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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
use crate::attr::CaseSensitivity;
use crate::bloom::BloomFilter;
use crate::nth_index_cache::NthIndexCache;
use crate::parser::SelectorImpl;
use crate::tree::{Element, OpaqueElement};
/// What kind of selector matching mode we should use.
///
/// There are two modes of selector matching. The difference is only noticeable
/// in presence of pseudo-elements.
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum MatchingMode {
/// Don't ignore any pseudo-element selectors.
Normal,
/// Ignores any stateless pseudo-element selectors in the rightmost sequence
/// of simple selectors.
///
/// This is useful, for example, to match against ::before when you aren't a
/// pseudo-element yourself.
///
/// For example, in presence of `::before:hover`, it would never match, but
/// `::before` would be ignored as in "matching".
///
/// It's required for all the selectors you match using this mode to have a
/// pseudo-element.
ForStatelessPseudoElement,
}
/// The mode to use when matching unvisited and visited links.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum VisitedHandlingMode {
/// All links are matched as if they are unvisted.
AllLinksUnvisited,
/// All links are matched as if they are visited and unvisited (both :link
/// and :visited match).
///
/// This is intended to be used from invalidation code, to be conservative
/// about whether we need to restyle a link.
AllLinksVisitedAndUnvisited,
/// A element's "relevant link" is the element being matched if it is a link
/// or the nearest ancestor link. The relevant link is matched as though it
/// is visited, and all other links are matched as if they are unvisited.
RelevantLinkVisited,
}
impl VisitedHandlingMode {
#[inline]
pub fn matches_visited(&self) -> bool {
matches!(
*self,
VisitedHandlingMode::RelevantLinkVisited |
VisitedHandlingMode::AllLinksVisitedAndUnvisited
)
}
#[inline]
pub fn matches_unvisited(&self) -> bool {
matches!(
*self,
VisitedHandlingMode::AllLinksUnvisited |
VisitedHandlingMode::AllLinksVisitedAndUnvisited
)
}
}
/// Which quirks mode is this document in.
///
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub enum QuirksMode {
/// Quirks mode.
Quirks,
/// Limited quirks mode.
LimitedQuirks,
/// No quirks mode.
NoQuirks,
}
impl QuirksMode {
#[inline]
pub fn classes_and_ids_case_sensitivity(self) -> CaseSensitivity {
match self {
QuirksMode::NoQuirks | QuirksMode::LimitedQuirks => CaseSensitivity::CaseSensitive,
QuirksMode::Quirks => CaseSensitivity::AsciiCaseInsensitive,
}
}
}
/// Data associated with the matching process for a element. This context is
/// used across many selectors for an element, so it's not appropriate for
/// transient data that applies to only a single selector.
pub struct MatchingContext<'a, Impl>
where
Impl: SelectorImpl,
{
/// Input with the matching mode we should use when matching selectors.
matching_mode: MatchingMode,
/// Input with the bloom filter used to fast-reject selectors.
pub bloom_filter: Option<&'a BloomFilter>,
/// An optional cache to speed up nth-index-like selectors.
pub nth_index_cache: Option<&'a mut NthIndexCache>,
/// The element which is going to match :scope pseudo-class. It can be
/// either one :scope element, or the scoping element.
///
/// Note that, although in theory there can be multiple :scope elements,
/// in current specs, at most one is specified, and when there is one,
/// scoping element is not relevant anymore, so we use a single field for
/// them.
///
/// When this is None, :scope will match the root element.
///
pub scope_element: Option<OpaqueElement>,
/// The current shadow host we're collecting :host rules for.
pub current_host: Option<OpaqueElement>,
/// Controls how matching for links is handled.
visited_handling: VisitedHandlingMode,
/// The current nesting level of selectors that we're matching.
///
/// FIXME(emilio): Consider putting the mutable stuff in a Cell, then make
/// MatchingContext immutable again.
nesting_level: usize,
/// Whether we're inside a negation or not.
in_negation: bool,
/// An optional hook function for checking whether a pseudo-element
/// should match when matching_mode is ForStatelessPseudoElement.
pub pseudo_element_matching_fn: Option<&'a dyn Fn(&Impl::PseudoElement) -> bool>,
/// Extra implementation-dependent matching data.
pub extra_data: Impl::ExtraMatchingData,
quirks_mode: QuirksMode,
classes_and_ids_case_sensitivity: CaseSensitivity,
_impl: ::std::marker::PhantomData<Impl>,
}
impl<'a, Impl> MatchingContext<'a, Impl>
where
Impl: SelectorImpl,
{
/// Constructs a new `MatchingContext`.
pub fn new(
matching_mode: MatchingMode,
bloom_filter: Option<&'a BloomFilter>,
nth_index_cache: Option<&'a mut NthIndexCache>,
quirks_mode: QuirksMode,
) -> Self {
Self::new_for_visited(
matching_mode,
bloom_filter,
nth_index_cache,
VisitedHandlingMode::AllLinksUnvisited,
quirks_mode,
)
}
/// Constructs a new `MatchingContext` for use in visited matching.
pub fn new_for_visited(
matching_mode: MatchingMode,
bloom_filter: Option<&'a BloomFilter>,
nth_index_cache: Option<&'a mut NthIndexCache>,
visited_handling: VisitedHandlingMode,
quirks_mode: QuirksMode,
) -> Self {
Self {
matching_mode,
bloom_filter,
visited_handling,
nth_index_cache,
quirks_mode,
classes_and_ids_case_sensitivity: quirks_mode.classes_and_ids_case_sensitivity(),
scope_element: None,
current_host: None,
nesting_level: 0,
in_negation: false,
pseudo_element_matching_fn: None,
extra_data: Default::default(),
_impl: ::std::marker::PhantomData,
}
}
/// Whether we're matching a nested selector.
#[inline]
pub fn is_nested(&self) -> bool {
self.nesting_level != 0
}
/// Whether we're matching inside a :not(..) selector.
#[inline]
pub fn in_negation(&self) -> bool {
self.in_negation
}
/// The quirks mode of the document.
#[inline]
pub fn quirks_mode(&self) -> QuirksMode {
self.quirks_mode
}
/// The matching-mode for this selector-matching operation.
#[inline]
pub fn matching_mode(&self) -> MatchingMode {
self.matching_mode
}
/// The case-sensitivity for class and ID selectors
#[inline]
pub fn classes_and_ids_case_sensitivity(&self) -> CaseSensitivity {
self.classes_and_ids_case_sensitivity
}
/// Runs F with a deeper nesting level.
#[inline]
pub fn nest<F, R>(&mut self, f: F) -> R
where
F: FnOnce(&mut Self) -> R,
{
self.nesting_level += 1;
let result = f(self);
self.nesting_level -= 1;
result
}
/// Runs F with a deeper nesting level, and marking ourselves in a negation,
/// for a :not(..) selector, for example.
#[inline]
pub fn nest_for_negation<F, R>(&mut self, f: F) -> R
where
F: FnOnce(&mut Self) -> R,
{
debug_assert!(!self.in_negation, "Someone messed up parsing?");
self.in_negation = true;
let result = self.nest(f);
self.in_negation = false;
result
}
#[inline]
pub fn visited_handling(&self) -> VisitedHandlingMode {
self.visited_handling
}
/// Runs F with a different VisitedHandlingMode.
#[inline]
pub fn with_visited_handling_mode<F, R>(
&mut self,
handling_mode: VisitedHandlingMode,
f: F,
) -> R
where
F: FnOnce(&mut Self) -> R,
{
let original_handling_mode = self.visited_handling;
self.visited_handling = handling_mode;
let result = f(self);
self.visited_handling = original_handling_mode;
result
}
/// Runs F with a given shadow host which is the root of the tree whose
/// rules we're matching.
#[inline]
pub fn with_shadow_host<F, E, R>(&mut self, host: Option<E>, f: F) -> R
where
E: Element,
F: FnOnce(&mut Self) -> R,
{
let original_host = self.current_host.take();
self.current_host = host.map(|h| h.opaque());
let result = f(self);
self.current_host = original_host;
result
}
/// Returns the current shadow host whose shadow root we're matching rules
/// against.
#[inline]
pub fn shadow_host(&self) -> Option<OpaqueElement> {
self.current_host.clone()
}
}