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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
commit43a97878ce14b72f0981164f87f2e35e14151312 (patch)
tree620249daf56c0258faa40cbdcf9cfba06de2a846 /servo/components/style/stylesheets/cascading_at_rule.rs
parentInitial commit. (diff)
downloadfirefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz
firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'servo/components/style/stylesheets/cascading_at_rule.rs')
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1 files changed, 70 insertions, 0 deletions
diff --git a/servo/components/style/stylesheets/cascading_at_rule.rs b/servo/components/style/stylesheets/cascading_at_rule.rs
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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
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+//! Cascading at-rule types and traits
+
+use crate::stylesheets::Origin;
+use std::fmt::{self, Write};
+use style_traits::{CssWriter, ToCss};
+
+/// Computes the cascade precedence as according to
+/// <http://dev.w3.org/csswg/css-cascade/#cascade-origin>
+#[inline]
+fn cascade_precendence(origin: Origin, important: bool) -> u8 {
+ match (origin, important) {
+ (Origin::UserAgent, true) => 1,
+ (Origin::User, true) => 2,
+ (Origin::Author, true) => 3,
+ (Origin::Author, false) => 4,
+ (Origin::User, false) => 5,
+ (Origin::UserAgent, false) => 6,
+ }
+}
+
+/// Cascading rule descriptor implementation.
+/// This is only used for at-rules which can cascade. These are @viewport and
+/// @page, although we don't currently implement @page as such.
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToShmem)]
+pub struct DescriptorDeclaration<T> {
+ /// Origin of the declaration
+ pub origin: Origin,
+ /// Declaration value
+ pub descriptor: T,
+ /// Indicates the presence of a !important property.
+ pub important: bool,
+}
+
+impl<T> DescriptorDeclaration<T> {
+ #[allow(missing_docs)]
+ pub fn new(origin: Origin, descriptor: T, important: bool) -> Self {
+ Self {
+ origin,
+ descriptor,
+ important,
+ }
+ }
+ /// Returns true iff self is equal or higher precedence to the other.
+ pub fn higher_or_equal_precendence(&self, other: &Self) -> bool {
+ let self_precedence = cascade_precendence(self.origin, self.important);
+ let other_precedence = cascade_precendence(other.origin, other.important);
+
+ self_precedence <= other_precedence
+ }
+}
+
+impl<T> ToCss for DescriptorDeclaration<T>
+where
+ T: ToCss,
+{
+ fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
+ where
+ W: Write,
+ {
+ self.descriptor.to_css(dest)?;
+ if self.important {
+ dest.write_str(" !important")?;
+ }
+ dest.write_char(';')
+ }
+}