From f35b406dfb2be5efb9e99c38972f4f3c93088203 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Thu, 3 Dec 2020 19:30:48 +0100
Subject: [PATCH] LibWeb: Virtualize Layout::Node::paint_fragment()

LineBoxFragment no longer needs to care what type of layout node a
fragment refers to during paint, it can just call paint_fragment(). :^)
---
 Libraries/LibWeb/Layout/InlineNode.h        | 2 +-
 Libraries/LibWeb/Layout/LineBoxFragment.cpp | 7 +------
 Libraries/LibWeb/Layout/Node.h              | 1 +
 Libraries/LibWeb/Layout/TextNode.h          | 2 +-
 4 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/Libraries/LibWeb/Layout/InlineNode.h b/Libraries/LibWeb/Layout/InlineNode.h
index 91a74a9caa..a140339599 100644
--- a/Libraries/LibWeb/Layout/InlineNode.h
+++ b/Libraries/LibWeb/Layout/InlineNode.h
@@ -36,7 +36,7 @@ public:
     virtual ~InlineNode() override;
     virtual const char* class_name() const override { return "InlineNode"; }
 
-    void paint_fragment(PaintContext&, const LineBoxFragment&, PaintPhase) const;
+    virtual void paint_fragment(PaintContext&, const LineBoxFragment&, PaintPhase) const override;
 
     virtual void split_into_lines(BlockBox& containing_block, LayoutMode) override;
 
diff --git a/Libraries/LibWeb/Layout/LineBoxFragment.cpp b/Libraries/LibWeb/Layout/LineBoxFragment.cpp
index 8e589469ff..af24ce2c38 100644
--- a/Libraries/LibWeb/Layout/LineBoxFragment.cpp
+++ b/Libraries/LibWeb/Layout/LineBoxFragment.cpp
@@ -29,7 +29,6 @@
 #include <LibWeb/Layout/InitialContainingBlockBox.h>
 #include <LibWeb/Layout/LineBoxFragment.h>
 #include <LibWeb/Layout/TextNode.h>
-#include <LibWeb/Layout/InlineNode.h>
 #include <LibWeb/Painting/PaintContext.h>
 #include <ctype.h>
 
@@ -42,11 +41,7 @@ void LineBoxFragment::paint(PaintContext& context, PaintPhase phase)
             return;
     }
 
-    if (is<InlineNode>(layout_node()))
-        downcast<InlineNode>(layout_node()).paint_fragment(context, *this, phase);
-
-    if (is<TextNode>(layout_node()))
-        downcast<TextNode>(layout_node()).paint_fragment(context, *this, phase);
+    layout_node().paint_fragment(context, *this, phase);
 }
 
 bool LineBoxFragment::ends_in_whitespace() const
diff --git a/Libraries/LibWeb/Layout/Node.h b/Libraries/LibWeb/Layout/Node.h
index 27809be760..07968f1e34 100644
--- a/Libraries/LibWeb/Layout/Node.h
+++ b/Libraries/LibWeb/Layout/Node.h
@@ -127,6 +127,7 @@ public:
 
     virtual void before_children_paint(PaintContext&, PaintPhase) {};
     virtual void paint(PaintContext&, PaintPhase);
+    virtual void paint_fragment(PaintContext&, const LineBoxFragment&, PaintPhase) const { }
     virtual void after_children_paint(PaintContext&, PaintPhase) {};
 
     bool is_floating() const;
diff --git a/Libraries/LibWeb/Layout/TextNode.h b/Libraries/LibWeb/Layout/TextNode.h
index 298acfd58a..389cf0f3e8 100644
--- a/Libraries/LibWeb/Layout/TextNode.h
+++ b/Libraries/LibWeb/Layout/TextNode.h
@@ -46,7 +46,7 @@ public:
     virtual const char* class_name() const override { return "TextNode"; }
     virtual bool is_text() const final { return true; }
 
-    void paint_fragment(PaintContext&, const LineBoxFragment&, PaintPhase) const;
+    virtual void paint_fragment(PaintContext&, const LineBoxFragment&, PaintPhase) const override;
 
     virtual void split_into_lines(BlockBox& container, LayoutMode) override;