Implements Stylesheet.ownerNode

8 files changed, 52 insertions, 23 deletions

diff --git a/components/script/dom/cssrulelist.rs b/components/script/dom/cssrulelist.rs
index 812434fd180..d4fde8ae308 100644
--- a/components/script/dom/cssrulelist.rs
+++ b/components/script/dom/cssrulelist.rs
@@ -5,7 +5,6 @@
 use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::CSSRuleListBinding::CSSRuleListMethods;
 use crate::dom::bindings::error::{Error, ErrorResult, Fallible};
-use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
 use crate::dom::bindings::root::{Dom, DomRoot, MutNullableDom};
 use crate::dom::csskeyframerule::CSSKeyframeRule;
@@ -13,6 +12,7 @@ use crate::dom::cssrule::CSSRule;
 use crate::dom::cssstylesheet::CSSStyleSheet;
 use crate::dom::htmlelement::HTMLElement;
 use crate::dom::window::Window;
+use crate::style::stylesheets::StylesheetLoader as StyleStylesheetLoader;
 use crate::stylesheet_loader::StylesheetLoader;
 use dom_struct::dom_struct;
 use servo_arc::Arc;
@@ -107,9 +107,11 @@ impl CSSRuleList {
         let owner = self
             .parent_stylesheet
             .get_owner()
-            .downcast::<HTMLElement>()
-            .unwrap();
-        let loader = StylesheetLoader::for_element(owner);
+            .map(DomRoot::downcast::<HTMLElement>)
+            .flatten();
+        let loader = owner
+            .as_ref()
+            .map(|element| StylesheetLoader::for_element(&**element));
         let new_rule = css_rules.with_raw_offset_arc(|arc| {
             arc.insert_rule(
                 &parent_stylesheet.shared_lock,
@@ -117,7 +119,7 @@ impl CSSRuleList {
                 &parent_stylesheet.contents,
                 index,
                 nested,
-                Some(&loader),
+                loader.as_ref().map(|l| l as &dyn StyleStylesheetLoader),
                 AllowImportRules::Yes,
             )
         })?;
diff --git a/components/script/dom/cssstyledeclaration.rs b/components/script/dom/cssstyledeclaration.rs
index ba7112b8899..3c0d63ce92f 100644
--- a/components/script/dom/cssstyledeclaration.rs
+++ b/components/script/dom/cssstyledeclaration.rs
@@ -113,8 +113,10 @@ impl CSSStyleOwner {
                 if changed {
                     // If this is changed, see also
                     // CSSStyleRule::SetSelectorText, which does the same thing.
-                    stylesheets_owner_from_node(rule.parent_stylesheet().owner().upcast::<Node>())
-                        .invalidate_stylesheets();
+                    if let Some(owner) = rule.parent_stylesheet().get_owner() {
+                        stylesheets_owner_from_node(owner.upcast::<Node>())
+                            .invalidate_stylesheets();
+                    }
                 }
                 result
             },
diff --git a/components/script/dom/cssstylerule.rs b/components/script/dom/cssstylerule.rs
index 30e4e197ce5..a84c5c598b7 100644
--- a/components/script/dom/cssstylerule.rs
+++ b/components/script/dom/cssstylerule.rs
@@ -117,8 +117,9 @@ impl CSSStyleRuleMethods for CSSStyleRule {
             let mut guard = self.cssrule.shared_lock().write();
             let stylerule = self.stylerule.write_with(&mut guard);
             mem::swap(&mut stylerule.selectors, &mut s);
-            stylesheets_owner_from_node(self.cssrule.parent_stylesheet().owner().upcast::<Node>())
-                .invalidate_stylesheets();
+            if let Some(owner) = self.cssrule.parent_stylesheet().get_owner() {
+                stylesheets_owner_from_node(owner.upcast::<Node>()).invalidate_stylesheets();
+            }
         }
     }
 }
diff --git a/components/script/dom/cssstylesheet.rs b/components/script/dom/cssstylesheet.rs
index 35277ddc0fc..7ee5e444394 100644
--- a/components/script/dom/cssstylesheet.rs
+++ b/components/script/dom/cssstylesheet.rs
@@ -6,7 +6,7 @@ use crate::dom::bindings::codegen::Bindings::CSSStyleSheetBinding::CSSStyleSheet
 use crate::dom::bindings::error::{Error, ErrorResult, Fallible};
 use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::reflector::{reflect_dom_object, DomObject};
-use crate::dom::bindings::root::{Dom, DomRoot, MutNullableDom};
+use crate::dom::bindings::root::{DomRoot, MutNullableDom};
 use crate::dom::bindings::str::DOMString;
 use crate::dom::cssrulelist::{CSSRuleList, RulesSource};
 use crate::dom::element::Element;
@@ -22,7 +22,7 @@ use style::stylesheets::Stylesheet as StyleStyleSheet;
 #[dom_struct]
 pub struct CSSStyleSheet {
     stylesheet: StyleSheet,
-    owner: Dom<Element>,
+    owner: MutNullableDom<Element>,
     rulelist: MutNullableDom<CSSRuleList>,
     #[ignore_malloc_size_of = "Arc"]
     style_stylesheet: Arc<StyleStyleSheet>,
@@ -39,7 +39,7 @@ impl CSSStyleSheet {
     ) -> CSSStyleSheet {
         CSSStyleSheet {
             stylesheet: StyleSheet::new_inherited(type_, href, title),
-            owner: Dom::from_ref(owner),
+            owner: MutNullableDom::new(Some(owner)),
             rulelist: MutNullableDom::new(None),
             style_stylesheet: stylesheet,
             origin_clean: Cell::new(true),
@@ -63,10 +63,6 @@ impl CSSStyleSheet {
         )
     }
 
-    pub fn owner(&self) -> DomRoot<Element> {
-        DomRoot::from_ref(&*self.owner)
-    }
-
     fn rulelist(&self) -> DomRoot<CSSRuleList> {
         self.rulelist.or_init(|| {
             let rules = self.style_stylesheet.contents.rules.clone();
@@ -78,16 +74,21 @@ impl CSSStyleSheet {
         self.style_stylesheet.disabled()
     }
 
-    pub fn get_owner(&self) -> &Element {
-        &*self.owner
+    pub fn get_owner(&self) -> Option<DomRoot<Element>> {
+        self.owner.get()
     }
 
     pub fn set_disabled(&self, disabled: bool) {
-        if self.style_stylesheet.set_disabled(disabled) {
-            stylesheets_owner_from_node(self.owner().upcast::<Node>()).invalidate_stylesheets();
+        if self.style_stylesheet.set_disabled(disabled) && self.get_owner().is_some() {
+            stylesheets_owner_from_node(self.get_owner().unwrap().upcast::<Node>())
+                .invalidate_stylesheets();
         }
     }
 
+    pub fn set_owner(&self, value: Option<&Element>) {
+        self.owner.set(value);
+    }
+
     pub fn shared_lock(&self) -> &SharedRwLock {
         &self.style_stylesheet.shared_lock
     }
diff --git a/components/script/dom/htmllinkelement.rs b/components/script/dom/htmllinkelement.rs
index 93879fb60b7..43df6000184 100644
--- a/components/script/dom/htmllinkelement.rs
+++ b/components/script/dom/htmllinkelement.rs
@@ -116,7 +116,7 @@ impl HTMLLinkElement {
             stylesheets_owner.remove_stylesheet(self.upcast(), s)
         }
         *self.stylesheet.borrow_mut() = Some(s.clone());
-        self.cssom_stylesheet.set(None);
+        self.clean_stylesheet_ownership();
         stylesheets_owner.add_stylesheet(self.upcast(), s);
     }
 
@@ -148,6 +148,13 @@ impl HTMLLinkElement {
             None => false,
         }
     }
+
+    fn clean_stylesheet_ownership(&self) {
+        if let Some(cssom_stylesheet) = self.cssom_stylesheet.get() {
+            cssom_stylesheet.set_owner(None);
+        }
+        self.cssom_stylesheet.set(None);
+    }
 }
 
 fn get_attr(element: &Element, local_name: &LocalName) -> Option<String> {
@@ -255,6 +262,7 @@ impl VirtualMethods for HTMLLinkElement {
         }
 
         if let Some(s) = self.stylesheet.borrow_mut().take() {
+            self.clean_stylesheet_ownership();
             stylesheets_owner_from_node(self).remove_stylesheet(self.upcast(), &s);
         }
     }
diff --git a/components/script/dom/htmlstyleelement.rs b/components/script/dom/htmlstyleelement.rs
index 6d10b0838f7..4e81837fc35 100644
--- a/components/script/dom/htmlstyleelement.rs
+++ b/components/script/dom/htmlstyleelement.rs
@@ -144,7 +144,7 @@ impl HTMLStyleElement {
             stylesheets_owner.remove_stylesheet(self.upcast(), s)
         }
         *self.stylesheet.borrow_mut() = Some(s.clone());
-        self.cssom_stylesheet.set(None);
+        self.clean_stylesheet_ownership();
         stylesheets_owner.add_stylesheet(self.upcast(), s);
     }
 
@@ -166,6 +166,13 @@ impl HTMLStyleElement {
             })
         })
     }
+
+    fn clean_stylesheet_ownership(&self) {
+        if let Some(cssom_stylesheet) = self.cssom_stylesheet.get() {
+            cssom_stylesheet.set_owner(None);
+        }
+        self.cssom_stylesheet.set(None);
+    }
 }
 
 impl VirtualMethods for HTMLStyleElement {
@@ -217,6 +224,7 @@ impl VirtualMethods for HTMLStyleElement {
 
         if context.tree_connected {
             if let Some(s) = self.stylesheet.borrow_mut().take() {
+                self.clean_stylesheet_ownership();
                 stylesheets_owner_from_node(self).remove_stylesheet(self.upcast(), &s)
             }
         }
diff --git a/components/script/dom/stylesheet.rs b/components/script/dom/stylesheet.rs
index 7d11ccdb897..56ce505d152 100644
--- a/components/script/dom/stylesheet.rs
+++ b/components/script/dom/stylesheet.rs
@@ -5,8 +5,10 @@
 use crate::dom::bindings::codegen::Bindings::StyleSheetBinding::StyleSheetMethods;
 use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::reflector::Reflector;
+use crate::dom::bindings::root::DomRoot;
 use crate::dom::bindings::str::DOMString;
 use crate::dom::cssstylesheet::CSSStyleSheet;
+use crate::dom::element::Element;
 use dom_struct::dom_struct;
 
 #[dom_struct]
@@ -44,6 +46,11 @@ impl StyleSheetMethods for StyleSheet {
         self.href.clone()
     }
 
+    // https://drafts.csswg.org/cssom/#dom-stylesheet-ownernode
+    fn GetOwnerNode(&self) -> Option<DomRoot<Element>> {
+        self.downcast::<CSSStyleSheet>().and_then(|s| s.get_owner())
+    }
+
     // https://drafts.csswg.org/cssom/#dom-stylesheet-title
     fn GetTitle(&self) -> Option<DOMString> {
         self.title.clone()
diff --git a/components/script/dom/webidls/StyleSheet.webidl b/components/script/dom/webidls/StyleSheet.webidl
index 827bd30a9af..67ac5f965e1 100644
--- a/components/script/dom/webidls/StyleSheet.webidl
+++ b/components/script/dom/webidls/StyleSheet.webidl
@@ -8,7 +8,7 @@ interface StyleSheet {
   readonly attribute DOMString type_;
   readonly attribute DOMString? href;
 
-  // readonly attribute (Element or ProcessingInstruction)? ownerNode;
+  readonly attribute Element? ownerNode;
   // readonly attribute StyleSheet? parentStyleSheet;
   readonly attribute DOMString? title;