From db439d224adec1ed2e754fde4577affec73422ba Mon Sep 17 00:00:00 2001
From: Callum Law <callumlaw1709@outlook.com>
Date: Sat, 19 Jul 2025 15:38:16 +1200
Subject: [PATCH] LibWeb: Support creating ColorResolutionContext from
 AbstractElement

No functionality changes.
---
 Libraries/LibWeb/CSS/CSSStyleValue.cpp | 14 ++++++++++++++
 Libraries/LibWeb/CSS/CSSStyleValue.h   |  1 +
 Libraries/LibWeb/CSS/Length.cpp        | 15 +++++++++++++++
 Libraries/LibWeb/CSS/Length.h          |  1 +
 4 files changed, 31 insertions(+)

diff --git a/Libraries/LibWeb/CSS/CSSStyleValue.cpp b/Libraries/LibWeb/CSS/CSSStyleValue.cpp
index 5a285d04dd6..907e7275976 100644
--- a/Libraries/LibWeb/CSS/CSSStyleValue.cpp
+++ b/Libraries/LibWeb/CSS/CSSStyleValue.cpp
@@ -75,6 +75,20 @@
 
 namespace Web::CSS {
 
+ColorResolutionContext ColorResolutionContext::for_element(DOM::AbstractElement const& element)
+{
+    auto color_scheme = element.computed_properties()->color_scheme(element.document().page().preferred_color_scheme(), element.document().supported_color_schemes());
+
+    CalculationResolutionContext calculation_resolution_context { .length_resolution_context = Length::ResolutionContext::for_element(element) };
+
+    return {
+        .color_scheme = color_scheme,
+        .current_color = element.computed_properties()->color_or_fallback(PropertyID::Color, { color_scheme, CSS::InitialValues::color(), element.document(), calculation_resolution_context }, CSS::InitialValues::color()),
+        .document = element.document(),
+        .calculation_resolution_context = calculation_resolution_context
+    };
+}
+
 ColorResolutionContext ColorResolutionContext::for_layout_node_with_style(Layout::NodeWithStyle const& layout_node)
 {
     return {
diff --git a/Libraries/LibWeb/CSS/CSSStyleValue.h b/Libraries/LibWeb/CSS/CSSStyleValue.h
index 81c5b266716..675a650df23 100644
--- a/Libraries/LibWeb/CSS/CSSStyleValue.h
+++ b/Libraries/LibWeb/CSS/CSSStyleValue.h
@@ -89,6 +89,7 @@ struct ColorResolutionContext {
     GC::Ptr<DOM::Document const> document;
     CalculationResolutionContext calculation_resolution_context;
 
+    [[nodiscard]] static ColorResolutionContext for_element(DOM::AbstractElement const&);
     [[nodiscard]] static ColorResolutionContext for_layout_node_with_style(Layout::NodeWithStyle const&);
 };
 
diff --git a/Libraries/LibWeb/CSS/Length.cpp b/Libraries/LibWeb/CSS/Length.cpp
index 158a065e30c..3feb8614489 100644
--- a/Libraries/LibWeb/CSS/Length.cpp
+++ b/Libraries/LibWeb/CSS/Length.cpp
@@ -137,6 +137,21 @@ CSSPixels Length::viewport_relative_length_to_px(CSSPixelRect const& viewport_re
     }
 }
 
+Length::ResolutionContext Length::ResolutionContext::for_element(DOM::AbstractElement const& element)
+{
+    auto const* root_element = element.element().document().document_element();
+
+    VERIFY(element.computed_properties());
+    VERIFY(root_element);
+    VERIFY(root_element->computed_properties());
+
+    return Length::ResolutionContext {
+        .viewport_rect = element.element().navigable()->viewport_rect(),
+        .font_metrics = { element.computed_properties()->font_size(), element.computed_properties()->first_available_computed_font().pixel_metrics() },
+        .root_font_metrics = { root_element->computed_properties()->font_size(), root_element->computed_properties()->first_available_computed_font().pixel_metrics() }
+    };
+}
+
 Length::ResolutionContext Length::ResolutionContext::for_window(HTML::Window const& window)
 {
     auto const& initial_font = window.associated_document().style_computer().initial_font();
diff --git a/Libraries/LibWeb/CSS/Length.h b/Libraries/LibWeb/CSS/Length.h
index b11b8a8d28c..4f84b938d0b 100644
--- a/Libraries/LibWeb/CSS/Length.h
+++ b/Libraries/LibWeb/CSS/Length.h
@@ -162,6 +162,7 @@ public:
     StringView unit_name() const;
 
     struct ResolutionContext {
+        [[nodiscard]] static ResolutionContext for_element(DOM::AbstractElement const&);
         [[nodiscard]] static ResolutionContext for_window(HTML::Window const&);
         [[nodiscard]] static ResolutionContext for_layout_node(Layout::Node const&);