gecko-dev/servo/components/style/stylesheets/style_rule.rs

80 строки
2.6 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 https://mozilla.org/MPL/2.0/. */
//! A style rule.
use crate::properties::PropertyDeclarationBlock;
use crate::selector_parser::SelectorImpl;
use crate::shared_lock::{DeepCloneParams, DeepCloneWithLock, Locked};
use crate::shared_lock::{SharedRwLock, SharedRwLockReadGuard, ToCssWithGuard};
use crate::str::CssStringWriter;
use cssparser::SourceLocation;
#[cfg(feature = "gecko")]
use malloc_size_of::MallocUnconditionalShallowSizeOf;
#[cfg(feature = "gecko")]
use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
use selectors::SelectorList;
use servo_arc::Arc;
use std::fmt::{self, Write};
/// A style rule, with selectors and declarations.
#[derive(Debug, ToShmem)]
pub struct StyleRule {
/// The list of selectors in this rule.
pub selectors: SelectorList<SelectorImpl>,
/// The declaration block with the properties it contains.
pub block: Arc<Locked<PropertyDeclarationBlock>>,
/// The location in the sheet where it was found.
pub source_location: SourceLocation,
}
impl DeepCloneWithLock for StyleRule {
/// Deep clones this StyleRule.
fn deep_clone_with_lock(
&self,
lock: &SharedRwLock,
guard: &SharedRwLockReadGuard,
_params: &DeepCloneParams,
) -> StyleRule {
StyleRule {
selectors: self.selectors.clone(),
block: Arc::new(lock.wrap(self.block.read_with(guard).clone())),
source_location: self.source_location.clone(),
}
}
}
impl StyleRule {
/// Measure heap usage.
#[cfg(feature = "gecko")]
pub fn size_of(&self, guard: &SharedRwLockReadGuard, ops: &mut MallocSizeOfOps) -> usize {
let mut n = 0;
n += self.selectors.0.size_of(ops);
n += self.block.unconditional_shallow_size_of(ops) +
self.block.read_with(guard).size_of(ops);
n
}
}
impl ToCssWithGuard for StyleRule {
/// https://drafts.csswg.org/cssom/#serialize-a-css-rule CSSStyleRule
fn to_css(&self, guard: &SharedRwLockReadGuard, dest: &mut CssStringWriter) -> fmt::Result {
use cssparser::ToCss;
// Step 1
self.selectors.to_css(dest)?;
// Step 2
dest.write_str(" { ")?;
// Step 3
let declaration_block = self.block.read_with(guard);
declaration_block.to_css(dest)?;
// Step 4
if !declaration_block.declarations().is_empty() {
dest.write_str(" ")?;
}
// Step 5
dest.write_str("}")
}
}