LibWeb: Add the 'float' CSS property to LayoutStyle

Note that we don't use the property for anything yet, as I'm still
wrapping my head around how to implement floats.

Libraries/LibWeb/CSS/StyleProperties.cpp

@@ -263,6 +263,21 @@ Optional<CSS::WhiteSpace> StyleProperties::white_space() const
     return {};
 }
 
+Optional<CSS::Float> StyleProperties::float_() const
+{
+    auto value = property(CSS::PropertyID::Float);
+    if (!value.has_value() || !value.value()->is_string())
+        return {};
+    auto string = value.value()->to_string();
+    if (string == "none")
+        return CSS::Float::None;
+    if (string == "left")
+        return CSS::Float::Left;
+    if (string == "right")
+        return CSS::Float::Right;
+    return {};
+}
+
 CSS::Display StyleProperties::display() const
 {
     auto display = string_or_fallback(CSS::PropertyID::Display, "inline");

Libraries/LibWeb/CSS/StyleProperties.h

@@ -62,6 +62,7 @@ public:
     Color color_or_fallback(CSS::PropertyID, const Document&, Color fallback) const;
     CSS::TextAlign text_align() const;
     CSS::Display display() const;
+    Optional<CSS::Float> float_() const;
     Optional<CSS::WhiteSpace> white_space() const;
 
     const Gfx::Font& font() const

Libraries/LibWeb/CSS/StyleValue.h

@@ -143,6 +143,12 @@ enum class WhiteSpace {
     PreWrap,
 };
 
+enum class Float {
+    None,
+    Left,
+    Right,
+};
+
 }
 
 class StyleValue : public RefCounted<StyleValue> {

Libraries/LibWeb/Layout/LayoutNode.cpp

@@ -181,6 +181,13 @@ Gfx::FloatPoint LayoutNode::box_type_agnostic_position() const
     return position;
 }
 
+bool LayoutNode::is_floating() const
+{
+    if (!has_style())
+        return false;
+    return style().float_() != CSS::Float::None;
+}
+
 bool LayoutNode::is_absolutely_positioned() const
 {
     if (!has_style())
@@ -216,6 +223,10 @@ void LayoutNodeWithStyle::apply_style(const StyleProperties& specified_style)
     if (white_space.has_value())
         style.set_white_space(white_space.value());
 
+    auto float_ = specified_style.float_();
+    if (float_.has_value())
+        style.set_float(float_.value());
+
     style.set_z_index(specified_style.z_index());
     style.set_width(specified_style.length_or_fallback(CSS::PropertyID::Width, {}));
     style.set_min_width(specified_style.length_or_fallback(CSS::PropertyID::MinWidth, {}));

Libraries/LibWeb/Layout/LayoutNode.h

@@ -181,6 +181,7 @@ public:
     };
     virtual void paint(PaintContext&, PaintPhase);
 
+    bool is_floating() const;
     bool is_absolutely_positioned() const;
     bool is_fixed_position() const;
 

Libraries/LibWeb/Layout/LayoutStyle.h

@@ -34,6 +34,7 @@ namespace Web {
 
 class InitialValues {
 public:
+    static CSS::Float float_() { return CSS::Float::None; }
     static CSS::WhiteSpace white_space() { return CSS::WhiteSpace::Normal; }
 };
 
@@ -45,6 +46,7 @@ public:
 
 class LayoutStyle {
 public:
+    CSS::Float float_() const { return m_float; }
     Optional<int> z_index() const { return m_z_index; }
     CSS::TextAlign text_align() const { return m_text_align; }
     CSS::Position position() const { return m_position; }
@@ -66,6 +68,7 @@ public:
     const BorderData& border_bottom() const { return m_border_bottom; }
 
 protected:
+    CSS::Float m_float { InitialValues::float_() };
     Optional<int> m_z_index;
     CSS::TextAlign m_text_align;
     CSS::Position m_position;
@@ -90,6 +93,7 @@ class ImmutableLayoutStyle final : public LayoutStyle {
 
 class MutableLayoutStyle final : public LayoutStyle {
 public:
+    void set_float(CSS::Float value) { m_float = value; }
     void set_z_index(Optional<int> value) { m_z_index = value; }
     void set_text_align(CSS::TextAlign text_align) { m_text_align = text_align; }
     void set_position(CSS::Position position) { m_position = position; }