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d15acc219e
Before this refactoring, getComputedStyle could have side effects, and left the style data in the element, so we could never arrive there without data. There are a few crashtests that caught this, but this was already broken if you called animate() on an element deep in a display: none subtree. MozReview-Commit-ID: 1AvOvhAyOP3
845 lines
34 KiB
Rust
845 lines
34 KiB
Rust
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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//! High-level interface to CSS selector matching.
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#![allow(unsafe_code)]
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#![deny(missing_docs)]
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use context::{ElementCascadeInputs, SelectorFlagsMap, SharedStyleContext, StyleContext};
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use data::{ElementData, ElementStyles, RestyleData};
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use dom::TElement;
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use invalidation::element::restyle_hints::{RESTYLE_CSS_ANIMATIONS, RESTYLE_CSS_TRANSITIONS};
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use invalidation::element::restyle_hints::{RESTYLE_SMIL, RESTYLE_STYLE_ATTRIBUTE};
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use invalidation::element::restyle_hints::RestyleHint;
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use properties::ComputedValues;
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use properties::longhands::display::computed_value as display;
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use rule_tree::{CascadeLevel, StrongRuleNode};
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use selector_parser::{PseudoElement, RestyleDamage};
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use selectors::matching::ElementSelectorFlags;
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use stylearc::Arc;
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/// Represents the result of comparing an element's old and new style.
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pub struct StyleDifference {
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/// The resulting damage.
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pub damage: RestyleDamage,
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/// Whether any styles changed.
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pub change: StyleChange,
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}
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impl StyleDifference {
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/// Creates a new `StyleDifference`.
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pub fn new(damage: RestyleDamage, change: StyleChange) -> Self {
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StyleDifference {
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change: change,
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damage: damage,
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}
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}
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}
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/// Represents whether or not the style of an element has changed.
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#[derive(Copy, Clone)]
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pub enum StyleChange {
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/// The style hasn't changed.
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Unchanged,
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/// The style has changed.
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Changed,
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}
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/// Whether or not newly computed values for an element need to be cascade
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/// to children.
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#[derive(PartialEq, Eq, PartialOrd, Ord, Copy, Clone, Debug)]
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pub enum ChildCascadeRequirement {
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/// Old and new computed values were the same, or we otherwise know that
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/// we won't bother recomputing style for children, so we can skip cascading
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/// the new values into child elements.
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CanSkipCascade = 0,
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/// Old and new computed values were different, so we must cascade the
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/// new values to children.
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///
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/// FIXME(heycam) Although this is "must" cascade, in the future we should
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/// track whether child elements rely specifically on inheriting particular
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/// property values. When we do that, we can treat `MustCascadeChildren` as
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/// "must cascade unless we know that changes to these properties can be
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/// ignored".
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MustCascadeChildren = 1,
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/// The same as `MustCascadeChildren`, but for the entire subtree. This is
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/// used to handle root font-size updates needing to recascade the whole
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/// document.
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MustCascadeDescendants = 2,
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}
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bitflags! {
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/// Flags that represent the result of replace_rules.
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pub flags RulesChanged: u8 {
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/// Normal rules are changed.
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const NORMAL_RULES_CHANGED = 0x01,
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/// Important rules are changed.
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const IMPORTANT_RULES_CHANGED = 0x02,
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}
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}
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impl RulesChanged {
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/// Return true if there are any normal rules changed.
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#[inline]
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pub fn normal_rules_changed(&self) -> bool {
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self.contains(NORMAL_RULES_CHANGED)
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}
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/// Return true if there are any important rules changed.
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#[inline]
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pub fn important_rules_changed(&self) -> bool {
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self.contains(IMPORTANT_RULES_CHANGED)
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}
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}
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/// Determines which styles are being cascaded currently.
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#[derive(PartialEq, Eq, Copy, Clone, Debug)]
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pub enum CascadeVisitedMode {
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/// Cascade the regular, unvisited styles.
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Unvisited,
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/// Cascade the styles used when an element's relevant link is visited. A
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/// "relevant link" is the element being matched if it is a link or the
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/// nearest ancestor link.
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Visited,
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}
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impl CascadeVisitedMode {
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/// Returns whether the cascade should filter to only visited dependent
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/// properties based on the cascade mode.
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pub fn visited_dependent_only(&self) -> bool {
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*self == CascadeVisitedMode::Visited
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}
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}
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trait PrivateMatchMethods: TElement {
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/// If there is no transition rule in the ComputedValues, it returns None.
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#[cfg(feature = "gecko")]
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fn get_after_change_style(
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&self,
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context: &mut StyleContext<Self>,
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primary_style: &Arc<ComputedValues>
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) -> Option<Arc<ComputedValues>> {
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use context::CascadeInputs;
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use style_resolver::StyleResolverForElement;
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use stylist::RuleInclusion;
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let rule_node = primary_style.rules();
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let without_transition_rules =
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context.shared.stylist.rule_tree().remove_transition_rule_if_applicable(rule_node);
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if without_transition_rules == *rule_node {
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// We don't have transition rule in this case, so return None to let
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// the caller use the original ComputedValues.
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return None;
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}
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// FIXME(bug 868975): We probably need to transition visited style as
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// well.
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let inputs =
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CascadeInputs {
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rules: Some(without_transition_rules),
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visited_rules: primary_style.get_visited_style().and_then(|s| s.rules.clone()),
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};
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let style =
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StyleResolverForElement::new(*self, context, RuleInclusion::All)
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.cascade_style_and_visited_with_default_parents(inputs);
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Some(style)
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}
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#[cfg(feature = "gecko")]
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fn needs_animations_update(&self,
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context: &mut StyleContext<Self>,
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old_values: Option<&Arc<ComputedValues>>,
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new_values: &ComputedValues)
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-> bool {
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let new_box_style = new_values.get_box();
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let has_new_animation_style = new_box_style.animation_name_count() >= 1 &&
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new_box_style.animation_name_at(0).0.is_some();
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let has_animations = self.has_css_animations();
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old_values.map_or(has_new_animation_style, |old| {
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let old_box_style = old.get_box();
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let old_display_style = old_box_style.clone_display();
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let new_display_style = new_box_style.clone_display();
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// If the traverse is triggered by CSS rule changes, we need to
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// try to update all CSS animations on the element if the element
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// has CSS animation style regardless of whether the animation is
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// running or not.
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// TODO: We should check which @keyframes changed/added/deleted
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// and update only animations corresponding to those @keyframes.
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(context.shared.traversal_flags.for_css_rule_changes() &&
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has_new_animation_style) ||
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!old_box_style.animations_equals(&new_box_style) ||
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(old_display_style == display::T::none &&
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new_display_style != display::T::none &&
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has_new_animation_style) ||
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(old_display_style != display::T::none &&
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new_display_style == display::T::none &&
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has_animations)
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})
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}
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#[cfg(feature = "gecko")]
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fn process_animations(&self,
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context: &mut StyleContext<Self>,
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old_values: &mut Option<Arc<ComputedValues>>,
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new_values: &mut Arc<ComputedValues>,
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important_rules_changed: bool) {
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use context::{CASCADE_RESULTS, CSS_ANIMATIONS, CSS_TRANSITIONS, EFFECT_PROPERTIES};
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use context::UpdateAnimationsTasks;
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// Bug 868975: These steps should examine and update the visited styles
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// in addition to the unvisited styles.
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let mut tasks = UpdateAnimationsTasks::empty();
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if self.needs_animations_update(context, old_values.as_ref(), new_values) {
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tasks.insert(CSS_ANIMATIONS);
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}
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let before_change_style = if self.might_need_transitions_update(old_values.as_ref().map(|s| &**s),
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new_values) {
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let after_change_style = if self.has_css_transitions() {
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self.get_after_change_style(context, new_values)
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} else {
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None
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};
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// In order to avoid creating a SequentialTask for transitions which
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// may not be updated, we check it per property to make sure Gecko
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// side will really update transition.
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let needs_transitions_update = {
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// We borrow new_values here, so need to add a scope to make
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// sure we release it before assigning a new value to it.
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let after_change_style_ref =
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after_change_style.as_ref().unwrap_or(&new_values);
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self.needs_transitions_update(old_values.as_ref().unwrap(),
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after_change_style_ref)
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};
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if needs_transitions_update {
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if let Some(values_without_transitions) = after_change_style {
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*new_values = values_without_transitions;
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}
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tasks.insert(CSS_TRANSITIONS);
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// We need to clone old_values into SequentialTask, so we can use it later.
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old_values.clone()
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} else {
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None
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}
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} else {
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None
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};
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if self.has_animations() {
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tasks.insert(EFFECT_PROPERTIES);
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if important_rules_changed {
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tasks.insert(CASCADE_RESULTS);
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}
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}
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if !tasks.is_empty() {
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let task = ::context::SequentialTask::update_animations(*self,
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before_change_style,
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tasks);
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context.thread_local.tasks.push(task);
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}
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}
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#[cfg(feature = "servo")]
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fn process_animations(&self,
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context: &mut StyleContext<Self>,
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old_values: &mut Option<Arc<ComputedValues>>,
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new_values: &mut Arc<ComputedValues>,
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_important_rules_changed: bool) {
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use animation;
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use dom::TNode;
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let possibly_expired_animations =
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&mut context.thread_local.current_element_info.as_mut().unwrap()
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.possibly_expired_animations;
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let shared_context = context.shared;
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if let Some(ref mut old) = *old_values {
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self.update_animations_for_cascade(shared_context, old,
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possibly_expired_animations,
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&context.thread_local.font_metrics_provider);
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}
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let new_animations_sender = &context.thread_local.new_animations_sender;
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let this_opaque = self.as_node().opaque();
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// Trigger any present animations if necessary.
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animation::maybe_start_animations(&shared_context,
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new_animations_sender,
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this_opaque, &new_values);
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// Trigger transitions if necessary. This will reset `new_values` back
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// to its old value if it did trigger a transition.
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if let Some(ref values) = *old_values {
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animation::start_transitions_if_applicable(
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new_animations_sender,
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this_opaque,
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&**values,
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new_values,
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&shared_context.timer,
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&possibly_expired_animations);
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}
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}
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/// Computes and applies non-redundant damage.
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#[cfg(feature = "gecko")]
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fn accumulate_damage_for(&self,
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shared_context: &SharedStyleContext,
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restyle: &mut RestyleData,
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old_values: &ComputedValues,
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new_values: &Arc<ComputedValues>,
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pseudo: Option<&PseudoElement>)
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-> ChildCascadeRequirement {
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use properties::computed_value_flags::*;
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// Don't accumulate damage if we're in a restyle for reconstruction.
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if shared_context.traversal_flags.for_reconstruct() {
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return ChildCascadeRequirement::MustCascadeChildren;
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}
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// If an ancestor is already getting reconstructed by Gecko's top-down
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// frame constructor, no need to apply damage. Similarly if we already
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// have an explicitly stored ReconstructFrame hint.
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//
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// See https://bugzilla.mozilla.org/show_bug.cgi?id=1301258#c12
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// for followup work to make the optimization here more optimal by considering
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// each bit individually.
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let skip_applying_damage =
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restyle.reconstructed_self_or_ancestor();
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let difference =
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self.compute_style_difference(&old_values, &new_values, pseudo);
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if !skip_applying_damage {
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restyle.damage |= difference.damage;
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}
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match difference.change {
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StyleChange::Unchanged => {
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// We need to cascade the children in order to ensure the
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// correct propagation of text-decoration-line, which is a reset
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// property.
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if old_values.flags.contains(HAS_TEXT_DECORATION_LINE) !=
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new_values.flags.contains(HAS_TEXT_DECORATION_LINE) {
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return ChildCascadeRequirement::MustCascadeChildren;
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}
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ChildCascadeRequirement::CanSkipCascade
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},
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StyleChange::Changed => ChildCascadeRequirement::MustCascadeChildren,
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}
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}
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/// Computes and applies restyle damage unless we've already maxed it out.
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#[cfg(feature = "servo")]
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fn accumulate_damage_for(&self,
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_shared_context: &SharedStyleContext,
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restyle: &mut RestyleData,
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old_values: &ComputedValues,
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new_values: &Arc<ComputedValues>,
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pseudo: Option<&PseudoElement>)
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-> ChildCascadeRequirement {
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let difference = self.compute_style_difference(&old_values, &new_values, pseudo);
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restyle.damage |= difference.damage;
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match difference.change {
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StyleChange::Changed => ChildCascadeRequirement::MustCascadeChildren,
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StyleChange::Unchanged => ChildCascadeRequirement::CanSkipCascade,
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}
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}
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#[cfg(feature = "servo")]
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fn update_animations_for_cascade(&self,
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context: &SharedStyleContext,
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style: &mut Arc<ComputedValues>,
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possibly_expired_animations: &mut Vec<::animation::PropertyAnimation>,
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font_metrics: &::font_metrics::FontMetricsProvider) {
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use animation::{self, Animation};
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use dom::TNode;
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// Finish any expired transitions.
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let this_opaque = self.as_node().opaque();
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animation::complete_expired_transitions(this_opaque, style, context);
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// Merge any running transitions into the current style, and cancel them.
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let had_running_animations = context.running_animations
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.read()
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.get(&this_opaque)
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.is_some();
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if had_running_animations {
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let mut all_running_animations = context.running_animations.write();
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for running_animation in all_running_animations.get_mut(&this_opaque).unwrap() {
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// This shouldn't happen frequently, but under some
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// circumstances mainly huge load or debug builds, the
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// constellation might be delayed in sending the
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// `TickAllAnimations` message to layout.
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//
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// Thus, we can't assume all the animations have been already
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// updated by layout, because other restyle due to script might
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// be triggered by layout before the animation tick.
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//
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// See #12171 and the associated PR for an example where this
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// happened while debugging other release panic.
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if !running_animation.is_expired() {
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animation::update_style_for_animation(context,
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running_animation,
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style,
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font_metrics);
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if let Animation::Transition(_, _, ref frame, _) = *running_animation {
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possibly_expired_animations.push(frame.property_animation.clone())
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}
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}
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}
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}
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}
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}
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|
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impl<E: TElement> PrivateMatchMethods for E {}
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|
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/// The public API that elements expose for selector matching.
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pub trait MatchMethods : TElement {
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/// Returns the closest parent element that doesn't have a display: contents
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/// style (and thus generates a box).
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///
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/// This is needed to correctly handle blockification of flex and grid
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/// items.
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///
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/// Returns itself if the element has no parent. In practice this doesn't
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/// happen because the root element is blockified per spec, but it could
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/// happen if we decide to not blockify for roots of disconnected subtrees,
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/// which is a kind of dubious beahavior.
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fn layout_parent(&self) -> Self {
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let mut current = self.clone();
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loop {
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current = match current.traversal_parent() {
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Some(el) => el,
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None => return current,
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};
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|
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let is_display_contents =
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current.borrow_data().unwrap().styles.primary().is_display_contents();
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|
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if !is_display_contents {
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return current;
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}
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}
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}
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|
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/// Updates the styles with the new ones, diffs them, and stores the restyle
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/// damage.
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fn finish_restyle(
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&self,
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context: &mut StyleContext<Self>,
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mut data: &mut ElementData,
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mut new_styles: ElementStyles,
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important_rules_changed: bool,
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) -> ChildCascadeRequirement {
|
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use dom::TNode;
|
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use std::cmp;
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use std::mem;
|
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|
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debug_assert!(new_styles.primary.is_some(), "How did that happen?");
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|
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if !context.shared.traversal_flags.for_animation_only() {
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self.process_animations(
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context,
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&mut data.styles.primary,
|
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&mut new_styles.primary.as_mut().unwrap(),
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important_rules_changed,
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);
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}
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|
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// First of all, update the styles.
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let old_styles = mem::replace(&mut data.styles, new_styles);
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|
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// Propagate the "can be fragmented" bit. It would be nice to
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// encapsulate this better.
|
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//
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// Note that this is technically not needed for pseudos since we already
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// do that when we resolve the non-pseudo style, but it doesn't hurt
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// anyway.
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if cfg!(feature = "servo") {
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let layout_parent =
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self.inheritance_parent().map(|e| e.layout_parent());
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let layout_parent_data =
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layout_parent.as_ref().and_then(|e| e.borrow_data());
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let layout_parent_style =
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layout_parent_data.as_ref().map(|d| d.styles.primary());
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|
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if let Some(ref p) = layout_parent_style {
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let can_be_fragmented =
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p.is_multicol() ||
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layout_parent.as_ref().unwrap().as_node().can_be_fragmented();
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unsafe { self.as_node().set_can_be_fragmented(can_be_fragmented); }
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}
|
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}
|
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|
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// Don't accumulate damage if we're in a restyle for reconstruction.
|
|
if context.shared.traversal_flags.for_reconstruct() {
|
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return ChildCascadeRequirement::MustCascadeChildren;
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}
|
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|
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let new_primary_style = data.styles.primary.as_ref().unwrap();
|
|
|
|
let mut cascade_requirement = ChildCascadeRequirement::CanSkipCascade;
|
|
if self.is_root() && !self.is_native_anonymous() {
|
|
let device = context.shared.stylist.device();
|
|
let new_font_size = new_primary_style.get_font().clone_font_size();
|
|
|
|
if old_styles.primary.as_ref().map_or(true, |s| s.get_font().clone_font_size() != new_font_size) {
|
|
debug_assert!(self.owner_doc_matches_for_testing(device));
|
|
device.set_root_font_size(new_font_size);
|
|
// If the root font-size changed since last time, and something
|
|
// in the document did use rem units, ensure we recascade the
|
|
// entire tree.
|
|
if device.used_root_font_size() {
|
|
cascade_requirement = ChildCascadeRequirement::MustCascadeDescendants;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Also, don't do anything if there was no style.
|
|
let old_primary_style = match old_styles.primary {
|
|
Some(s) => s,
|
|
None => return ChildCascadeRequirement::MustCascadeChildren,
|
|
};
|
|
|
|
cascade_requirement = cmp::max(
|
|
cascade_requirement,
|
|
self.accumulate_damage_for(
|
|
context.shared,
|
|
&mut data.restyle,
|
|
&old_primary_style,
|
|
new_primary_style,
|
|
None,
|
|
)
|
|
);
|
|
|
|
if data.styles.pseudos.is_empty() && old_styles.pseudos.is_empty() {
|
|
return cascade_requirement;
|
|
}
|
|
|
|
// If it matched a different number of pseudos, reconstruct.
|
|
if data.styles.pseudos.is_empty() != old_styles.pseudos.is_empty() {
|
|
data.restyle.damage |= RestyleDamage::reconstruct();
|
|
return cascade_requirement;
|
|
}
|
|
|
|
let pseudo_styles =
|
|
old_styles.pseudos.as_array().unwrap().iter().zip(
|
|
data.styles.pseudos.as_array().unwrap().iter());
|
|
|
|
for (i, (old, new)) in pseudo_styles.enumerate() {
|
|
match (old, new) {
|
|
(&Some(ref old), &Some(ref new)) => {
|
|
self.accumulate_damage_for(
|
|
context.shared,
|
|
&mut data.restyle,
|
|
old,
|
|
new,
|
|
Some(&PseudoElement::from_eager_index(i)),
|
|
);
|
|
}
|
|
(&None, &None) => {},
|
|
_ => {
|
|
data.restyle.damage |= RestyleDamage::reconstruct();
|
|
return cascade_requirement;
|
|
}
|
|
}
|
|
}
|
|
|
|
cascade_requirement
|
|
}
|
|
|
|
|
|
/// Applies selector flags to an element, deferring mutations of the parent
|
|
/// until after the traversal.
|
|
///
|
|
/// TODO(emilio): This is somewhat inefficient, because it doesn't take
|
|
/// advantage of us knowing that the traversal is sequential.
|
|
fn apply_selector_flags(&self,
|
|
map: &mut SelectorFlagsMap<Self>,
|
|
element: &Self,
|
|
flags: ElementSelectorFlags) {
|
|
// Handle flags that apply to the element.
|
|
let self_flags = flags.for_self();
|
|
if !self_flags.is_empty() {
|
|
if element == self {
|
|
// If this is the element we're styling, we have exclusive
|
|
// access to the element, and thus it's fine inserting them,
|
|
// even from the worker.
|
|
unsafe { element.set_selector_flags(self_flags); }
|
|
} else {
|
|
// Otherwise, this element is an ancestor of the current element
|
|
// we're styling, and thus multiple children could write to it
|
|
// if we did from here.
|
|
//
|
|
// Instead, we can read them, and post them if necessary as a
|
|
// sequential task in order for them to be processed later.
|
|
if !element.has_selector_flags(self_flags) {
|
|
map.insert_flags(*element, self_flags);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Handle flags that apply to the parent.
|
|
let parent_flags = flags.for_parent();
|
|
if !parent_flags.is_empty() {
|
|
if let Some(p) = element.parent_element() {
|
|
if !p.has_selector_flags(parent_flags) {
|
|
map.insert_flags(p, parent_flags);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Computes and applies restyle damage.
|
|
fn accumulate_damage(&self,
|
|
shared_context: &SharedStyleContext,
|
|
restyle: &mut RestyleData,
|
|
old_values: Option<&ComputedValues>,
|
|
new_values: &Arc<ComputedValues>,
|
|
pseudo: Option<&PseudoElement>)
|
|
-> ChildCascadeRequirement {
|
|
let old_values = match old_values {
|
|
Some(v) => v,
|
|
None => return ChildCascadeRequirement::MustCascadeChildren,
|
|
};
|
|
|
|
// ::before and ::after are element-backed in Gecko, so they do the
|
|
// damage calculation for themselves, when there's an actual pseudo.
|
|
let is_existing_before_or_after =
|
|
cfg!(feature = "gecko") &&
|
|
pseudo.map_or(false, |p| p.is_before_or_after()) &&
|
|
self.existing_style_for_restyle_damage(old_values, pseudo)
|
|
.is_some();
|
|
|
|
if is_existing_before_or_after {
|
|
return ChildCascadeRequirement::CanSkipCascade;
|
|
}
|
|
|
|
self.accumulate_damage_for(shared_context,
|
|
restyle,
|
|
old_values,
|
|
new_values,
|
|
pseudo)
|
|
}
|
|
|
|
/// Updates the rule nodes without re-running selector matching, using just
|
|
/// the rule tree.
|
|
///
|
|
/// Returns true if an !important rule was replaced.
|
|
fn replace_rules(
|
|
&self,
|
|
replacements: RestyleHint,
|
|
context: &mut StyleContext<Self>,
|
|
cascade_inputs: &mut ElementCascadeInputs,
|
|
) -> bool {
|
|
let mut result = false;
|
|
result |= self.replace_rules_internal(
|
|
replacements,
|
|
context,
|
|
CascadeVisitedMode::Unvisited,
|
|
cascade_inputs,
|
|
);
|
|
if !context.shared.traversal_flags.for_animation_only() {
|
|
result |= self.replace_rules_internal(
|
|
replacements,
|
|
context,
|
|
CascadeVisitedMode::Visited,
|
|
cascade_inputs
|
|
);
|
|
}
|
|
result
|
|
}
|
|
|
|
/// Updates the rule nodes without re-running selector matching, using just
|
|
/// the rule tree, for a specific visited mode.
|
|
///
|
|
/// Returns true if an !important rule was replaced.
|
|
fn replace_rules_internal(
|
|
&self,
|
|
replacements: RestyleHint,
|
|
context: &mut StyleContext<Self>,
|
|
cascade_visited: CascadeVisitedMode,
|
|
cascade_inputs: &mut ElementCascadeInputs,
|
|
) -> bool {
|
|
use properties::PropertyDeclarationBlock;
|
|
use shared_lock::Locked;
|
|
|
|
debug_assert!(replacements.intersects(RestyleHint::replacements()) &&
|
|
(replacements & !RestyleHint::replacements()).is_empty());
|
|
|
|
let stylist = &context.shared.stylist;
|
|
let guards = &context.shared.guards;
|
|
|
|
let primary_rules =
|
|
match cascade_visited {
|
|
CascadeVisitedMode::Unvisited => cascade_inputs.primary.rules.as_mut(),
|
|
CascadeVisitedMode::Visited => cascade_inputs.primary.visited_rules.as_mut(),
|
|
};
|
|
|
|
let primary_rules = match primary_rules {
|
|
Some(r) => r,
|
|
None => return false,
|
|
};
|
|
|
|
let replace_rule_node = |level: CascadeLevel,
|
|
pdb: Option<&Arc<Locked<PropertyDeclarationBlock>>>,
|
|
path: &mut StrongRuleNode| -> bool {
|
|
let new_node = stylist.rule_tree()
|
|
.update_rule_at_level(level, pdb, path, guards);
|
|
match new_node {
|
|
Some(n) => {
|
|
*path = n;
|
|
level.is_important()
|
|
},
|
|
None => false,
|
|
}
|
|
};
|
|
|
|
if !context.shared.traversal_flags.for_animation_only() {
|
|
let mut result = false;
|
|
if replacements.contains(RESTYLE_STYLE_ATTRIBUTE) {
|
|
let style_attribute = self.style_attribute();
|
|
result |= replace_rule_node(CascadeLevel::StyleAttributeNormal,
|
|
style_attribute,
|
|
primary_rules);
|
|
result |= replace_rule_node(CascadeLevel::StyleAttributeImportant,
|
|
style_attribute,
|
|
primary_rules);
|
|
// FIXME(emilio): Still a hack!
|
|
self.unset_dirty_style_attribute();
|
|
}
|
|
return result;
|
|
}
|
|
|
|
// Animation restyle hints are processed prior to other restyle
|
|
// hints in the animation-only traversal.
|
|
//
|
|
// Non-animation restyle hints will be processed in a subsequent
|
|
// normal traversal.
|
|
if replacements.intersects(RestyleHint::for_animations()) {
|
|
debug_assert!(context.shared.traversal_flags.for_animation_only());
|
|
|
|
if replacements.contains(RESTYLE_SMIL) {
|
|
replace_rule_node(CascadeLevel::SMILOverride,
|
|
self.get_smil_override(),
|
|
primary_rules);
|
|
}
|
|
|
|
let replace_rule_node_for_animation = |level: CascadeLevel,
|
|
primary_rules: &mut StrongRuleNode| {
|
|
let animation_rule = self.get_animation_rule_by_cascade(level);
|
|
replace_rule_node(level,
|
|
animation_rule.as_ref(),
|
|
primary_rules);
|
|
};
|
|
|
|
// Apply Transition rules and Animation rules if the corresponding restyle hint
|
|
// is contained.
|
|
if replacements.contains(RESTYLE_CSS_TRANSITIONS) {
|
|
replace_rule_node_for_animation(CascadeLevel::Transitions,
|
|
primary_rules);
|
|
}
|
|
|
|
if replacements.contains(RESTYLE_CSS_ANIMATIONS) {
|
|
replace_rule_node_for_animation(CascadeLevel::Animations,
|
|
primary_rules);
|
|
}
|
|
}
|
|
|
|
false
|
|
}
|
|
|
|
/// Given the old and new style of this element, and whether it's a
|
|
/// pseudo-element, compute the restyle damage used to determine which
|
|
/// kind of layout or painting operations we'll need.
|
|
fn compute_style_difference(
|
|
&self,
|
|
old_values: &ComputedValues,
|
|
new_values: &Arc<ComputedValues>,
|
|
pseudo: Option<&PseudoElement>
|
|
) -> StyleDifference {
|
|
debug_assert!(pseudo.map_or(true, |p| p.is_eager()));
|
|
if let Some(source) = self.existing_style_for_restyle_damage(old_values, pseudo) {
|
|
return RestyleDamage::compute_style_difference(source, new_values)
|
|
}
|
|
|
|
let new_display = new_values.get_box().clone_display();
|
|
let old_display = old_values.get_box().clone_display();
|
|
|
|
let new_style_is_display_none = new_display == display::T::none;
|
|
let old_style_is_display_none = old_display == display::T::none;
|
|
|
|
// If there's no style source, that likely means that Gecko couldn't
|
|
// find a style context.
|
|
//
|
|
// This happens with display:none elements, and not-yet-existing
|
|
// pseudo-elements.
|
|
if new_style_is_display_none && old_style_is_display_none {
|
|
// The style remains display:none. No need for damage.
|
|
return StyleDifference::new(RestyleDamage::empty(), StyleChange::Unchanged)
|
|
}
|
|
|
|
if pseudo.map_or(false, |p| p.is_before_or_after()) {
|
|
let old_style_generates_no_pseudo =
|
|
old_style_is_display_none ||
|
|
old_values.ineffective_content_property();
|
|
|
|
let new_style_generates_no_pseudo =
|
|
new_style_is_display_none ||
|
|
new_values.ineffective_content_property();
|
|
|
|
if old_style_generates_no_pseudo != new_style_generates_no_pseudo {
|
|
return StyleDifference::new(RestyleDamage::reconstruct(), StyleChange::Changed)
|
|
}
|
|
|
|
// The pseudo-element will remain undisplayed, so just avoid
|
|
// triggering any change.
|
|
//
|
|
// NOTE(emilio): We will only arrive here for pseudo-elements that
|
|
// aren't generated (see the is_existing_before_or_after check in
|
|
// accumulate_damage).
|
|
//
|
|
// However, it may be the case that the style of this element would
|
|
// make us think we need a pseudo, but we don't, like for pseudos in
|
|
// replaced elements, that's why we need the old != new instead of
|
|
// just check whether the new style would generate a pseudo.
|
|
return StyleDifference::new(RestyleDamage::empty(), StyleChange::Unchanged)
|
|
}
|
|
|
|
if pseudo.map_or(false, |p| p.is_first_letter()) {
|
|
// No one cares about this pseudo, and we've checked above that
|
|
// we're not switching from a "cares" to a "doesn't care" state
|
|
// or vice versa.
|
|
return StyleDifference::new(RestyleDamage::empty(),
|
|
StyleChange::Unchanged)
|
|
}
|
|
|
|
// If we are changing display property we need to accumulate
|
|
// reconstruction damage for the change.
|
|
// FIXME: Bug 1378972: This is a workaround for bug 1374175, we should
|
|
// generate more accurate restyle damage in fallback cases.
|
|
let needs_reconstruction = new_display != old_display;
|
|
let damage = if needs_reconstruction {
|
|
RestyleDamage::reconstruct()
|
|
} else {
|
|
RestyleDamage::empty()
|
|
};
|
|
// We don't really know if there was a change in any style (since we
|
|
// didn't actually call compute_style_difference) but we return
|
|
// StyleChange::Changed conservatively.
|
|
StyleDifference::new(damage, StyleChange::Changed)
|
|
}
|
|
}
|
|
|
|
impl<E: TElement> MatchMethods for E {}
|