LibHTML: Move selector matching into a SelectorEngine namespace

Libraries/LibHTML/CSS/SelectorEngine.cpp

@@ -0,0 +1,64 @@
+#include <LibHTML/CSS/SelectorEngine.h>
+#include <LibHTML/DOM/Element.h>
+
+namespace SelectorEngine {
+
+bool matches(const Selector::Component& component, const Element& element)
+{
+    switch (component.type) {
+    case Selector::Component::Type::Id:
+        return component.value == element.attribute("id");
+    case Selector::Component::Type::Class:
+        return element.has_class(component.value);
+    case Selector::Component::Type::TagName:
+        return component.value == element.tag_name();
+    default:
+        ASSERT_NOT_REACHED();
+    }
+}
+
+bool matches(const Selector& selector, int component_index, const Element& element)
+{
+    auto& component = selector.components()[component_index];
+    if (!matches(component, element))
+        return false;
+    switch (component.relation) {
+    case Selector::Component::Relation::None:
+        return true;
+    case Selector::Component::Relation::Descendant:
+        ASSERT(component_index != 0);
+        for (auto* ancestor = element.parent(); ancestor; ancestor = ancestor->parent()) {
+            if (!is<Element>(*ancestor))
+                continue;
+            if (matches(selector, component_index - 1, to<Element>(*ancestor)))
+                return true;
+        }
+        return false;
+    case Selector::Component::Relation::ImmediateChild:
+        ASSERT(component_index != 0);
+        if (!element.parent() || !is<Element>(*element.parent()))
+            return false;
+        return matches(selector, component_index - 1, to<Element>(*element.parent()));
+    case Selector::Component::Relation::AdjacentSibling:
+        ASSERT(component_index != 0);
+        if (auto* sibling = element.previous_element_sibling())
+            return matches(selector, component_index - 1, *sibling);
+        return false;
+    case Selector::Component::Relation::GeneralSibling:
+        ASSERT(component_index != 0);
+        for (auto* sibling = element.previous_element_sibling(); sibling; sibling = sibling->previous_element_sibling()) {
+            if (matches(selector, component_index - 1, *sibling))
+                return true;
+        }
+        return false;
+    }
+    ASSERT_NOT_REACHED();
+}
+
+bool matches(const Selector& selector, const Element& element)
+{
+    ASSERT(!selector.components().is_empty());
+    return matches(selector, selector.components().size() - 1, element);
+}
+
+}

Libraries/LibHTML/CSS/SelectorEngine.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <LibHTML/CSS/Selector.h>
+
+class Element;
+
+namespace SelectorEngine {
+
+bool matches(const Selector&, const Element&);
+
+}

Libraries/LibHTML/CSS/StyleResolver.cpp

@@ -1,3 +1,4 @@
+#include <LibHTML/CSS/SelectorEngine.h>
 #include <LibHTML/CSS/StyleResolver.h>
 #include <LibHTML/CSS/StyleSheet.h>
 #include <LibHTML/DOM/Document.h>
@@ -15,64 +16,6 @@ StyleResolver::~StyleResolver()
 {
 }
 
-static bool matches(const Selector::Component& component, const Element& element)
-{
-    switch (component.type) {
-    case Selector::Component::Type::Id:
-        return component.value == element.attribute("id");
-    case Selector::Component::Type::Class:
-        return element.has_class(component.value);
-    case Selector::Component::Type::TagName:
-        return component.value == element.tag_name();
-    default:
-        ASSERT_NOT_REACHED();
-    }
-}
-
-static bool matches(const Selector& selector, int component_index, const Element& element)
-{
-    auto& component = selector.components()[component_index];
-    if (!matches(component, element))
-        return false;
-    switch (component.relation) {
-    case Selector::Component::Relation::None:
-        return true;
-    case Selector::Component::Relation::Descendant:
-        ASSERT(component_index != 0);
-        for (auto* ancestor = element.parent(); ancestor; ancestor = ancestor->parent()) {
-            if (!is<Element>(*ancestor))
-                continue;
-            if (matches(selector, component_index - 1, to<Element>(*ancestor)))
-                return true;
-        }
-        return false;
-    case Selector::Component::Relation::ImmediateChild:
-        ASSERT(component_index != 0);
-        if (!element.parent() || !is<Element>(*element.parent()))
-            return false;
-        return matches(selector, component_index - 1, to<Element>(*element.parent()));
-    case Selector::Component::Relation::AdjacentSibling:
-        ASSERT(component_index != 0);
-        if (auto* sibling = element.previous_element_sibling())
-            return matches(selector, component_index - 1, *sibling);
-        return false;
-    case Selector::Component::Relation::GeneralSibling:
-        ASSERT(component_index != 0);
-        for (auto* sibling = element.previous_element_sibling(); sibling; sibling = sibling->previous_element_sibling()) {
-            if (matches(selector, component_index - 1, *sibling))
-                return true;
-        }
-        return false;
-    }
-    ASSERT_NOT_REACHED();
-}
-
-static bool matches(const Selector& selector, const Element& element)
-{
-    ASSERT(!selector.components().is_empty());
-    return matches(selector, selector.components().size() - 1, element);
-}
-
 static StyleSheet& default_stylesheet()
 {
     static StyleSheet* sheet;
@@ -100,7 +43,7 @@ NonnullRefPtrVector<StyleRule> StyleResolver::collect_matching_rules(const Eleme
     for_each_stylesheet([&](auto& sheet) {
         for (auto& rule : sheet.rules()) {
             for (auto& selector : rule.selectors()) {
-                if (matches(selector, element)) {
+                if (SelectorEngine::matches(selector, element)) {
                     matching_rules.append(rule);
                     break;
                 }

Libraries/LibHTML/Makefile.shared

@@ -24,6 +24,7 @@ LIBHTML_OBJS = \
     CSS/StyleProperties.o \
     CSS/StyleResolver.o \
     CSS/DefaultStyleSheetSource.o \
+    CSS/SelectorEngine.o \
     Parser/HTMLParser.o \
     Parser/CSSParser.o \
     Layout/LayoutNode.o \