LibWeb: Add proper parsing of the AlignItems property

This teaches all the relevant places about 'align-items'.

Userland/Libraries/LibWeb/CSS/ComputedValues.h

@@ -69,6 +69,7 @@ public:
     FlexBasisData flex_basis() const { return m_noninherited.flex_basis; }
     Optional<float> flex_grow_factor() const { return m_noninherited.flex_grow_factor; }
     Optional<float> flex_shrink_factor() const { return m_noninherited.flex_shrink_factor; }
+    CSS::AlignItems align_items() const { return m_noninherited.align_items; }
     Optional<float> opacity() const { return m_noninherited.opacity; }
     CSS::JustifyContent justify_content() const { return m_noninherited.justify_content; }
     Optional<BoxShadowData> box_shadow() const { return m_noninherited.box_shadow; }
@@ -152,6 +153,7 @@ protected:
         CSS::FlexBasisData flex_basis {};
         Optional<float> flex_grow_factor;
         Optional<float> flex_shrink_factor;
+        CSS::AlignItems align_items;
         CSS::JustifyContent justify_content { InitialValues::justify_content() };
         CSS::Overflow overflow_x { InitialValues::overflow() };
         CSS::Overflow overflow_y { InitialValues::overflow() };
@@ -204,6 +206,7 @@ public:
     void set_flex_basis(FlexBasisData value) { m_noninherited.flex_basis = value; }
     void set_flex_grow_factor(Optional<float> value) { m_noninherited.flex_grow_factor = value; }
     void set_flex_shrink_factor(Optional<float> value) { m_noninherited.flex_shrink_factor = value; }
+    void set_align_items(CSS::AlignItems value) { m_noninherited.align_items = value; }
     void set_opacity(Optional<float> value) { m_noninherited.opacity = value; }
     void set_justify_content(CSS::JustifyContent value) { m_noninherited.justify_content = value; }
     void set_box_shadow(Optional<BoxShadowData> value) { m_noninherited.box_shadow = move(value); }

Userland/Libraries/LibWeb/CSS/StyleProperties.cpp

@@ -424,6 +424,27 @@ Optional<CSS::JustifyContent> StyleProperties::justify_content() const
     }
 }
 
+Optional<CSS::AlignItems> StyleProperties::align_items() const
+{
+    auto value = property(CSS::PropertyID::AlignItems);
+    if (!value.has_value())
+        return {};
+    switch (value.value()->to_identifier()) {
+    case CSS::ValueID::FlexStart:
+        return CSS::AlignItems::FlexStart;
+    case CSS::ValueID::FlexEnd:
+        return CSS::AlignItems::FlexEnd;
+    case CSS::ValueID::Center:
+        return CSS::AlignItems::Center;
+    case CSS::ValueID::Baseline:
+        return CSS::AlignItems::Baseline;
+    case CSS::ValueID::Stretch:
+        return CSS::AlignItems::Stretch;
+    default:
+        return {};
+    }
+}
+
 Optional<CSS::Position> StyleProperties::position() const
 {
     auto value = property(CSS::PropertyID::Position);

Userland/Libraries/LibWeb/CSS/StyleProperties.h

@@ -55,6 +55,7 @@ public:
     Optional<CSS::FlexBasisData> flex_basis() const;
     Optional<float> flex_grow_factor() const;
     Optional<float> flex_shrink_factor() const;
+    Optional<CSS::AlignItems> align_items() const;
     Optional<float> opacity() const;
     Optional<CSS::JustifyContent> justify_content() const;
     Optional<CSS::Overflow> overflow_x() const;

Userland/Libraries/LibWeb/CSS/StyleValue.h

@@ -211,6 +211,14 @@ enum class JustifyContent {
     SpaceAround,
 };
 
+enum class AlignItems {
+    FlexStart,
+    FlexEnd,
+    Center,
+    Baseline,
+    Stretch,
+};
+
 class StyleValue : public RefCounted<StyleValue> {
 public:
     virtual ~StyleValue();

Userland/Libraries/LibWeb/Layout/Node.cpp

@@ -269,6 +269,10 @@ void NodeWithStyle::apply_style(const CSS::StyleProperties& specified_style)
     if (justify_content.has_value())
         computed_values.set_justify_content(justify_content.value());
 
+    auto align_items = specified_style.align_items();
+    if (align_items.has_value())
+        computed_values.set_align_items(align_items.value());
+
     auto position = specified_style.position();
     if (position.has_value()) {
         computed_values.set_position(position.value());