Auto merge of #24360 - servo:build-box-tree, r=SimonSapin

Call BoxTreeRoot::construct from layout_thread_2020

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components/layout_2020/dom_traversal.rs

@@ -17,7 +17,7 @@ use style::properties::ComputedValues;
 use style::selector_parser::PseudoElement;
 
 #[derive(Clone, Copy)]
-pub(super) enum WhichPseudoElement {
+pub enum WhichPseudoElement {
     Before,
     After,
 }
@@ -252,24 +252,24 @@ where
     unimplemented!()
 }
 
-pub(super) struct BoxSlot<'dom> {
+pub struct BoxSlot<'dom> {
     slot: Option<Arc<AtomicRefCell<Option<LayoutBox>>>>,
     marker: marker<&'dom ()>,
 }
 
 impl BoxSlot<'_> {
-    pub fn new(slot: Arc<AtomicRefCell<Option<LayoutBox>>>) -> Self {
+    pub(crate) fn new(slot: Arc<AtomicRefCell<Option<LayoutBox>>>) -> Self {
         *slot.borrow_mut() = None;
         let slot = Some(slot);
         Self { slot, marker }
     }
 
-    pub fn dummy() -> Self {
+    pub(crate) fn dummy() -> Self {
         let slot = None;
         Self { slot, marker }
     }
 
-    pub fn set(mut self, box_: LayoutBox) {
+    pub(crate) fn set(mut self, box_: LayoutBox) {
         if let Some(slot) = &mut self.slot {
             *slot.borrow_mut() = Some(box_);
         }
@@ -284,7 +284,7 @@ impl Drop for BoxSlot<'_> {
     }
 }
 
-pub(crate) trait NodeExt<'dom>: 'dom + Copy + LayoutNode + Send + Sync {
+pub trait NodeExt<'dom>: 'dom + Copy + LayoutNode + Send + Sync {
     fn is_element(self) -> bool;
     fn as_text(self) -> Option<String>;
     fn first_child(self) -> Option<Self>;

components/layout_2020/element_data.rs

@@ -8,7 +8,7 @@ use atomic_refcell::AtomicRefCell;
 use servo_arc::Arc;
 
 #[derive(Default)]
-pub(crate) struct LayoutDataForElement {
+pub struct LayoutDataForElement {
     pub(super) self_box: Arc<AtomicRefCell<Option<LayoutBox>>>,
     pub(super) pseudo_elements: Option<Box<PseudoElementBoxes>>,
 }

components/layout_2020/flow/mod.rs

@@ -27,6 +27,8 @@ mod float;
 pub mod inline;
 mod root;
 
+pub use root::BoxTreeRoot;
+
 #[derive(Debug)]
 pub(crate) struct BlockFormattingContext {
     pub contents: BlockContainer,

components/layout_2020/flow/root.rs

@@ -22,17 +22,7 @@ use style::properties::ComputedValues;
 use style::values::computed::{Length, LengthOrAuto};
 use style_traits::CSSPixel;
 
-// FIXME
-// impl crate::dom::Document {
-//     pub(crate) fn layout(
-//         &self,
-//         viewport: crate::geom::Size<crate::geom::CssPx>,
-//     ) -> Vec<Fragment> {
-//         BoxTreeRoot::construct(self).layout(viewport)
-//     }
-// }
-
-struct BoxTreeRoot(BlockFormattingContext);
+pub struct BoxTreeRoot(BlockFormattingContext);
 
 impl BoxTreeRoot {
     pub fn construct<'dom>(

components/layout_2020/lib.rs

@@ -17,19 +17,21 @@ use style::Zero;
 
 pub mod context;
 pub mod data;
-pub mod dom_traversal;
-pub mod element_data;
-pub mod flow;
-pub mod fragments;
-pub mod geom;
-pub mod opaque_node;
-pub mod positioned;
+mod dom_traversal;
+mod element_data;
+mod flow;
+mod fragments;
+mod geom;
+mod opaque_node;
+mod positioned;
 pub mod query;
-pub mod replaced;
-pub mod style_ext;
+mod replaced;
+mod style_ext;
 pub mod traversal;
 pub mod wrapper;
 
+pub use flow::BoxTreeRoot;
+
 use crate::dom_traversal::{Contents, NodeExt};
 use crate::flow::{BlockFormattingContext, FlowChildren};
 use crate::geom::flow_relative::Vec2;

components/layout_thread_2020/dom_wrapper.rs

@@ -109,6 +109,13 @@ pub struct ServoLayoutNode<'a> {
     chain: PhantomData<&'a ()>,
 }
 
+// Those are supposed to be sound, but they aren't because the entire system
+// between script and layout so far has been designed to work around their
+// absence. Switching the entire thing to the inert crate infra will help.
+
+unsafe impl Send for ServoLayoutNode<'_> {}
+unsafe impl Sync for ServoLayoutNode<'_> {}
+
 impl<'ln> Debug for ServoLayoutNode<'ln> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         if let Some(el) = self.as_element() {

components/layout_thread_2020/lib.rs

@@ -45,6 +45,7 @@ use layout::query::{
     process_text_index_request,
 };
 use layout::traversal::RecalcStyle;
+use layout::BoxTreeRoot;
 use layout_traits::LayoutThreadFactory;
 use libc::c_void;
 use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
@@ -166,6 +167,9 @@ pub struct LayoutThread {
     /// The number of Web fonts that have been requested but not yet loaded.
     outstanding_web_fonts: Arc<AtomicUsize>,
 
+    /// The root box tree.
+    box_tree_root: RefCell<Option<BoxTreeRoot>>,
+
     /// The document-specific shared lock used for author-origin stylesheets
     document_shared_lock: Option<SharedRwLock>,
 
@@ -492,6 +496,7 @@ impl LayoutThread {
             new_animations_sender: new_animations_sender,
             _new_animations_receiver: new_animations_receiver,
             outstanding_web_fonts: Arc::new(AtomicUsize::new(0)),
+            box_tree_root: Default::default(),
             document_shared_lock: None,
             epoch: Cell::new(Epoch(0)),
             viewport_size: Size2D::new(Au(0), Au(0)),
@@ -1075,6 +1080,11 @@ impl LayoutThread {
 
         if token.should_traverse() {
             driver::traverse_dom(&traversal, token, None);
+
+            let shared = DomTraversal::<ServoLayoutElement>::shared_context(&traversal);
+            let box_tree =
+                BoxTreeRoot::construct(shared, document.root_element().unwrap().as_node());
+            *self.box_tree_root.borrow_mut() = Some(box_tree);
         }
 
         for element in elements_with_snapshot {