ladybird/Libraries/LibWeb/HTML/HTMLObjectElement.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

105 lines
3.8 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <andreas@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibCore/Forward.h>
#include <LibGfx/Forward.h>
#include <LibWeb/HTML/FormAssociatedElement.h>
#include <LibWeb/HTML/HTMLElement.h>
#include <LibWeb/HTML/NavigableContainer.h>
#include <LibWeb/Layout/ImageProvider.h>
namespace Web::HTML {
class HTMLObjectElement final
: public NavigableContainer
, public FormAssociatedElement
, public Layout::ImageProvider {
WEB_PLATFORM_OBJECT(HTMLObjectElement, NavigableContainer)
GC_DECLARE_ALLOCATOR(HTMLObjectElement);
FORM_ASSOCIATED_ELEMENT(NavigableContainer, HTMLObjectElement)
enum class Representation {
Unknown,
Image,
ContentNavigable,
Children,
};
public:
virtual ~HTMLObjectElement() override;
virtual void form_associated_element_attribute_changed(FlyString const& name, Optional<String> const& value, Optional<FlyString> const& namespace_) override;
virtual void form_associated_element_was_removed(DOM::Node*) override;
String data() const;
void set_data(String const& data) { MUST(set_attribute(HTML::AttributeNames::data, data)); }
String type() const { return get_attribute_value(HTML::AttributeNames::type); }
// ^FormAssociatedElement
// https://html.spec.whatwg.org/multipage/forms.html#category-listed
virtual bool is_listed() const override { return true; }
virtual void visit_edges(Cell::Visitor&) override;
private:
HTMLObjectElement(DOM::Document&, DOM::QualifiedName);
virtual bool is_html_object_element() const override { return true; }
virtual void initialize(JS::Realm&) override;
virtual bool is_presentational_hint(FlyString const&) const override;
virtual void apply_presentational_hints(GC::Ref<CSS::CascadedProperties>) const override;
virtual GC::Ptr<Layout::Node> create_layout_node(GC::Ref<CSS::ComputedProperties>) override;
virtual void adjust_computed_style(CSS::ComputedProperties&) override;
bool has_ancestor_media_element_or_object_element_not_showing_fallback_content() const;
void queue_element_task_to_run_object_representation_steps();
void run_object_representation_handler_steps(Fetch::Infrastructure::Response const&, MimeSniff::MimeType const&, ReadonlyBytes);
void run_object_representation_completed_steps(Representation);
void run_object_representation_fallback_steps();
void load_image();
void update_layout_and_child_objects(Representation);
void resource_did_load(Fetch::Infrastructure::Response const&, ReadonlyBytes);
void resource_did_fail();
// ^DOM::Element
virtual i32 default_tab_index_value() const override;
// ^Layout::ImageProvider
virtual bool is_image_available() const override;
virtual Optional<CSSPixels> intrinsic_width() const override;
virtual Optional<CSSPixels> intrinsic_height() const override;
virtual Optional<CSSPixelFraction> intrinsic_aspect_ratio() const override;
virtual RefPtr<Gfx::ImmutableBitmap> current_image_bitmap(Gfx::IntSize = {}) const override;
virtual void set_visible_in_viewport(bool) override;
virtual GC::Ref<DOM::Element const> to_html_element() const override { return *this; }
GC::Ptr<DecodedImageData> image_data() const;
Representation m_representation { Representation::Unknown };
GC::Ptr<SharedResourceRequest> m_resource_request;
GC::Ptr<DOM::DocumentObserver> m_document_observer;
Optional<DOM::DocumentLoadEventDelayer> m_document_load_event_delayer_for_object_representation_task;
Optional<DOM::DocumentLoadEventDelayer> m_document_load_event_delayer_for_resource_load;
};
}
namespace Web::DOM {
template<>
inline bool Node::fast_is<HTML::HTMLObjectElement>() const { return is_html_object_element(); }
}