LibWeb: Give CSSLoader a backpointer to its owner element

This allows CSSLoader to set up the style sheet owner node internally,
and avoids an awkward weak link between CSSLoader and Document.

Userland/Libraries/LibWeb/HTML/HTMLLinkElement.cpp

@@ -36,7 +36,7 @@ namespace Web::HTML {
 
 HTMLLinkElement::HTMLLinkElement(DOM::Document& document, QualifiedName qualified_name)
     : HTMLElement(document, move(qualified_name))
-    , m_css_loader(document)
+    , m_css_loader(*this)
 {
     m_css_loader.on_load = [&] {
         document.update_style();
@@ -53,10 +53,8 @@ void HTMLLinkElement::inserted_into(Node& node)
 
     if (m_relationship & Relationship::Stylesheet && !(m_relationship & Relationship::Alternate)) {
         m_css_loader.load_from_url(document().complete_url(href()));
-        if (auto sheet = m_css_loader.style_sheet()) {
-            sheet->set_owner_node(this);
+        if (auto sheet = m_css_loader.style_sheet())
             document().style_sheets().add_sheet(sheet.release_nonnull());
-        }
     }
 }
 

Userland/Libraries/LibWeb/HTML/HTMLLinkElement.h

@@ -55,8 +55,8 @@ private:
         };
     };
 
-    unsigned m_relationship { 0 };
     CSSLoader m_css_loader;
+    unsigned m_relationship { 0 };
 };
 
 }

Userland/Libraries/LibWeb/HTML/HTMLStyleElement.cpp

@@ -34,7 +34,7 @@ namespace Web::HTML {
 
 HTMLStyleElement::HTMLStyleElement(DOM::Document& document, QualifiedName qualified_name)
     : HTMLElement(document, move(qualified_name))
-    , m_css_loader(document)
+    , m_css_loader(*this)
 {
     m_css_loader.on_load = [&] {
         document.update_style();
@@ -54,10 +54,8 @@ void HTMLStyleElement::children_changed()
     });
     m_css_loader.load_from_text(builder.to_string());
 
-    if (auto sheet = m_css_loader.style_sheet()) {
-        sheet->set_owner_node(this);
+    if (auto sheet = m_css_loader.style_sheet())
         document().style_sheets().add_sheet(sheet.release_nonnull());
-    }
 
     HTMLElement::children_changed();
 }

Userland/Libraries/LibWeb/Loader/CSSLoader.cpp

@@ -29,21 +29,24 @@
 #include <LibWeb/CSS/CSSImportRule.h>
 #include <LibWeb/CSS/Parser/CSSParser.h>
 #include <LibWeb/CSS/StyleSheet.h>
+#include <LibWeb/DOM/Element.h>
 #include <LibWeb/Loader/CSSLoader.h>
 #include <LibWeb/Loader/ResourceLoader.h>
 
 namespace Web {
 
-CSSLoader::CSSLoader(DOM::Document& document)
-    : m_document(&document)
+CSSLoader::CSSLoader(DOM::Element& owner_element)
+    : m_owner_element(owner_element)
 {
 }
 
 void CSSLoader::load_from_text(const String& text)
 {
-    m_style_sheet = parse_css(CSS::ParsingContext(*m_document), text);
-    if (!m_style_sheet)
+    m_style_sheet = parse_css(CSS::ParsingContext(m_owner_element.document()), text);
+    if (!m_style_sheet) {
         m_style_sheet = CSS::CSSStyleSheet::create({});
+        m_style_sheet->set_owner_node(&m_owner_element);
+    }
 
     load_next_import_if_needed();
 }
@@ -51,6 +54,7 @@ void CSSLoader::load_from_text(const String& text)
 void CSSLoader::load_from_url(const URL& url)
 {
     m_style_sheet = CSS::CSSStyleSheet::create({});
+    m_style_sheet->set_owner_node(&m_owner_element);
 
     LoadRequest request;
     request.set_url(url);
@@ -67,7 +71,7 @@ void CSSLoader::resource_did_load()
         dbgln_if(CSS_LOADER_DEBUG, "CSSLoader: Resource did load, has encoded data. URL: {}", resource()->url());
     }
 
-    auto sheet = parse_css(CSS::ParsingContext(*m_document), resource()->encoded_data());
+    auto sheet = parse_css(CSS::ParsingContext(m_owner_element.document()), resource()->encoded_data());
     if (!sheet) {
         dbgln_if(CSS_LOADER_DEBUG, "CSSLoader: Failed to parse stylesheet: {}", resource()->url());
         return;

Userland/Libraries/LibWeb/Loader/CSSLoader.h

@@ -34,7 +34,7 @@ namespace Web {
 
 class CSSLoader : public ResourceClient {
 public:
-    CSSLoader(DOM::Document& document);
+    explicit CSSLoader(DOM::Element& owner_element);
 
     void load_from_text(const String&);
     void load_from_url(const URL&);
@@ -51,8 +51,9 @@ private:
     virtual void resource_did_load() override;
     virtual void resource_did_fail() override;
 
+    DOM::Element& m_owner_element;
+
     RefPtr<CSS::CSSStyleSheet> m_style_sheet;
-    const DOM::Document* m_document;
 };
 
 }