chromium/third_party/blink/renderer/core/layout/svg/layout_svg_foreign_object.h

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_SVG_LAYOUT_SVG_FOREIGN_OBJECT_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_SVG_LAYOUT_SVG_FOREIGN_OBJECT_H_

#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/layout/svg/layout_svg_block.h"

namespace blink {

// LayoutSVGForeignObject is the LayoutObject associated with <foreignobject>.
// http://www.w3.org/TR/SVG/extend.html#ForeignObjectElement
//
// Foreign object is a way of inserting arbitrary non-SVG content into SVG.
// A good example of this is HTML in SVG. Because of this, CSS content has to
// be aware of SVG: e.g. when determining containing blocks we stop at the
// enclosing foreign object (see LayoutObject::ComputeIsFixedContainer).
//
// Note that SVG is also allowed in HTML with the HTML5 parsing rules so SVG
// content also has to be aware of CSS objects.
// See http://www.w3.org/TR/html5/syntax.html#elements-0 with the rules for
// 'foreign elements'. TODO(jchaffraix): Find a better place for this paragraph.
//
// The coordinate space for the descendants of the foreignObject does not
// include the effective zoom (it is baked into any lengths as usual). The
// transform that defines the userspace of the element is:
//
//   [CSS transform] * [inverse effective zoom] (* ['x' and 'y' translation])
//
// Because of this, the frame rect and visual rect includes effective zoom. The
// object bounding box (ObjectBoundingBox method) is however not zoomed to be
// compatible with the expectations of the getBBox() DOM interface.
class LayoutSVGForeignObject final : public LayoutSVGBlock { … };

template <>
struct DowncastTraits<LayoutSVGForeignObject> { … };

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_SVG_LAYOUT_SVG_FOREIGN_OBJECT_H_