Source code

Revision control

Copy as Markdown

Other Tools

/* 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, NthIndexCacheInner};
use crate::parser::{Selector, SelectorImpl};
use crate::relative_selector::cache::RelativeSelectorCache;
use crate::relative_selector::filter::RelativeSelectorFilterMap;
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
)
}
}
/// Whether we need to set selector invalidation flags on elements for this
/// match request.
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum NeedsSelectorFlags {
No,
Yes,
}
/// Whether we're matching in the contect of invalidation.
#[derive(PartialEq)]
pub enum MatchingForInvalidation {
No,
Yes,
}
/// 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,
}
}
}
/// Whether or not this matching considered relative selector.
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum RelativeSelectorMatchingState {
/// Was not considered for any relative selector.
None,
/// Relative selector was considered for a match, but the element to be
/// under matching would not anchor the relative selector. i.e. The
/// relative selector was not part of the first compound selector (in match
/// order).
Considered,
/// Same as above, but the relative selector was part of the first compound
/// selector (in match order).
ConsideredAnchor,
}
impl RelativeSelectorMatchingState {
/// Update the matching state to indicate that the relative selector matching
/// happened in the subject position.
pub fn considered_anchor(&mut self) {
*self = Self::ConsideredAnchor;
}
/// Update the matching state to indicate that the relative selector matching
/// happened in a non-subject position.
pub fn considered(&mut self) {
// Being considered an anchor is stronger (e.g. `:has(.a):is(:has(.b) .c)`).
if *self == Self::ConsideredAnchor {
*self = Self::ConsideredAnchor;
} else {
*self = Self::Considered;
}
}
}
/// Set of caches (And cache-likes) that speed up expensive selector matches.
#[derive(Default)]
pub struct SelectorCaches {
/// A cache to speed up nth-index-like selectors.
pub nth_index: NthIndexCache,
/// A cache to speed up relative selector matches. See module documentation.
pub relative_selector: RelativeSelectorCache,
/// A map of bloom filters to fast-reject relative selector matches.
pub relative_selector_filter_map: RelativeSelectorFilterMap,
}
/// 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>,
/// 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.
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<'a>,
/// The current element we're anchoring on for evaluating the relative selector.
current_relative_selector_anchor: Option<OpaqueElement>,
pub considered_relative_selector: RelativeSelectorMatchingState,
quirks_mode: QuirksMode,
needs_selector_flags: NeedsSelectorFlags,
/// Whether we're matching in the contect of invalidation.
matching_for_invalidation: MatchingForInvalidation,
/// Caches to speed up expensive selector matches.
pub selector_caches: &'a mut SelectorCaches,
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>,
selector_caches: &'a mut SelectorCaches,
quirks_mode: QuirksMode,
needs_selector_flags: NeedsSelectorFlags,
matching_for_invalidation: MatchingForInvalidation,
) -> Self {
Self::new_for_visited(
matching_mode,
bloom_filter,
selector_caches,
VisitedHandlingMode::AllLinksUnvisited,
quirks_mode,
needs_selector_flags,
matching_for_invalidation,
)
}
/// Constructs a new `MatchingContext` for use in visited matching.
pub fn new_for_visited(
matching_mode: MatchingMode,
bloom_filter: Option<&'a BloomFilter>,
selector_caches: &'a mut SelectorCaches,
visited_handling: VisitedHandlingMode,
quirks_mode: QuirksMode,
needs_selector_flags: NeedsSelectorFlags,
matching_for_invalidation: MatchingForInvalidation,
) -> Self {
Self {
matching_mode,
bloom_filter,
visited_handling,
quirks_mode,
classes_and_ids_case_sensitivity: quirks_mode.classes_and_ids_case_sensitivity(),
needs_selector_flags,
matching_for_invalidation,
scope_element: None,
current_host: None,
nesting_level: 0,
in_negation: false,
pseudo_element_matching_fn: None,
extra_data: Default::default(),
current_relative_selector_anchor: None,
considered_relative_selector: RelativeSelectorMatchingState::None,
selector_caches,
_impl: ::std::marker::PhantomData,
}
}
// Grab a reference to the appropriate cache.
#[inline]
pub fn nth_index_cache(
&mut self,
is_of_type: bool,
is_from_end: bool,
selectors: &[Selector<Impl>],
) -> &mut NthIndexCacheInner {
self.selector_caches
.nth_index
.get(is_of_type, is_from_end, selectors)
}
/// 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
}
/// Whether we need to set selector flags.
#[inline]
pub fn needs_selector_flags(&self) -> bool {
self.needs_selector_flags == NeedsSelectorFlags::Yes
}
/// Whether or not we're matching to invalidate.
#[inline]
pub fn matching_for_invalidation(&self) -> bool {
self.matching_for_invalidation == MatchingForInvalidation::Yes
}
/// 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,
{
let old_in_negation = self.in_negation;
self.in_negation = true;
let result = self.nest(f);
self.in_negation = old_in_negation;
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
}
/// Runs F with a deeper nesting level, with the given element as the anchor,
/// for a :has(...) selector, for example.
#[inline]
pub fn nest_for_relative_selector<F, R>(&mut self, anchor: OpaqueElement, f: F) -> R
where
F: FnOnce(&mut Self) -> R,
{
debug_assert!(
self.current_relative_selector_anchor.is_none(),
"Nesting should've been rejected at parse time"
);
self.current_relative_selector_anchor = Some(anchor);
let result = self.nest(f);
self.current_relative_selector_anchor = None;
result
}
/// Returns the current anchor element to evaluate the relative selector against.
#[inline]
pub fn relative_selector_anchor(&self) -> Option<OpaqueElement> {
self.current_relative_selector_anchor
}
}