ladybird/Libraries/LibWeb/CSS/SelectorEngine.h

/*
 * Copyright (c) 2018-2024, Andreas Kling <andreas@ladybird.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <LibWeb/CSS/Selector.h>
#include <LibWeb/DOM/Element.h>

namespace Web::SelectorEngine {

enum class SelectorKind {
    Normal,
    Relative,
};

struct MatchContext {
    GC::Ptr<CSS::CSSStyleSheet const> style_sheet_for_rule {};
    GC::Ptr<DOM::Element const> subject {};
    bool collect_per_element_selector_involvement_metadata { false };
    CSS::PseudoClassBitmap attempted_pseudo_class_matches {};
};

bool matches(CSS::Selector const&, DOM::Element const&, GC::Ptr<DOM::Element const> shadow_host, MatchContext& context, Optional<CSS::PseudoElement> = {}, GC::Ptr<DOM::ParentNode const> scope = {}, SelectorKind selector_kind = SelectorKind::Normal, GC::Ptr<DOM::Element const> anchor = nullptr);

}
Meta: Add license header to source files As suggested by Joshua, this commit adds the 2-clause BSD license as a comment block to the top of every source file. For the first pass, I've just added myself for simplicity. I encourage everyone to add themselves as copyright holders of any file they've added or modified in some significant way. If I've added myself in error somewhere, feel free to replace it with the appropriate copyright holder instead. Going forward, all new source files should include a license header. 2020-01-18 09:38:21 +01:00			`/*`
Meta: Update my e-mail address everywhere 2024-10-04 13:19:50 +02:00			`* Copyright (c) 2018-2024, Andreas Kling <andreas@ladybird.org>`
Meta: Add license header to source files As suggested by Joshua, this commit adds the 2-clause BSD license as a comment block to the top of every source file. For the first pass, I've just added myself for simplicity. I encourage everyone to add themselves as copyright holders of any file they've added or modified in some significant way. If I've added myself in error somewhere, feel free to replace it with the appropriate copyright holder instead. Going forward, all new source files should include a license header. 2020-01-18 09:38:21 +01:00			`*`
Everything: Move to SPDX license identifiers in all files. SPDX License Identifiers are a more compact / standardized way of representing file license information. See: https://spdx.dev/resources/use/#identifiers This was done with the `ambr` search and replace tool. ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt * 2021-04-22 01:24:48 -07:00			`* SPDX-License-Identifier: BSD-2-Clause`
Meta: Add license header to source files As suggested by Joshua, this commit adds the 2-clause BSD license as a comment block to the top of every source file. For the first pass, I've just added myself for simplicity. I encourage everyone to add themselves as copyright holders of any file they've added or modified in some significant way. If I've added myself in error somewhere, feel free to replace it with the appropriate copyright holder instead. Going forward, all new source files should include a license header. 2020-01-18 09:38:21 +01:00			`*/`

LibHTML: Move selector matching into a SelectorEngine namespace 2019-10-08 15:33:58 +02:00			`#pragma once`

LibWeb: Rename directory LibHTML => LibWeb Let's rename this to LibWeb since it aims to provide more parts of the web platform than just HTML. :^) 2020-03-07 10:32:51 +01:00			`#include <LibWeb/CSS/Selector.h>`
LibWeb: Move DOM classes into the Web::DOM namespace LibWeb keeps growing and the Web namespace is filling up fast. Let's put DOM stuff into Web::DOM, just like we already started doing with SVG stuff in Web::SVG. 2020-07-26 19:37:56 +02:00			`#include <LibWeb/DOM/Element.h>`
LibHTML: Move selector matching into a SelectorEngine namespace 2019-10-08 15:33:58 +02:00
LibWeb: Move DOM classes into the Web::DOM namespace LibWeb keeps growing and the Web namespace is filling up fast. Let's put DOM stuff into Web::DOM, just like we already started doing with SVG stuff in Web::SVG. 2020-07-26 19:37:56 +02:00			`namespace Web::SelectorEngine {`
LibWeb: Move everything into the Web namespace 2020-03-07 10:27:02 +01:00
LibWeb: Implement the `:has()` pseudo-class See https://drafts.csswg.org/selectors-4/#relational. 2024-07-13 09:19:30 -07:00			`enum class SelectorKind {`
			`Normal,`
			`Relative,`
			`};`

LibWeb: Optimize :hover style invalidation Instead of recalculating styles for all nodes in the common ancestor of the new and old hovered nodes' subtrees, this change introduces the following approach: - While calculating ComputedProperties, a flag is saved if any rule applied to an element is affected by the hover state during the execution of SelectorEngine::matches(). - When the hovered element changes, styles are marked for recalculation only if the flag saved in ComputedProperties indicates that the element could be affected by the hover state. 2025-01-03 20:39:25 +03:00			`struct MatchContext {`
			`GC::Ptr<CSS::CSSStyleSheet const> style_sheet_for_rule {};`
LibWeb: Use invalidation sets for :has() invalidation Prior to this change, we invalidated all elements in the document if it used any selectors with :has(). This change aims to improve that by applying a combination of techniques: - Collect metadata for each element if it was matched against a selector with :has() in the subject position. This is needed to invalidate all elements that could be affected by selectors like `div:has(.a:empty)` because they are not covered by the invalidation sets. - Use invalidation sets to invalidate elements that are affected by selectors with :has() in a non-subject position. Selectors like `.a:has(.b) + .c` still cause whole-document invalidation because invalidation sets cover only descendants, not siblings. As a result, there is no performance improvement on github.com due to this limitation. However, youtube.com and discord.com benefit from this change. 2025-01-29 03:31:46 +01:00			`GC::Ptr<DOM::Element const> subject {};`
			`bool collect_per_element_selector_involvement_metadata { false };`
LibWeb: Make :hover invalidation logic reusable for all pseudo classes We achieve this by keeping track of all checked pseudo class selectors in the SelectorEngine code. We also give StyleComputer per-pseudo-class rule caches. 2025-04-17 13:39:30 +02:00			`CSS::PseudoClassBitmap attempted_pseudo_class_matches {};`
LibWeb: Optimize :hover style invalidation Instead of recalculating styles for all nodes in the common ancestor of the new and old hovered nodes' subtrees, this change introduces the following approach: - While calculating ComputedProperties, a flag is saved if any rule applied to an element is affected by the hover state during the execution of SelectorEngine::matches(). - When the hovered element changes, styles are marked for recalculation only if the flag saved in ComputedProperties indicates that the element could be affected by the hover state. 2025-01-03 20:39:25 +03:00			`};`

LibWeb/CSS: Move and rename PseudoElement types to prep for code gen The upcoming generated types will match those for pseudo-classes: A PseudoElementSelector type, that then holds a PseudoElement enum defining what it is. That enum will be at the top level in the Web::CSS namespace. In order to keep the diffs clearer, this commit renames and moves the types, and then a following one will replace the handwritten enum with a generated one. 2025-03-20 16:56:46 +00:00			`bool matches(CSS::Selector const&, DOM::Element const&, GC::Ptr<DOM::Element const> shadow_host, MatchContext& context, Optional<CSS::PseudoElement> = {}, GC::Ptr<DOM::ParentNode const> scope = {}, SelectorKind selector_kind = SelectorKind::Normal, GC::Ptr<DOM::Element const> anchor = nullptr);`
LibWeb: Move everything into the Web namespace 2020-03-07 10:27:02 +01:00
			`}`