layout: Implement node geometry queries against `BoxTree`'s `Fragment`

This is a followup to #36629, continuing to implement script-based
layout queries  using the `Fragment`s attached to the `BoxTree`. In this
change, geometry queris (apart from parent offset) are calculated using
`Fragment`s hanging of the `BoxTree`.

In order to make this work, all `Fragment`s for inlines split by blocks,
need to be accessible in the `BoxTree`. This required some changes to
the way that box tree items were stored in DOM `BoxSlot`s. Now every
inline level item can have more than a single `BoxTree` item. These are
carefully collected by the `InlineFormattingContextBuilder` -- currently
a bit fragile, but with more documentation.

Co-authored-by: Oriol Brufau <obrufau@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>

1 files changed, 20 insertions, 26 deletions

diff --git a/components/layout/query.rs b/components/layout/query.rs
index 3409f7c1923..3badff83672 100644
--- a/components/layout/query.rs
+++ b/components/layout/query.rs
@@ -46,40 +46,34 @@ use crate::fragment_tree::{
 use crate::geom::{PhysicalRect, PhysicalVec};
 use crate::taffy::SpecificTaffyGridInfo;
 
-pub fn process_content_box_request(
-    requested_node: OpaqueNode,
-    fragment_tree: Option<Arc<FragmentTree>>,
-) -> Option<Rect<Au>> {
-    let rects = fragment_tree?.get_content_boxes_for_node(requested_node);
+pub fn process_content_box_request<'dom>(node: impl LayoutNode<'dom> + 'dom) -> Option<Rect<Au>> {
+    let rects: Vec<_> = node
+        .fragments_for_pseudo(None)
+        .iter()
+        .filter_map(Fragment::cumulative_content_box_rect)
+        .collect();
     if rects.is_empty() {
         return None;
     }
 
-    Some(
-        rects
-            .iter()
-            .fold(Rect::zero(), |unioned_rect, rect| rect.union(&unioned_rect)),
-    )
+    Some(rects.iter().fold(Rect::zero(), |unioned_rect, rect| {
+        rect.to_untyped().union(&unioned_rect)
+    }))
 }
 
-pub fn process_content_boxes_request(
-    requested_node: OpaqueNode,
-    fragment_tree: Option<Arc<FragmentTree>>,
-) -> Vec<Rect<Au>> {
-    fragment_tree
-        .map(|tree| tree.get_content_boxes_for_node(requested_node))
-        .unwrap_or_default()
+pub fn process_content_boxes_request<'dom>(node: impl LayoutNode<'dom> + 'dom) -> Vec<Rect<Au>> {
+    node.fragments_for_pseudo(None)
+        .iter()
+        .filter_map(Fragment::cumulative_content_box_rect)
+        .map(|rect| rect.to_untyped())
+        .collect()
 }
 
-pub fn process_node_geometry_request(
-    requested_node: OpaqueNode,
-    fragment_tree: Option<Arc<FragmentTree>>,
-) -> Rect<i32> {
-    if let Some(fragment_tree) = fragment_tree {
-        fragment_tree.get_border_dimensions_for_node(requested_node)
-    } else {
-        Rect::zero()
-    }
+pub fn process_client_rect_request<'dom>(node: impl LayoutNode<'dom> + 'dom) -> Rect<i32> {
+    node.fragments_for_pseudo(None)
+        .first()
+        .map(Fragment::client_rect)
+        .unwrap_or_default()
 }
 
 /// <https://drafts.csswg.org/cssom-view/#scrolling-area>