From bbed6cddcd3971be9cb74ebc927e6ae57135ea28 Mon Sep 17 00:00:00 2001
From: Jo Steven Novaryo <65610990+stevennovaryo@users.noreply.github.com>
Date: Fri, 18 Jul 2025 13:39:09 +0800
Subject: [PATCH] css: Refactor `StyleSheetInDocument` owner (#38136)

Refactor `documentotshadowroot::StyleSheetInDocument`, renaming it into
`ServoStylesheetInDocument` to avoid confusion with Stylo's
`StylesheetInDocument` trait.

To support constructed stylesheet. The `ServoStylesheetInDocument.owner`
would contains enum of:
- `Dom<Element>` - for stylesheet parsed from an element.
- `Dom<CSSStylesheet>` - for constructed stylesheet.

Testing: No WPT regression.
Fixes: #38133

---------

Signed-off-by: Jo Steven Novaryo <jo.steven.novaryo@huawei.com>
---
 components/script/dom/document.rs             | 36 ++++++----
 components/script/dom/documentorshadowroot.rs | 70 +++++++++++++------
 components/script/dom/htmllinkelement.rs      | 10 ++-
 components/script/dom/htmlstyleelement.rs     | 10 ++-
 components/script/dom/shadowroot.rs           | 35 ++++++----
 components/script/dom/stylesheetlist.rs       |  8 ++-
 6 files changed, 112 insertions(+), 57 deletions(-)

diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 5b572df39ad..89f323983eb 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -134,7 +134,9 @@ use crate::dom::customelementregistry::CustomElementDefinition;
 use crate::dom::customevent::CustomEvent;
 use crate::dom::datatransfer::DataTransfer;
 use crate::dom::documentfragment::DocumentFragment;
-use crate::dom::documentorshadowroot::{DocumentOrShadowRoot, StyleSheetInDocument};
+use crate::dom::documentorshadowroot::{
+    DocumentOrShadowRoot, ServoStylesheetInDocument, StylesheetSource,
+};
 use crate::dom::documenttype::DocumentType;
 use crate::dom::domimplementation::DOMImplementation;
 use crate::dom::element::{
@@ -332,7 +334,7 @@ pub(crate) struct Document {
     style_shared_lock: StyleSharedRwLock,
     /// List of stylesheets associated with nodes in this document. |None| if the list needs to be refreshed.
     #[custom_trace]
-    stylesheets: DomRefCell<DocumentStylesheetSet<StyleSheetInDocument>>,
+    stylesheets: DomRefCell<DocumentStylesheetSet<ServoStylesheetInDocument>>,
     stylesheet_list: MutNullableDom<StyleSheetList>,
     ready_state: Cell<DocumentReadyState>,
     /// Whether the DOMContentLoaded event has already been dispatched.
@@ -4889,23 +4891,29 @@ impl Document {
 
         stylesheets
             .get(Origin::Author, index)
-            .and_then(|s| s.owner.upcast::<Node>().get_cssom_stylesheet())
+            .and_then(|s| s.owner.get_cssom_object())
     }
 
     /// Add a stylesheet owned by `owner` to the list of document sheets, in the
     /// correct tree position.
     #[cfg_attr(crown, allow(crown::unrooted_must_root))] // Owner needs to be rooted already necessarily.
-    pub(crate) fn add_stylesheet(&self, owner: &Element, sheet: Arc<Stylesheet>) {
+    pub(crate) fn add_stylesheet(&self, owner: StylesheetSource, sheet: Arc<Stylesheet>) {
         let stylesheets = &mut *self.stylesheets.borrow_mut();
-        let insertion_point = stylesheets
-            .iter()
-            .map(|(sheet, _origin)| sheet)
-            .find(|sheet_in_doc| {
-                owner
-                    .upcast::<Node>()
-                    .is_before(sheet_in_doc.owner.upcast())
-            })
-            .cloned();
+
+        // TODO(stevennovayo): support constructed stylesheet for adopted stylesheet and its ordering
+        let insertion_point = match &owner {
+            StylesheetSource::Element(owner_elem) => stylesheets
+                .iter()
+                .map(|(sheet, _origin)| sheet)
+                .find(|sheet_in_doc| match sheet_in_doc.owner {
+                    StylesheetSource::Element(ref other_elem) => {
+                        owner_elem.upcast::<Node>().is_before(other_elem.upcast())
+                    },
+                    StylesheetSource::Constructed(_) => unreachable!(),
+                })
+                .cloned(),
+            StylesheetSource::Constructed(_) => unreachable!(),
+        };
 
         if self.has_browsing_context() {
             self.window.layout_mut().add_stylesheet(
@@ -4932,7 +4940,7 @@ impl Document {
 
     /// Remove a stylesheet owned by `owner` from the list of document sheets.
     #[cfg_attr(crown, allow(crown::unrooted_must_root))] // Owner needs to be rooted already necessarily.
-    pub(crate) fn remove_stylesheet(&self, owner: &Element, stylesheet: &Arc<Stylesheet>) {
+    pub(crate) fn remove_stylesheet(&self, owner: StylesheetSource, stylesheet: &Arc<Stylesheet>) {
         if self.has_browsing_context() {
             self.window
                 .layout_mut()
diff --git a/components/script/dom/documentorshadowroot.rs b/components/script/dom/documentorshadowroot.rs
index d46cfacd76d..0173be600c4 100644
--- a/components/script/dom/documentorshadowroot.rs
+++ b/components/script/dom/documentorshadowroot.rs
@@ -26,46 +26,77 @@ use crate::dom::element::Element;
 use crate::dom::htmlelement::HTMLElement;
 use crate::dom::node::{self, Node, VecPreOrderInsertionHelper};
 use crate::dom::shadowroot::ShadowRoot;
+use crate::dom::types::CSSStyleSheet;
 use crate::dom::window::Window;
 use crate::script_runtime::CanGc;
 use crate::stylesheet_set::StylesheetSetRef;
 
+/// Stylesheet could be constructed by a CSSOM object CSSStylesheet or parsed
+/// from HTML element such as `<style>` or `<link>`.
 #[derive(Clone, JSTraceable, MallocSizeOf)]
 #[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
-pub(crate) struct StyleSheetInDocument {
+pub(crate) enum StylesheetSource {
+    Element(Dom<Element>),
+    // TODO(stevennovaryo): This type of enum would not be used until we implement adopted stylesheet
+    #[allow(dead_code)]
+    Constructed(Dom<CSSStyleSheet>),
+}
+
+impl StylesheetSource {
+    pub(crate) fn get_cssom_object(&self) -> Option<DomRoot<CSSStyleSheet>> {
+        match self {
+            StylesheetSource::Element(el) => el.upcast::<Node>().get_cssom_stylesheet(),
+            StylesheetSource::Constructed(ss) => Some(ss.as_rooted()),
+        }
+    }
+
+    pub(crate) fn is_a_valid_owner(&self) -> bool {
+        match self {
+            StylesheetSource::Element(el) => el.as_stylesheet_owner().is_some(),
+            StylesheetSource::Constructed(ss) => ss.is_constructed(),
+        }
+    }
+}
+
+#[derive(Clone, JSTraceable, MallocSizeOf)]
+#[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
+pub(crate) struct ServoStylesheetInDocument {
     #[ignore_malloc_size_of = "Arc"]
     #[no_trace]
     pub(crate) sheet: Arc<Stylesheet>,
-    pub(crate) owner: Dom<Element>,
+    /// The object that owns this stylesheet. For constructed stylesheet, it would be the
+    /// CSSOM object itself, and for stylesheet generated by an element, it would be the
+    /// html element. This is used to get the CSSOM Stylesheet within a DocumentOrShadowDOM.
+    pub(crate) owner: StylesheetSource,
 }
 
 // This is necessary because this type is contained within a Stylo type which needs
 // Stylo's version of MallocSizeOf.
-impl stylo_malloc_size_of::MallocSizeOf for StyleSheetInDocument {
+impl stylo_malloc_size_of::MallocSizeOf for ServoStylesheetInDocument {
     fn size_of(&self, ops: &mut stylo_malloc_size_of::MallocSizeOfOps) -> usize {
-        <StyleSheetInDocument as malloc_size_of::MallocSizeOf>::size_of(self, ops)
+        <ServoStylesheetInDocument as malloc_size_of::MallocSizeOf>::size_of(self, ops)
     }
 }
 
-impl fmt::Debug for StyleSheetInDocument {
+impl fmt::Debug for ServoStylesheetInDocument {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         self.sheet.fmt(formatter)
     }
 }
 
-impl PartialEq for StyleSheetInDocument {
+impl PartialEq for ServoStylesheetInDocument {
     fn eq(&self, other: &Self) -> bool {
         Arc::ptr_eq(&self.sheet, &other.sheet)
     }
 }
 
-impl ToMediaListKey for StyleSheetInDocument {
+impl ToMediaListKey for ServoStylesheetInDocument {
     fn to_media_list_key(&self) -> MediaListKey {
         self.sheet.contents.to_media_list_key()
     }
 }
 
-impl ::style::stylesheets::StylesheetInDocument for StyleSheetInDocument {
+impl ::style::stylesheets::StylesheetInDocument for ServoStylesheetInDocument {
     fn enabled(&self) -> bool {
         self.sheet.enabled()
     }
@@ -85,7 +116,7 @@ impl ::style::stylesheets::StylesheetInDocument for StyleSheetInDocument {
 
 // https://w3c.github.io/webcomponents/spec/shadow/#extensions-to-the-documentorshadowroot-mixin
 #[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
-#[derive(JSTraceable, MallocSizeOf)]
+#[derive(Clone, JSTraceable, MallocSizeOf)]
 pub(crate) struct DocumentOrShadowRoot {
     window: Dom<Window>,
 }
@@ -225,18 +256,18 @@ impl DocumentOrShadowRoot {
     /// Remove a stylesheet owned by `owner` from the list of document sheets.
     #[cfg_attr(crown, allow(crown::unrooted_must_root))] // Owner needs to be rooted already necessarily.
     pub(crate) fn remove_stylesheet(
-        owner: &Element,
+        owner: StylesheetSource,
         s: &Arc<Stylesheet>,
-        mut stylesheets: StylesheetSetRef<StyleSheetInDocument>,
+        mut stylesheets: StylesheetSetRef<ServoStylesheetInDocument>,
     ) {
         let guard = s.shared_lock.read();
 
         // FIXME(emilio): Would be nice to remove the clone, etc.
         stylesheets.remove_stylesheet(
             None,
-            StyleSheetInDocument {
+            ServoStylesheetInDocument {
                 sheet: s.clone(),
-                owner: Dom::from_ref(owner),
+                owner,
             },
             &guard,
         );
@@ -246,18 +277,15 @@ impl DocumentOrShadowRoot {
     /// correct tree position.
     #[cfg_attr(crown, allow(crown::unrooted_must_root))] // Owner needs to be rooted already necessarily.
     pub(crate) fn add_stylesheet(
-        owner: &Element,
-        mut stylesheets: StylesheetSetRef<StyleSheetInDocument>,
+        owner: StylesheetSource,
+        mut stylesheets: StylesheetSetRef<ServoStylesheetInDocument>,
         sheet: Arc<Stylesheet>,
-        insertion_point: Option<StyleSheetInDocument>,
+        insertion_point: Option<ServoStylesheetInDocument>,
         style_shared_lock: &StyleSharedRwLock,
     ) {
-        debug_assert!(owner.as_stylesheet_owner().is_some(), "Wat");
+        debug_assert!(owner.is_a_valid_owner(), "Wat");
 
-        let sheet = StyleSheetInDocument {
-            sheet,
-            owner: Dom::from_ref(owner),
-        };
+        let sheet = ServoStylesheetInDocument { sheet, owner };
 
         let guard = style_shared_lock.read();
 
diff --git a/components/script/dom/htmllinkelement.rs b/components/script/dom/htmllinkelement.rs
index 2a2f94b80e7..e6b11ae79ce 100644
--- a/components/script/dom/htmllinkelement.rs
+++ b/components/script/dom/htmllinkelement.rs
@@ -23,6 +23,7 @@ use net_traits::{
     FetchMetadata, FetchResponseListener, NetworkError, ReferrerPolicy, ResourceFetchTiming,
     ResourceTimingType,
 };
+use script_bindings::root::Dom;
 use servo_arc::Arc;
 use servo_url::{ImmutableOrigin, ServoUrl};
 use style::attr::AttrValue;
@@ -41,6 +42,7 @@ use crate::dom::bindings::str::{DOMString, USVString};
 use crate::dom::csp::{GlobalCspReporting, Violation};
 use crate::dom::cssstylesheet::CSSStyleSheet;
 use crate::dom::document::Document;
+use crate::dom::documentorshadowroot::StylesheetSource;
 use crate::dom::domtokenlist::DOMTokenList;
 use crate::dom::element::{
     AttributeMutation, Element, ElementCreator, cors_setting_for_element,
@@ -178,11 +180,13 @@ impl HTMLLinkElement {
     pub(crate) fn set_stylesheet(&self, s: Arc<Stylesheet>) {
         let stylesheets_owner = self.stylesheet_list_owner();
         if let Some(ref s) = *self.stylesheet.borrow() {
-            stylesheets_owner.remove_stylesheet(self.upcast(), s)
+            stylesheets_owner
+                .remove_stylesheet(StylesheetSource::Element(Dom::from_ref(self.upcast())), s)
         }
         *self.stylesheet.borrow_mut() = Some(s.clone());
         self.clean_stylesheet_ownership();
-        stylesheets_owner.add_stylesheet(self.upcast(), s);
+        stylesheets_owner
+            .add_stylesheet(StylesheetSource::Element(Dom::from_ref(self.upcast())), s);
     }
 
     pub(crate) fn get_stylesheet(&self) -> Option<Arc<Stylesheet>> {
@@ -416,7 +420,7 @@ impl VirtualMethods for HTMLLinkElement {
         if let Some(s) = self.stylesheet.borrow_mut().take() {
             self.clean_stylesheet_ownership();
             self.stylesheet_list_owner()
-                .remove_stylesheet(self.upcast(), &s);
+                .remove_stylesheet(StylesheetSource::Element(Dom::from_ref(self.upcast())), &s);
         }
     }
 }
diff --git a/components/script/dom/htmlstyleelement.rs b/components/script/dom/htmlstyleelement.rs
index 0852e889675..bedc76d6b59 100644
--- a/components/script/dom/htmlstyleelement.rs
+++ b/components/script/dom/htmlstyleelement.rs
@@ -8,6 +8,7 @@ use dom_struct::dom_struct;
 use html5ever::{LocalName, Prefix};
 use js::rust::HandleObject;
 use net_traits::ReferrerPolicy;
+use script_bindings::root::Dom;
 use servo_arc::Arc;
 use style::media_queries::MediaList as StyleMediaList;
 use style::stylesheets::{AllowImportRules, Origin, Stylesheet, UrlExtraData};
@@ -22,6 +23,7 @@ use crate::dom::bindings::str::DOMString;
 use crate::dom::csp::{CspReporting, InlineCheckType};
 use crate::dom::cssstylesheet::CSSStyleSheet;
 use crate::dom::document::Document;
+use crate::dom::documentorshadowroot::StylesheetSource;
 use crate::dom::element::{AttributeMutation, Element, ElementCreator};
 use crate::dom::htmlelement::HTMLElement;
 use crate::dom::medialist::MediaList;
@@ -153,11 +155,13 @@ impl HTMLStyleElement {
     pub(crate) fn set_stylesheet(&self, s: Arc<Stylesheet>) {
         let stylesheets_owner = self.stylesheet_list_owner();
         if let Some(ref s) = *self.stylesheet.borrow() {
-            stylesheets_owner.remove_stylesheet(self.upcast(), s)
+            stylesheets_owner
+                .remove_stylesheet(StylesheetSource::Element(Dom::from_ref(self.upcast())), s)
         }
         *self.stylesheet.borrow_mut() = Some(s.clone());
         self.clean_stylesheet_ownership();
-        stylesheets_owner.add_stylesheet(self.upcast(), s);
+        stylesheets_owner
+            .add_stylesheet(StylesheetSource::Element(Dom::from_ref(self.upcast())), s);
     }
 
     pub(crate) fn get_stylesheet(&self) -> Option<Arc<Stylesheet>> {
@@ -192,7 +196,7 @@ impl HTMLStyleElement {
         if let Some(s) = self.stylesheet.borrow_mut().take() {
             self.clean_stylesheet_ownership();
             self.stylesheet_list_owner()
-                .remove_stylesheet(self.upcast(), &s)
+                .remove_stylesheet(StylesheetSource::Element(Dom::from_ref(self.upcast())), &s)
         }
     }
 }
diff --git a/components/script/dom/shadowroot.rs b/components/script/dom/shadowroot.rs
index 33944d3ac5c..3d58cc8073c 100644
--- a/components/script/dom/shadowroot.rs
+++ b/components/script/dom/shadowroot.rs
@@ -32,7 +32,9 @@ use crate::dom::bindings::str::DOMString;
 use crate::dom::cssstylesheet::CSSStyleSheet;
 use crate::dom::document::Document;
 use crate::dom::documentfragment::DocumentFragment;
-use crate::dom::documentorshadowroot::{DocumentOrShadowRoot, StyleSheetInDocument};
+use crate::dom::documentorshadowroot::{
+    DocumentOrShadowRoot, ServoStylesheetInDocument, StylesheetSource,
+};
 use crate::dom::element::Element;
 use crate::dom::htmlslotelement::HTMLSlotElement;
 use crate::dom::node::{
@@ -62,7 +64,7 @@ pub(crate) struct ShadowRoot {
     host: MutNullableDom<Element>,
     /// List of author styles associated with nodes in this shadow tree.
     #[custom_trace]
-    author_styles: DomRefCell<AuthorStyles<StyleSheetInDocument>>,
+    author_styles: DomRefCell<AuthorStyles<ServoStylesheetInDocument>>,
     stylesheet_list: MutNullableDom<StyleSheetList>,
     window: Dom<Window>,
 
@@ -175,22 +177,29 @@ impl ShadowRoot {
 
         stylesheets
             .get(index)
-            .and_then(|s| s.owner.upcast::<Node>().get_cssom_stylesheet())
+            .and_then(|s| s.owner.get_cssom_object())
     }
 
     /// Add a stylesheet owned by `owner` to the list of shadow root sheets, in the
     /// correct tree position.
     #[cfg_attr(crown, allow(crown::unrooted_must_root))] // Owner needs to be rooted already necessarily.
-    pub(crate) fn add_stylesheet(&self, owner: &Element, sheet: Arc<Stylesheet>) {
+    pub(crate) fn add_stylesheet(&self, owner: StylesheetSource, sheet: Arc<Stylesheet>) {
         let stylesheets = &mut self.author_styles.borrow_mut().stylesheets;
-        let insertion_point = stylesheets
-            .iter()
-            .find(|sheet_in_shadow| {
-                owner
-                    .upcast::<Node>()
-                    .is_before(sheet_in_shadow.owner.upcast())
-            })
-            .cloned();
+
+        // TODO(stevennovayo): support constructed stylesheet for adopted stylesheet and its ordering
+        let insertion_point = match &owner {
+            StylesheetSource::Element(owner_elem) => stylesheets
+                .iter()
+                .find(|sheet_in_shadow| match sheet_in_shadow.owner {
+                    StylesheetSource::Element(ref other_elem) => {
+                        owner_elem.upcast::<Node>().is_before(other_elem.upcast())
+                    },
+                    StylesheetSource::Constructed(_) => unreachable!(),
+                })
+                .cloned(),
+            StylesheetSource::Constructed(_) => unreachable!(),
+        };
+
         DocumentOrShadowRoot::add_stylesheet(
             owner,
             StylesheetSetRef::Author(stylesheets),
@@ -202,7 +211,7 @@ impl ShadowRoot {
 
     /// Remove a stylesheet owned by `owner` from the list of shadow root sheets.
     #[cfg_attr(crown, allow(crown::unrooted_must_root))] // Owner needs to be rooted already necessarily.
-    pub(crate) fn remove_stylesheet(&self, owner: &Element, s: &Arc<Stylesheet>) {
+    pub(crate) fn remove_stylesheet(&self, owner: StylesheetSource, s: &Arc<Stylesheet>) {
         DocumentOrShadowRoot::remove_stylesheet(
             owner,
             s,
diff --git a/components/script/dom/stylesheetlist.rs b/components/script/dom/stylesheetlist.rs
index 628c044c3b7..ab9452cad5f 100644
--- a/components/script/dom/stylesheetlist.rs
+++ b/components/script/dom/stylesheetlist.rs
@@ -11,7 +11,7 @@ use crate::dom::bindings::reflector::{Reflector, reflect_dom_object};
 use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::cssstylesheet::CSSStyleSheet;
 use crate::dom::document::Document;
-use crate::dom::element::Element;
+use crate::dom::documentorshadowroot::StylesheetSource;
 use crate::dom::shadowroot::ShadowRoot;
 use crate::dom::stylesheet::StyleSheet;
 use crate::dom::window::Window;
@@ -39,7 +39,8 @@ impl StyleSheetListOwner {
         }
     }
 
-    pub(crate) fn add_stylesheet(&self, owner: &Element, sheet: Arc<Stylesheet>) {
+    #[cfg_attr(crown, allow(crown::unrooted_must_root))] // Owner needs to be rooted already necessarily.
+    pub(crate) fn add_stylesheet(&self, owner: StylesheetSource, sheet: Arc<Stylesheet>) {
         match *self {
             StyleSheetListOwner::Document(ref doc) => doc.add_stylesheet(owner, sheet),
             StyleSheetListOwner::ShadowRoot(ref shadow_root) => {
@@ -48,7 +49,8 @@ impl StyleSheetListOwner {
         }
     }
 
-    pub(crate) fn remove_stylesheet(&self, owner: &Element, s: &Arc<Stylesheet>) {
+    #[cfg_attr(crown, allow(crown::unrooted_must_root))] // Owner needs to be rooted already necessarily.
+    pub(crate) fn remove_stylesheet(&self, owner: StylesheetSource, s: &Arc<Stylesheet>) {
         match *self {
             StyleSheetListOwner::Document(ref doc) => doc.remove_stylesheet(owner, s),
             StyleSheetListOwner::ShadowRoot(ref shadow_root) => {