LibWeb: Let Paintable perform the painting

This patch adds a bunch of Paintable subclasses, each corresponding to
the Layout::Node subclasses that had a paint() override. All painting
logic is moved from layout nodes into their corresponding paintables.

Paintables are now created by asking a Layout::Box to produce one:

    static NonnullOwnPtr<Paintable> Layout::Box::create_paintable()

Note that inline nodes still have their painting logic. Since they
are not boxes, and all paintables have a corresponding box, we'll need
to come up with some other solution for them.

1 files changed, 2 insertions, 10 deletions

diff --git a/Userland/Libraries/LibWeb/Layout/Box.h b/Userland/Libraries/LibWeb/Layout/Box.h
index 03c4f13565..730bebcbf4 100644
--- a/Userland/Libraries/LibWeb/Layout/Box.h
+++ b/Userland/Libraries/LibWeb/Layout/Box.h
@@ -32,13 +32,6 @@ public:
 
     bool is_body() const;
 
-    virtual void paint(PaintContext&, Painting::PaintPhase) override;
-    virtual void paint_border(PaintContext& context);
-    virtual void paint_box_shadow(PaintContext& context);
-    virtual void paint_background(PaintContext& context);
-
-    Painting::BorderRadiusData normalized_border_radius_data();
-
     virtual Optional<float> intrinsic_width() const { return {}; }
     virtual Optional<float> intrinsic_height() const { return {}; }
     virtual Optional<float> intrinsic_aspect_ratio() const { return {}; }
@@ -47,13 +40,12 @@ public:
     bool has_intrinsic_height() const { return intrinsic_height().has_value(); }
     bool has_intrinsic_aspect_ratio() const { return intrinsic_aspect_ratio().has_value(); }
 
-    virtual void before_children_paint(PaintContext&, Painting::PaintPhase) override;
-    virtual void after_children_paint(PaintContext&, Painting::PaintPhase) override;
-
     virtual ~Box() override;
 
     virtual void did_set_rect() { }
 
+    virtual OwnPtr<Painting::Paintable> create_paintable() const;
+
 protected:
     Box(DOM::Document&, DOM::Node*, NonnullRefPtr<CSS::StyleProperties>);
     Box(DOM::Document&, DOM::Node*, CSS::ComputedValues);