LibWeb/CSS: Absolutize grid-related StyleValues

Author: https://github.com/AtkinsSJ
Commit: 7de17dce9d
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/6857
Reviewed-by: https://github.com/tcl3 ✅

Libraries/LibWeb/CSS/GridTrackPlacement.cpp

@@ -1,12 +1,14 @@
 /*
  * Copyright (c) 2023, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
  * Copyright (c) 2022, Martin Falisse <mfalisse@outlook.com>
+ * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
 #include "GridTrackPlacement.h"
 #include <AK/StringBuilder.h>
+#include <LibWeb/CSS/StyleValues/IntegerStyleValue.h>
 
 namespace Web::CSS {
 
@@ -38,4 +40,34 @@ String GridTrackPlacement::to_string(SerializationMode mode) const
     return MUST(builder.to_string());
 }
 
+GridTrackPlacement GridTrackPlacement::absolutized(ComputationContext const& context) const
+{
+    auto absolutize_integer_or_calculated = [&context](IntegerOrCalculated const& integer_or_calculated) {
+        if (!integer_or_calculated.is_calculated())
+            return integer_or_calculated;
+        auto absolutized = integer_or_calculated.calculated()->absolutized(context);
+        if (absolutized->is_calculated())
+            return IntegerOrCalculated { absolutized->as_calculated() };
+        VERIFY(absolutized->is_integer());
+        return IntegerOrCalculated { absolutized->as_integer().integer() };
+    };
+
+    return m_value.visit(
+        [this](Auto const&) {
+            return *this;
+        },
+        [&](AreaOrLine const& area_or_line) -> GridTrackPlacement {
+            return AreaOrLine {
+                .line_number = area_or_line.line_number.map(absolutize_integer_or_calculated),
+                .name = area_or_line.name,
+            };
+        },
+        [&](Span const& span) -> GridTrackPlacement {
+            return Span {
+                .value = absolutize_integer_or_calculated(span.value),
+                .name = span.name,
+            };
+        });
+}
+
 }