LibWeb/DOM: Move pseudo-element scroll offsets into PseudoElement

Author: https://github.com/AtkinsSJ
Commit: f98312d022
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5132
Reviewed-by: https://github.com/tcl3

Libraries/LibWeb/DOM/Element.cpp

@@ -3031,7 +3031,7 @@ void Element::scroll(double x, double y)
     //               as the element is not eligible to be the Document.scrollingElement.
     if (x == 0
         && y == 0
-        && scroll_offset(ScrollOffsetFor::Self).is_zero()
+        && scroll_offset({}).is_zero()
         && this != document.body()
         && this != document.document_element()) {
         return;
@@ -3397,6 +3397,25 @@ IntersectionObserver::IntersectionObserverRegistration& Element::get_intersectio
     return *registration_iterator;
 }
 
+CSSPixelPoint Element::scroll_offset(Optional<CSS::PseudoElement> pseudo_element_type) const
+{
+    if (pseudo_element_type.has_value()) {
+        if (auto pseudo_element = get_pseudo_element(*pseudo_element_type); pseudo_element.has_value())
+            return pseudo_element->scroll_offset();
+        return {};
+    }
+    return m_scroll_offset;
+}
+
+void Element::set_scroll_offset(Optional<CSS::PseudoElement> pseudo_element_type, CSSPixelPoint offset)
+{
+    if (pseudo_element_type.has_value()) {
+        if (auto pseudo_element = get_pseudo_element(*pseudo_element_type); pseudo_element.has_value())
+            pseudo_element->set_scroll_offset(offset);
+    }
+    m_scroll_offset = offset;
+}
+
 // https://html.spec.whatwg.org/multipage/dom.html#translation-mode
 Element::TranslationMode Element::translation_mode() const
 {

Libraries/LibWeb/DOM/Element.h

@@ -373,13 +373,8 @@ public:
     void unregister_intersection_observer(Badge<IntersectionObserver::IntersectionObserver>, GC::Ref<IntersectionObserver::IntersectionObserver>);
     IntersectionObserver::IntersectionObserverRegistration& get_intersection_observer_registration(Badge<DOM::Document>, IntersectionObserver::IntersectionObserver const&);
 
-    enum class ScrollOffsetFor {
-        Self,
-        PseudoBefore,
-        PseudoAfter
-    };
-    CSSPixelPoint scroll_offset(ScrollOffsetFor type) const { return m_scroll_offset[to_underlying(type)]; }
-    void set_scroll_offset(ScrollOffsetFor type, CSSPixelPoint offset) { m_scroll_offset[to_underlying(type)] = offset; }
+    CSSPixelPoint scroll_offset(Optional<CSS::PseudoElement> type) const;
+    void set_scroll_offset(Optional<CSS::PseudoElement> type, CSSPixelPoint offset);
 
     enum class TranslationMode {
         TranslateEnabled,
@@ -595,7 +590,7 @@ private:
     // Element objects have an internal [[RegisteredIntersectionObservers]] slot, which is initialized to an empty list.
     OwnPtr<Vector<IntersectionObserver::IntersectionObserverRegistration>> m_registered_intersection_observers;
 
-    Array<CSSPixelPoint, 3> m_scroll_offset;
+    CSSPixelPoint m_scroll_offset;
 
     bool m_in_top_layer : 1 { false };
     bool m_rendered_in_top_layer : 1 { false };

Libraries/LibWeb/DOM/PseudoElement.h

@@ -35,6 +35,9 @@ class PseudoElement : public JS::Cell {
     CSS::CountersSet& ensure_counters_set();
     void set_counters_set(OwnPtr<CSS::CountersSet>&&);
 
+    CSSPixelPoint scroll_offset() const { return m_scroll_offset; }
+    void set_scroll_offset(CSSPixelPoint value) { m_scroll_offset = value; }
+
     virtual void visit_edges(JS::Cell::Visitor&) override;
 
 private:
@@ -43,6 +46,7 @@ private:
     GC::Ptr<CSS::ComputedProperties> m_computed_properties;
     HashMap<FlyString, CSS::StyleProperty> m_custom_properties;
     OwnPtr<CSS::CountersSet> m_counters_set;
+    CSSPixelPoint m_scroll_offset {};
 };
 
 // https://drafts.csswg.org/css-view-transitions/#pseudo-element-tree

Libraries/LibWeb/Painting/PaintableBox.cpp

@@ -96,15 +96,13 @@ CSSPixelPoint PaintableBox::scroll_offset() const
     }
 
     auto const& node = layout_node();
-    if (node.is_generated_for_before_pseudo_element())
-        return node.pseudo_element_generator()->scroll_offset(DOM::Element::ScrollOffsetFor::PseudoBefore);
-    if (node.is_generated_for_after_pseudo_element())
-        return node.pseudo_element_generator()->scroll_offset(DOM::Element::ScrollOffsetFor::PseudoAfter);
+    if (auto pseudo_element = node.generated_for_pseudo_element(); pseudo_element.has_value())
+        return node.pseudo_element_generator()->scroll_offset(*pseudo_element);
 
     if (!(dom_node() && is<DOM::Element>(*dom_node())))
         return {};
 
-    return static_cast<DOM::Element const*>(dom_node())->scroll_offset(DOM::Element::ScrollOffsetFor::Self);
+    return static_cast<DOM::Element const*>(dom_node())->scroll_offset({});
 }
 
 void PaintableBox::set_scroll_offset(CSSPixelPoint offset)
@@ -127,12 +125,10 @@ void PaintableBox::set_scroll_offset(CSSPixelPoint offset)
         return;
 
     auto& node = layout_node();
-    if (node.is_generated_for_before_pseudo_element()) {
-        node.pseudo_element_generator()->set_scroll_offset(DOM::Element::ScrollOffsetFor::PseudoBefore, offset);
-    } else if (node.is_generated_for_after_pseudo_element()) {
-        node.pseudo_element_generator()->set_scroll_offset(DOM::Element::ScrollOffsetFor::PseudoAfter, offset);
+    if (auto pseudo_element = node.generated_for_pseudo_element(); pseudo_element.has_value()) {
+        node.pseudo_element_generator()->set_scroll_offset(*pseudo_element, offset);
     } else if (is<DOM::Element>(*dom_node())) {
-        static_cast<DOM::Element*>(dom_node())->set_scroll_offset(DOM::Element::ScrollOffsetFor::Self, offset);
+        static_cast<DOM::Element*>(dom_node())->set_scroll_offset({}, offset);
     } else {
         return;
     }