LibWeb: Implement the SVG clip-rule attribute

This controls the fill rule used when rasterizing `<clipPath>` elements.

Userland/Libraries/LibWeb/CSS/ComputedValues.h

@@ -27,6 +27,8 @@
 
 namespace Web::CSS {
 
+using ClipRule = FillRule;
+
 struct FlexBasisContent { };
 using FlexBasis = Variant<FlexBasisContent, Size>;
 
@@ -134,6 +136,7 @@ public:
     static float opacity() { return 1.0f; }
     static float fill_opacity() { return 1.0f; }
     static CSS::FillRule fill_rule() { return CSS::FillRule::Nonzero; }
+    static CSS::ClipRule clip_rule() { return CSS::ClipRule::Nonzero; }
     static float stroke_opacity() { return 1.0f; }
     static float stop_opacity() { return 1.0f; }
     static CSS::TextAnchor text_anchor() { return CSS::TextAnchor::Start; }
@@ -430,6 +433,7 @@ public:
     Optional<MaskReference> const& mask() const { return m_noninherited.mask; }
     CSS::MaskType mask_type() const { return m_noninherited.mask_type; }
     Optional<ClipPathReference> const& clip_path() const { return m_noninherited.clip_path; }
+    CSS::ClipRule clip_rule() const { return m_inherited.clip_rule; }
 
     LengthPercentage const& cx() const { return m_noninherited.cx; }
     LengthPercentage const& cy() const { return m_noninherited.cy; }
@@ -505,6 +509,7 @@ protected:
         float stroke_opacity { InitialValues::stroke_opacity() };
         LengthPercentage stroke_width { Length::make_px(1) };
         CSS::TextAnchor text_anchor { InitialValues::text_anchor() };
+        CSS::ClipRule clip_rule { InitialValues::clip_rule() };
 
         Vector<ShadowData> text_shadow;
 
@@ -731,6 +736,7 @@ public:
     void set_mask(MaskReference value) { m_noninherited.mask = value; }
     void set_mask_type(CSS::MaskType value) { m_noninherited.mask_type = value; }
     void set_clip_path(ClipPathReference value) { m_noninherited.clip_path = value; }
+    void set_clip_rule(CSS::ClipRule value) { m_inherited.clip_rule = value; }
 
     void set_cx(LengthPercentage cx) { m_noninherited.cx = cx; }
     void set_cy(LengthPercentage cy) { m_noninherited.cy = cy; }

Userland/Libraries/LibWeb/CSS/Properties.json

@@ -716,6 +716,13 @@
     ],
     "initial": "none"
   },
+  "clip-rule": {
+    "affects-layout": false,
+    "animation-type": "discrete",
+    "inherited": true,
+    "initial": "nonzero",
+    "valid-types": [ "fill-rule" ]
+  },
   "color": {
     "affects-layout": false,
     "animation-type": "by-computed-value",

Userland/Libraries/LibWeb/CSS/StyleProperties.cpp

@@ -336,6 +336,12 @@ Optional<CSS::FillRule> StyleProperties::fill_rule() const
     return value_id_to_fill_rule(value->to_identifier());
 }
 
+Optional<CSS::ClipRule> StyleProperties::clip_rule() const
+{
+    auto value = property(CSS::PropertyID::ClipRule);
+    return value_id_to_fill_rule(value->to_identifier());
+}
+
 Optional<CSS::FlexDirection> StyleProperties::flex_direction() const
 {
     auto value = property(CSS::PropertyID::FlexDirection);

Userland/Libraries/LibWeb/CSS/StyleProperties.h

@@ -148,6 +148,7 @@ public:
     float fill_opacity() const;
     float stroke_opacity() const;
     Optional<CSS::FillRule> fill_rule() const;
+    Optional<CSS::ClipRule> clip_rule() const;
 
     Gfx::Font const& first_available_computed_font() const { return m_font_list->first(); }