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/* 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
//! A [`@margin`][margin] rule.
//!
use crate::properties::PropertyDeclarationBlock;
use crate::shared_lock::{DeepCloneWithLock, Locked};
use crate::shared_lock::{SharedRwLock, SharedRwLockReadGuard, ToCssWithGuard};
use crate::str::CssStringWriter;
use cssparser::SourceLocation;
#[cfg(feature = "gecko")]
use malloc_size_of::{MallocSizeOf, MallocSizeOfOps, MallocUnconditionalShallowSizeOf};
use servo_arc::Arc;
use std::fmt::{self, Write};
macro_rules! margin_rule_types {
($($(#[$($meta:tt)+])* $id:ident => $val:literal,)+) => {
/// [`@margin`][margin] rule names.
///
#[derive(Clone, Copy, Eq, MallocSizeOf, PartialEq, ToShmem)]
#[repr(u8)]
pub enum MarginRuleType {
$($(#[$($meta)+])* $id,)+
}
/// All [`@margin`][margin] rule names, with a preceding '@'.
///
/// This array lets us have just one single memory region used for
/// to_str, name, and the Debug implementation.
const MARGIN_RULE_AT_NAMES:&[&'static str] = &[
$( concat!('@', $val), )+
];
impl MarginRuleType {
/// Matches the rule type for this name. This does not expect a
/// leading '@'.
pub fn match_name(name: &str) -> Option<Self> {
Some(match_ignore_ascii_case! { name,
$( $val => MarginRuleType::$id, )+
_ => return None,
})
}
}
}
}
margin_rule_types! {
/// [`@top-left-corner`][top-left-corner] margin rule
///
TopLeftCorner => "top-left-corner",
/// [`@top-left`][top-left] margin rule
///
TopLeft => "top-left",
/// [`@top-center`][top-center] margin rule
///
TopCenter => "top-center",
/// [`@top-right`][top-right] margin rule
///
TopRight => "top-right",
/// [`@top-right-corner`][top-right-corner] margin rule
///
TopRightCorner => "top-right-corner",
/// [`@bottom-left-corner`][bottom-left-corner] margin rule
///
BottomLeftCorner => "bottom-left-corner",
/// [`@bottom-left`][bottom-left] margin rule
///
BottomLeft => "bottom-left",
/// [`@bottom-center`][bottom-center] margin rule
///
BottomCenter => "bottom-center",
/// [`@bottom-right`][bottom-right] margin rule
///
BottomRight => "bottom-right",
/// [`@bottom-right-corner`][bottom-right-corner] margin rule
///
BottomRightCorner => "bottom-right-corner",
/// [`@left-top`][left-top] margin rule
///
LeftTop => "left-top",
/// [`@left-middle`][left-middle] margin rule
///
LeftMiddle => "left-middle",
/// [`@left-bottom`][left-bottom] margin rule
///
LeftBottom => "left-bottom",
/// [`@right-top`][right-top] margin rule
///
RightTop => "right-top",
/// [`@right-middle`][right-middle] margin rule
///
RightMiddle => "right-middle",
/// [`@right-bottom`][right-bottom] margin rule
///
RightBottom => "right-bottom",
}
impl MarginRuleType {
#[inline]
fn to_str(&self) -> &'static str {
&MARGIN_RULE_AT_NAMES[*self as usize]
}
#[inline]
fn name(&self) -> &'static str {
// Use the at-name array, skipping the first character to get
// the name without the @ sign.
&MARGIN_RULE_AT_NAMES[*self as usize][1..]
}
}
// Implement Debug manually so that it will share the same string memory as
// MarginRuleType::name and MarginRuleType::to_str.
impl fmt::Debug for MarginRuleType {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
f.write_str(self.name())
}
}
/// A [`@margin`][margin] rule.
///
#[derive(Clone, Debug, ToShmem)]
pub struct MarginRule {
/// Type of this margin rule.
pub rule_type: MarginRuleType,
/// The declaration block this margin rule contains.
pub block: Arc<Locked<PropertyDeclarationBlock>>,
/// The source position this rule was found at.
pub source_location: SourceLocation,
}
impl MarginRule {
/// 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)
}
/// Gets the name for this margin rule.
#[inline]
pub fn name(&self) -> &'static str {
self.rule_type.name()
}
}
impl ToCssWithGuard for MarginRule {
/// Serialization of a margin-rule is not specced, this is adapted from how
/// page-rules and style-rules are serialized.
fn to_css(&self, guard: &SharedRwLockReadGuard, dest: &mut CssStringWriter) -> fmt::Result {
dest.write_str(self.rule_type.to_str())?;
dest.write_str(" { ")?;
let declaration_block = self.block.read_with(guard);
declaration_block.to_css(dest)?;
if !declaration_block.declarations().is_empty() {
dest.write_char(' ')?;
}
dest.write_char('}')
}
}
impl DeepCloneWithLock for MarginRule {
fn deep_clone_with_lock(
&self,
lock: &SharedRwLock,
guard: &SharedRwLockReadGuard,
) -> Self {
MarginRule {
rule_type: self.rule_type,
block: Arc::new(lock.wrap(self.block.read_with(&guard).clone())),
source_location: self.source_location.clone(),
}
}
}