LibWeb: Parse oblique font-style with an angle value

Author: https://github.com/tcl3
Commit: c0f9b11070
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4552
Reviewed-by: https://github.com/konradekk

Libraries/LibWeb/CSS/StyleValues/FontStyleStyleValue.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/CSS/CSSStyleValue.h>
+#include <LibWeb/CSS/Enums.h>
+
+namespace Web::CSS {
+
+class FontStyleStyleValue final : public StyleValueWithDefaultOperators<FontStyleStyleValue> {
+public:
+    static ValueComparingNonnullRefPtr<FontStyleStyleValue const> create(FontStyle font_style, ValueComparingRefPtr<CSSStyleValue const> angle_value = {})
+    {
+        return adopt_ref(*new (nothrow) FontStyleStyleValue(font_style, angle_value));
+    }
+
+    virtual ~FontStyleStyleValue() override;
+
+    FontStyle font_style() const { return m_font_style; }
+    ValueComparingRefPtr<CSSStyleValue const> angle() const { return m_angle_value; }
+
+    virtual String to_string(SerializationMode) const override;
+
+    bool equals(CSSStyleValue const& other) const override
+    {
+        if (type() != other.type())
+            return false;
+        auto const& other_font_style = other.as_font_style();
+        return m_font_style == other_font_style.m_font_style && m_angle_value == other_font_style.m_angle_value;
+    }
+
+    bool properties_equal(FontStyleStyleValue const& other) const { return m_font_style == other.m_font_style && m_angle_value == other.m_angle_value; }
+
+private:
+    FontStyleStyleValue(FontStyle, ValueComparingRefPtr<CSSStyleValue const> angle_value);
+
+    FontStyle m_font_style;
+    ValueComparingRefPtr<CSSStyleValue const> m_angle_value;
+};
+
+}