Hoist more stuff from the concrete wrapper implementations into the trait definitions to allow sharing.

components/layout/wrapper.rs

@@ -102,12 +102,24 @@ pub trait LayoutNode<'ln> : Sized + Copy + Clone {
 
     fn dump(self);
 
-    fn traverse_preorder(self) -> LayoutTreeIterator<'ln, Self>;
+    fn traverse_preorder(self) -> LayoutTreeIterator<'ln, Self> {
+        LayoutTreeIterator::new(self)
+    }
 
     /// Returns an iterator over this node's children.
-    fn children(self) -> LayoutNodeChildrenIterator<'ln, Self>;
+    fn children(self) -> LayoutNodeChildrenIterator<'ln, Self> {
+        LayoutNodeChildrenIterator {
+            current: self.first_child(),
+            phantom: PhantomData,
+        }
+    }
 
-    fn rev_children(self) -> LayoutNodeReverseChildrenIterator<'ln, Self>;
+    fn rev_children(self) -> LayoutNodeReverseChildrenIterator<'ln, Self> {
+        LayoutNodeReverseChildrenIterator {
+            current: self.last_child(),
+            phantom: PhantomData,
+        }
+    }
 
     /// Converts self into an `OpaqueNode`.
     fn opaque(&self) -> OpaqueNode;
@@ -323,24 +335,6 @@ impl<'ln> LayoutNode<'ln> for ServoLayoutNode<'ln> {
         self.dump_indent(0);
     }
 
-    fn traverse_preorder(self) -> LayoutTreeIterator<'ln, Self> {
-        LayoutTreeIterator::new(self)
-    }
-
-    fn children(self) -> LayoutNodeChildrenIterator<'ln, Self> {
-        LayoutNodeChildrenIterator {
-            current: self.first_child(),
-            phantom: PhantomData,
-        }
-    }
-
-    fn rev_children(self) -> LayoutNodeReverseChildrenIterator<'ln, Self> {
-        LayoutNodeReverseChildrenIterator {
-            current: self.last_child(),
-            phantom: PhantomData,
-        }
-    }
-
     fn opaque(&self) -> OpaqueNode {
         OpaqueNodeMethods::from_jsmanaged(unsafe { self.get_jsmanaged() })
     }
@@ -844,6 +838,10 @@ pub trait ThreadSafeLayoutNode<'ln> : Clone + Copy + Sized {
     type ConcreteThreadSafeLayoutElement: ThreadSafeLayoutElement<'ln, ConcreteThreadSafeLayoutNode = Self>;
     type ChildrenIterator: Iterator<Item = Self> + Sized;
 
+    /// Creates a new `ThreadSafeLayoutNode` for the same `LayoutNode`
+    /// with a different pseudo-element type.
+    fn with_pseudo(&self, pseudo: PseudoElementType<display::T>) -> Self;
+
     /// Converts self into an `OpaqueNode`.
     fn opaque(&self) -> OpaqueNode;
 
@@ -866,10 +864,22 @@ pub trait ThreadSafeLayoutNode<'ln> : Clone + Copy + Sized {
     fn get_pseudo_element_type(&self) -> PseudoElementType<display::T>;
 
     #[inline]
-    fn get_before_pseudo(&self) -> Option<Self>;
+    fn get_before_pseudo(&self) -> Option<Self> {
+        let layout_data_ref = self.borrow_layout_data();
+        let node_layout_data_wrapper = layout_data_ref.as_ref().unwrap();
+        node_layout_data_wrapper.data.before_style.as_ref().map(|style| {
+            self.with_pseudo(PseudoElementType::Before(style.get_box().display))
+        })
+    }
 
     #[inline]
-    fn get_after_pseudo(&self) -> Option<Self>;
+    fn get_after_pseudo(&self) -> Option<Self> {
+        let layout_data_ref = self.borrow_layout_data();
+        let node_layout_data_wrapper = layout_data_ref.as_ref().unwrap();
+        node_layout_data_wrapper.data.after_style.as_ref().map(|style| {
+            self.with_pseudo(PseudoElementType::After(style.get_box().display))
+        })
+    }
 
     /// Borrows the layout data immutably. Fails on a conflicting borrow.
     ///
@@ -1034,15 +1044,6 @@ impl<'ln> ServoThreadSafeLayoutNode<'ln> {
         }
     }
 
-    /// Creates a new `ServoThreadSafeLayoutNode` for the same `LayoutNode`
-    /// with a different pseudo-element type.
-    fn with_pseudo(&self, pseudo: PseudoElementType<display::T>) -> ServoThreadSafeLayoutNode<'ln> {
-        ServoThreadSafeLayoutNode {
-            node: self.node.clone(),
-            pseudo: pseudo,
-        }
-    }
-
     /// Returns the interior of this node as a `LayoutJS`. This is highly unsafe for layout to
     /// call and as such is marked `unsafe`.
     unsafe fn get_jsmanaged(&self) -> &LayoutJS<Node> {
@@ -1062,6 +1063,13 @@ impl<'ln> ThreadSafeLayoutNode<'ln> for ServoThreadSafeLayoutNode<'ln> {
     type ConcreteThreadSafeLayoutElement = ServoThreadSafeLayoutElement<'ln>;
     type ChildrenIterator = ThreadSafeLayoutNodeChildrenIterator<'ln, Self>;
 
+    fn with_pseudo(&self, pseudo: PseudoElementType<display::T>) -> ServoThreadSafeLayoutNode<'ln> {
+        ServoThreadSafeLayoutNode {
+            node: self.node.clone(),
+            pseudo: pseudo,
+        }
+    }
+
     fn opaque(&self) -> OpaqueNode {
         OpaqueNodeMethods::from_jsmanaged(unsafe { self.get_jsmanaged() })
     }
@@ -1104,22 +1112,6 @@ impl<'ln> ThreadSafeLayoutNode<'ln> for ServoThreadSafeLayoutNode<'ln> {
         self.pseudo
     }
 
-    fn get_before_pseudo(&self) -> Option<ServoThreadSafeLayoutNode<'ln>> {
-        let layout_data_ref = self.borrow_layout_data();
-        let node_layout_data_wrapper = layout_data_ref.as_ref().unwrap();
-        node_layout_data_wrapper.data.before_style.as_ref().map(|style| {
-            self.with_pseudo(PseudoElementType::Before(style.get_box().display))
-        })
-    }
-
-    fn get_after_pseudo(&self) -> Option<ServoThreadSafeLayoutNode<'ln>> {
-        let layout_data_ref = self.borrow_layout_data();
-        let node_layout_data_wrapper = layout_data_ref.as_ref().unwrap();
-        node_layout_data_wrapper.data.after_style.as_ref().map(|style| {
-            self.with_pseudo(PseudoElementType::After(style.get_box().display))
-        })
-    }
-
     fn borrow_layout_data(&self) -> Ref<Option<LayoutDataWrapper>> {
         self.node.borrow_layout_data()
     }
@@ -1254,7 +1246,7 @@ pub struct ThreadSafeLayoutNodeChildrenIterator<'ln, ConcreteNode: ThreadSafeLay
 
 impl<'ln, ConcreteNode> ThreadSafeLayoutNodeChildrenIterator<'ln, ConcreteNode>
                         where ConcreteNode: DangerousThreadSafeLayoutNode<'ln> {
-    fn new(parent: ConcreteNode) -> Self {
+    pub fn new(parent: ConcreteNode) -> Self {
         let first_child: Option<ConcreteNode> = match parent.get_pseudo_element_type() {
             PseudoElementType::Normal => {
                 parent.get_before_pseudo().or_else(|| {