From d5aca1c6c4addd9e1f64a31149bf10498b24238f Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Thu, 24 Mar 2022 16:06:43 +0100
Subject: [PATCH] LibWeb: Treate SVG paintable coordinates as relative to <svg>
 element

Normally, paintable coordinates are relative to the nearest containing
block, but in the SVG case, since <svg> doesn't form a containing block,
we have to specialize the computation of SVGPaintable::absolute_rect().
---
 .../Libraries/LibWeb/Painting/PaintableBox.cpp   | 16 ++++++++++------
 .../Libraries/LibWeb/Painting/PaintableBox.h     |  2 ++
 .../Libraries/LibWeb/Painting/SVGPaintable.cpp   | 12 ++++++++++++
 .../Libraries/LibWeb/Painting/SVGPaintable.h     |  2 ++
 4 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/Userland/Libraries/LibWeb/Painting/PaintableBox.cpp b/Userland/Libraries/LibWeb/Painting/PaintableBox.cpp
index b89eeb1b65..8b3814a305 100644
--- a/Userland/Libraries/LibWeb/Painting/PaintableBox.cpp
+++ b/Userland/Libraries/LibWeb/Painting/PaintableBox.cpp
@@ -66,14 +66,18 @@ Gfx::FloatPoint PaintableBox::effective_offset() const
     return m_offset;
 }
 
+Gfx::FloatRect PaintableBox::compute_absolute_rect() const
+{
+    Gfx::FloatRect rect { effective_offset(), content_size() };
+    for (auto const* block = containing_block(); block && block->paintable(); block = block->paintable()->containing_block())
+        rect.translate_by(block->paint_box()->effective_offset());
+    return rect;
+}
+
 Gfx::FloatRect PaintableBox::absolute_rect() const
 {
-    if (!m_absolute_rect.has_value()) {
-        Gfx::FloatRect rect { effective_offset(), content_size() };
-        for (auto const* block = containing_block(); block && block->paintable(); block = block->paintable()->containing_block())
-            rect.translate_by(block->paint_box()->effective_offset());
-        m_absolute_rect = rect;
-    }
+    if (!m_absolute_rect.has_value())
+        m_absolute_rect = compute_absolute_rect();
     return *m_absolute_rect;
 }
 
diff --git a/Userland/Libraries/LibWeb/Painting/PaintableBox.h b/Userland/Libraries/LibWeb/Painting/PaintableBox.h
index 4d3a7fc5f5..028a619fec 100644
--- a/Userland/Libraries/LibWeb/Painting/PaintableBox.h
+++ b/Userland/Libraries/LibWeb/Painting/PaintableBox.h
@@ -126,6 +126,8 @@ protected:
     virtual void paint_background(PaintContext&) const;
     virtual void paint_box_shadow(PaintContext&) const;
 
+    virtual Gfx::FloatRect compute_absolute_rect() const;
+
 private:
     Painting::BorderRadiusData normalized_border_radius_data() const;
 
diff --git a/Userland/Libraries/LibWeb/Painting/SVGPaintable.cpp b/Userland/Libraries/LibWeb/Painting/SVGPaintable.cpp
index 22f8898f5e..e1dae92297 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGPaintable.cpp
+++ b/Userland/Libraries/LibWeb/Painting/SVGPaintable.cpp
@@ -5,6 +5,7 @@
  */
 
 #include <LibWeb/Layout/ImageBox.h>
+#include <LibWeb/Layout/SVGSVGBox.h>
 #include <LibWeb/Painting/SVGPaintable.h>
 
 namespace Web::Painting {
@@ -35,4 +36,15 @@ void SVGPaintable::after_children_paint(PaintContext& context, PaintPhase phase)
     context.svg_context().restore();
 }
 
+Gfx::FloatRect SVGPaintable::compute_absolute_rect() const
+{
+    if (auto* svg_svg_box = layout_box().first_ancestor_of_type<Layout::SVGSVGBox>()) {
+        Gfx::FloatRect rect { effective_offset(), content_size() };
+        for (Layout::Box const* ancestor = svg_svg_box; ancestor && ancestor->paintable(); ancestor = ancestor->paintable()->containing_block())
+            rect.translate_by(ancestor->paint_box()->effective_offset());
+        return rect;
+    }
+    return PaintableBox::compute_absolute_rect();
+}
+
 }
diff --git a/Userland/Libraries/LibWeb/Painting/SVGPaintable.h b/Userland/Libraries/LibWeb/Painting/SVGPaintable.h
index 59eb8f008e..b1783e16eb 100644
--- a/Userland/Libraries/LibWeb/Painting/SVGPaintable.h
+++ b/Userland/Libraries/LibWeb/Painting/SVGPaintable.h
@@ -20,6 +20,8 @@ public:
 
 protected:
     SVGPaintable(Layout::SVGBox const&);
+
+    virtual Gfx::FloatRect compute_absolute_rect() const override;
 };
 
 }