LibWeb: Store ShadowStyleValue's color as a StyleValue

Colors can be specified in a way that `Gfx::Color` can't represent, such
as named system colors, `currentColor`, or functions involving `calc()`.

Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp

@@ -4280,7 +4280,7 @@ RefPtr<CSSStyleValue> Parser::parse_single_shadow_value(TokenStream<ComponentVal
 {
     auto transaction = tokens.begin_transaction();
 
-    Optional<Color> color;
+    RefPtr<CSSStyleValue> color;
     RefPtr<CSSStyleValue> offset_x;
     RefPtr<CSSStyleValue> offset_y;
     RefPtr<CSSStyleValue> blur_radius;
@@ -4296,10 +4296,10 @@ RefPtr<CSSStyleValue> Parser::parse_single_shadow_value(TokenStream<ComponentVal
     };
 
     while (tokens.has_next_token()) {
-        if (auto maybe_color = parse_color(tokens); maybe_color.has_value()) {
+        if (auto maybe_color = parse_color_value(tokens); maybe_color) {
-            if (color.has_value())
+            if (color)
                 return nullptr;
-            color = maybe_color.release_value();
+            color = maybe_color.release_nonnull();
             continue;
         }
 
@@ -4355,9 +4355,9 @@ RefPtr<CSSStyleValue> Parser::parse_single_shadow_value(TokenStream<ComponentVal
         return nullptr;
     }
 
-    // FIXME: If color is absent, default to `currentColor`
+    // If color is absent, default to `currentColor`
-    if (!color.has_value())
+    if (!color)
-        color = Color::NamedColor::Black;
+        color = CSSKeywordValue::create(Keyword::Currentcolor);
 
     // x/y offsets are required
     if (!offset_x || !offset_y)
@@ -4374,7 +4374,7 @@ RefPtr<CSSStyleValue> Parser::parse_single_shadow_value(TokenStream<ComponentVal
         placement = ShadowPlacement::Outer;
 
     transaction.commit();
-    return ShadowStyleValue::create(color.release_value(), offset_x.release_nonnull(), offset_y.release_nonnull(), blur_radius.release_nonnull(), spread_distance.release_nonnull(), placement.release_value());
+    return ShadowStyleValue::create(color.release_nonnull(), offset_x.release_nonnull(), offset_y.release_nonnull(), blur_radius.release_nonnull(), spread_distance.release_nonnull(), placement.release_value());
 }
 
 RefPtr<CSSStyleValue> Parser::parse_content_value(TokenStream<ComponentValue>& tokens)

Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.cpp

@@ -175,7 +175,7 @@ static RefPtr<CSSStyleValue const> style_value_for_shadow(Vector<ShadowData> con
 
     auto make_shadow_style_value = [](ShadowData const& shadow) {
         return ShadowStyleValue::create(
-            shadow.color,
+            CSSColorValue::create(shadow.color),
             style_value_for_length_percentage(shadow.offset_x),
             style_value_for_length_percentage(shadow.offset_y),
             style_value_for_length_percentage(shadow.blur_radius),

Userland/Libraries/LibWeb/CSS/StyleComputer.cpp

@@ -1316,7 +1316,7 @@ static NonnullRefPtr<CSSStyleValue const> interpolate_box_shadow(DOM::Element& e
         values.ensure_capacity(other.size());
         for (size_t i = values.size(); i < other.size(); i++) {
             values.unchecked_append(ShadowStyleValue::create(
-                Color::Transparent,
+                CSSColorValue::create(Color::Transparent),
                 LengthStyleValue::create(Length::make_px(0)),
                 LengthStyleValue::create(Length::make_px(0)),
                 LengthStyleValue::create(Length::make_px(0)),
@@ -1339,7 +1339,7 @@ static NonnullRefPtr<CSSStyleValue const> interpolate_box_shadow(DOM::Element& e
         auto const& from_shadow = from_shadows[i]->as_shadow();
         auto const& to_shadow = to_shadows[i]->as_shadow();
         auto result_shadow = ShadowStyleValue::create(
-            interpolate_color(from_shadow.color(), to_shadow.color(), delta),
+            CSSColorValue::create(interpolate_color(from_shadow.color()->to_color({}), to_shadow.color()->to_color({}), delta)),
             interpolate_value(element, from_shadow.offset_x(), to_shadow.offset_x(), delta),
             interpolate_value(element, from_shadow.offset_y(), to_shadow.offset_y(), delta),
             interpolate_value(element, from_shadow.blur_radius(), to_shadow.blur_radius(), delta),

Userland/Libraries/LibWeb/CSS/StyleProperties.cpp

@@ -895,7 +895,7 @@ Vector<ShadowData> StyleProperties::shadow(PropertyID property_id, Layout::Node
         return {};
     };
 
-    auto make_shadow_data = [resolve_to_length](ShadowStyleValue const& value) -> Optional<ShadowData> {
+    auto make_shadow_data = [resolve_to_length, &layout_node](ShadowStyleValue const& value) -> Optional<ShadowData> {
         auto maybe_offset_x = resolve_to_length(value.offset_x());
         if (!maybe_offset_x.has_value())
             return {};
@@ -909,7 +909,7 @@ Vector<ShadowData> StyleProperties::shadow(PropertyID property_id, Layout::Node
         if (!maybe_spread_distance.has_value())
             return {};
         return ShadowData {
-            value.color(),
+            value.color()->to_color(verify_cast<Layout::NodeWithStyle>(layout_node)),
             maybe_offset_x.release_value(),
             maybe_offset_y.release_value(),
             maybe_blur_radius.release_value(),

Userland/Libraries/LibWeb/CSS/StyleValues/ShadowStyleValue.cpp

@@ -15,8 +15,7 @@ namespace Web::CSS {
 String ShadowStyleValue::to_string() const
 {
     StringBuilder builder;
-    serialize_a_srgb_value(builder, m_properties.color);
+    builder.appendff("{} {} {} {} {}", m_properties.color->to_string(), m_properties.offset_x->to_string(), m_properties.offset_y->to_string(), m_properties.blur_radius->to_string(), m_properties.spread_distance->to_string());
-    builder.appendff(" {} {} {} {}", m_properties.offset_x->to_string(), m_properties.offset_y->to_string(), m_properties.blur_radius->to_string(), m_properties.spread_distance->to_string());
     if (m_properties.placement == ShadowPlacement::Inner)
         builder.append(" inset"sv);
     return MUST(builder.to_string());

Userland/Libraries/LibWeb/CSS/StyleValues/ShadowStyleValue.h

@@ -23,18 +23,18 @@ enum class ShadowPlacement {
 class ShadowStyleValue final : public StyleValueWithDefaultOperators<ShadowStyleValue> {
 public:
     static ValueComparingNonnullRefPtr<ShadowStyleValue> create(
-        Color color,
+        ValueComparingNonnullRefPtr<CSSStyleValue const> color,
         ValueComparingNonnullRefPtr<CSSStyleValue const> offset_x,
         ValueComparingNonnullRefPtr<CSSStyleValue const> offset_y,
         ValueComparingNonnullRefPtr<CSSStyleValue const> blur_radius,
         ValueComparingNonnullRefPtr<CSSStyleValue const> spread_distance,
         ShadowPlacement placement)
     {
-        return adopt_ref(*new (nothrow) ShadowStyleValue(color, move(offset_x), move(offset_y), move(blur_radius), move(spread_distance), placement));
+        return adopt_ref(*new (nothrow) ShadowStyleValue(move(color), move(offset_x), move(offset_y), move(blur_radius), move(spread_distance), placement));
     }
     virtual ~ShadowStyleValue() override = default;
 
-    Color color() const { return m_properties.color; }
+    ValueComparingNonnullRefPtr<CSSStyleValue const> const& color() const { return m_properties.color; }
     ValueComparingNonnullRefPtr<CSSStyleValue const> const& offset_x() const { return m_properties.offset_x; }
     ValueComparingNonnullRefPtr<CSSStyleValue const> const& offset_y() const { return m_properties.offset_y; }
     ValueComparingNonnullRefPtr<CSSStyleValue const> const& blur_radius() const { return m_properties.blur_radius; }
@@ -47,7 +47,7 @@ public:
 
 private:
     ShadowStyleValue(
-        Color color,
+        ValueComparingNonnullRefPtr<CSSStyleValue const> color,
         ValueComparingNonnullRefPtr<CSSStyleValue const> offset_x,
         ValueComparingNonnullRefPtr<CSSStyleValue const> offset_y,
         ValueComparingNonnullRefPtr<CSSStyleValue const> blur_radius,
@@ -55,7 +55,7 @@ private:
         ShadowPlacement placement)
         : StyleValueWithDefaultOperators(Type::Shadow)
         , m_properties {
-            .color = color,
+            .color = move(color),
             .offset_x = move(offset_x),
             .offset_y = move(offset_y),
             .blur_radius = move(blur_radius),
@@ -68,7 +68,7 @@ private:
     virtual ValueComparingNonnullRefPtr<CSSStyleValue const> absolutized(CSSPixelRect const& viewport_rect, Length::FontMetrics const& font_metrics, Length::FontMetrics const& root_font_metrics) const override;
 
     struct Properties {
-        Color color;
+        ValueComparingNonnullRefPtr<CSSStyleValue const> color;
         ValueComparingNonnullRefPtr<CSSStyleValue const> offset_x;
         ValueComparingNonnullRefPtr<CSSStyleValue const> offset_y;
         ValueComparingNonnullRefPtr<CSSStyleValue const> blur_radius;