-use these
 use layout::block::BlockFlowData;
+use layout::box::RenderBox;
 use layout::context::LayoutContext;
 use layout::debug::DebugMethods;
 use layout::inline::InlineFlowData;
@@ -137,6 +138,28 @@ impl @FlowContext {
     }
 }
 
+// Actual methods that do not require much flow-specific logic
+impl @FlowContext {
+    fn iter_boxes_for_node<T>(node: Node, cb: pure fn&(@RenderBox) -> T) {
+        match self.kind {
+            RootFlow(d) => match d.box {
+                Some(box) if box.node == node => { cb(box); },
+                _ => {}
+            },
+            BlockFlow(d) => match d.box {
+                Some(box) if box.node == node => { cb(box); },
+                _ => {}
+            },
+            InlineFlow(d) => {
+                for d.boxes.each |box| {
+                    if box.node == node { cb(*box); }
+                }
+            },
+            _ => fail fmt!("Don't know how to iterate node's RenderBoxes for %?", self.kind)
+        }
+    }
+}
+
 
 /* The tree holding FlowContexts */
 enum FlowTree { FlowTree }