LibWeb: Remove hand-rolled is_foo() helpers in Layout::Node classes

31 files changed, 39 insertions, 82 deletions

diff --git a/Libraries/LibWeb/DOM/Element.cpp b/Libraries/LibWeb/DOM/Element.cpp
index 8c14451599..b7a128939d 100644
--- a/Libraries/LibWeb/DOM/Element.cpp
+++ b/Libraries/LibWeb/DOM/Element.cpp
@@ -44,6 +44,7 @@
 #include <LibWeb/Layout/TableRowBox.h>
 #include <LibWeb/Layout/TableRowGroupBox.h>
 #include <LibWeb/Layout/TreeBuilder.h>
+#include <LibWeb/Layout/WidgetBox.h>
 
 namespace Web::DOM {
 
@@ -213,7 +214,7 @@ void Element::recompute_style()
     }
 
     // Don't bother with style on widgets. NATIVE LOOK & FEEL BABY!
-    if (layout_node()->is_widget())
+    if (is<Layout::WidgetBox>(layout_node()))
         return;
 
     auto diff = compute_style_difference(layout_node()->specified_style(), *style, document());
diff --git a/Libraries/LibWeb/Dump.cpp b/Libraries/LibWeb/Dump.cpp
index b82ec1243b..8256381b65 100644
--- a/Libraries/LibWeb/Dump.cpp
+++ b/Libraries/LibWeb/Dump.cpp
@@ -141,7 +141,7 @@ void dump_tree(StringBuilder& builder, const Layout::Node& layout_node, bool sho
         color_off = "\033[0m";
     }
 
-    if (!layout_node.is_box()) {
+    if (!is<Layout::Box>(layout_node)) {
         builder.appendff("{}{}{} <{}{}{}>",
             nonbox_color_on,
             layout_node.class_name(),
@@ -205,7 +205,7 @@ void dump_tree(StringBuilder& builder, const Layout::Node& layout_node, bool sho
         builder.append("\n");
     }
 
-    if (layout_node.is_block() && static_cast<const Layout::BlockBox&>(layout_node).children_are_inline()) {
+    if (is<Layout::BlockBox>(layout_node) && static_cast<const Layout::BlockBox&>(layout_node).children_are_inline()) {
         auto& block = static_cast<const Layout::BlockBox&>(layout_node);
         for (size_t line_box_index = 0; line_box_index < block.line_boxes().size(); ++line_box_index) {
             auto& line_box = block.line_boxes()[line_box_index];
@@ -231,7 +231,7 @@ void dump_tree(StringBuilder& builder, const Layout::Node& layout_node, bool sho
                     fragment.start(),
                     fragment.length(),
                     enclosing_int_rect(fragment.absolute_rect()).to_string());
-                if (fragment.layout_node().is_text()) {
+                if (is<Layout::TextNode>(fragment.layout_node())) {
                     for (size_t i = 0; i < indent; ++i)
                         builder.append("  ");
                     auto& layout_text = static_cast<const Layout::TextNode&>(fragment.layout_node());
diff --git a/Libraries/LibWeb/HTML/HTMLElement.cpp b/Libraries/LibWeb/HTML/HTMLElement.cpp
index 317d4bc3ef..eb5356a594 100644
--- a/Libraries/LibWeb/HTML/HTMLElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLElement.cpp
@@ -28,6 +28,7 @@
 #include <LibWeb/DOM/Document.h>
 #include <LibWeb/HTML/HTMLAnchorElement.h>
 #include <LibWeb/HTML/HTMLElement.h>
+#include <LibWeb/Layout/BreakNode.h>
 #include <LibWeb/Layout/TextNode.h>
 
 namespace Web::HTML {
@@ -119,9 +120,9 @@ String HTMLElement::inner_text()
 
     Function<void(const Layout::Node&)> recurse = [&](auto& node) {
         for (auto* child = node.first_child(); child; child = child->next_sibling()) {
-            if (child->is_text())
+            if (is<Layout::TextNode>(child))
                 builder.append(downcast<Layout::TextNode>(*child).text_for_rendering());
-            if (child->is_break())
+            if (is<Layout::BreakNode>(child))
                 builder.append('\n');
             recurse(*child);
         }
diff --git a/Libraries/LibWeb/Layout/BlockBox.cpp b/Libraries/LibWeb/Layout/BlockBox.cpp
index b01db3f579..b25a459886 100644
--- a/Libraries/LibWeb/Layout/BlockBox.cpp
+++ b/Libraries/LibWeb/Layout/BlockBox.cpp
@@ -94,7 +94,7 @@ HitTestResult BlockBox::hit_test(const Gfx::IntPoint& position, HitTestType type
             if (is<Box>(fragment.layout_node()) && downcast<Box>(fragment.layout_node()).stacking_context())
                 continue;
             if (enclosing_int_rect(fragment.absolute_rect()).contains(position)) {
-                if (fragment.layout_node().is_block())
+                if (is<BlockBox>(fragment.layout_node()))
                     return downcast<BlockBox>(fragment.layout_node()).hit_test(position, type);
                 return { fragment.layout_node(), fragment.text_index_at(position.x()) };
             }
diff --git a/Libraries/LibWeb/Layout/BlockBox.h b/Libraries/LibWeb/Layout/BlockBox.h
index 14fd57efcb..fb1b3ad4e5 100644
--- a/Libraries/LibWeb/Layout/BlockBox.h
+++ b/Libraries/LibWeb/Layout/BlockBox.h
@@ -51,9 +51,6 @@ public:
     void for_each_fragment(Callback) const;
 
     virtual void split_into_lines(InlineFormattingContext&, LayoutMode) override;
-
-private:
-    virtual bool is_block() const override { return true; }
 };
 
 template<typename Callback>
diff --git a/Libraries/LibWeb/Layout/BlockFormattingContext.cpp b/Libraries/LibWeb/Layout/BlockFormattingContext.cpp
index 245efc6361..402a86f127 100644
--- a/Libraries/LibWeb/Layout/BlockFormattingContext.cpp
+++ b/Libraries/LibWeb/Layout/BlockFormattingContext.cpp
@@ -48,7 +48,7 @@ BlockFormattingContext::~BlockFormattingContext()
 
 bool BlockFormattingContext::is_initial() const
 {
-    return context_box().is_initial_containing_block();
+    return is<InitialContainingBlockBox>(context_box());
 }
 
 void BlockFormattingContext::run(Box& box, LayoutMode layout_mode)
@@ -85,7 +85,7 @@ void BlockFormattingContext::run(Box& box, LayoutMode layout_mode)
 
 void BlockFormattingContext::compute_width(Box& box)
 {
-    if (box.is_replaced()) {
+    if (is<ReplacedBox>(box)) {
         // FIXME: This should not be done *by* ReplacedBox
         auto& replaced = downcast<ReplacedBox>(box);
         replaced.prepare_for_replaced_layout();
@@ -414,7 +414,7 @@ void BlockFormattingContext::compute_width_for_absolutely_positioned_block(Box&
 
 void BlockFormattingContext::compute_height(Box& box)
 {
-    if (box.is_replaced()) {
+    if (is<ReplacedBox>(box)) {
         compute_height_for_block_level_replaced_element_in_normal_flow(downcast<ReplacedBox>(box));
         return;
     }
@@ -471,9 +471,9 @@ void BlockFormattingContext::layout_block_level_children(Box& box, LayoutMode la
         layout_inside(child_box, layout_mode);
         compute_height(child_box);
 
-        if (child_box.is_replaced())
+        if (is<ReplacedBox>(child_box))
             place_block_level_replaced_element_in_normal_flow(child_box, box);
-        else if (child_box.is_block())
+        else if (is<BlockBox>(child_box))
             place_block_level_non_replaced_element_in_normal_flow(child_box, box);
 
         // FIXME: This should be factored differently. It's uncool that we mutate the tree *during* layout!
diff --git a/Libraries/LibWeb/Layout/Box.cpp b/Libraries/LibWeb/Layout/Box.cpp
index 5a0c57accc..c7a0a868d0 100644
--- a/Libraries/LibWeb/Layout/Box.cpp
+++ b/Libraries/LibWeb/Layout/Box.cpp
@@ -165,7 +165,7 @@ void Box::set_containing_line_box_fragment(LineBoxFragment& fragment)
 StackingContext* Box::enclosing_stacking_context()
 {
     for (auto* ancestor = parent(); ancestor; ancestor = ancestor->parent()) {
-        if (!ancestor->is_box())
+        if (!is<Box>(ancestor))
             continue;
         auto& ancestor_box = downcast<Box>(*ancestor);
         if (!ancestor_box.establishes_stacking_context())
diff --git a/Libraries/LibWeb/Layout/Box.h b/Libraries/LibWeb/Layout/Box.h
index 6c52072f40..a836761087 100644
--- a/Libraries/LibWeb/Layout/Box.h
+++ b/Libraries/LibWeb/Layout/Box.h
@@ -112,8 +112,6 @@ protected:
     Vector<LineBox> m_line_boxes;
 
 private:
-    virtual bool is_box() const final { return true; }
-
     Gfx::FloatPoint m_offset;
     Gfx::FloatSize m_size;
 
diff --git a/Libraries/LibWeb/Layout/BreakNode.h b/Libraries/LibWeb/Layout/BreakNode.h
index 7ebe866b7a..58ebbe3322 100644
--- a/Libraries/LibWeb/Layout/BreakNode.h
+++ b/Libraries/LibWeb/Layout/BreakNode.h
@@ -39,7 +39,6 @@ public:
     const HTML::HTMLBRElement& dom_node() const { return downcast<HTML::HTMLBRElement>(*Node::dom_node()); }
 
 private:
-    virtual bool is_break() const override { return true; }
     virtual void split_into_lines(InlineFormattingContext&, LayoutMode) override;
 };
 
diff --git a/Libraries/LibWeb/Layout/ButtonBox.h b/Libraries/LibWeb/Layout/ButtonBox.h
index a48342ad2b..f26c7ed8d8 100644
--- a/Libraries/LibWeb/Layout/ButtonBox.h
+++ b/Libraries/LibWeb/Layout/ButtonBox.h
@@ -43,7 +43,6 @@ public:
     HTML::HTMLInputElement& dom_node() { return static_cast<HTML::HTMLInputElement&>(ReplacedBox::dom_node()); }
 
 private:
-    virtual bool is_button() const override { return true; }
     virtual bool wants_mouse_events() const override { return true; }
     virtual void handle_mousedown(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned modifiers) override;
     virtual void handle_mouseup(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned modifiers) override;
diff --git a/Libraries/LibWeb/Layout/CanvasBox.h b/Libraries/LibWeb/Layout/CanvasBox.h
index 052f21aeab..150e28ae21 100644
--- a/Libraries/LibWeb/Layout/CanvasBox.h
+++ b/Libraries/LibWeb/Layout/CanvasBox.h
@@ -40,9 +40,6 @@ public:
     virtual void paint(PaintContext&, PaintPhase) override;
 
     const HTML::HTMLCanvasElement& dom_node() const { return static_cast<const HTML::HTMLCanvasElement&>(ReplacedBox::dom_node()); }
-
-private:
-    virtual bool is_canvas() const override { return true; }
 };
 
 }
diff --git a/Libraries/LibWeb/Layout/CheckBox.h b/Libraries/LibWeb/Layout/CheckBox.h
index 7a97025383..47809c07f9 100644
--- a/Libraries/LibWeb/Layout/CheckBox.h
+++ b/Libraries/LibWeb/Layout/CheckBox.h
@@ -42,7 +42,6 @@ public:
     HTML::HTMLInputElement& dom_node() { return static_cast<HTML::HTMLInputElement&>(ReplacedBox::dom_node()); }
 
 private:
-    virtual bool is_check_box() const override { return true; }
     virtual bool wants_mouse_events() const override { return true; }
     virtual void handle_mousedown(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned modifiers) override;
     virtual void handle_mouseup(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned modifiers) override;
diff --git a/Libraries/LibWeb/Layout/FormattingContext.cpp b/Libraries/LibWeb/Layout/FormattingContext.cpp
index 8256ceccc3..c6f565aa27 100644
--- a/Libraries/LibWeb/Layout/FormattingContext.cpp
+++ b/Libraries/LibWeb/Layout/FormattingContext.cpp
@@ -31,7 +31,10 @@
 #include <LibWeb/Layout/FormattingContext.h>
 #include <LibWeb/Layout/InlineFormattingContext.h>
 #include <LibWeb/Layout/ReplacedBox.h>
+#include <LibWeb/Layout/TableBox.h>
+#include <LibWeb/Layout/TableCellBox.h>
 #include <LibWeb/Layout/TableFormattingContext.h>
+#include <LibWeb/Layout/TableRowBox.h>
 
 namespace Web::Layout {
 
@@ -55,7 +58,7 @@ bool FormattingContext::creates_block_formatting_context(const Box& box)
         return true;
     if (box.is_inline_block())
         return true;
-    if (box.is_table_cell())
+    if (is<TableCellBox>(box))
         return true;
     // FIXME: table-caption
     // FIXME: anonymous table cells
@@ -76,7 +79,7 @@ void FormattingContext::layout_inside(Box& box, LayoutMode layout_mode)
         context.run(box, layout_mode);
         return;
     }
-    if (box.is_table()) {
+    if (is<TableBox>(box)) {
         TableFormattingContext context(box, this);
         context.run(box, layout_mode);
     } else if (box.children_are_inline()) {
diff --git a/Libraries/LibWeb/Layout/FrameBox.h b/Libraries/LibWeb/Layout/FrameBox.h
index 7c2d9db529..93a5216f3f 100644
--- a/Libraries/LibWeb/Layout/FrameBox.h
+++ b/Libraries/LibWeb/Layout/FrameBox.h
@@ -43,7 +43,6 @@ public:
     HTML::HTMLIFrameElement& dom_node() { return downcast<HTML::HTMLIFrameElement>(ReplacedBox::dom_node()); }
 
 private:
-    virtual bool is_frame() const final { return true; }
     virtual void did_set_rect() override;
 };
 
diff --git a/Libraries/LibWeb/Layout/ImageBox.h b/Libraries/LibWeb/Layout/ImageBox.h
index 46c56bdf4f..a404ca1ca0 100644
--- a/Libraries/LibWeb/Layout/ImageBox.h
+++ b/Libraries/LibWeb/Layout/ImageBox.h
@@ -46,8 +46,6 @@ public:
     void set_visible_in_viewport(Badge<InitialContainingBlockBox>, bool);
 
 private:
-    virtual bool is_image() const override { return true; }
-
     int preferred_width() const;
     int preferred_height() const;
 
diff --git a/Libraries/LibWeb/Layout/InitialContainingBlockBox.h b/Libraries/LibWeb/Layout/InitialContainingBlockBox.h
index 1e74cefd55..b7b4810364 100644
--- a/Libraries/LibWeb/Layout/InitialContainingBlockBox.h
+++ b/Libraries/LibWeb/Layout/InitialContainingBlockBox.h
@@ -49,8 +49,6 @@ public:
 
     void did_set_viewport_rect(Badge<Frame>, const Gfx::IntRect&);
 
-    virtual bool is_initial_containing_block() const override { return true; }
-
     void build_stacking_context_tree();
 
     void recompute_selection_states();
diff --git a/Libraries/LibWeb/Layout/InlineFormattingContext.cpp b/Libraries/LibWeb/Layout/InlineFormattingContext.cpp
index b8d0b6cee0..74b2b6ad06 100644
--- a/Libraries/LibWeb/Layout/InlineFormattingContext.cpp
+++ b/Libraries/LibWeb/Layout/InlineFormattingContext.cpp
@@ -199,7 +199,7 @@ void InlineFormattingContext::run(Box&, LayoutMode layout_mode)
 
 void InlineFormattingContext::dimension_box_on_line(Box& box, LayoutMode layout_mode)
 {
-    if (box.is_replaced()) {
+    if (is<ReplacedBox>(box)) {
         auto& replaced = downcast<ReplacedBox>(box);
         replaced.set_width(compute_width_for_replaced_element(replaced));
         replaced.set_height(compute_height_for_replaced_element(replaced));
diff --git a/Libraries/LibWeb/Layout/InlineNode.h b/Libraries/LibWeb/Layout/InlineNode.h
index f35a50330a..8f47b24f34 100644
--- a/Libraries/LibWeb/Layout/InlineNode.h
+++ b/Libraries/LibWeb/Layout/InlineNode.h
@@ -38,9 +38,6 @@ public:
     virtual void paint_fragment(PaintContext&, const LineBoxFragment&, PaintPhase) const override;
 
     virtual void split_into_lines(InlineFormattingContext&, LayoutMode) override;
-
-private:
-    virtual bool is_inline_node() const final { return true; }
 };
 
 }
diff --git a/Libraries/LibWeb/Layout/LineBoxFragment.cpp b/Libraries/LibWeb/Layout/LineBoxFragment.cpp
index e6a6cfeeda..106f9d18d2 100644
--- a/Libraries/LibWeb/Layout/LineBoxFragment.cpp
+++ b/Libraries/LibWeb/Layout/LineBoxFragment.cpp
@@ -75,7 +75,7 @@ const Gfx::FloatRect LineBoxFragment::absolute_rect() const
 
 int LineBoxFragment::text_index_at(float x) const
 {
-    if (!layout_node().is_text())
+    if (!is<TextNode>(layout_node()))
         return 0;
     auto& layout_text = downcast<TextNode>(layout_node());
     auto& font = layout_text.specified_style().font();
@@ -108,7 +108,7 @@ Gfx::FloatRect LineBoxFragment::selection_rect(const Gfx::Font& font) const
     auto selection = layout_node().root().selection().normalized();
     if (!selection.is_valid())
         return {};
-    if (!layout_node().is_text())
+    if (!is<TextNode>(layout_node()))
         return {};
 
     const auto start_index = m_start;
diff --git a/Libraries/LibWeb/Layout/ListItemBox.h b/Libraries/LibWeb/Layout/ListItemBox.h
index adf5e63b0f..39b5af84e3 100644
--- a/Libraries/LibWeb/Layout/ListItemBox.h
+++ b/Libraries/LibWeb/Layout/ListItemBox.h
@@ -41,8 +41,6 @@ public:
     void layout_marker();
 
 private:
-    virtual bool is_list_item() const override { return true; }
-
     RefPtr<ListItemMarkerBox> m_marker;
 };
 
diff --git a/Libraries/LibWeb/Layout/Node.cpp b/Libraries/LibWeb/Layout/Node.cpp
index 4376e3bb36..a85ce22f92 100644
--- a/Libraries/LibWeb/Layout/Node.cpp
+++ b/Libraries/LibWeb/Layout/Node.cpp
@@ -35,6 +35,7 @@
 #include <LibWeb/Layout/InitialContainingBlockBox.h>
 #include <LibWeb/Layout/Node.h>
 #include <LibWeb/Layout/ReplacedBox.h>
+#include <LibWeb/Layout/TextNode.h>
 #include <LibWeb/Page/Frame.h>
 #include <typeinfo>
 
@@ -56,7 +57,7 @@ Node::~Node()
 
 bool Node::can_contain_boxes_with_position_absolute() const
 {
-    return style().position() != CSS::Position::Static || is_initial_containing_block();
+    return style().position() != CSS::Position::Static || is<InitialContainingBlockBox>(*this);
 }
 
 const BlockBox* Node::containing_block() const
@@ -68,7 +69,7 @@ const BlockBox* Node::containing_block() const
         return downcast<BlockBox>(ancestor);
     };
 
-    if (is_text())
+    if (is<TextNode>(*this))
         return nearest_block_ancestor();
 
     auto position = style().position();
@@ -165,7 +166,7 @@ float Node::font_size() const
 
 Gfx::FloatPoint Node::box_type_agnostic_position() const
 {
-    if (is_box())
+    if (is<Box>(*this))
         return downcast<Box>(*this).absolute_position();
     ASSERT(is_inline());
     Gfx::FloatPoint position;
@@ -303,4 +304,9 @@ String Node::class_name() const
     return demangle(typeid(*this).name());
 }
 
+bool Node::is_inline_block() const
+{
+    return is_inline() && is<BlockBox>(*this);
+}
+
 }
diff --git a/Libraries/LibWeb/Layout/Node.h b/Libraries/LibWeb/Layout/Node.h
index 4ae2da141a..4af3761713 100644
--- a/Libraries/LibWeb/Layout/Node.h
+++ b/Libraries/LibWeb/Layout/Node.h
@@ -95,24 +95,6 @@ public:
 
     String class_name() const;
 
-    virtual bool is_initial_containing_block() const { return false; }
-    virtual bool is_text() const { return false; }
-    virtual bool is_block() const { return false; }
-    virtual bool is_replaced() const { return false; }
-    virtual bool is_widget() const { return false; }
-    virtual bool is_frame() const { return false; }
-    virtual bool is_image() const { return false; }
-    virtual bool is_canvas() const { return false; }
-    virtual bool is_box() const { return false; }
-    virtual bool is_table() const { return false; }
-    virtual bool is_table_row() const { return false; }
-    virtual bool is_table_cell() const { return false; }
-    virtual bool is_table_row_group() const { return false; }
-    virtual bool is_break() const { return false; }
-    virtual bool is_check_box() const { return false; }
-    virtual bool is_button() const { return false; }
-    virtual bool is_list_item() const { return false; }
-    virtual bool is_inline_node() const { return false; }
     bool has_style() const { return m_has_style; }
 
     virtual bool can_have_children() const { return true; }
@@ -120,7 +102,7 @@ public:
     bool is_inline() const { return m_inline; }
     void set_inline(bool b) { m_inline = b; }
 
-    bool is_inline_block() const { return is_inline() && is_block(); }
+    bool is_inline_block() const;
 
     virtual bool wants_mouse_events() const { return false; }
 
diff --git a/Libraries/LibWeb/Layout/ReplacedBox.h b/Libraries/LibWeb/Layout/ReplacedBox.h
index e7f1ece198..f1da91a197 100644
--- a/Libraries/LibWeb/Layout/ReplacedBox.h
+++ b/Libraries/LibWeb/Layout/ReplacedBox.h
@@ -39,8 +39,6 @@ public:
     const DOM::Element& dom_node() const { return downcast<DOM::Element>(*Node::dom_node()); }
     DOM::Element& dom_node() { return downcast<DOM::Element>(*Node::dom_node()); }
 
-    virtual bool is_replaced() const final { return true; }
-
     bool has_intrinsic_width() const { return m_has_intrinsic_width; }
     bool has_intrinsic_height() const { return m_has_intrinsic_height; }
     bool has_intrinsic_ratio() const { return m_has_intrinsic_ratio; }
diff --git a/Libraries/LibWeb/Layout/TableBox.h b/Libraries/LibWeb/Layout/TableBox.h
index 93bdb18a60..0c34c6a61c 100644
--- a/Libraries/LibWeb/Layout/TableBox.h
+++ b/Libraries/LibWeb/Layout/TableBox.h
@@ -34,9 +34,6 @@ class TableBox final : public Layout::BlockBox {
 public:
     TableBox(DOM::Document&, DOM::Element&, NonnullRefPtr<CSS::StyleProperties>);
     virtual ~TableBox() override;
-
-private:
-    virtual bool is_table() const override { return true; }
 };
 
 }
diff --git a/Libraries/LibWeb/Layout/TableCellBox.h b/Libraries/LibWeb/Layout/TableCellBox.h
index ce5d72a2d0..b1a8bb0160 100644
--- a/Libraries/LibWeb/Layout/TableCellBox.h
+++ b/Libraries/LibWeb/Layout/TableCellBox.h
@@ -41,7 +41,6 @@ public:
     size_t colspan() const;
 
 private:
-    virtual bool is_table_cell() const override { return true; }
     virtual float width_of_logical_containing_block() const override;
 };
 
diff --git a/Libraries/LibWeb/Layout/TableRowBox.h b/Libraries/LibWeb/Layout/TableRowBox.h
index 154947701d..0a63f44efc 100644
--- a/Libraries/LibWeb/Layout/TableRowBox.h
+++ b/Libraries/LibWeb/Layout/TableRowBox.h
@@ -34,9 +34,6 @@ class TableRowBox final : public Box {
 public:
     TableRowBox(DOM::Document&, DOM::Element&, NonnullRefPtr<CSS::StyleProperties>);
     virtual ~TableRowBox() override;
-
-private:
-    virtual bool is_table_row() const override { return true; }
 };
 
 }
diff --git a/Libraries/LibWeb/Layout/TableRowGroupBox.h b/Libraries/LibWeb/Layout/TableRowGroupBox.h
index f1781466b8..6a9fd6956c 100644
--- a/Libraries/LibWeb/Layout/TableRowGroupBox.h
+++ b/Libraries/LibWeb/Layout/TableRowGroupBox.h
@@ -36,9 +36,6 @@ public:
     virtual ~TableRowGroupBox() override;
 
     size_t column_count() const;
-
-private:
-    virtual bool is_table_row_group() const override { return true; }
 };
 
 }
diff --git a/Libraries/LibWeb/Layout/TextNode.h b/Libraries/LibWeb/Layout/TextNode.h
index 5e0ac342ba..85189a77b4 100644
--- a/Libraries/LibWeb/Layout/TextNode.h
+++ b/Libraries/LibWeb/Layout/TextNode.h
@@ -43,8 +43,6 @@ public:
     const String& text_for_style(const CSS::StyleProperties&) const;
     const String& text_for_rendering() const { return m_text_for_rendering; }
 
-    virtual bool is_text() const final { return true; }
-
     virtual void paint_fragment(PaintContext&, const LineBoxFragment&, PaintPhase) const override;
 
     virtual void split_into_lines(InlineFormattingContext&, LayoutMode) override;
diff --git a/Libraries/LibWeb/Layout/WidgetBox.h b/Libraries/LibWeb/Layout/WidgetBox.h
index 24778e0f01..8c7445a1fc 100644
--- a/Libraries/LibWeb/Layout/WidgetBox.h
+++ b/Libraries/LibWeb/Layout/WidgetBox.h
@@ -38,8 +38,6 @@ public:
     GUI::Widget& widget() { return m_widget; }
     const GUI::Widget& widget() const { return m_widget; }
 
-    virtual bool is_widget() const final { return true; }
-
     void update_widget();
 
 private:
diff --git a/Libraries/LibWeb/LayoutTreeModel.cpp b/Libraries/LibWeb/LayoutTreeModel.cpp
index 3bcb6f3552..02d3850509 100644
--- a/Libraries/LibWeb/LayoutTreeModel.cpp
+++ b/Libraries/LibWeb/LayoutTreeModel.cpp
@@ -29,6 +29,7 @@
 #include <LibWeb/DOM/Document.h>
 #include <LibWeb/DOM/Element.h>
 #include <LibWeb/DOM/Text.h>
+#include <LibWeb/Layout/InitialContainingBlockBox.h>
 #include <LibWeb/Layout/TextNode.h>
 #include <ctype.h>
 #include <stdio.h>
@@ -119,14 +120,14 @@ GUI::Variant LayoutTreeModel::data(const GUI::ModelIndex& index, GUI::ModelRole
 {
     auto& node = *static_cast<Layout::Node*>(index.internal_data());
     if (role == GUI::ModelRole::Icon) {
-        if (node.is_initial_containing_block())
+        if (is<Layout::InitialContainingBlockBox>(node))
             return m_document_icon;
-        if (node.is_text())
+        if (is<Layout::TextNode>(node))
             return m_text_icon;
         return m_element_icon;
     }
     if (role == GUI::ModelRole::Display) {
-        if (node.is_text())
+        if (is<Layout::TextNode>(node))
             return String::format("TextNode: %s", with_whitespace_collapsed(downcast<Layout::TextNode>(node).text_for_rendering()).characters());
         StringBuilder builder;
         builder.append(node.class_name());
diff --git a/Libraries/LibWeb/Painting/StackingContext.cpp b/Libraries/LibWeb/Painting/StackingContext.cpp
index fe24a4c642..e07d640613 100644
--- a/Libraries/LibWeb/Painting/StackingContext.cpp
+++ b/Libraries/LibWeb/Painting/StackingContext.cpp
@@ -50,7 +50,7 @@ StackingContext::StackingContext(Box& box, StackingContext* parent)
 
 void StackingContext::paint(PaintContext& context, PaintPhase phase)
 {
-    if (!m_box.is_initial_containing_block()) {
+    if (!is<InitialContainingBlockBox>(m_box)) {
         m_box.paint(context, phase);
     } else {
         // NOTE: InitialContainingBlockBox::paint() merely calls StackingContext::paint()
@@ -65,7 +65,7 @@ void StackingContext::paint(PaintContext& context, PaintPhase phase)
 HitTestResult StackingContext::hit_test(const Gfx::IntPoint& position, HitTestType type) const
 {
     HitTestResult result;
-    if (!m_box.is_initial_containing_block()) {
+    if (!is<InitialContainingBlockBox>(m_box)) {
         result = m_box.hit_test(position, type);
     } else {
         // NOTE: InitialContainingBlockBox::hit_test() merely calls StackingContext::hit_test()