gecko-dev/servo/components/selectors/visitor.rs

47 строки
1.5 KiB
Rust

/* 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/. */
//! Visitor traits for selectors.
#![deny(missing_docs)]
use attr::NamespaceConstraint;
use parser::{Combinator, Component, SelectorImpl};
/// A trait to visit selector properties.
///
/// All the `visit_foo` methods return a boolean indicating whether the
/// traversal should continue or not.
pub trait SelectorVisitor {
/// The selector implementation this visitor wants to visit.
type Impl: SelectorImpl;
/// Visit an attribute selector that may match (there are other selectors
/// that may never match, like those containing whitespace or the empty
/// string).
fn visit_attribute_selector(
&mut self,
_namespace: &NamespaceConstraint<&<Self::Impl as SelectorImpl>::NamespaceUrl>,
_local_name: &<Self::Impl as SelectorImpl>::LocalName,
_local_name_lower: &<Self::Impl as SelectorImpl>::LocalName,
) -> bool {
true
}
/// Visit a simple selector.
fn visit_simple_selector(&mut self, _: &Component<Self::Impl>) -> bool {
true
}
/// Visits a complex selector.
///
/// Gets the combinator to the right of the selector, or `None` if the
/// selector is the rightmost one.
fn visit_complex_selector(&mut self,
_combinator_to_right: Option<Combinator>)
-> bool {
true
}
}