stylo 0.17.0

The Stylo CSS engine
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45

/* 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/. */

//! Resolved values for counter properties

use super::{Context, ToResolvedValue};
use crate::values::computed;
#[cfg(feature = "gecko")]
use selectors::parser::PseudoElement;

/// https://drafts.csswg.org/css-content/#content-property
///
/// We implement this at resolved value time because otherwise it causes us to allocate a bunch of
/// useless initial structs for all ::before / ::after, which is a bit unfortunate.
///
/// Though these should be temporary, mostly, so if this causes complexity in
/// other places, it should be fine to move to `StyleAdjuster`.
///
/// See https://github.com/w3c/csswg-drafts/issues/4632 for where some related
/// issues are being discussed.
impl ToResolvedValue for computed::Content {
    type ResolvedValue = Self;

    #[inline]
    fn to_resolved_value(self, context: &Context) -> Self {
        let (is_before_or_after, is_marker) = match context.style.pseudo() {
            Some(ref pseudo) => (pseudo.is_before_or_after(), pseudo.is_marker()),
            None => (false, false),
        };
        match self {
            Self::Normal if is_before_or_after => Self::None,
            // For now, make `content: none` resolve to `normal` for pseudos
            // other than ::before, ::after and ::marker, as we don't respect it.
            // https://github.com/w3c/csswg-drafts/issues/6124
            Self::None if !is_before_or_after && !is_marker => Self::Normal,
            other => other,
        }
    }

    #[inline]
    fn from_resolved_value(resolved: Self) -> Self {
        resolved
    }
}