servo/components/style/stylesheets/page_rule.rs

71 lines
2.4 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/. */
//! A [`@page`][page] rule.
//!
//! [page]: https://drafts.csswg.org/css2/page.html#page-box
use cssparser::SourceLocation;
#[cfg(feature = "gecko")]
use malloc_size_of::{MallocSizeOf, MallocSizeOfOps, MallocUnconditionalShallowSizeOf};
use properties::PropertyDeclarationBlock;
use servo_arc::Arc;
use shared_lock::{DeepCloneParams, DeepCloneWithLock, Locked};
use shared_lock::{SharedRwLock, SharedRwLockReadGuard, ToCssWithGuard};
use std::fmt::{self, Write};
use str::CssStringWriter;
/// A [`@page`][page] rule.
///
/// This implements only a limited subset of the CSS
/// 2.2 syntax.
///
/// In this subset, [page selectors][page-selectors] are not implemented.
///
/// [page]: https://drafts.csswg.org/css2/page.html#page-box
/// [page-selectors]: https://drafts.csswg.org/css2/page.html#page-selectors
#[derive(Debug)]
pub struct PageRule {
/// The declaration block this page rule contains.
pub block: Arc<Locked<PropertyDeclarationBlock>>,
/// The source position this rule was found at.
pub source_location: SourceLocation,
}
impl PageRule {
/// Measure heap usage.
#[cfg(feature = "gecko")]
pub fn size_of(&self, guard: &SharedRwLockReadGuard, ops: &mut MallocSizeOfOps) -> usize {
// Measurement of other fields may be added later.
self.block.unconditional_shallow_size_of(ops) + self.block.read_with(guard).size_of(ops)
}
}
impl ToCssWithGuard for PageRule {
/// Serialization of PageRule is not specced, adapted from steps for
/// StyleRule.
fn to_css(&self, guard: &SharedRwLockReadGuard, dest: &mut CssStringWriter) -> fmt::Result {
dest.write_str("@page { ")?;
let declaration_block = self.block.read_with(guard);
declaration_block.to_css(dest)?;
if !declaration_block.declarations().is_empty() {
dest.write_str(" ")?;
}
dest.write_str("}")
}
}
impl DeepCloneWithLock for PageRule {
fn deep_clone_with_lock(
&self,
lock: &SharedRwLock,
guard: &SharedRwLockReadGuard,
_params: &DeepCloneParams,
) -> Self {
PageRule {
block: Arc::new(lock.wrap(self.block.read_with(&guard).clone())),
source_location: self.source_location.clone(),
}
}
}