/* 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/. */
//! Legacy presentational attributes defined in the HTML5 specification: `
`,
//! ``, and so forth.
use std::sync::Arc;
use node::TElementAttributes;
use properties::PropertyDeclaration;
use selector_matching::Stylist;
use selectors::Element;
use selectors::matching::DeclarationBlock;
use smallvec::VecLike;
/// Legacy presentational attributes that take a nonnegative integer as defined in HTML5 ยง 2.4.4.2.
#[derive(Copy, Clone, PartialEq, Eq)]
pub enum UnsignedIntegerAttribute {
/// `
`
ColSpan,
}
/// Extension methods for `Stylist` that cause rules to be synthesized for legacy attributes.
pub trait PresentationalHintSynthesis {
/// Synthesizes rules from various HTML attributes (mostly legacy junk from HTML4) that confer
/// *presentational hints* as defined in the HTML5 specification. This handles stuff like
/// ``, ``, `
`, and so forth.
///
/// NB: Beware! If you add an attribute to this list, be sure to add it to
/// `common_style_affecting_attributes` or `rare_style_affecting_attributes` as appropriate. If
/// you don't, you risk strange random nondeterministic failures due to false positives in
/// style sharing.
fn synthesize_presentational_hints_for_legacy_attributes(
&self, element: &E, matching_rules_list: &mut V, shareable: &mut bool)
where E: Element + TElementAttributes,
V: VecLike>>;
}
impl PresentationalHintSynthesis for Stylist {
fn synthesize_presentational_hints_for_legacy_attributes(
&self, element: &E, matching_rules_list: &mut V, shareable: &mut bool)
where E: Element + TElementAttributes,
V: VecLike>> {
let length = matching_rules_list.len();
element.synthesize_presentational_hints_for_legacy_attributes(matching_rules_list);
if matching_rules_list.len() != length {
// Never share style for elements with preshints
*shareable = false;
}
}
}
/// A convenience function to create a declaration block from a single declaration. This is
/// primarily used in `synthesize_rules_for_legacy_attributes`.
#[inline]
pub fn from_declaration(rule: PropertyDeclaration) -> DeclarationBlock> {
DeclarationBlock::from_declarations(Arc::new(vec![rule]))
}