ladybird/Libraries/LibWeb/SVG/SVGForeignObjectElement.h
Andreas Kling b981e6f7bc LibWeb: Avoid many style invalidations on DOM attribute mutation
Many times, attribute mutation doesn't necessitate a full style
invalidation on the element. However, the conditions are pretty
elaborate, so this first version has a lot of false positives.

We only need to invalidate style when any of these things apply:

1. The change may affect the match state of a selector somewhere.
2. The change may affect presentational hints applied to the element.

For (1) in this first version, we have a fixed list of attribute names
that may affect selectors. We also collect all names referenced by
attribute selectors anywhere in the document.

For (2), we add a new Element::is_presentational_hint() virtual that
tells us whether a given attribute name is a presentational hint.

This drastically reduces style work on many websites. As an example,
https://cnn.com/ is once again browseable.
2024-12-24 17:17:09 +01:00

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1.3 KiB
C++

/*
* Copyright (c) 2022, Andreas Kling <andreas@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibWeb/SVG/SVGGraphicsElement.h>
namespace Web::SVG {
// https://svgwg.org/svg2-draft/embedded.html#InterfaceSVGForeignObjectElement
class SVGForeignObjectElement final : public SVGGraphicsElement {
WEB_PLATFORM_OBJECT(SVGForeignObjectElement, SVGGraphicsElement);
GC_DECLARE_ALLOCATOR(SVGForeignObjectElement);
public:
virtual ~SVGForeignObjectElement() override;
virtual GC::Ptr<Layout::Node> create_layout_node(GC::Ref<CSS::ComputedProperties>) override;
GC::Ref<SVG::SVGAnimatedLength> x();
GC::Ref<SVG::SVGAnimatedLength> y();
GC::Ref<SVG::SVGAnimatedLength> width();
GC::Ref<SVG::SVGAnimatedLength> height();
private:
SVGForeignObjectElement(DOM::Document& document, DOM::QualifiedName qualified_name);
virtual void initialize(JS::Realm&) override;
virtual void visit_edges(Cell::Visitor&) override;
virtual bool is_presentational_hint(FlyString const&) const override;
virtual void apply_presentational_hints(GC::Ref<CSS::CascadedProperties>) const override;
GC::Ptr<SVG::SVGAnimatedLength> m_x;
GC::Ptr<SVG::SVGAnimatedLength> m_y;
GC::Ptr<SVG::SVGAnimatedLength> m_width;
GC::Ptr<SVG::SVGAnimatedLength> m_height;
};
}