style/stylesheets/
style_rule.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5//! A style rule.
6
7use crate::derives::*;
8use crate::properties::PropertyDeclarationBlock;
9use crate::selector_parser::SelectorImpl;
10use crate::shared_lock::{
11    DeepCloneWithLock, Locked, SharedRwLock, SharedRwLockReadGuard, ToCssWithGuard,
12};
13use crate::stylesheets::{style_or_page_rule_to_css, CssRules};
14use cssparser::SourceLocation;
15#[cfg(feature = "gecko")]
16use malloc_size_of::{
17    MallocSizeOf, MallocSizeOfOps, MallocUnconditionalShallowSizeOf, MallocUnconditionalSizeOf,
18};
19use selectors::SelectorList;
20use servo_arc::Arc;
21use std::fmt::{self, Write};
22use style_traits::CssStringWriter;
23
24/// A style rule, with selectors and declarations.
25#[derive(Debug, ToShmem)]
26pub struct StyleRule {
27    /// The list of selectors in this rule.
28    pub selectors: SelectorList<SelectorImpl>,
29    /// The declaration block with the properties it contains.
30    pub block: Arc<Locked<PropertyDeclarationBlock>>,
31    /// The nested rules to this style rule. Only non-`None` when nesting is enabled.
32    pub rules: Option<Arc<Locked<CssRules>>>,
33    /// The location in the sheet where it was found.
34    pub source_location: SourceLocation,
35}
36
37impl DeepCloneWithLock for StyleRule {
38    /// Deep clones this StyleRule.
39    fn deep_clone_with_lock(
40        &self,
41        lock: &SharedRwLock,
42        guard: &SharedRwLockReadGuard,
43    ) -> StyleRule {
44        StyleRule {
45            selectors: self.selectors.clone(),
46            block: Arc::new(lock.wrap(self.block.read_with(guard).clone())),
47            rules: self.rules.as_ref().map(|rules| {
48                let rules = rules.read_with(guard);
49                Arc::new(lock.wrap(rules.deep_clone_with_lock(lock, guard)))
50            }),
51            source_location: self.source_location.clone(),
52        }
53    }
54}
55
56impl StyleRule {
57    /// Measure heap usage.
58    #[cfg(feature = "gecko")]
59    pub fn size_of(&self, guard: &SharedRwLockReadGuard, ops: &mut MallocSizeOfOps) -> usize {
60        let mut n = 0;
61        n += self.selectors.unconditional_size_of(ops);
62        n += self.block.unconditional_shallow_size_of(ops)
63            + self.block.read_with(guard).size_of(ops);
64        if let Some(ref rules) = self.rules {
65            n += rules.unconditional_shallow_size_of(ops)
66                + rules.read_with(guard).size_of(guard, ops)
67        }
68        n
69    }
70}
71
72impl ToCssWithGuard for StyleRule {
73    /// https://drafts.csswg.org/cssom/#serialize-a-css-rule CSSStyleRule
74    fn to_css(&self, guard: &SharedRwLockReadGuard, dest: &mut CssStringWriter) -> fmt::Result {
75        use cssparser::ToCss;
76        self.selectors.to_css(dest)?;
77        dest.write_char(' ')?;
78        style_or_page_rule_to_css(self.rules.as_ref(), &self.block, guard, dest)
79    }
80}
style/stylesheets/style_rule.rs

style/stylesheets/
style_rule.rs
