mirror of
https://github.com/servo/servo.git
synced 2025-07-01 04:23:39 +01:00
e92a79619e
style: Account for cousin sharing in the revalidation logic. Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1361013 <!-- Reviewable:start --> --- This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/16670) <!-- Reviewable:end -->
1447 lines
59 KiB
Rust
1447 lines
59 KiB
Rust
/* 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 http://mozilla.org/MPL/2.0/. */
|
||
|
||
//! Selector matching.
|
||
|
||
#![deny(missing_docs)]
|
||
|
||
use {Atom, LocalName};
|
||
use bit_vec::BitVec;
|
||
use context::QuirksMode;
|
||
use data::ComputedStyle;
|
||
use dom::{AnimationRules, PresentationalHintsSynthetizer, TElement};
|
||
use error_reporting::RustLogReporter;
|
||
use font_metrics::FontMetricsProvider;
|
||
use keyframes::KeyframesAnimation;
|
||
use media_queries::Device;
|
||
use pdqsort::sort_by;
|
||
use properties::{self, CascadeFlags, ComputedValues};
|
||
#[cfg(feature = "servo")]
|
||
use properties::INHERIT_ALL;
|
||
use properties::PropertyDeclarationBlock;
|
||
use restyle_hints::{RestyleHint, DependencySet};
|
||
use rule_tree::{CascadeLevel, RuleTree, StrongRuleNode, StyleSource};
|
||
use selector_parser::{SelectorImpl, PseudoElement, Snapshot};
|
||
use selectors::Element;
|
||
use selectors::bloom::BloomFilter;
|
||
use selectors::matching::{AFFECTED_BY_STYLE_ATTRIBUTE, AFFECTED_BY_PRESENTATIONAL_HINTS};
|
||
use selectors::matching::{ElementSelectorFlags, StyleRelations, matches_selector};
|
||
use selectors::parser::{Combinator, Component, Selector, SelectorInner, SelectorIter};
|
||
use selectors::parser::{SelectorMethods, LocalName as LocalNameSelector};
|
||
use selectors::visitor::SelectorVisitor;
|
||
use shared_lock::{Locked, SharedRwLockReadGuard, StylesheetGuards};
|
||
use sink::Push;
|
||
use smallvec::VecLike;
|
||
use std::borrow::Borrow;
|
||
use std::collections::HashMap;
|
||
use std::fmt;
|
||
use std::hash::Hash;
|
||
#[cfg(feature = "servo")]
|
||
use std::marker::PhantomData;
|
||
use std::sync::Arc;
|
||
use style_traits::viewport::ViewportConstraints;
|
||
use stylesheets::{CssRule, FontFaceRule, Origin, StyleRule, Stylesheet, UserAgentStylesheets};
|
||
use thread_state;
|
||
use viewport::{self, MaybeNew, ViewportRule};
|
||
|
||
pub use ::fnv::FnvHashMap;
|
||
|
||
/// This structure holds all the selectors and device characteristics
|
||
/// for a given document. The selectors are converted into `Rule`s
|
||
/// (defined in rust-selectors), and introduced in a `SelectorMap`
|
||
/// depending on the pseudo-element (see `PerPseudoElementSelectorMap`),
|
||
/// and stylesheet origin (see the fields of `PerPseudoElementSelectorMap`).
|
||
///
|
||
/// This structure is effectively created once per pipeline, in the
|
||
/// LayoutThread corresponding to that pipeline.
|
||
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
|
||
pub struct Stylist {
|
||
/// Device that the stylist is currently evaluating against.
|
||
///
|
||
/// This field deserves a bigger comment due to the different use that Gecko
|
||
/// and Servo give to it (that we should eventually unify).
|
||
///
|
||
/// With Gecko, the device is never changed. Gecko manually tracks whether
|
||
/// the device data should be reconstructed, and "resets" the state of the
|
||
/// device.
|
||
///
|
||
/// On Servo, on the other hand, the device is a really cheap representation
|
||
/// that is recreated each time some constraint changes and calling
|
||
/// `set_device`.
|
||
///
|
||
/// In both cases, the device is actually _owned_ by the Stylist, and it's
|
||
/// only an `Arc` so we can implement `add_stylesheet` more idiomatically.
|
||
pub device: Arc<Device>,
|
||
|
||
/// Viewport constraints based on the current device.
|
||
viewport_constraints: Option<ViewportConstraints>,
|
||
|
||
/// If true, the quirks-mode stylesheet is applied.
|
||
quirks_mode: QuirksMode,
|
||
|
||
/// If true, the device has changed, and the stylist needs to be updated.
|
||
is_device_dirty: bool,
|
||
|
||
/// The current selector maps, after evaluating media
|
||
/// rules against the current device.
|
||
element_map: PerPseudoElementSelectorMap,
|
||
|
||
/// The rule tree, that stores the results of selector matching.
|
||
///
|
||
/// FIXME(emilio): Not `pub`!
|
||
pub rule_tree: RuleTree,
|
||
|
||
/// The selector maps corresponding to a given pseudo-element
|
||
/// (depending on the implementation)
|
||
pseudos_map: FnvHashMap<PseudoElement, PerPseudoElementSelectorMap>,
|
||
|
||
/// A map with all the animations indexed by name.
|
||
animations: FnvHashMap<Atom, KeyframesAnimation>,
|
||
|
||
/// Applicable declarations for a given non-eagerly cascaded pseudo-element.
|
||
/// These are eagerly computed once, and then used to resolve the new
|
||
/// computed values on the fly on layout.
|
||
///
|
||
/// FIXME(emilio): Use the rule tree!
|
||
precomputed_pseudo_element_decls: FnvHashMap<PseudoElement, Vec<ApplicableDeclarationBlock>>,
|
||
|
||
/// A monotonically increasing counter to represent the order on which a
|
||
/// style rule appears in a stylesheet, needed to sort them by source order.
|
||
rules_source_order: usize,
|
||
|
||
/// Selector dependencies used to compute restyle hints.
|
||
dependencies: DependencySet,
|
||
|
||
/// Selectors that require explicit cache revalidation (i.e. which depend
|
||
/// on state that is not otherwise visible to the cache, like attributes or
|
||
/// tree-structural state like child index and pseudos).
|
||
#[cfg_attr(feature = "servo", ignore_heap_size_of = "Arc")]
|
||
selectors_for_cache_revalidation: Vec<SelectorInner<SelectorImpl>>,
|
||
|
||
/// The total number of selectors.
|
||
num_selectors: usize,
|
||
|
||
/// The total number of declarations.
|
||
num_declarations: usize,
|
||
|
||
/// The total number of times the stylist has been rebuilt.
|
||
num_rebuilds: usize,
|
||
}
|
||
|
||
/// This struct holds data which user of Stylist may want to extract
|
||
/// from stylesheets which can be done at the same time as updating.
|
||
pub struct ExtraStyleData<'a> {
|
||
/// A list of effective font-face rules and their origin.
|
||
#[cfg(feature = "gecko")]
|
||
pub font_faces: &'a mut Vec<(Arc<Locked<FontFaceRule>>, Origin)>,
|
||
|
||
#[allow(missing_docs)]
|
||
#[cfg(feature = "servo")]
|
||
pub marker: PhantomData<&'a usize>,
|
||
}
|
||
|
||
#[cfg(feature = "gecko")]
|
||
impl<'a> ExtraStyleData<'a> {
|
||
/// Clear the internal @font-face rule list.
|
||
fn clear_font_faces(&mut self) {
|
||
self.font_faces.clear();
|
||
}
|
||
|
||
/// Add the given @font-face rule.
|
||
fn add_font_face(&mut self, rule: &Arc<Locked<FontFaceRule>>, origin: Origin) {
|
||
self.font_faces.push((rule.clone(), origin));
|
||
}
|
||
}
|
||
|
||
#[cfg(feature = "servo")]
|
||
impl<'a> ExtraStyleData<'a> {
|
||
fn clear_font_faces(&mut self) {}
|
||
fn add_font_face(&mut self, _: &Arc<Locked<FontFaceRule>>, _: Origin) {}
|
||
}
|
||
|
||
impl Stylist {
|
||
/// Construct a new `Stylist`, using a given `Device`.
|
||
#[inline]
|
||
pub fn new(device: Device) -> Self {
|
||
let mut stylist = Stylist {
|
||
viewport_constraints: None,
|
||
device: Arc::new(device),
|
||
is_device_dirty: true,
|
||
quirks_mode: QuirksMode::NoQuirks,
|
||
|
||
element_map: PerPseudoElementSelectorMap::new(),
|
||
pseudos_map: Default::default(),
|
||
animations: Default::default(),
|
||
precomputed_pseudo_element_decls: Default::default(),
|
||
rules_source_order: 0,
|
||
rule_tree: RuleTree::new(),
|
||
dependencies: DependencySet::new(),
|
||
selectors_for_cache_revalidation: vec![],
|
||
num_selectors: 0,
|
||
num_declarations: 0,
|
||
num_rebuilds: 0,
|
||
};
|
||
|
||
SelectorImpl::each_eagerly_cascaded_pseudo_element(|pseudo| {
|
||
stylist.pseudos_map.insert(pseudo, PerPseudoElementSelectorMap::new());
|
||
});
|
||
|
||
// FIXME: Add iso-8859-9.css when the document’s encoding is ISO-8859-8.
|
||
|
||
stylist
|
||
}
|
||
|
||
/// Returns the number of selectors.
|
||
pub fn num_selectors(&self) -> usize {
|
||
self.num_selectors
|
||
}
|
||
|
||
/// Returns the number of declarations.
|
||
pub fn num_declarations(&self) -> usize {
|
||
self.num_declarations
|
||
}
|
||
|
||
/// Returns the number of times the stylist has been rebuilt.
|
||
pub fn num_rebuilds(&self) -> usize {
|
||
self.num_rebuilds
|
||
}
|
||
|
||
/// Returns the number of dependencies in the DependencySet.
|
||
pub fn num_dependencies(&self) -> usize {
|
||
self.dependencies.len()
|
||
}
|
||
|
||
/// Returns the number of revalidation_selectors.
|
||
pub fn num_revalidation_selectors(&self) -> usize {
|
||
self.selectors_for_cache_revalidation.len()
|
||
}
|
||
|
||
/// Update the stylist for the given document stylesheets, and optionally
|
||
/// with a set of user agent stylesheets.
|
||
///
|
||
/// This method resets all the style data each time the stylesheets change
|
||
/// (which is indicated by the `stylesheets_changed` parameter), or the
|
||
/// device is dirty, which means we need to re-evaluate media queries.
|
||
pub fn update<'a>(&mut self,
|
||
doc_stylesheets: &[Arc<Stylesheet>],
|
||
guards: &StylesheetGuards,
|
||
ua_stylesheets: Option<&UserAgentStylesheets>,
|
||
stylesheets_changed: bool,
|
||
author_style_disabled: bool,
|
||
extra_data: &mut ExtraStyleData<'a>) -> bool {
|
||
if !(self.is_device_dirty || stylesheets_changed) {
|
||
return false;
|
||
}
|
||
self.num_rebuilds += 1;
|
||
|
||
let cascaded_rule = ViewportRule {
|
||
declarations: viewport::Cascade::from_stylesheets(
|
||
doc_stylesheets, guards.author, &self.device
|
||
).finish(),
|
||
};
|
||
|
||
self.viewport_constraints =
|
||
ViewportConstraints::maybe_new(&self.device, &cascaded_rule, self.quirks_mode);
|
||
|
||
if let Some(ref constraints) = self.viewport_constraints {
|
||
Arc::get_mut(&mut self.device).unwrap()
|
||
.account_for_viewport_rule(constraints);
|
||
}
|
||
|
||
self.element_map = PerPseudoElementSelectorMap::new();
|
||
self.pseudos_map = Default::default();
|
||
self.animations = Default::default();
|
||
SelectorImpl::each_eagerly_cascaded_pseudo_element(|pseudo| {
|
||
self.pseudos_map.insert(pseudo, PerPseudoElementSelectorMap::new());
|
||
});
|
||
|
||
self.precomputed_pseudo_element_decls = Default::default();
|
||
self.rules_source_order = 0;
|
||
self.dependencies.clear();
|
||
self.animations.clear();
|
||
self.selectors_for_cache_revalidation.clear();
|
||
self.num_selectors = 0;
|
||
self.num_declarations = 0;
|
||
|
||
extra_data.clear_font_faces();
|
||
|
||
if let Some(ua_stylesheets) = ua_stylesheets {
|
||
for stylesheet in &ua_stylesheets.user_or_user_agent_stylesheets {
|
||
self.add_stylesheet(&stylesheet, guards.ua_or_user, extra_data);
|
||
}
|
||
|
||
if self.quirks_mode != QuirksMode::NoQuirks {
|
||
self.add_stylesheet(&ua_stylesheets.quirks_mode_stylesheet,
|
||
guards.ua_or_user, extra_data);
|
||
}
|
||
}
|
||
|
||
// Only use author stylesheets if author styles are enabled.
|
||
let sheets_to_add = doc_stylesheets.iter().filter(|s| {
|
||
!author_style_disabled || s.origin != Origin::Author
|
||
});
|
||
|
||
for ref stylesheet in sheets_to_add {
|
||
self.add_stylesheet(stylesheet, guards.author, extra_data);
|
||
}
|
||
|
||
SelectorImpl::each_precomputed_pseudo_element(|pseudo| {
|
||
if let Some(map) = self.pseudos_map.remove(&pseudo) {
|
||
let declarations =
|
||
map.user_agent.get_universal_rules(
|
||
guards.ua_or_user, CascadeLevel::UANormal, CascadeLevel::UAImportant
|
||
);
|
||
self.precomputed_pseudo_element_decls.insert(pseudo, declarations);
|
||
}
|
||
});
|
||
|
||
self.is_device_dirty = false;
|
||
true
|
||
}
|
||
|
||
fn add_stylesheet<'a>(&mut self, stylesheet: &Stylesheet, guard: &SharedRwLockReadGuard,
|
||
extra_data: &mut ExtraStyleData<'a>) {
|
||
if stylesheet.disabled() || !stylesheet.is_effective_for_device(&self.device, guard) {
|
||
return;
|
||
}
|
||
|
||
// Cheap `Arc` clone so that the closure below can borrow `&mut Stylist`.
|
||
let device = self.device.clone();
|
||
|
||
stylesheet.effective_rules(&device, guard, |rule| {
|
||
match *rule {
|
||
CssRule::Style(ref locked) => {
|
||
let style_rule = locked.read_with(&guard);
|
||
self.num_declarations += style_rule.block.read_with(&guard).len();
|
||
for selector in &style_rule.selectors.0 {
|
||
self.num_selectors += 1;
|
||
self.add_rule_to_map(guard, selector, locked, stylesheet);
|
||
self.dependencies.note_selector(selector);
|
||
self.note_for_revalidation(selector);
|
||
}
|
||
self.rules_source_order += 1;
|
||
}
|
||
CssRule::Import(ref import) => {
|
||
let import = import.read_with(guard);
|
||
self.add_stylesheet(&import.stylesheet, guard, extra_data)
|
||
}
|
||
CssRule::Keyframes(ref keyframes_rule) => {
|
||
let keyframes_rule = keyframes_rule.read_with(guard);
|
||
debug!("Found valid keyframes rule: {:?}", *keyframes_rule);
|
||
|
||
// Don't let a prefixed keyframes animation override a non-prefixed one.
|
||
let needs_insertion = keyframes_rule.vendor_prefix.is_none() ||
|
||
self.animations.get(keyframes_rule.name.as_atom()).map_or(true, |rule|
|
||
rule.vendor_prefix.is_some());
|
||
if needs_insertion {
|
||
let animation = KeyframesAnimation::from_keyframes(
|
||
&keyframes_rule.keyframes, keyframes_rule.vendor_prefix.clone(), guard);
|
||
debug!("Found valid keyframe animation: {:?}", animation);
|
||
self.animations.insert(keyframes_rule.name.as_atom().clone(), animation);
|
||
}
|
||
}
|
||
CssRule::FontFace(ref rule) => {
|
||
extra_data.add_font_face(&rule, stylesheet.origin);
|
||
}
|
||
// We don't care about any other rule.
|
||
_ => {}
|
||
}
|
||
});
|
||
}
|
||
|
||
#[inline]
|
||
fn add_rule_to_map(&mut self,
|
||
guard: &SharedRwLockReadGuard,
|
||
selector: &Selector<SelectorImpl>,
|
||
rule: &Arc<Locked<StyleRule>>,
|
||
stylesheet: &Stylesheet)
|
||
{
|
||
let map = if let Some(ref pseudo) = selector.pseudo_element {
|
||
self.pseudos_map
|
||
.entry(pseudo.clone())
|
||
.or_insert_with(PerPseudoElementSelectorMap::new)
|
||
.borrow_for_origin(&stylesheet.origin)
|
||
} else {
|
||
self.element_map.borrow_for_origin(&stylesheet.origin)
|
||
};
|
||
|
||
map.insert(Rule::new(guard,
|
||
selector.inner.clone(),
|
||
rule.clone(),
|
||
self.rules_source_order,
|
||
selector.specificity));
|
||
}
|
||
|
||
#[inline]
|
||
fn note_for_revalidation(&mut self, selector: &Selector<SelectorImpl>) {
|
||
if needs_revalidation(selector) {
|
||
self.selectors_for_cache_revalidation.push(selector.inner.clone());
|
||
}
|
||
}
|
||
|
||
/// Computes the style for a given "precomputed" pseudo-element, taking the
|
||
/// universal rules and applying them.
|
||
///
|
||
/// If `inherit_all` is true, then all properties are inherited from the
|
||
/// parent; otherwise, non-inherited properties are reset to their initial
|
||
/// values. The flow constructor uses this flag when constructing anonymous
|
||
/// flows.
|
||
pub fn precomputed_values_for_pseudo(&self,
|
||
guards: &StylesheetGuards,
|
||
pseudo: &PseudoElement,
|
||
parent: Option<&Arc<ComputedValues>>,
|
||
cascade_flags: CascadeFlags,
|
||
font_metrics: &FontMetricsProvider)
|
||
-> ComputedStyle {
|
||
debug_assert!(pseudo.is_precomputed());
|
||
|
||
let rule_node = match self.precomputed_pseudo_element_decls.get(pseudo) {
|
||
Some(declarations) => {
|
||
// FIXME(emilio): When we've taken rid of the cascade we can just
|
||
// use into_iter.
|
||
self.rule_tree.insert_ordered_rules(
|
||
declarations.into_iter().map(|a| (a.source.clone(), a.level)))
|
||
}
|
||
None => self.rule_tree.root(),
|
||
};
|
||
|
||
// NOTE(emilio): We skip calculating the proper layout parent style
|
||
// here.
|
||
//
|
||
// It'd be fine to assert that this isn't called with a parent style
|
||
// where display contents is in effect, but in practice this is hard to
|
||
// do for stuff like :-moz-fieldset-content with a
|
||
// <fieldset style="display: contents">. That is, the computed value of
|
||
// display for the fieldset is "contents", even though it's not the used
|
||
// value, so we don't need to adjust in a different way anyway.
|
||
//
|
||
// In practice, I don't think any anonymous content can be a direct
|
||
// descendant of a display: contents element where display: contents is
|
||
// the actual used value, and the computed value of it would need
|
||
// blockification.
|
||
let computed =
|
||
properties::cascade(&self.device,
|
||
&rule_node,
|
||
guards,
|
||
parent.map(|p| &**p),
|
||
parent.map(|p| &**p),
|
||
None,
|
||
&RustLogReporter,
|
||
font_metrics,
|
||
cascade_flags,
|
||
self.quirks_mode);
|
||
ComputedStyle::new(rule_node, Arc::new(computed))
|
||
}
|
||
|
||
/// Returns the style for an anonymous box of the given type.
|
||
#[cfg(feature = "servo")]
|
||
pub fn style_for_anonymous(&self,
|
||
guards: &StylesheetGuards,
|
||
pseudo: &PseudoElement,
|
||
parent_style: &Arc<ComputedValues>)
|
||
-> Arc<ComputedValues> {
|
||
use font_metrics::ServoMetricsProvider;
|
||
|
||
// For most (but not all) pseudo-elements, we inherit all values from the parent.
|
||
let inherit_all = match *pseudo {
|
||
PseudoElement::ServoText |
|
||
PseudoElement::ServoInputText => false,
|
||
PseudoElement::ServoAnonymousBlock |
|
||
PseudoElement::ServoAnonymousTable |
|
||
PseudoElement::ServoAnonymousTableCell |
|
||
PseudoElement::ServoAnonymousTableRow |
|
||
PseudoElement::ServoAnonymousTableWrapper |
|
||
PseudoElement::ServoTableWrapper |
|
||
PseudoElement::ServoInlineBlockWrapper |
|
||
PseudoElement::ServoInlineAbsolute => true,
|
||
PseudoElement::Before |
|
||
PseudoElement::After |
|
||
PseudoElement::Selection |
|
||
PseudoElement::DetailsSummary |
|
||
PseudoElement::DetailsContent => {
|
||
unreachable!("That pseudo doesn't represent an anonymous box!")
|
||
}
|
||
};
|
||
let mut cascade_flags = CascadeFlags::empty();
|
||
if inherit_all {
|
||
cascade_flags.insert(INHERIT_ALL);
|
||
}
|
||
self.precomputed_values_for_pseudo(guards, &pseudo, Some(parent_style), cascade_flags,
|
||
&ServoMetricsProvider)
|
||
.values.unwrap()
|
||
}
|
||
|
||
/// Computes a pseudo-element style lazily during layout.
|
||
///
|
||
/// This can only be done for a certain set of pseudo-elements, like
|
||
/// :selection.
|
||
///
|
||
/// Check the documentation on lazy pseudo-elements in
|
||
/// docs/components/style.md
|
||
pub fn lazily_compute_pseudo_element_style<E>(&self,
|
||
guards: &StylesheetGuards,
|
||
element: &E,
|
||
pseudo: &PseudoElement,
|
||
parent: &Arc<ComputedValues>,
|
||
font_metrics: &FontMetricsProvider)
|
||
-> Option<ComputedStyle>
|
||
where E: TElement +
|
||
fmt::Debug +
|
||
PresentationalHintsSynthetizer
|
||
{
|
||
debug_assert!(pseudo.is_lazy());
|
||
if self.pseudos_map.get(pseudo).is_none() {
|
||
return None;
|
||
}
|
||
|
||
let mut declarations = vec![];
|
||
|
||
// Apply the selector flags. We should be in sequential mode
|
||
// already, so we can directly apply the parent flags.
|
||
let mut set_selector_flags = |element: &E, flags: ElementSelectorFlags| {
|
||
if cfg!(feature = "servo") {
|
||
// Servo calls this function from the worker, but only for internal
|
||
// pseudos, so we should never generate selector flags here.
|
||
unreachable!("internal pseudo generated slow selector flags?");
|
||
}
|
||
|
||
// Gecko calls this from sequential mode, so we can directly apply
|
||
// the flags.
|
||
debug_assert!(thread_state::get() == thread_state::LAYOUT);
|
||
let self_flags = flags.for_self();
|
||
if !self_flags.is_empty() {
|
||
unsafe { element.set_selector_flags(self_flags); }
|
||
}
|
||
let parent_flags = flags.for_parent();
|
||
if !parent_flags.is_empty() {
|
||
if let Some(p) = element.parent_element() {
|
||
unsafe { p.set_selector_flags(parent_flags); }
|
||
}
|
||
}
|
||
};
|
||
|
||
|
||
self.push_applicable_declarations(element,
|
||
None,
|
||
None,
|
||
None,
|
||
AnimationRules(None, None),
|
||
Some(pseudo),
|
||
guards,
|
||
&mut declarations,
|
||
&mut set_selector_flags);
|
||
|
||
if declarations.is_empty() {
|
||
return None
|
||
}
|
||
|
||
let rule_node =
|
||
self.rule_tree.insert_ordered_rules(
|
||
declarations.into_iter().map(|a| (a.source, a.level)));
|
||
|
||
// Read the comment on `precomputed_values_for_pseudo` to see why it's
|
||
// difficult to assert that display: contents nodes never arrive here
|
||
// (tl;dr: It doesn't apply for replaced elements and such, but the
|
||
// computed value is still "contents").
|
||
let computed =
|
||
properties::cascade(&self.device,
|
||
&rule_node,
|
||
guards,
|
||
Some(&**parent),
|
||
Some(&**parent),
|
||
None,
|
||
&RustLogReporter,
|
||
font_metrics,
|
||
CascadeFlags::empty(),
|
||
self.quirks_mode);
|
||
|
||
Some(ComputedStyle::new(rule_node, Arc::new(computed)))
|
||
}
|
||
|
||
/// Set a given device, which may change the styles that apply to the
|
||
/// document.
|
||
///
|
||
/// This means that we may need to rebuild style data even if the
|
||
/// stylesheets haven't changed.
|
||
///
|
||
/// Also, the device that arrives here may need to take the viewport rules
|
||
/// into account.
|
||
///
|
||
/// TODO(emilio): Probably should be unified with `update`, right now I
|
||
/// don't think we take into account dynamic updates to viewport rules.
|
||
///
|
||
/// Probably worth to make the stylist own a single `Device`, and have a
|
||
/// `update_device` function?
|
||
///
|
||
/// feature = "servo" because gecko only has one device, and manually tracks
|
||
/// when the device is dirty.
|
||
///
|
||
/// FIXME(emilio): The semantics of the device for Servo and Gecko are
|
||
/// different enough we may want to unify them.
|
||
#[cfg(feature = "servo")]
|
||
pub fn set_device(&mut self, mut device: Device, guard: &SharedRwLockReadGuard,
|
||
stylesheets: &[Arc<Stylesheet>]) {
|
||
let cascaded_rule = ViewportRule {
|
||
declarations: viewport::Cascade::from_stylesheets(stylesheets, guard, &device).finish(),
|
||
};
|
||
|
||
self.viewport_constraints =
|
||
ViewportConstraints::maybe_new(&device, &cascaded_rule, self.quirks_mode);
|
||
|
||
if let Some(ref constraints) = self.viewport_constraints {
|
||
device.account_for_viewport_rule(constraints);
|
||
}
|
||
|
||
fn mq_eval_changed(guard: &SharedRwLockReadGuard, rules: &[CssRule],
|
||
before: &Device, after: &Device, quirks_mode: QuirksMode) -> bool {
|
||
for rule in rules {
|
||
let changed = rule.with_nested_rules_and_mq(guard, |rules, mq| {
|
||
if let Some(mq) = mq {
|
||
if mq.evaluate(before, quirks_mode) != mq.evaluate(after, quirks_mode) {
|
||
return true
|
||
}
|
||
}
|
||
mq_eval_changed(guard, rules, before, after, quirks_mode)
|
||
});
|
||
if changed {
|
||
return true
|
||
}
|
||
}
|
||
false
|
||
}
|
||
self.is_device_dirty |= stylesheets.iter().any(|stylesheet| {
|
||
let mq = stylesheet.media.read_with(guard);
|
||
if mq.evaluate(&self.device, self.quirks_mode) != mq.evaluate(&device, self.quirks_mode) {
|
||
return true
|
||
}
|
||
|
||
mq_eval_changed(guard, &stylesheet.rules.read_with(guard).0, &self.device, &device, self.quirks_mode)
|
||
});
|
||
|
||
self.device = Arc::new(device);
|
||
}
|
||
|
||
/// Returns the viewport constraints that apply to this document because of
|
||
/// a @viewport rule.
|
||
pub fn viewport_constraints(&self) -> Option<&ViewportConstraints> {
|
||
self.viewport_constraints.as_ref()
|
||
}
|
||
|
||
/// Sets the quirks mode of the document.
|
||
pub fn set_quirks_mode(&mut self, quirks_mode: QuirksMode) {
|
||
// FIXME(emilio): We don't seem to change the quirks mode dynamically
|
||
// during multiple layout passes, but this is totally bogus, in the
|
||
// sense that it's updated asynchronously.
|
||
//
|
||
// This should probably be an argument to `update`, and use the quirks
|
||
// mode info in the `SharedLayoutContext`.
|
||
self.quirks_mode = quirks_mode;
|
||
}
|
||
|
||
/// Returns the applicable CSS declarations for the given element.
|
||
///
|
||
/// This corresponds to `ElementRuleCollector` in WebKit.
|
||
///
|
||
/// The returned `StyleRelations` indicate hints about which kind of rules
|
||
/// have matched.
|
||
pub fn push_applicable_declarations<E, V, F>(
|
||
&self,
|
||
element: &E,
|
||
parent_bf: Option<&BloomFilter>,
|
||
style_attribute: Option<&Arc<Locked<PropertyDeclarationBlock>>>,
|
||
smil_override: Option<&Arc<Locked<PropertyDeclarationBlock>>>,
|
||
animation_rules: AnimationRules,
|
||
pseudo_element: Option<&PseudoElement>,
|
||
guards: &StylesheetGuards,
|
||
applicable_declarations: &mut V,
|
||
flags_setter: &mut F)
|
||
-> StyleRelations
|
||
where E: TElement +
|
||
fmt::Debug +
|
||
PresentationalHintsSynthetizer,
|
||
V: Push<ApplicableDeclarationBlock> + VecLike<ApplicableDeclarationBlock>,
|
||
F: FnMut(&E, ElementSelectorFlags),
|
||
{
|
||
debug_assert!(!self.is_device_dirty);
|
||
// Gecko definitely has pseudo-elements with style attributes, like
|
||
// ::-moz-color-swatch.
|
||
debug_assert!(cfg!(feature = "gecko") ||
|
||
style_attribute.is_none() || pseudo_element.is_none(),
|
||
"Style attributes do not apply to pseudo-elements");
|
||
debug_assert!(pseudo_element.as_ref().map_or(true, |p| !p.is_precomputed()));
|
||
|
||
let map = match pseudo_element {
|
||
Some(ref pseudo) => self.pseudos_map.get(pseudo).unwrap(),
|
||
None => &self.element_map,
|
||
};
|
||
|
||
let mut relations = StyleRelations::empty();
|
||
|
||
debug!("Determining if style is shareable: pseudo: {}", pseudo_element.is_some());
|
||
// Step 1: Normal user-agent rules.
|
||
map.user_agent.get_all_matching_rules(element,
|
||
parent_bf,
|
||
applicable_declarations,
|
||
&mut relations,
|
||
flags_setter,
|
||
CascadeLevel::UANormal);
|
||
debug!("UA normal: {:?}", relations);
|
||
|
||
if pseudo_element.is_none() {
|
||
// Step 2: Presentational hints.
|
||
let length_before_preshints = applicable_declarations.len();
|
||
element.synthesize_presentational_hints_for_legacy_attributes(applicable_declarations);
|
||
if applicable_declarations.len() != length_before_preshints {
|
||
if cfg!(debug_assertions) {
|
||
for declaration in &applicable_declarations[length_before_preshints..] {
|
||
assert_eq!(declaration.level, CascadeLevel::PresHints);
|
||
}
|
||
}
|
||
// Never share style for elements with preshints
|
||
relations |= AFFECTED_BY_PRESENTATIONAL_HINTS;
|
||
}
|
||
debug!("preshints: {:?}", relations);
|
||
}
|
||
|
||
if element.matches_user_and_author_rules() {
|
||
// Step 3: User and author normal rules.
|
||
map.user.get_all_matching_rules(element,
|
||
parent_bf,
|
||
applicable_declarations,
|
||
&mut relations,
|
||
flags_setter,
|
||
CascadeLevel::UserNormal);
|
||
debug!("user normal: {:?}", relations);
|
||
map.author.get_all_matching_rules(element,
|
||
parent_bf,
|
||
applicable_declarations,
|
||
&mut relations,
|
||
flags_setter,
|
||
CascadeLevel::AuthorNormal);
|
||
debug!("author normal: {:?}", relations);
|
||
|
||
// Step 4: Normal style attributes.
|
||
if let Some(sa) = style_attribute {
|
||
if sa.read_with(guards.author).any_normal() {
|
||
relations |= AFFECTED_BY_STYLE_ATTRIBUTE;
|
||
Push::push(
|
||
applicable_declarations,
|
||
ApplicableDeclarationBlock::from_declarations(sa.clone(),
|
||
CascadeLevel::StyleAttributeNormal));
|
||
}
|
||
}
|
||
|
||
debug!("style attr: {:?}", relations);
|
||
|
||
// Step 5: SMIL override.
|
||
// Declarations from SVG SMIL animation elements.
|
||
if let Some(so) = smil_override {
|
||
Push::push(
|
||
applicable_declarations,
|
||
ApplicableDeclarationBlock::from_declarations(so.clone(),
|
||
CascadeLevel::SMILOverride));
|
||
}
|
||
debug!("SMIL: {:?}", relations);
|
||
|
||
// Step 6: Animations.
|
||
// The animations sheet (CSS animations, script-generated animations,
|
||
// and CSS transitions that are no longer tied to CSS markup)
|
||
if let Some(anim) = animation_rules.0 {
|
||
Push::push(
|
||
applicable_declarations,
|
||
ApplicableDeclarationBlock::from_declarations(anim,
|
||
CascadeLevel::Animations));
|
||
}
|
||
debug!("animation: {:?}", relations);
|
||
|
||
// Step 7: Author-supplied `!important` rules.
|
||
map.author.get_all_matching_rules(element,
|
||
parent_bf,
|
||
applicable_declarations,
|
||
&mut relations,
|
||
flags_setter,
|
||
CascadeLevel::AuthorImportant);
|
||
|
||
debug!("author important: {:?}", relations);
|
||
|
||
// Step 8: `!important` style attributes.
|
||
if let Some(sa) = style_attribute {
|
||
if sa.read_with(guards.author).any_important() {
|
||
relations |= AFFECTED_BY_STYLE_ATTRIBUTE;
|
||
Push::push(
|
||
applicable_declarations,
|
||
ApplicableDeclarationBlock::from_declarations(sa.clone(),
|
||
CascadeLevel::StyleAttributeImportant));
|
||
}
|
||
}
|
||
|
||
debug!("style attr important: {:?}", relations);
|
||
|
||
// Step 9: User `!important` rules.
|
||
map.user.get_all_matching_rules(element,
|
||
parent_bf,
|
||
applicable_declarations,
|
||
&mut relations,
|
||
flags_setter,
|
||
CascadeLevel::UserImportant);
|
||
|
||
debug!("user important: {:?}", relations);
|
||
} else {
|
||
debug!("skipping non-agent rules");
|
||
}
|
||
|
||
// Step 10: UA `!important` rules.
|
||
map.user_agent.get_all_matching_rules(element,
|
||
parent_bf,
|
||
applicable_declarations,
|
||
&mut relations,
|
||
flags_setter,
|
||
CascadeLevel::UAImportant);
|
||
|
||
debug!("UA important: {:?}", relations);
|
||
|
||
// Step 11: Transitions.
|
||
// The transitions sheet (CSS transitions that are tied to CSS markup)
|
||
if let Some(anim) = animation_rules.1 {
|
||
Push::push(
|
||
applicable_declarations,
|
||
ApplicableDeclarationBlock::from_declarations(anim, CascadeLevel::Transitions));
|
||
}
|
||
debug!("transition: {:?}", relations);
|
||
|
||
debug!("push_applicable_declarations: shareable: {:?}", relations);
|
||
|
||
relations
|
||
}
|
||
|
||
/// Return whether the device is dirty, that is, whether the screen size or
|
||
/// media type have changed (for now).
|
||
#[inline]
|
||
pub fn is_device_dirty(&self) -> bool {
|
||
self.is_device_dirty
|
||
}
|
||
|
||
/// Returns the map of registered `@keyframes` animations.
|
||
#[inline]
|
||
pub fn animations(&self) -> &FnvHashMap<Atom, KeyframesAnimation> {
|
||
&self.animations
|
||
}
|
||
|
||
/// Returns the rule root node.
|
||
#[inline]
|
||
pub fn rule_tree_root(&self) -> StrongRuleNode {
|
||
self.rule_tree.root()
|
||
}
|
||
|
||
/// Computes the match results of a given element against the set of
|
||
/// revalidation selectors.
|
||
pub fn match_revalidation_selectors<E, F>(&self,
|
||
element: &E,
|
||
bloom: &BloomFilter,
|
||
flags_setter: &mut F)
|
||
-> BitVec
|
||
where E: TElement,
|
||
F: FnMut(&E, ElementSelectorFlags),
|
||
{
|
||
use selectors::matching::StyleRelations;
|
||
use selectors::matching::matches_selector;
|
||
|
||
let len = self.selectors_for_cache_revalidation.len();
|
||
let mut results = BitVec::from_elem(len, false);
|
||
|
||
for (i, ref selector) in self.selectors_for_cache_revalidation
|
||
.iter().enumerate() {
|
||
results.set(i, matches_selector(selector,
|
||
element,
|
||
Some(bloom),
|
||
&mut StyleRelations::empty(),
|
||
flags_setter));
|
||
}
|
||
|
||
results
|
||
}
|
||
|
||
/// Given an element, and a snapshot that represents a previous state of the
|
||
/// element, compute the appropriate restyle hint, that is, the kind of
|
||
/// restyle we need to do.
|
||
pub fn compute_restyle_hint<E>(&self,
|
||
element: &E,
|
||
snapshot: &Snapshot)
|
||
-> RestyleHint
|
||
where E: TElement,
|
||
{
|
||
self.dependencies.compute_hint(element, snapshot)
|
||
}
|
||
|
||
/// Computes styles for a given declaration with parent_style.
|
||
pub fn compute_for_declarations(&self,
|
||
guards: &StylesheetGuards,
|
||
parent_style: &Arc<ComputedValues>,
|
||
declarations: Arc<Locked<PropertyDeclarationBlock>>)
|
||
-> Arc<ComputedValues> {
|
||
use font_metrics::get_metrics_provider_for_product;
|
||
|
||
let v = vec![
|
||
ApplicableDeclarationBlock::from_declarations(declarations.clone(),
|
||
CascadeLevel::StyleAttributeNormal)
|
||
];
|
||
let rule_node =
|
||
self.rule_tree.insert_ordered_rules(v.into_iter().map(|a| (a.source, a.level)));
|
||
|
||
let metrics = get_metrics_provider_for_product();
|
||
Arc::new(properties::cascade(&self.device,
|
||
&rule_node,
|
||
guards,
|
||
Some(parent_style),
|
||
Some(parent_style),
|
||
None,
|
||
&RustLogReporter,
|
||
&metrics,
|
||
CascadeFlags::empty(),
|
||
self.quirks_mode))
|
||
}
|
||
}
|
||
|
||
impl Drop for Stylist {
|
||
fn drop(&mut self) {
|
||
// This is the last chance to GC the rule tree. If we have dropped all
|
||
// strong rule node references before the Stylist is dropped, then this
|
||
// will cause the rule tree to be destroyed correctly. If we haven't
|
||
// dropped all strong rule node references before now, then we will
|
||
// leak them, since there will be no way to call gc() on the rule tree
|
||
// after this point.
|
||
//
|
||
// TODO(emilio): We can at least assert all the elements in the free
|
||
// list are indeed free.
|
||
unsafe { self.rule_tree.gc(); }
|
||
}
|
||
}
|
||
|
||
/// Visitor determine whether a selector requires cache revalidation.
|
||
///
|
||
/// Note that we just check simple selectors and eagerly return when the first
|
||
/// need for revalidation is found, so we don't need to store state on the
|
||
/// visitor.
|
||
///
|
||
/// Also, note that it's important to check the whole selector, due to cousins
|
||
/// sharing arbitrarily deep in the DOM, not just the rightmost part of it
|
||
/// (unfortunately, though).
|
||
///
|
||
/// With cousin sharing, we not only need to care about selectors in stuff like
|
||
/// foo:first-child, but also about selectors like p:first-child foo, since the
|
||
/// two parents may have shared style, and in that case we can test cousins
|
||
/// whose matching depends on the selector up in the chain.
|
||
///
|
||
/// TODO(emilio): We can optimize when matching only siblings to only match the
|
||
/// rightmost selector until a descendant combinator is found, I guess, and in
|
||
/// general when we're sharing at depth `n`, to the `n + 1` sequences of
|
||
/// descendant combinators.
|
||
///
|
||
/// I don't think that in presence of the bloom filter it's worth it, though.
|
||
struct RevalidationVisitor;
|
||
|
||
impl SelectorVisitor for RevalidationVisitor {
|
||
type Impl = SelectorImpl;
|
||
|
||
|
||
fn visit_complex_selector(&mut self,
|
||
_: SelectorIter<SelectorImpl>,
|
||
combinator: Option<Combinator>) -> bool {
|
||
let is_sibling_combinator =
|
||
combinator.map_or(false, |c| c.is_sibling());
|
||
|
||
!is_sibling_combinator
|
||
}
|
||
|
||
|
||
/// Check whether sequence of simple selectors containing this simple
|
||
/// selector to be explicitly matched against both the style sharing cache
|
||
/// entry and the candidate.
|
||
///
|
||
/// We use this for selectors that can have different matching behavior
|
||
/// between siblings that are otherwise identical as far as the cache is
|
||
/// concerned.
|
||
fn visit_simple_selector(&mut self, s: &Component<SelectorImpl>) -> bool {
|
||
match *s {
|
||
Component::AttrExists(_) |
|
||
Component::AttrEqual(_, _, _) |
|
||
Component::AttrIncludes(_, _) |
|
||
Component::AttrDashMatch(_, _) |
|
||
Component::AttrPrefixMatch(_, _) |
|
||
Component::AttrSubstringMatch(_, _) |
|
||
Component::AttrSuffixMatch(_, _) |
|
||
Component::Empty |
|
||
Component::FirstChild |
|
||
Component::LastChild |
|
||
Component::OnlyChild |
|
||
Component::NthChild(..) |
|
||
Component::NthLastChild(..) |
|
||
Component::NthOfType(..) |
|
||
Component::NthLastOfType(..) |
|
||
Component::FirstOfType |
|
||
Component::LastOfType |
|
||
Component::OnlyOfType => {
|
||
false
|
||
},
|
||
Component::NonTSPseudoClass(ref p) => {
|
||
!p.needs_cache_revalidation()
|
||
},
|
||
_ => {
|
||
true
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Returns true if the given selector needs cache revalidation.
|
||
pub fn needs_revalidation(selector: &Selector<SelectorImpl>) -> bool {
|
||
let mut visitor = RevalidationVisitor;
|
||
!selector.visit(&mut visitor)
|
||
}
|
||
|
||
/// Map that contains the CSS rules for a specific PseudoElement
|
||
/// (or lack of PseudoElement).
|
||
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
|
||
struct PerPseudoElementSelectorMap {
|
||
/// Rules from user agent stylesheets
|
||
user_agent: SelectorMap,
|
||
/// Rules from author stylesheets
|
||
author: SelectorMap,
|
||
/// Rules from user stylesheets
|
||
user: SelectorMap,
|
||
}
|
||
|
||
impl PerPseudoElementSelectorMap {
|
||
#[inline]
|
||
fn new() -> Self {
|
||
PerPseudoElementSelectorMap {
|
||
user_agent: SelectorMap::new(),
|
||
author: SelectorMap::new(),
|
||
user: SelectorMap::new(),
|
||
}
|
||
}
|
||
|
||
#[inline]
|
||
fn borrow_for_origin(&mut self, origin: &Origin) -> &mut SelectorMap {
|
||
match *origin {
|
||
Origin::UserAgent => &mut self.user_agent,
|
||
Origin::Author => &mut self.author,
|
||
Origin::User => &mut self.user,
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Map element data to Rules whose last simple selector starts with them.
|
||
///
|
||
/// e.g.,
|
||
/// "p > img" would go into the set of Rules corresponding to the
|
||
/// element "img"
|
||
/// "a .foo .bar.baz" would go into the set of Rules corresponding to
|
||
/// the class "bar"
|
||
///
|
||
/// Because we match Rules right-to-left (i.e., moving up the tree
|
||
/// from an element), we need to compare the last simple selector in the
|
||
/// Rule with the element.
|
||
///
|
||
/// So, if an element has ID "id1" and classes "foo" and "bar", then all
|
||
/// the rules it matches will have their last simple selector starting
|
||
/// either with "#id1" or with ".foo" or with ".bar".
|
||
///
|
||
/// Hence, the union of the rules keyed on each of element's classes, ID,
|
||
/// element name, etc. will contain the Rules that actually match that
|
||
/// element.
|
||
///
|
||
/// TODO: Tune the initial capacity of the HashMap
|
||
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
|
||
pub struct SelectorMap {
|
||
/// A hash from an ID to rules which contain that ID selector.
|
||
pub id_hash: FnvHashMap<Atom, Vec<Rule>>,
|
||
/// A hash from a class name to rules which contain that class selector.
|
||
pub class_hash: FnvHashMap<Atom, Vec<Rule>>,
|
||
/// A hash from local name to rules which contain that local name selector.
|
||
pub local_name_hash: FnvHashMap<LocalName, Vec<Rule>>,
|
||
/// Rules that don't have ID, class, or element selectors.
|
||
pub other_rules: Vec<Rule>,
|
||
/// Whether this hash is empty.
|
||
pub empty: bool,
|
||
}
|
||
|
||
#[inline]
|
||
fn sort_by_key<T, F: Fn(&T) -> K, K: Ord>(v: &mut [T], f: F) {
|
||
sort_by(v, |a, b| f(a).cmp(&f(b)))
|
||
}
|
||
|
||
impl SelectorMap {
|
||
/// Trivially constructs an empty `SelectorMap`.
|
||
pub fn new() -> Self {
|
||
SelectorMap {
|
||
id_hash: HashMap::default(),
|
||
class_hash: HashMap::default(),
|
||
local_name_hash: HashMap::default(),
|
||
other_rules: Vec::new(),
|
||
empty: true,
|
||
}
|
||
}
|
||
|
||
/// Append to `rule_list` all Rules in `self` that match element.
|
||
///
|
||
/// Extract matching rules as per element's ID, classes, tag name, etc..
|
||
/// Sort the Rules at the end to maintain cascading order.
|
||
pub fn get_all_matching_rules<E, V, F>(&self,
|
||
element: &E,
|
||
parent_bf: Option<&BloomFilter>,
|
||
matching_rules_list: &mut V,
|
||
relations: &mut StyleRelations,
|
||
flags_setter: &mut F,
|
||
cascade_level: CascadeLevel)
|
||
where E: Element<Impl=SelectorImpl>,
|
||
V: VecLike<ApplicableDeclarationBlock>,
|
||
F: FnMut(&E, ElementSelectorFlags),
|
||
{
|
||
if self.empty {
|
||
return
|
||
}
|
||
|
||
// At the end, we're going to sort the rules that we added, so remember where we began.
|
||
let init_len = matching_rules_list.len();
|
||
if let Some(id) = element.get_id() {
|
||
SelectorMap::get_matching_rules_from_hash(element,
|
||
parent_bf,
|
||
&self.id_hash,
|
||
&id,
|
||
matching_rules_list,
|
||
relations,
|
||
flags_setter,
|
||
cascade_level)
|
||
}
|
||
|
||
element.each_class(|class| {
|
||
SelectorMap::get_matching_rules_from_hash(element,
|
||
parent_bf,
|
||
&self.class_hash,
|
||
class,
|
||
matching_rules_list,
|
||
relations,
|
||
flags_setter,
|
||
cascade_level);
|
||
});
|
||
|
||
SelectorMap::get_matching_rules_from_hash(element,
|
||
parent_bf,
|
||
&self.local_name_hash,
|
||
element.get_local_name(),
|
||
matching_rules_list,
|
||
relations,
|
||
flags_setter,
|
||
cascade_level);
|
||
|
||
SelectorMap::get_matching_rules(element,
|
||
parent_bf,
|
||
&self.other_rules,
|
||
matching_rules_list,
|
||
relations,
|
||
flags_setter,
|
||
cascade_level);
|
||
|
||
// Sort only the rules we just added.
|
||
sort_by_key(&mut matching_rules_list[init_len..],
|
||
|block| (block.specificity, block.source_order));
|
||
}
|
||
|
||
/// Append to `rule_list` all universal Rules (rules with selector `*|*`) in
|
||
/// `self` sorted by specificity and source order.
|
||
pub fn get_universal_rules(&self,
|
||
guard: &SharedRwLockReadGuard,
|
||
cascade_level: CascadeLevel,
|
||
important_cascade_level: CascadeLevel)
|
||
-> Vec<ApplicableDeclarationBlock> {
|
||
debug_assert!(!cascade_level.is_important());
|
||
debug_assert!(important_cascade_level.is_important());
|
||
if self.empty {
|
||
return vec![];
|
||
}
|
||
|
||
let mut matching_rules_list = vec![];
|
||
|
||
// We need to insert important rules _after_ normal rules for this to be
|
||
// correct, and also to not trigger rule tree assertions.
|
||
let mut important = vec![];
|
||
for rule in self.other_rules.iter() {
|
||
if rule.selector.complex.iter_raw().next().is_none() {
|
||
let style_rule = rule.style_rule.read_with(guard);
|
||
let block = style_rule.block.read_with(guard);
|
||
if block.any_normal() {
|
||
matching_rules_list.push(
|
||
rule.to_applicable_declaration_block(cascade_level));
|
||
}
|
||
if block.any_important() {
|
||
important.push(
|
||
rule.to_applicable_declaration_block(important_cascade_level));
|
||
}
|
||
}
|
||
}
|
||
|
||
let normal_len = matching_rules_list.len();
|
||
matching_rules_list.extend(important.into_iter());
|
||
|
||
sort_by_key(&mut matching_rules_list[0..normal_len],
|
||
|block| (block.specificity, block.source_order));
|
||
sort_by_key(&mut matching_rules_list[normal_len..],
|
||
|block| (block.specificity, block.source_order));
|
||
|
||
matching_rules_list
|
||
}
|
||
|
||
fn get_matching_rules_from_hash<E, Str, BorrowedStr: ?Sized, Vector, F>(
|
||
element: &E,
|
||
parent_bf: Option<&BloomFilter>,
|
||
hash: &FnvHashMap<Str, Vec<Rule>>,
|
||
key: &BorrowedStr,
|
||
matching_rules: &mut Vector,
|
||
relations: &mut StyleRelations,
|
||
flags_setter: &mut F,
|
||
cascade_level: CascadeLevel)
|
||
where E: Element<Impl=SelectorImpl>,
|
||
Str: Borrow<BorrowedStr> + Eq + Hash,
|
||
BorrowedStr: Eq + Hash,
|
||
Vector: VecLike<ApplicableDeclarationBlock>,
|
||
F: FnMut(&E, ElementSelectorFlags),
|
||
{
|
||
if let Some(rules) = hash.get(key) {
|
||
SelectorMap::get_matching_rules(element,
|
||
parent_bf,
|
||
rules,
|
||
matching_rules,
|
||
relations,
|
||
flags_setter,
|
||
cascade_level)
|
||
}
|
||
}
|
||
|
||
/// Adds rules in `rules` that match `element` to the `matching_rules` list.
|
||
fn get_matching_rules<E, V, F>(element: &E,
|
||
parent_bf: Option<&BloomFilter>,
|
||
rules: &[Rule],
|
||
matching_rules: &mut V,
|
||
relations: &mut StyleRelations,
|
||
flags_setter: &mut F,
|
||
cascade_level: CascadeLevel)
|
||
where E: Element<Impl=SelectorImpl>,
|
||
V: VecLike<ApplicableDeclarationBlock>,
|
||
F: FnMut(&E, ElementSelectorFlags),
|
||
{
|
||
for rule in rules.iter() {
|
||
let any_declaration_for_importance = if cascade_level.is_important() {
|
||
rule.any_important_declarations()
|
||
} else {
|
||
rule.any_normal_declarations()
|
||
};
|
||
if any_declaration_for_importance &&
|
||
matches_selector(&rule.selector, element, parent_bf,
|
||
relations, flags_setter) {
|
||
matching_rules.push(
|
||
rule.to_applicable_declaration_block(cascade_level));
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Insert rule into the correct hash.
|
||
/// Order in which to try: id_hash, class_hash, local_name_hash, other_rules.
|
||
pub fn insert(&mut self, rule: Rule) {
|
||
self.empty = false;
|
||
|
||
if let Some(id_name) = SelectorMap::get_id_name(&rule) {
|
||
find_push(&mut self.id_hash, id_name, rule);
|
||
return;
|
||
}
|
||
|
||
if let Some(class_name) = SelectorMap::get_class_name(&rule) {
|
||
find_push(&mut self.class_hash, class_name, rule);
|
||
return;
|
||
}
|
||
|
||
if let Some(LocalNameSelector { name, lower_name }) = SelectorMap::get_local_name(&rule) {
|
||
// If the local name in the selector isn't lowercase, insert it into
|
||
// the rule hash twice. This means that, during lookup, we can always
|
||
// find the rules based on the local name of the element, regardless
|
||
// of whether it's an html element in an html document (in which case
|
||
// we match against lower_name) or not (in which case we match against
|
||
// name).
|
||
//
|
||
// In the case of a non-html-element-in-html-document with a
|
||
// lowercase localname and a non-lowercase selector, the rulehash
|
||
// lookup may produce superfluous selectors, but the subsequent
|
||
// selector matching work will filter them out.
|
||
if name != lower_name {
|
||
find_push(&mut self.local_name_hash, lower_name, rule.clone());
|
||
}
|
||
find_push(&mut self.local_name_hash, name, rule);
|
||
|
||
return;
|
||
}
|
||
|
||
self.other_rules.push(rule);
|
||
}
|
||
|
||
/// Retrieve the first ID name in Rule, or None otherwise.
|
||
pub fn get_id_name(rule: &Rule) -> Option<Atom> {
|
||
for ss in rule.selector.complex.iter() {
|
||
// TODO(pradeep): Implement case-sensitivity based on the
|
||
// document type and quirks mode.
|
||
if let Component::ID(ref id) = *ss {
|
||
return Some(id.clone());
|
||
}
|
||
}
|
||
|
||
None
|
||
}
|
||
|
||
/// Retrieve the FIRST class name in Rule, or None otherwise.
|
||
pub fn get_class_name(rule: &Rule) -> Option<Atom> {
|
||
for ss in rule.selector.complex.iter() {
|
||
// TODO(pradeep): Implement case-sensitivity based on the
|
||
// document type and quirks mode.
|
||
if let Component::Class(ref class) = *ss {
|
||
return Some(class.clone());
|
||
}
|
||
}
|
||
|
||
None
|
||
}
|
||
|
||
/// Retrieve the name if it is a type selector, or None otherwise.
|
||
pub fn get_local_name(rule: &Rule) -> Option<LocalNameSelector<SelectorImpl>> {
|
||
for ss in rule.selector.complex.iter() {
|
||
if let Component::LocalName(ref n) = *ss {
|
||
return Some(LocalNameSelector {
|
||
name: n.name.clone(),
|
||
lower_name: n.lower_name.clone(),
|
||
})
|
||
}
|
||
}
|
||
|
||
None
|
||
}
|
||
}
|
||
|
||
/// A rule, that wraps a style rule, but represents a single selector of the
|
||
/// rule.
|
||
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
|
||
#[derive(Clone, Debug)]
|
||
pub struct Rule {
|
||
/// The selector this struct represents. We store this and the
|
||
/// any_{important,normal} booleans inline in the Rule to avoid
|
||
/// pointer-chasing when gathering applicable declarations, which
|
||
/// can ruin performance when there are a lot of rules.
|
||
#[cfg_attr(feature = "servo", ignore_heap_size_of = "Arc")]
|
||
pub selector: SelectorInner<SelectorImpl>,
|
||
/// The actual style rule.
|
||
#[cfg_attr(feature = "servo", ignore_heap_size_of = "Arc")]
|
||
pub style_rule: Arc<Locked<StyleRule>>,
|
||
/// The source order this style rule appears in.
|
||
pub source_order: usize,
|
||
/// Bottom 30 bits: The specificity of the rule this selector represents.
|
||
/// 31st bit: Whether the rule's declaration block has any important declarations.
|
||
/// 32nd bit: Whether the rule's declaration block has any normal declarations.
|
||
specificity_and_bits: u32,
|
||
}
|
||
|
||
/// Masks for specificity_and_bits.
|
||
const SPECIFICITY_MASK: u32 = 0x3fffffff;
|
||
const ANY_IMPORTANT_DECLARATIONS_BIT: u32 = 1 << 30;
|
||
const ANY_NORMAL_DECLARATIONS_BIT: u32 = 1 << 31;
|
||
|
||
impl Rule {
|
||
/// Returns the specificity of the rule.
|
||
pub fn specificity(&self) -> u32 {
|
||
self.specificity_and_bits & SPECIFICITY_MASK
|
||
}
|
||
|
||
fn any_important_declarations(&self) -> bool {
|
||
(self.specificity_and_bits & ANY_IMPORTANT_DECLARATIONS_BIT) != 0
|
||
}
|
||
|
||
fn any_normal_declarations(&self) -> bool {
|
||
(self.specificity_and_bits & ANY_NORMAL_DECLARATIONS_BIT) != 0
|
||
}
|
||
|
||
fn to_applicable_declaration_block(&self, level: CascadeLevel) -> ApplicableDeclarationBlock {
|
||
ApplicableDeclarationBlock {
|
||
source: StyleSource::Style(self.style_rule.clone()),
|
||
level: level,
|
||
source_order: self.source_order,
|
||
specificity: self.specificity(),
|
||
}
|
||
}
|
||
|
||
/// Creates a new Rule.
|
||
pub fn new(guard: &SharedRwLockReadGuard,
|
||
selector: SelectorInner<SelectorImpl>,
|
||
style_rule: Arc<Locked<StyleRule>>,
|
||
source_order: usize,
|
||
specificity: u32)
|
||
-> Self
|
||
{
|
||
let (any_important, any_normal) = {
|
||
let block = style_rule.read_with(guard).block.read_with(guard);
|
||
(block.any_important(), block.any_normal())
|
||
};
|
||
debug_assert!(specificity & (ANY_IMPORTANT_DECLARATIONS_BIT | ANY_NORMAL_DECLARATIONS_BIT) == 0);
|
||
let mut specificity_and_bits = specificity;
|
||
if any_important {
|
||
specificity_and_bits |= ANY_IMPORTANT_DECLARATIONS_BIT;
|
||
}
|
||
if any_normal {
|
||
specificity_and_bits |= ANY_NORMAL_DECLARATIONS_BIT;
|
||
}
|
||
|
||
Rule {
|
||
selector: selector,
|
||
style_rule: style_rule,
|
||
source_order: source_order,
|
||
specificity_and_bits: specificity_and_bits,
|
||
}
|
||
}
|
||
}
|
||
|
||
/// A property declaration together with its precedence among rules of equal
|
||
/// specificity so that we can sort them.
|
||
///
|
||
/// This represents the declarations in a given declaration block for a given
|
||
/// importance.
|
||
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
|
||
#[derive(Debug, Clone)]
|
||
pub struct ApplicableDeclarationBlock {
|
||
/// The style source, either a style rule, or a property declaration block.
|
||
#[cfg_attr(feature = "servo", ignore_heap_size_of = "Arc")]
|
||
pub source: StyleSource,
|
||
/// The cascade level this applicable declaration block is in.
|
||
pub level: CascadeLevel,
|
||
/// The source order of this block.
|
||
pub source_order: usize,
|
||
/// The specificity of the selector this block is represented by.
|
||
pub specificity: u32,
|
||
}
|
||
|
||
impl ApplicableDeclarationBlock {
|
||
/// Constructs an applicable declaration block from a given property
|
||
/// declaration block and importance.
|
||
#[inline]
|
||
pub fn from_declarations(declarations: Arc<Locked<PropertyDeclarationBlock>>,
|
||
level: CascadeLevel)
|
||
-> Self {
|
||
ApplicableDeclarationBlock {
|
||
source: StyleSource::Declarations(declarations),
|
||
level: level,
|
||
source_order: 0,
|
||
specificity: 0,
|
||
}
|
||
}
|
||
}
|
||
|
||
#[inline]
|
||
fn find_push<Str: Eq + Hash>(map: &mut FnvHashMap<Str, Vec<Rule>>, key: Str,
|
||
value: Rule) {
|
||
map.entry(key).or_insert_with(Vec::new).push(value)
|
||
}
|