/*
* Copyright (c) 2018-2024, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021-2023, Sam Atkins <atkinssj@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibWeb/CSS/Parser/Parser.h>
#include <LibWeb/CSS/SelectorEngine.h>
#include <LibWeb/CSS/StyleProperties.h>
#include <LibWeb/CSS/ValueID.h>
#include <LibWeb/DOM/Attr.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/DOM/Element.h>
#include <LibWeb/DOM/NamedNodeMap.h>
#include <LibWeb/DOM/Text.h>
#include <LibWeb/HTML/AttributeNames.h>
#include <LibWeb/HTML/HTMLAnchorElement.h>
#include <LibWeb/HTML/HTMLAreaElement.h>
#include <LibWeb/HTML/HTMLButtonElement.h>
#include <LibWeb/HTML/HTMLDetailsElement.h>
#include <LibWeb/HTML/HTMLDialogElement.h>
#include <LibWeb/HTML/HTMLFieldSetElement.h>
#include <LibWeb/HTML/HTMLHtmlElement.h>
#include <LibWeb/HTML/HTMLInputElement.h>
#include <LibWeb/HTML/HTMLMediaElement.h>
#include <LibWeb/HTML/HTMLOptGroupElement.h>
#include <LibWeb/HTML/HTMLOptionElement.h>
#include <LibWeb/HTML/HTMLProgressElement.h>
#include <LibWeb/HTML/HTMLSelectElement.h>
#include <LibWeb/HTML/HTMLTextAreaElement.h>
#include <LibWeb/Infra/Strings.h>
#include <LibWeb/Namespace.h>
namespace Web::SelectorEngine {
// https://drafts.csswg.org/selectors-4/#the-lang-pseudo
static inline bool matches_lang_pseudo_class(DOM::Element const& element, Vector<FlyString> const& languages)
{
FlyString element_language;
for (auto const* e = &element; e; e = e->parent_element()) {
auto lang = e->attribute(HTML::AttributeNames::lang);
if (lang.has_value()) {
element_language = lang.release_value();
break;
}
}
if (element_language.is_empty())
return false;
// FIXME: This is ad-hoc. Implement a proper language range matching algorithm as recommended by BCP47.
for (auto const& language : languages) {
if (language.is_empty())
continue;
if (language == "*"sv)
return true;
if (!element_language.to_string().contains('-') && Infra::is_ascii_case_insensitive_match(element_language, language))
return true;
auto parts = element_language.to_string().split_limit('-', 2).release_value_but_fixme_should_propagate_errors();
if (Infra::is_ascii_case_insensitive_match(parts[0], language))
return true;
}
return false;
}
// https://html.spec.whatwg.org/multipage/semantics-other.html#selector-link
static inline bool matches_link_pseudo_class(DOM::Element const& element)
{
// All a elements that have an href attribute, and all area elements that have an href attribute, must match one of :link and :visited.
if (!is<HTML::HTMLAnchorElement>(element) && !is<HTML::HTMLAreaElement>(element))
return false;
return element.has_attribute(HTML::AttributeNames::href);
}
static inline bool matches_hover_pseudo_class(DOM::Element const& element)
{
auto* hovered_node = element.document().hovered_node();
if (!hovered_node)
return false;
if (&element == hovered_node)
return true;
return element.is_ancestor_of(*hovered_node);
}
// https://html.spec.whatwg.org/multipage/semantics-other.html#selector-checked
static inline bool matches_checked_pseudo_class(DOM::Element const& element)
{
// The :checked pseudo-class must match any element falling into one of the following categories:
// - input elements whose type attribute is in the Checkbox state and whose checkedness state is true
// - input elements whose type attribute is in the Radio Button state and whose checkedness state is true
if (is<HTML::HTMLInputElement>(element)) {
auto const& input_element = static_cast<HTML::HTMLInputElement const&>(element);
switch (input_element.type_state()) {
case HTML::HTMLInputElement::TypeAttributeState::Checkbox:
case HTML::HTMLInputElement::TypeAttributeState::RadioButton:
return static_cast<HTML::HTMLInputElement const&>(element).checked();
default:
return false;
}
}
// - option elements whose selectedness is true
if (is<HTML::HTMLOptionElement>(element)) {
return static_cast<HTML::HTMLOptionElement const&>(element).selected();
}
return false;
}
// https://html.spec.whatwg.org/multipage/semantics-other.html#selector-indeterminate
static inline bool matches_indeterminate_pseudo_class(DOM::Element const& element)
{
// The :indeterminate pseudo-class must match any element falling into one of the following categories:
// - input elements whose type attribute is in the Checkbox state and whose indeterminate IDL attribute is set to true
// FIXME: - input elements whose type attribute is in the Radio Button state and whose radio button group contains no input elements whose checkedness state is true.
if (is<HTML::HTMLInputElement>(element)) {
auto const& input_element = static_cast<HTML::HTMLInputElement const&>(element);
switch (input_element.type_state()) {
case HTML::HTMLInputElement::TypeAttributeState::Checkbox:
return input_element.indeterminate();
default:
return false;
}
}
// - progress elements with no value content attribute
if (is<HTML::HTMLProgressElement>(element)) {
return !element.has_attribute(HTML::AttributeNames::value);
}
return false;
}
static inline bool matches_attribute(CSS::Selector::SimpleSelector::Attribute const& attribute, [[maybe_unused]] Optional<CSS::CSSStyleSheet const&> style_sheet_for_rule, DOM::Element const& element)
{
// FIXME: Check the attribute's namespace, once we support that in DOM::Element!
auto const& attribute_name = attribute.qualified_name.name.name;
auto const* attr = element.namespace_uri() == Namespace::HTML ? element.attributes()->get_attribute_with_lowercase_qualified_name(attribute_name)
: element.attributes()->get_attribute(attribute_name);
if (attribute.match_type == CSS::Selector::SimpleSelector::Attribute::MatchType::HasAttribute) {
// Early way out in case of an attribute existence selector.
return attr != nullptr;
}
if (!attr)
return false;
auto const case_insensitive_match = (attribute.case_type == CSS::Selector::SimpleSelector::Attribute::CaseType::CaseInsensitiveMatch);
auto const case_sensitivity = case_insensitive_match
? CaseSensitivity::CaseInsensitive
: CaseSensitivity::CaseSensitive;
switch (attribute.match_type) {
case CSS::Selector::SimpleSelector::Attribute::MatchType::ExactValueMatch:
return case_insensitive_match
? Infra::is_ascii_case_insensitive_match(attr->value(), attribute.value)
: attr->value() == attribute.value;
case CSS::Selector::SimpleSelector::Attribute::MatchType::ContainsWord: {
if (attribute.value.is_empty()) {
// This selector is always false is match value is empty.
return false;
}
auto const& attribute_value = attr->value();
auto const view = attribute_value.bytes_as_string_view().split_view(' ');
auto const size = view.size();
for (size_t i = 0; i < size; ++i) {
auto const value = view.at(i);
if (case_insensitive_match
? Infra::is_ascii_case_insensitive_match(value, attribute.value)
: value == attribute.value) {
return true;
}
}
return false;
}
case CSS::Selector::SimpleSelector::Attribute::MatchType::ContainsString:
return !attribute.value.is_empty()
&& attr->value().contains(attribute.value, case_sensitivity);
case CSS::Selector::SimpleSelector::Attribute::MatchType::StartsWithSegment: {
auto const& element_attr_value = attr->value();
if (element_attr_value.is_empty()) {
// If the attribute value on element is empty, the selector is true
// if the match value is also empty and false otherwise.
return attribute.value.is_empty();
}
if (attribute.value.is_empty()) {
return false;
}
auto segments = element_attr_value.bytes_as_string_view().split_view('-');
return case_insensitive_match
? Infra::is_ascii_case_insensitive_match(segments.first(), attribute.value)
: segments.first() == attribute.value;
}
case CSS::Selector::SimpleSelector::Attribute::MatchType::StartsWithString:
return !attribute.value.is_empty()
&& attr->value().bytes_as_string_view().starts_with(attribute.value, case_sensitivity);
case CSS::Selector::SimpleSelector::Attribute::MatchType::EndsWithString:
return !attribute.value.is_empty()
&& attr->value().bytes_as_string_view().ends_with(attribute.value, case_sensitivity);
default:
break;
}
return false;
}
static inline DOM::Element const* previous_sibling_with_same_tag_name(DOM::Element const& element)
{
for (auto const* sibling = element.previous_element_sibling(); sibling; sibling = sibling->previous_element_sibling()) {
if (sibling->tag_name() == element.tag_name())
return sibling;
}
return nullptr;
}
static inline DOM::Element const* next_sibling_with_same_tag_name(DOM::Element const& element)
{
for (auto const* sibling = element.next_element_sibling(); sibling; sibling = sibling->next_element_sibling()) {
if (sibling->tag_name() == element.tag_name())
return sibling;
}
return nullptr;
}
// https://html.spec.whatwg.org/multipage/semantics-other.html#selector-read-write
static bool matches_read_write_pseudo_class(DOM::Element const& element)
{
// The :read-write pseudo-class must match any element falling into one of the following categories,
// which for the purposes of Selectors are thus considered user-alterable: [SELECTORS]
// - input elements to which the readonly attribute applies, and that are mutable
// (i.e. that do not have the readonly attribute specified and that are not disabled)
if (is<HTML::HTMLInputElement>(element)) {
auto& input_element = static_cast<HTML::HTMLInputElement const&>(element);
if (input_element.has_attribute(HTML::AttributeNames::readonly))
return false;
if (!input_element.enabled())
return false;
return true;
}
// - textarea elements that do not have a readonly attribute, and that are not disabled
if (is<HTML::HTMLTextAreaElement>(element)) {
auto& input_element = static_cast<HTML::HTMLTextAreaElement const&>(element);
if (input_element.has_attribute(HTML::AttributeNames::readonly))
return false;
if (!input_element.enabled())
return false;
return true;
}
// - elements that are editing hosts or editable and are neither input elements nor textarea elements
return element.is_editable();
}
// https://www.w3.org/TR/selectors-4/#open-state
static bool matches_open_state_pseudo_class(DOM::Element const& element, bool open)
{
// The :open pseudo-class represents an element that has both “open” and “closed” states,
// and which is currently in the “open” state.
// The :closed pseudo-class represents an element that has both “open” and “closed” states,
// and which is currently in the closed state.
// NOTE: Spec specifically suggests supporting <details>, <dialog>, and <select>.
// There may be others we want to treat as open or closed.
if (is<HTML::HTMLDetailsElement>(element) || is<HTML::HTMLDialogElement>(element))
return open == element.has_attribute(HTML::AttributeNames::open);
if (is<HTML::HTMLSelectElement>(element))
return open == static_cast<HTML::HTMLSelectElement const&>(element).is_open();
return false;
}
static inline bool matches_pseudo_class(CSS::Selector::SimpleSelector::PseudoClassSelector const& pseudo_class, Optional<CSS::CSSStyleSheet const&> style_sheet_for_rule, DOM::Element const& element, JS::GCPtr<DOM::ParentNode const> scope)
{
switch (pseudo_class.type) {
case CSS::PseudoClass::Link:
case CSS::PseudoClass::AnyLink:
// NOTE: AnyLink should match whether the link is visited or not, so if we ever start matching
// :visited, we'll need to handle these differently.
return matches_link_pseudo_class(element);
case CSS::PseudoClass::LocalLink: {
// The :local-link pseudo-class allows authors to style hyperlinks based on the users current location
// within a site. It represents an element that is the source anchor of a hyperlink whose target’s
// absolute URL matches the element’s own document URL. If the hyperlink’s target includes a fragment
// URL, then the fragment URL of the current URL must also match; if it does not, then the fragment
// URL portion of the current URL is not taken into account in the comparison.
if (!matches_link_pseudo_class(element))
return false;
auto document_url = element.document().url();
URL::URL target_url = element.document().parse_url(element.attribute(HTML::AttributeNames::href).value_or({}));
if (target_url.fragment().has_value())
return document_url.equals(target_url, URL::ExcludeFragment::No);
return document_url.equals(target_url, URL::ExcludeFragment::Yes);
}
case CSS::PseudoClass::Visited:
// FIXME: Maybe match this selector sometimes?
return false;
case CSS::PseudoClass::Active:
return element.is_active();
case CSS::PseudoClass::Hover:
return matches_hover_pseudo_class(element);
case CSS::PseudoClass::Focus:
return element.is_focused();
case CSS::PseudoClass::FocusVisible:
// FIXME: We should only apply this when a visible focus is useful. Decide when that is!
return element.is_focused();
case CSS::PseudoClass::FocusWithin: {
auto* focused_element = element.document().focused_element();
return focused_element && element.is_inclusive_ancestor_of(*focused_element);
}
case CSS::PseudoClass::FirstChild:
return !element.previous_element_sibling();
case CSS::PseudoClass::LastChild:
return !element.next_element_sibling();
case CSS::PseudoClass::OnlyChild:
return !(element.previous_element_sibling() || element.next_element_sibling());
case CSS::PseudoClass::Empty: {
if (!element.has_children())
return true;
if (element.first_child_of_type<DOM::Element>())
return false;
// NOTE: CSS Selectors level 4 changed ":empty" to also match whitespace-only text nodes.
// However, none of the major browser supports this yet, so let's just hang back until they do.
bool has_nonempty_text_child = false;
element.for_each_child_of_type<DOM::Text>([&](auto const& text_child) {
if (!text_child.data().is_empty()) {
has_nonempty_text_child = true;
return IterationDecision::Break;
}
return IterationDecision::Continue;
});
return !has_nonempty_text_child;
}
case CSS::PseudoClass::Root:
return is<HTML::HTMLHtmlElement>(element);
case CSS::PseudoClass::Host:
// FIXME: Implement :host selector.
return false;
case CSS::PseudoClass::Scope:
return scope ? &element == scope : is<HTML::HTMLHtmlElement>(element);
case CSS::PseudoClass::FirstOfType:
return !previous_sibling_with_same_tag_name(element);
case CSS::PseudoClass::LastOfType:
return !next_sibling_with_same_tag_name(element);
case CSS::PseudoClass::OnlyOfType:
return !previous_sibling_with_same_tag_name(element) && !next_sibling_with_same_tag_name(element);
case CSS::PseudoClass::Lang:
return matches_lang_pseudo_class(element, pseudo_class.languages);
case CSS::PseudoClass::Disabled:
// https://html.spec.whatwg.org/multipage/semantics-other.html#selector-disabled
// The :disabled pseudo-class must match any element that is actually disabled.
return element.is_actually_disabled();
case CSS::PseudoClass::Enabled:
// https://html.spec.whatwg.org/multipage/semantics-other.html#selector-enabled
// The :enabled pseudo-class must match any button, input, select, textarea, optgroup, option, fieldset element, or form-associated custom element that is not actually disabled.
return (is<HTML::HTMLButtonElement>(element) || is<HTML::HTMLInputElement>(element) || is<HTML::HTMLSelectElement>(element) || is<HTML::HTMLTextAreaElement>(element) || is<HTML::HTMLOptGroupElement>(element) || is<HTML::HTMLOptionElement>(element) || is<HTML::HTMLFieldSetElement>(element))
&& !element.is_actually_disabled();
case CSS::PseudoClass::Checked:
return matches_checked_pseudo_class(element);
case CSS::PseudoClass::Indeterminate:
return matches_indeterminate_pseudo_class(element);
case CSS::PseudoClass::Defined:
return element.is_defined();
case CSS::PseudoClass::Is:
case CSS::PseudoClass::Where:
for (auto& selector : pseudo_class.argument_selector_list) {
if (matches(selector, style_sheet_for_rule, element))
return true;
}
return false;
case CSS::PseudoClass::Not:
for (auto& selector : pseudo_class.argument_selector_list) {
if (matches(selector, style_sheet_for_rule, element))
return false;
}
return true;
case CSS::PseudoClass::NthChild:
case CSS::PseudoClass::NthLastChild:
case CSS::PseudoClass::NthOfType:
case CSS::PseudoClass::NthLastOfType: {
auto const step_size = pseudo_class.nth_child_pattern.step_size;
auto const offset = pseudo_class.nth_child_pattern.offset;
if (step_size == 0 && offset == 0)
return false; // "If both a and b are equal to zero, the pseudo-class represents no element in the document tree."
auto const* parent = element.parent_element();
if (!parent)
return false;
auto matches_selector_list = [&style_sheet_for_rule](CSS::SelectorList const& list, DOM::Element const& element) {
if (list.is_empty())
return true;
for (auto const& child_selector : list) {
if (matches(child_selector, style_sheet_for_rule, element)) {
return true;
}
}
return false;
};
int index = 1;
switch (pseudo_class.type) {
case CSS::PseudoClass::NthChild: {
if (!matches_selector_list(pseudo_class.argument_selector_list, element))
return false;
for (auto* child = parent->first_child_of_type<DOM::Element>(); child && child != &element; child = child->next_element_sibling()) {
if (matches_selector_list(pseudo_class.argument_selector_list, *child))
++index;
}
break;
}
case CSS::PseudoClass::NthLastChild: {
if (!matches_selector_list(pseudo_class.argument_selector_list, element))
return false;
for (auto* child = parent->last_child_of_type<DOM::Element>(); child && child != &element; child = child->previous_element_sibling()) {
if (matches_selector_list(pseudo_class.argument_selector_list, *child))
++index;
}
break;
}
case CSS::PseudoClass::NthOfType: {
for (auto* child = previous_sibling_with_same_tag_name(element); child; child = previous_sibling_with_same_tag_name(*child))
++index;
break;
}
case CSS::PseudoClass::NthLastOfType: {
for (auto* child = next_sibling_with_same_tag_name(element); child; child = next_sibling_with_same_tag_name(*child))
++index;
break;
}
default:
VERIFY_NOT_REACHED();
}
// When "step_size == -1", selector represents first "offset" elements in document tree.
if (step_size == -1)
return !(offset <= 0 || index > offset);
// When "step_size == 1", selector represents last "offset" elements in document tree.
if (step_size == 1)
return !(offset < 0 || index < offset);
// When "step_size == 0", selector picks only the "offset" element.
if (step_size == 0)
return index == offset;
// If both are negative, nothing can match.
if (step_size < 0 && offset < 0)
return false;
// Like "a % b", but handles negative integers correctly.
auto const canonical_modulo = [](int a, int b) -> int {
int c = a % b;
if ((c < 0 && b > 0) || (c > 0 && b < 0)) {
c += b;
}
return c;
};
// When "step_size < 0", we start at "offset" and count backwards.
if (step_size < 0)
return index <= offset && canonical_modulo(index - offset, -step_size) == 0;
// Otherwise, we start at "offset" and count forwards.
return index >= offset && canonical_modulo(index - offset, step_size) == 0;
}
case CSS::PseudoClass::Playing: {
if (!is<HTML::HTMLMediaElement>(element))
return false;
auto const& media_element = static_cast<HTML::HTMLMediaElement const&>(element);
return !media_element.paused();
}
case CSS::PseudoClass::Paused: {
if (!is<HTML::HTMLMediaElement>(element))
return false;
auto const& media_element = static_cast<HTML::HTMLMediaElement const&>(element);
return media_element.paused();
}
case CSS::PseudoClass::Seeking: {
if (!is<HTML::HTMLMediaElement>(element))
return false;
auto const& media_element = static_cast<HTML::HTMLMediaElement const&>(element);
return media_element.seeking();
}
case CSS::PseudoClass::Muted: {
if (!is<HTML::HTMLMediaElement>(element))
return false;
auto const& media_element = static_cast<HTML::HTMLMediaElement const&>(element);
return media_element.muted();
}
case CSS::PseudoClass::VolumeLocked: {
// FIXME: Currently we don't allow the user to specify an override volume, so this is always false.
// Once we do, implement this!
return false;
}
case CSS::PseudoClass::Buffering: {
if (!is<HTML::HTMLMediaElement>(element))
return false;
auto const& media_element = static_cast<HTML::HTMLMediaElement const&>(element);
return media_element.blocked();
}
case CSS::PseudoClass::Stalled: {
if (!is<HTML::HTMLMediaElement>(element))
return false;
auto const& media_element = static_cast<HTML::HTMLMediaElement const&>(element);
return media_element.stalled();
}
case CSS::PseudoClass::Target:
return element.is_target();
case CSS::PseudoClass::TargetWithin: {
auto* target_element = element.document().target_element();
if (!target_element)
return false;
return element.is_inclusive_ancestor_of(*target_element);
}
case CSS::PseudoClass::Dir: {
// "Values other than ltr and rtl are not invalid, but do not match anything."
// - https://www.w3.org/TR/selectors-4/#the-dir-pseudo
if (!first_is_one_of(pseudo_class.identifier, CSS::ValueID::Ltr, CSS::ValueID::Rtl))
return false;
switch (element.directionality()) {
case DOM::Element::Directionality::Ltr:
return pseudo_class.identifier == CSS::ValueID::Ltr;
case DOM::Element::Directionality::Rtl:
return pseudo_class.identifier == CSS::ValueID::Rtl;
}
VERIFY_NOT_REACHED();
}
case CSS::PseudoClass::ReadOnly:
return !matches_read_write_pseudo_class(element);
case CSS::PseudoClass::ReadWrite:
return matches_read_write_pseudo_class(element);
case CSS::PseudoClass::PlaceholderShown: {
// https://html.spec.whatwg.org/multipage/semantics-other.html#selector-placeholder-shown
// The :placeholder-shown pseudo-class must match any element falling into one of the following categories:
// - input elements that have a placeholder attribute whose value is currently being presented to the user.
if (is<HTML::HTMLInputElement>(element) && element.has_attribute(HTML::AttributeNames::placeholder)) {
auto const& input_element = static_cast<HTML::HTMLInputElement const&>(element);
return input_element.placeholder_element() && input_element.placeholder_value().has_value();
}
// - FIXME: textarea elements that have a placeholder attribute whose value is currently being presented to the user.
return false;
}
case CSS::PseudoClass::Open:
case CSS::PseudoClass::Closed:
return matches_open_state_pseudo_class(element, pseudo_class.type == CSS::PseudoClass::Open);
case CSS::PseudoClass::Modal: {
// https://drafts.csswg.org/selectors/#modal-state
if (is<HTML::HTMLDialogElement>(element)) {
auto const& dialog_element = static_cast<HTML::HTMLDialogElement const&>(element);
return dialog_element.is_modal();
}
// FIXME: fullscreen elements are also modal.
return false;
}
}
return false;
}
static ALWAYS_INLINE bool matches_namespace(
CSS::Selector::SimpleSelector::QualifiedName const& qualified_name,
DOM::Element const& element,
Optional<CSS::CSSStyleSheet const&> style_sheet_for_rule)
{
switch (qualified_name.namespace_type) {
case CSS::Selector::SimpleSelector::QualifiedName::NamespaceType::Default:
// "if no default namespace has been declared for selectors, this is equivalent to *|E."
if (!style_sheet_for_rule.has_value() || !style_sheet_for_rule->default_namespace_rule())
return true;
// "Otherwise it is equivalent to ns|E where ns is the default namespace."
return element.namespace_uri() == style_sheet_for_rule->default_namespace_rule()->namespace_uri();
case CSS::Selector::SimpleSelector::QualifiedName::NamespaceType::None:
// "elements with name E without a namespace"
return !element.namespace_uri().has_value();
case CSS::Selector::SimpleSelector::QualifiedName::NamespaceType::Any:
// "elements with name E in any namespace, including those without a namespace"
return true;
case CSS::Selector::SimpleSelector::QualifiedName::NamespaceType::Named:
// "elements with name E in namespace ns"
// Unrecognized namespace prefixes are invalid, so don't match.
// (We can't detect this at parse time, since a namespace rule may be inserted later.)
// So, if we don't have a context to look up namespaces from, we fail to match.
if (!style_sheet_for_rule.has_value())
return false;
auto selector_namespace = style_sheet_for_rule->namespace_uri(qualified_name.namespace_);
return selector_namespace.has_value() && selector_namespace.value() == element.namespace_uri();
}
VERIFY_NOT_REACHED();
}
static inline bool matches(CSS::Selector::SimpleSelector const& component, Optional<CSS::CSSStyleSheet const&> style_sheet_for_rule, DOM::Element const& element, JS::GCPtr<DOM::ParentNode const> scope)
{
switch (component.type) {
case CSS::Selector::SimpleSelector::Type::Universal:
case CSS::Selector::SimpleSelector::Type::TagName: {
auto const& qualified_name = component.qualified_name();
// Reject if the tag name doesn't match
if (component.type == CSS::Selector::SimpleSelector::Type::TagName) {
// See https://html.spec.whatwg.org/multipage/semantics-other.html#case-sensitivity-of-selectors
if (element.document().document_type() == DOM::Document::Type::HTML) {
if (qualified_name.name.lowercase_name != element.local_name())
return false;
} else if (!Infra::is_ascii_case_insensitive_match(qualified_name.name.name, element.local_name())) {
return false;
}
}
return matches_namespace(qualified_name, element, style_sheet_for_rule);
}
case CSS::Selector::SimpleSelector::Type::Id:
return component.name() == element.id();
case CSS::Selector::SimpleSelector::Type::Class:
return element.has_class(component.name());
case CSS::Selector::SimpleSelector::Type::Attribute:
return matches_attribute(component.attribute(), style_sheet_for_rule, element);
case CSS::Selector::SimpleSelector::Type::PseudoClass:
return matches_pseudo_class(component.pseudo_class(), style_sheet_for_rule, element, scope);
case CSS::Selector::SimpleSelector::Type::PseudoElement:
// Pseudo-element matching/not-matching is handled in the top level matches().
return true;
default:
VERIFY_NOT_REACHED();
}
}
static inline bool matches(CSS::Selector const& selector, Optional<CSS::CSSStyleSheet const&> style_sheet_for_rule, int component_list_index, DOM::Element const& element, JS::GCPtr<DOM::ParentNode const> scope)
{
auto& relative_selector = selector.compound_selectors()[component_list_index];
for (auto& simple_selector : relative_selector.simple_selectors) {
if (!matches(simple_selector, style_sheet_for_rule, element, scope))
return false;
}
switch (relative_selector.combinator) {
case CSS::Selector::Combinator::None:
return true;
case CSS::Selector::Combinator::Descendant:
VERIFY(component_list_index != 0);
for (auto* ancestor = element.parent(); ancestor; ancestor = ancestor->parent()) {
if (!is<DOM::Element>(*ancestor))
continue;
if (matches(selector, style_sheet_for_rule, component_list_index - 1, static_cast<DOM::Element const&>(*ancestor), scope))
return true;
}
return false;
case CSS::Selector::Combinator::ImmediateChild:
VERIFY(component_list_index != 0);
if (!element.parent() || !is<DOM::Element>(*element.parent()))
return false;
return matches(selector, style_sheet_for_rule, component_list_index - 1, static_cast<DOM::Element const&>(*element.parent()), scope);
case CSS::Selector::Combinator::NextSibling:
VERIFY(component_list_index != 0);
if (auto* sibling = element.previous_element_sibling())
return matches(selector, style_sheet_for_rule, component_list_index - 1, *sibling, scope);
return false;
case CSS::Selector::Combinator::SubsequentSibling:
VERIFY(component_list_index != 0);
for (auto* sibling = element.previous_element_sibling(); sibling; sibling = sibling->previous_element_sibling()) {
if (matches(selector, style_sheet_for_rule, component_list_index - 1, *sibling, scope))
return true;
}
return false;
case CSS::Selector::Combinator::Column:
TODO();
}
VERIFY_NOT_REACHED();
}
bool matches(CSS::Selector const& selector, Optional<CSS::CSSStyleSheet const&> style_sheet_for_rule, DOM::Element const& element, Optional<CSS::Selector::PseudoElement::Type> pseudo_element, JS::GCPtr<DOM::ParentNode const> scope)
{
VERIFY(!selector.compound_selectors().is_empty());
if (pseudo_element.has_value() && selector.pseudo_element().has_value() && selector.pseudo_element().value().type() != pseudo_element)
return false;
if (!pseudo_element.has_value() && selector.pseudo_element().has_value())
return false;
return matches(selector, style_sheet_for_rule, selector.compound_selectors().size() - 1, element, scope);
}
static bool fast_matches_simple_selector(CSS::Selector::SimpleSelector const& simple_selector, Optional<CSS::CSSStyleSheet const&> style_sheet_for_rule, DOM::Element const& element)
{
switch (simple_selector.type) {
case CSS::Selector::SimpleSelector::Type::Universal:
return matches_namespace(simple_selector.qualified_name(), element, style_sheet_for_rule);
case CSS::Selector::SimpleSelector::Type::TagName:
if (element.document().document_type() == DOM::Document::Type::HTML) {
if (simple_selector.qualified_name().name.lowercase_name != element.local_name())
return false;
} else if (!Infra::is_ascii_case_insensitive_match(simple_selector.qualified_name().name.name, element.local_name())) {
return false;
}
return matches_namespace(simple_selector.qualified_name(), element, style_sheet_for_rule);
case CSS::Selector::SimpleSelector::Type::Class:
return element.has_class(simple_selector.name());
case CSS::Selector::SimpleSelector::Type::Id:
return simple_selector.name() == element.id();
case CSS::Selector::SimpleSelector::Type::Attribute:
return matches_attribute(simple_selector.attribute(), style_sheet_for_rule, element);
case CSS::Selector::SimpleSelector::Type::PseudoClass:
return matches_pseudo_class(simple_selector.pseudo_class(), style_sheet_for_rule, element, nullptr);
default:
VERIFY_NOT_REACHED();
}
}
static bool fast_matches_compound_selector(CSS::Selector::CompoundSelector const& compound_selector, Optional<CSS::CSSStyleSheet const&> style_sheet_for_rule, DOM::Element const& element)
{
for (auto const& simple_selector : compound_selector.simple_selectors) {
if (!fast_matches_simple_selector(simple_selector, style_sheet_for_rule, element))
return false;
}
return true;
}
bool fast_matches(CSS::Selector const& selector, Optional<CSS::CSSStyleSheet const&> style_sheet_for_rule, DOM::Element const& element_to_match)
{
DOM::Element const* current = &element_to_match;
ssize_t compound_selector_index = selector.compound_selectors().size() - 1;
if (!fast_matches_compound_selector(selector.compound_selectors().last(), style_sheet_for_rule, *current))
return false;
// NOTE: If we fail after following a child combinator, we may need to backtrack
// to the last matched descendant. We store the state here.
struct {
JS::GCPtr<DOM::Element const> element;
ssize_t compound_selector_index = 0;
} backtrack_state;
for (;;) {
// NOTE: There should always be a leftmost compound selector without combinator that kicks us out of this loop.
VERIFY(compound_selector_index >= 0);
auto const* compound_selector = &selector.compound_selectors()[compound_selector_index];
switch (compound_selector->combinator) {
case CSS::Selector::Combinator::None:
return true;
case CSS::Selector::Combinator::Descendant:
backtrack_state = { current->parent_element(), compound_selector_index };
compound_selector = &selector.compound_selectors()[--compound_selector_index];
for (current = current->parent_element(); current; current = current->parent_element()) {
if (fast_matches_compound_selector(*compound_selector, style_sheet_for_rule, *current))
break;
}
if (!current)
return false;
break;
case CSS::Selector::Combinator::ImmediateChild:
compound_selector = &selector.compound_selectors()[--compound_selector_index];
current = current->parent_element();
if (!current)
return false;
if (!fast_matches_compound_selector(*compound_selector, style_sheet_for_rule, *current)) {
if (backtrack_state.element) {
current = backtrack_state.element;
compound_selector_index = backtrack_state.compound_selector_index;
continue;
}
return false;
}
break;
default:
VERIFY_NOT_REACHED();
}
}
}
bool can_use_fast_matches(CSS::Selector const& selector)
{
for (auto const& compound_selector : selector.compound_selectors()) {
if (compound_selector.combinator != CSS::Selector::Combinator::None
&& compound_selector.combinator != CSS::Selector::Combinator::Descendant
&& compound_selector.combinator != CSS::Selector::Combinator::ImmediateChild) {
return false;
}
for (auto const& simple_selector : compound_selector.simple_selectors) {
if (simple_selector.type == CSS::Selector::SimpleSelector::Type::PseudoClass) {
auto const pseudo_class = simple_selector.pseudo_class().type;
if (pseudo_class != CSS::PseudoClass::FirstChild
&& pseudo_class != CSS::PseudoClass::LastChild
&& pseudo_class != CSS::PseudoClass::OnlyChild
&& pseudo_class != CSS::PseudoClass::Hover
&& pseudo_class != CSS::PseudoClass::Active
&& pseudo_class != CSS::PseudoClass::Focus
&& pseudo_class != CSS::PseudoClass::FocusVisible
&& pseudo_class != CSS::PseudoClass::FocusWithin
&& pseudo_class != CSS::PseudoClass::Link
&& pseudo_class != CSS::PseudoClass::AnyLink
&& pseudo_class != CSS::PseudoClass::Visited
&& pseudo_class != CSS::PseudoClass::LocalLink
&& pseudo_class != CSS::PseudoClass::Empty
&& pseudo_class != CSS::PseudoClass::Root
&& pseudo_class != CSS::PseudoClass::Enabled
&& pseudo_class != CSS::PseudoClass::Disabled
&& pseudo_class != CSS::PseudoClass::Checked) {
return false;
}
} else if (simple_selector.type != CSS::Selector::SimpleSelector::Type::TagName
&& simple_selector.type != CSS::Selector::SimpleSelector::Type::Universal
&& simple_selector.type != CSS::Selector::SimpleSelector::Type::Class
&& simple_selector.type != CSS::Selector::SimpleSelector::Type::Id
&& simple_selector.type != CSS::Selector::SimpleSelector::Type::Attribute) {
return false;
}
}
}
return true;
}
}