Clean up aux layout data creation

src/servo/css/styles.rs

@@ -1,7 +1,9 @@
-#[doc="High-level interface to CSS selector matching."]
-
+/**
+ * High-level interface to CSS selector matching.
+ */
 use std::arc::{ARC, get, clone};
 
+use core::dvec::DVec;
 use css::values::*;
 use css::values::Stylesheet;
 use dom::element::{HTMLDivElement, HTMLHeadElement, HTMLImageElement, UnknownElement, HTMLScriptElement};
@@ -39,7 +41,7 @@ impl NodeKind : DefaultStyleMethods {
     /* TODO: this belongs in the UA stylesheet */
     fn default_display_type() -> CSSDisplay {
         match self {
-          Text(*) => { DisplayInline }
+          Text(*) => DisplayInline,
           Element(element) => {
             match *element.kind {
               HTMLDivElement => DisplayBlock,
@@ -80,75 +82,64 @@ fn empty_style_for_node_kind(kind: NodeKind) -> SpecifiedStyle {
      mut width : Initial}
 }
 
-trait StylePriv {
-    fn initialize_style() -> ~[@LayoutData];
-}
-
-impl Node : StylePriv {
-    #[doc="
-        Set a default auxiliary data so that other threads can modify it.
-        
-        This is, importantly, the function that creates the layout
-        data for the node (the reader-auxiliary box in the RCU model)
-        and populates it with the default style.
-
-     "]
-    // TODO: we should look into folding this into building the dom,
-    // instead of doing a linear sweep afterwards.
-    fn initialize_style() -> ~[@LayoutData] {
-        if !self.has_aux() {
-            let node_kind = self.read(|n| copy *n.kind);
-            let the_layout_data = @LayoutData({
-                mut style : ~empty_style_for_node_kind(node_kind),
-                mut box : None
-            });
-
-            self.set_aux(the_layout_data);
-
-            ~[the_layout_data]
-        } else {
-            ~[]
-        }
-    }
-}
-
 trait StyleMethods {
-    fn initialize_style_for_subtree() -> ~[@LayoutData];
+    fn initialize_layout_data() -> Option<@LayoutData>;
+
     fn style() -> SpecifiedStyle;
+    fn initialize_style_for_subtree(ctx: &LayoutContext, refs: &DVec<@LayoutData>);
     fn recompute_style_for_subtree(ctx: &LayoutContext, styles : ARC<Stylesheet>);
 }
 
 impl Node : StyleMethods {
-    #[doc="Sequentially initialize the nodes' auxilliary data so they can be updated in parallel."]
-    fn initialize_style_for_subtree() -> ~[@LayoutData] {
-        let mut handles = self.initialize_style();
-        
-        for NodeTree.each_child(self) |kid| {
-            handles += kid.initialize_style_for_subtree();
+    /** If none exists, creates empty layout data for the node (the reader-auxiliary
+     * box in the RCU model) and populates it with an empty style object.
+     */
+    fn initialize_layout_data() -> Option<@LayoutData> {
+        match self.has_aux() {
+            false => {
+                let node_kind = self.read(|n| copy *n.kind);
+                let data = @LayoutData({
+                    mut style : ~empty_style_for_node_kind(node_kind),
+                    mut flow  : None
+                });
+                self.set_aux(data); Some(data)
+            },
+            true => None
         }
-
-        return handles;
     }
-    
-    #[doc="
-        Returns the computed style for the given node. If CSS selector matching has not yet been
-        performed, fails.
-
-        TODO: Return a safe reference; don't copy.
-    "]
+        
+    /** 
+     * Returns the computed style for the given node. If CSS selector
+     * matching has not yet been performed, fails.
+     */
     fn style() -> SpecifiedStyle {
         if !self.has_aux() {
             fail ~"get_style() called on a node without a style!";
         }
+        // TODO: return a safe reference; don't copy!
         return copy *self.aux(|x| copy x).style;
     }
 
-    #[doc="
-        Performs CSS selector matching on a subtree.
+    /**
+     * Initializes layout data and styles for a Node tree, if any nodes do not have
+     * this data already. Append created layout data to the task's GC roots.
+     */
+    fn initialize_style_for_subtree(_ctx: &LayoutContext, refs: &DVec<@LayoutData>) {
+        do self.traverse_preorder |n| {
+            match n.initialize_layout_data() {
+                Some(r) => refs.push(r),
+                None => {}
+            }
+        }
+    }
 
-This is, importantly, the function that updates the layout data for the node (the reader-
-auxiliary box in the RCU model) with the computed style.
-"]
+    /**
+     * Performs CSS selector matching on a subtree.
+
+     * This is, importantly, the function that updates the layout data for
+     * the node (the reader-auxiliary box in the RCU model) with the
+     * computed style.
+     */
     fn recompute_style_for_subtree(ctx: &LayoutContext, styles : ARC<Stylesheet>) {
         let mut i = 0u;
         

src/servo/dom/node.rs

@@ -12,7 +12,7 @@ use js::glue::bindgen::RUST_OBJECT_TO_JSVAL;
 use js::jsapi::{JSClass, JSObject, JSPropertySpec, JSContext, jsid, jsval, JSBool};
 use js::rust::{bare_compartment, compartment, methods};
 use js::{JSPROP_ENUMERATE, JSPROP_SHARED};
-use layout::base::RenderBox;
+use layout::base::FlowContext;
 use layout::debug::DebugMethods;
 use ptr::null;
 use std::arc::ARC;
@@ -37,6 +37,18 @@ impl NodeTree : tree::ReadMethods<Node> {
     }
 }
 
+impl Node {
+    fn traverse_preorder(preorder_cb: &fn(Node)) {
+        preorder_cb(self);
+        do NodeTree.each_child(self) |child| { child.traverse_preorder(preorder_cb); true }
+    }
+
+    fn traverse_postorder(postorder_cb: &fn(Node)) {
+        do NodeTree.each_child(self) |child| { child.traverse_postorder(postorder_cb); true }
+        postorder_cb(self);
+    }
+}
+
 
 impl Node : DebugMethods {
     /* Dumps the subtree rooted at this node, for debugging. */
@@ -105,7 +117,7 @@ fn define_bindings(compartment: bare_compartment, doc: @Document,
    Note that there may be multiple boxes per DOM node. */
 enum LayoutData = {
     mut style: ~SpecifiedStyle,
-    mut box: Option<@RenderBox>
+    mut flow:  Option<@FlowContext>
 };
 
 type Node = rcu::Handle<NodeData, LayoutData>;
@@ -151,5 +163,4 @@ impl NodeScope : tree::WriteMethods<Node> {
     fn with_tree_fields<R>(node: Node, f: fn(tree::Tree<Node>) -> R) -> R {
         self.write(node, |n| f(n.tree))
     }
-}
-
+}

src/servo/layout/box_builder.rs

@@ -1,11 +1,11 @@
 /** Creates CSS boxes from a DOM. */
 use au = gfx::geometry;
 use core::dvec::DVec;
-use css::styles::SpecifiedStyle;
+use css::styles::{SpecifiedStyle, empty_style_for_node_kind};
 use css::values::{CSSDisplay, DisplayBlock, DisplayInline, DisplayInlineBlock, DisplayNone};
 use css::values::{Inherit, Initial, Specified};
 use dom::element::*;
-use dom::node::{Comment, Doctype, Element, Text, Node, NodeTree};
+use dom::node::{Comment, Doctype, Element, Text, Node, NodeTree, LayoutData};
 use layout::base::{RenderBox, BoxData, GenericBox, ImageBox, TextBox, RenderBoxTree};
 use layout::base::{FlowContext, FlowContextData, BlockFlow, InlineFlow, InlineBlockFlow, RootFlow, FlowTree};
 use layout::block::BlockFlowData;

src/servo/layout/layout_task.rs

@@ -10,7 +10,7 @@ use core::dvec::DVec;
 use css::resolve::apply::apply_style;
 use css::values::Stylesheet;
 use dl = gfx::display_list;
-use dom::node::Node;
+use dom::node::{Node, LayoutData};
 use dom::event::{Event, ReflowEvent};
 use geom::point::Point2D;
 use geom::rect::Rect;
@@ -41,7 +41,7 @@ fn LayoutTask(render_task: RenderTask, image_cache_task: ImageCacheTask) -> Layo
     do spawn_listener::<Msg>|request| {
 
         // This just keeps our dom aux objects alive
-        let mut layout_data_refs = ~[];
+        let layout_data_refs = DVec();
         let font_cache = FontCache();
 
         loop {
@@ -65,7 +65,7 @@ fn LayoutTask(render_task: RenderTask, image_cache_task: ImageCacheTask) -> Layo
                     };
 
                     do util::time::time(~"layout") {
-                        layout_data_refs += node.initialize_style_for_subtree();
+                        node.initialize_style_for_subtree(&layout_ctx, &layout_data_refs);
                         node.recompute_style_for_subtree(&layout_ctx, styles);
 
                         // TODO: this should care about root flow, not root box.