LibWeb: Add FormattingContext::automatic_content_height()

This function should return the automatic height of the formatting
context's root box.

Until now, we've been relying on some magical handshakes between parent
and child context, when negotiating the height of child context root
boxes. This is a step towards something more reasonable.

Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp

@@ -39,6 +39,11 @@ bool BlockFormattingContext::is_initial() const
     return is<InitialContainingBlock>(root());
 }
 
+float BlockFormattingContext::automatic_content_height() const
+{
+    return compute_auto_height_for_block_formatting_context_root(m_state, root());
+}
+
 void BlockFormattingContext::run(Box const&, LayoutMode layout_mode)
 {
     if (is_initial()) {

Userland/Libraries/LibWeb/Layout/BlockFormattingContext.h

@@ -23,6 +23,7 @@ public:
 
     virtual void run(Box const&, LayoutMode) override;
     virtual void run_intrinsic_sizing(Box const&) override;
+    virtual float automatic_content_height() const override;
 
     bool is_initial() const;
 

Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp

@@ -52,6 +52,11 @@ FlexFormattingContext::FlexFormattingContext(LayoutState& state, Box const& flex
 
 FlexFormattingContext::~FlexFormattingContext() = default;
 
+float FlexFormattingContext::automatic_content_height() const
+{
+    return m_state.get(flex_container()).content_height();
+}
+
 void FlexFormattingContext::run(Box const& run_box, LayoutMode layout_mode)
 {
     VERIFY(&run_box == &flex_container());

Userland/Libraries/LibWeb/Layout/FlexFormattingContext.h

@@ -19,6 +19,7 @@ public:
     virtual bool inhibits_floating() const override { return true; }
 
     virtual void run(Box const&, LayoutMode) override;
+    virtual float automatic_content_height() const override;
 
     Box const& flex_container() const { return context_box(); }
 

Userland/Libraries/LibWeb/Layout/FormattingContext.cpp

@@ -103,6 +103,7 @@ OwnPtr<FormattingContext> FormattingContext::create_independent_formatting_conte
                 : FormattingContext(Type::Block, state, box)
             {
             }
+            virtual float automatic_content_height() const override { return 0; };
             virtual void run(Box const&, LayoutMode) override { }
         };
         return make<ReplacedFormattingContext>(state, child_box);
@@ -144,6 +145,7 @@ OwnPtr<FormattingContext> FormattingContext::create_independent_formatting_conte
                 : FormattingContext(Type::Block, state, box)
             {
             }
+            virtual float automatic_content_height() const override { return 0; };
             virtual void run(Box const&, LayoutMode) override { }
         };
         return make<DummyFormattingContext>(state, child_box);

Userland/Libraries/LibWeb/Layout/FormattingContext.h

@@ -26,6 +26,9 @@ public:
 
     virtual void run(Box const&, LayoutMode) = 0;
 
+    // This function returns the automatic content height of the context's root box.
+    virtual float automatic_content_height() const = 0;
+
     Box const& context_box() const { return m_context_box; }
 
     FormattingContext* parent() { return m_parent; }

Userland/Libraries/LibWeb/Layout/GridFormattingContext.cpp

@@ -1002,7 +1002,12 @@ void GridFormattingContext::run(Box const& box, LayoutMode)
     float total_y = 0;
     for (auto& grid_row : grid_rows)
         total_y += grid_row.base_size;
-    box_state.set_content_height(total_y);
+    m_automatic_content_height = total_y;
+}
+
+float GridFormattingContext::automatic_content_height() const
+{
+    return m_automatic_content_height;
 }
 
 }

Userland/Libraries/LibWeb/Layout/GridFormattingContext.h

@@ -18,6 +18,10 @@ public:
     ~GridFormattingContext();
 
     virtual void run(Box const&, LayoutMode) override;
+    virtual float automatic_content_height() const override;
+
+private:
+    float m_automatic_content_height { 0 };
 };
 
 }

Userland/Libraries/LibWeb/Layout/InlineFormattingContext.cpp

@@ -78,6 +78,11 @@ float InlineFormattingContext::available_space_for_line(float y) const
     return space.right - space.left;
 }
 
+float InlineFormattingContext::automatic_content_height() const
+{
+    return compute_auto_height_for_block_formatting_context_root(m_state, containing_block());
+}
+
 void InlineFormattingContext::run(Box const&, LayoutMode layout_mode)
 {
     VERIFY(containing_block().children_are_inline());

Userland/Libraries/LibWeb/Layout/InlineFormattingContext.h

@@ -24,6 +24,7 @@ public:
     BlockContainer const& containing_block() const { return static_cast<BlockContainer const&>(context_box()); }
 
     virtual void run(Box const&, LayoutMode) override;
+    virtual float automatic_content_height() const override;
 
     void dimension_box_on_line(Box const&, LayoutMode);
 

Userland/Libraries/LibWeb/Layout/SVGFormattingContext.cpp

@@ -20,6 +20,11 @@ SVGFormattingContext::SVGFormattingContext(LayoutState& state, Box const& box, F
 
 SVGFormattingContext::~SVGFormattingContext() = default;
 
+float SVGFormattingContext::automatic_content_height() const
+{
+    return 0;
+}
+
 void SVGFormattingContext::run(Box const& box, LayoutMode)
 {
     auto& svg_svg_element = verify_cast<SVG::SVGSVGElement>(*box.dom_node());

Userland/Libraries/LibWeb/Layout/SVGFormattingContext.h

@@ -17,6 +17,7 @@ public:
     ~SVGFormattingContext();
 
     virtual void run(Box const&, LayoutMode) override;
+    virtual float automatic_content_height() const override;
 };
 
 }

Userland/Libraries/LibWeb/Layout/TableFormattingContext.cpp

@@ -107,7 +107,7 @@ void TableFormattingContext::run(Box const& box, LayoutMode)
         box_state.set_content_width(total_content_width);
 
     // FIXME: This is a total hack, we should respect the 'height' property.
-    box_state.set_content_height(total_content_height);
+    m_automatic_content_height = total_content_height;
 }
 
 void TableFormattingContext::calculate_column_widths(Box const& row, CSS::Length const& table_width, Vector<ColumnWidth>& column_widths)
@@ -209,4 +209,9 @@ void TableFormattingContext::layout_row(Box const& row, Vector<ColumnWidth>& col
     }
 }
 
+float TableFormattingContext::automatic_content_height() const
+{
+    return m_automatic_content_height;
+}
+
 }

Userland/Libraries/LibWeb/Layout/TableFormattingContext.h

@@ -24,10 +24,13 @@ public:
     ~TableFormattingContext();
 
     virtual void run(Box const&, LayoutMode) override;
+    virtual float automatic_content_height() const override;
 
 private:
     void calculate_column_widths(Box const& row, CSS::Length const& table_width, Vector<ColumnWidth>& column_widths);
     void layout_row(Box const& row, Vector<ColumnWidth>& column_widths);
+
+    float m_automatic_content_height { 0 };
 };
 
 }