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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /servo/components/style/properties_and_values/rule.rs | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'servo/components/style/properties_and_values/rule.rs')
-rw-r--r-- | servo/components/style/properties_and_values/rule.rs | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/servo/components/style/properties_and_values/rule.rs b/servo/components/style/properties_and_values/rule.rs new file mode 100644 index 0000000000..96617eccce --- /dev/null +++ b/servo/components/style/properties_and_values/rule.rs @@ -0,0 +1,348 @@ +/* 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/. */ + +//! The [`@property`] at-rule. +//! +//! https://drafts.css-houdini.org/css-properties-values-api-1/#at-property-rule + +use super::{ + registry::{PropertyRegistration, PropertyRegistrationData}, + syntax::Descriptor, + value::{AllowComputationallyDependent, SpecifiedValue as SpecifiedRegisteredValue}, +}; +use crate::custom_properties::{Name as CustomPropertyName, SpecifiedValue}; +use crate::error_reporting::ContextualParseError; +use crate::parser::{Parse, ParserContext}; +use crate::shared_lock::{SharedRwLockReadGuard, ToCssWithGuard}; +use crate::str::CssStringWriter; +use crate::values::{computed, serialize_atom_name}; +use cssparser::{ + AtRuleParser, BasicParseErrorKind, CowRcStr, DeclarationParser, ParseErrorKind, Parser, + ParserInput, QualifiedRuleParser, RuleBodyItemParser, RuleBodyParser, SourceLocation, +}; +use malloc_size_of::{MallocSizeOf, MallocSizeOfOps}; +use selectors::parser::SelectorParseErrorKind; +use servo_arc::Arc; +use std::fmt::{self, Write}; +use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss}; +use to_shmem::{SharedMemoryBuilder, ToShmem}; + +/// Parse the block inside a `@property` rule. +/// +/// Valid `@property` rules result in a registered custom property, as if `registerProperty()` had +/// been called with equivalent parameters. +pub fn parse_property_block<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + name: PropertyRuleName, + source_location: SourceLocation, +) -> Result<PropertyRegistration, ParseError<'i>> { + let mut descriptors = PropertyDescriptors::default(); + let mut parser = PropertyRuleParser { + context, + descriptors: &mut descriptors, + }; + let mut iter = RuleBodyParser::new(input, &mut parser); + while let Some(declaration) = iter.next() { + if !context.error_reporting_enabled() { + continue; + } + if let Err((error, slice)) = declaration { + let location = error.location; + let error = if matches!( + error.kind, + ParseErrorKind::Custom(StyleParseErrorKind::PropertySyntaxField(_)) + ) { + // If the provided string is not a valid syntax string (if it + // returns failure when consume a syntax definition is called on + // it), the descriptor is invalid and must be ignored. + ContextualParseError::UnsupportedValue(slice, error) + } else { + // Unknown descriptors are invalid and ignored, but do not + // invalidate the @property rule. + ContextualParseError::UnsupportedPropertyDescriptor(slice, error) + }; + context.log_css_error(location, error); + } + } + + // https://drafts.css-houdini.org/css-properties-values-api-1/#the-syntax-descriptor: + // + // The syntax descriptor is required for the @property rule to be valid; if it’s + // missing, the @property rule is invalid. + let Some(syntax) = descriptors.syntax else { + return Err(input.new_error(BasicParseErrorKind::AtRuleBodyInvalid)); + }; + + // https://drafts.css-houdini.org/css-properties-values-api-1/#inherits-descriptor: + // + // The inherits descriptor is required for the @property rule to be valid; if it’s + // missing, the @property rule is invalid. + let Some(inherits) = descriptors.inherits else { + return Err(input.new_error(BasicParseErrorKind::AtRuleBodyInvalid)); + }; + + if PropertyRegistration::validate_initial_value(&syntax, descriptors.initial_value.as_deref()) + .is_err() + { + return Err(input.new_error(BasicParseErrorKind::AtRuleBodyInvalid)); + } + + Ok(PropertyRegistration { + name, + data: PropertyRegistrationData { + syntax, + inherits, + initial_value: descriptors.initial_value, + }, + url_data: context.url_data.clone(), + source_location, + }) +} + +struct PropertyRuleParser<'a, 'b: 'a> { + context: &'a ParserContext<'b>, + descriptors: &'a mut PropertyDescriptors, +} + +/// Default methods reject all at rules. +impl<'a, 'b, 'i> AtRuleParser<'i> for PropertyRuleParser<'a, 'b> { + type Prelude = (); + type AtRule = (); + type Error = StyleParseErrorKind<'i>; +} + +impl<'a, 'b, 'i> QualifiedRuleParser<'i> for PropertyRuleParser<'a, 'b> { + type Prelude = (); + type QualifiedRule = (); + type Error = StyleParseErrorKind<'i>; +} + +impl<'a, 'b, 'i> RuleBodyItemParser<'i, (), StyleParseErrorKind<'i>> + for PropertyRuleParser<'a, 'b> +{ + fn parse_qualified(&self) -> bool { + false + } + fn parse_declarations(&self) -> bool { + true + } +} + +macro_rules! property_descriptors { + ( + $( #[$doc: meta] $name: tt $ident: ident: $ty: ty, )* + ) => { + /// Data inside a `@property` rule. + /// + /// <https://drafts.css-houdini.org/css-properties-values-api-1/#at-property-rule> + #[derive(Clone, Debug, Default, PartialEq)] + struct PropertyDescriptors { + $( + #[$doc] + $ident: Option<$ty>, + )* + } + + impl PropertyRegistration { + fn decl_to_css(&self, dest: &mut CssStringWriter) -> fmt::Result { + $( + let $ident = Option::<&$ty>::from(&self.data.$ident); + if let Some(ref value) = $ident { + dest.write_str(concat!($name, ": "))?; + value.to_css(&mut CssWriter::new(dest))?; + dest.write_str("; ")?; + } + )* + Ok(()) + } + } + + impl<'a, 'b, 'i> DeclarationParser<'i> for PropertyRuleParser<'a, 'b> { + type Declaration = (); + type Error = StyleParseErrorKind<'i>; + + fn parse_value<'t>( + &mut self, + name: CowRcStr<'i>, + input: &mut Parser<'i, 't>, + ) -> Result<(), ParseError<'i>> { + match_ignore_ascii_case! { &*name, + $( + $name => { + // DeclarationParser also calls parse_entirely so we’d normally not need + // to, but in this case we do because we set the value as a side effect + // rather than returning it. + let value = input.parse_entirely(|i| Parse::parse(self.context, i))?; + self.descriptors.$ident = Some(value) + }, + )* + _ => return Err(input.new_custom_error(SelectorParseErrorKind::UnexpectedIdent(name.clone()))), + } + Ok(()) + } + } + } +} + +property_descriptors! { + /// <https://drafts.css-houdini.org/css-properties-values-api-1/#the-syntax-descriptor> + "syntax" syntax: Descriptor, + + /// <https://drafts.css-houdini.org/css-properties-values-api-1/#inherits-descriptor> + "inherits" inherits: Inherits, + + /// <https://drafts.css-houdini.org/css-properties-values-api-1/#initial-value-descriptor> + "initial-value" initial_value: InitialValue, +} + +/// Errors that can happen when registering a property. +#[allow(missing_docs)] +pub enum PropertyRegistrationError { + NoInitialValue, + InvalidInitialValue, + InitialValueNotComputationallyIndependent, +} + +impl PropertyRegistration { + /// Measure heap usage. + #[cfg(feature = "gecko")] + pub fn size_of(&self, _: &SharedRwLockReadGuard, ops: &mut MallocSizeOfOps) -> usize { + MallocSizeOf::size_of(self, ops) + } + + /// Computes the value of the computationally independent initial value. + pub fn compute_initial_value( + &self, + computed_context: &computed::Context, + ) -> Result<InitialValue, ()> { + let Some(ref initial) = self.data.initial_value else { + return Err(()); + }; + + if self.data.syntax.is_universal() { + return Ok(Arc::clone(initial)); + } + + let mut input = ParserInput::new(initial.css_text()); + let mut input = Parser::new(&mut input); + input.skip_whitespace(); + + match SpecifiedRegisteredValue::compute( + &mut input, + &self.data, + &self.url_data, + computed_context, + AllowComputationallyDependent::No, + ) { + Ok(computed) => Ok(Arc::new(computed)), + Err(_) => Err(()), + } + } + + /// Performs syntax validation as per the initial value descriptor. + /// https://drafts.css-houdini.org/css-properties-values-api-1/#initial-value-descriptor + pub fn validate_initial_value( + syntax: &Descriptor, + initial_value: Option<&SpecifiedValue>, + ) -> Result<(), PropertyRegistrationError> { + use crate::properties::CSSWideKeyword; + // If the value of the syntax descriptor is the universal syntax definition, then the + // initial-value descriptor is optional. If omitted, the initial value of the property is + // the guaranteed-invalid value. + if syntax.is_universal() && initial_value.is_none() { + return Ok(()); + } + + // Otherwise, if the value of the syntax descriptor is not the universal syntax definition, + // the following conditions must be met for the @property rule to be valid: + + // The initial-value descriptor must be present. + let Some(initial) = initial_value else { + return Err(PropertyRegistrationError::NoInitialValue); + }; + + // A value that references the environment or other variables is not computationally + // independent. + if initial.has_references() { + return Err(PropertyRegistrationError::InitialValueNotComputationallyIndependent); + } + + let mut input = ParserInput::new(initial.css_text()); + let mut input = Parser::new(&mut input); + input.skip_whitespace(); + + // The initial-value cannot include CSS-wide keywords. + if input.try_parse(CSSWideKeyword::parse).is_ok() { + return Err(PropertyRegistrationError::InitialValueNotComputationallyIndependent); + } + + match SpecifiedRegisteredValue::parse( + &mut input, + syntax, + &initial.url_data, + AllowComputationallyDependent::No, + ) { + Ok(_) => {}, + Err(_) => return Err(PropertyRegistrationError::InvalidInitialValue), + } + + Ok(()) + } +} + +impl ToCssWithGuard for PropertyRegistration { + /// <https://drafts.css-houdini.org/css-properties-values-api-1/#serialize-a-csspropertyrule> + fn to_css(&self, _guard: &SharedRwLockReadGuard, dest: &mut CssStringWriter) -> fmt::Result { + dest.write_str("@property ")?; + self.name.to_css(&mut CssWriter::new(dest))?; + dest.write_str(" { ")?; + self.decl_to_css(dest)?; + dest.write_char('}') + } +} + +impl ToShmem for PropertyRegistration { + fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> to_shmem::Result<Self> { + Err(String::from( + "ToShmem failed for PropertyRule: cannot handle @property rules", + )) + } +} + +/// A custom property name wrapper that includes the `--` prefix in its serialization +#[derive(Clone, Debug, PartialEq, MallocSizeOf)] +pub struct PropertyRuleName(pub CustomPropertyName); + +impl ToCss for PropertyRuleName { + fn to_css<W: Write>(&self, dest: &mut CssWriter<W>) -> fmt::Result { + dest.write_str("--")?; + serialize_atom_name(&self.0, dest) + } +} + +/// <https://drafts.css-houdini.org/css-properties-values-api-1/#inherits-descriptor> +#[derive(Clone, Debug, MallocSizeOf, Parse, PartialEq, ToCss)] +pub enum Inherits { + /// `true` value for the `inherits` descriptor + True, + /// `false` value for the `inherits` descriptor + False, +} + +/// Specifies the initial value of the custom property registration represented by the @property +/// rule, controlling the property’s initial value. +/// +/// The SpecifiedValue is wrapped in an Arc to avoid copying when using it. +pub type InitialValue = Arc<SpecifiedValue>; + +impl Parse for InitialValue { + fn parse<'i, 't>( + context: &ParserContext, + input: &mut Parser<'i, 't>, + ) -> Result<Self, ParseError<'i>> { + input.skip_whitespace(); + Ok(Arc::new(SpecifiedValue::parse(input, &context.url_data)?)) + } +} |