From b3c4b4fd971034517bd79e947b932a024f6b2965 Mon Sep 17 00:00:00 2001
From: Andreas Kling <andreas@ladybird.org>
Date: Sat, 7 Dec 2024 01:10:11 +0100
Subject: [PATCH] LibWeb: Serialize resolved CSS values in dedicated
 serialization mode

This doesn't actually do anything differently yet, but it will in the
very next commit.
---
 Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp       | 10 +++++++---
 Libraries/LibWeb/CSS/CSSStyleDeclaration.h         |  3 +++
 Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h |  2 ++
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp b/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
index 29e0c5576fc..8012796cd3d 100644
--- a/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
+++ b/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
@@ -271,7 +271,9 @@ String CSSStyleDeclaration::get_property_value(StringView property_name) const
     if (property_id.value() == PropertyID::Custom) {
         auto maybe_custom_property = custom_property(FlyString::from_utf8_without_validation(property_name.bytes()));
         if (maybe_custom_property.has_value()) {
-            return maybe_custom_property.value().value->to_string(Web::CSS::CSSStyleValue::SerializationMode::Normal);
+            return maybe_custom_property.value().value->to_string(
+                computed_flag() ? Web::CSS::CSSStyleValue::SerializationMode::ResolvedValue
+                                : Web::CSS::CSSStyleValue::SerializationMode::Normal);
         }
         return {};
     }
@@ -302,7 +304,7 @@ String CSSStyleDeclaration::get_property_value(StringView property_name) const
 
         // 3. If important flags of all declarations in list are same, then return the serialization of list.
         // NOTE: Currently we implement property-specific shorthand serialization in ShorthandStyleValue::to_string().
-        return ShorthandStyleValue::create(property_id.value(), longhand_ids, list)->to_string(CSSStyleValue::SerializationMode::Normal);
+        return ShorthandStyleValue::create(property_id.value(), longhand_ids, list)->to_string(computed_flag() ? CSSStyleValue::SerializationMode::ResolvedValue : CSSStyleValue::SerializationMode::Normal);
 
         // 4. Return the empty string.
         // NOTE: This is handled by the loop.
@@ -311,7 +313,9 @@ String CSSStyleDeclaration::get_property_value(StringView property_name) const
     auto maybe_property = property(property_id.value());
     if (!maybe_property.has_value())
         return {};
-    return maybe_property->value->to_string(Web::CSS::CSSStyleValue::SerializationMode::Normal);
+    return maybe_property->value->to_string(
+        computed_flag() ? Web::CSS::CSSStyleValue::SerializationMode::ResolvedValue
+                        : Web::CSS::CSSStyleValue::SerializationMode::Normal);
 }
 
 // https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-getpropertypriority
diff --git a/Libraries/LibWeb/CSS/CSSStyleDeclaration.h b/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
index be6b6765f81..251f2a4263c 100644
--- a/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
+++ b/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
@@ -50,6 +50,9 @@ public:
 
     virtual GC::Ptr<CSSRule> parent_rule() const;
 
+    // https://drafts.csswg.org/cssom/#cssstyledeclaration-computed-flag
+    [[nodiscard]] virtual bool computed_flag() const { return false; }
+
 protected:
     explicit CSSStyleDeclaration(JS::Realm&);
 
diff --git a/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h b/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h
index 459965d090d..beb40f92cf2 100644
--- a/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h
+++ b/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h
@@ -38,6 +38,8 @@ private:
 
     virtual void visit_edges(Cell::Visitor&) override;
 
+    virtual bool computed_flag() const override { return true; }
+
     RefPtr<CSSStyleValue const> style_value_for_property(Layout::NodeWithStyle const&, PropertyID) const;
 
     GC::Ref<DOM::Element> m_element;