selectors/context.rs
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291
/* 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.
///
/// See: https://quirks.spec.whatwg.org/
#[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.
///
/// See https://drafts.csswg.org/selectors-4/#scope-pseudo
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()
}
}