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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 */
//! Traits that nodes must implement. Breaks the otherwise-cyclic dependency
//! between layout and style.
use crate::attr::{AttrSelectorOperation, CaseSensitivity, NamespaceConstraint};
use crate::bloom::BloomFilter;
use crate::matching::{ElementSelectorFlags, MatchingContext};
use crate::parser::SelectorImpl;
use std::fmt::Debug;
use std::ptr::NonNull;
/// Opaque representation of an Element, for identity comparisons.
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub struct OpaqueElement(NonNull<()>);
unsafe impl Send for OpaqueElement {}
impl OpaqueElement {
/// Creates a new OpaqueElement from an arbitrarily-typed pointer.
pub fn new<T>(ptr: &T) -> Self {
unsafe {
ptr as *const T as *const () as *mut (),
pub trait Element: Sized + Clone + Debug {
type Impl: SelectorImpl;
/// Converts self into an opaque representation.
fn opaque(&self) -> OpaqueElement;
fn parent_element(&self) -> Option<Self>;
/// Whether the parent node of this element is a shadow root.
fn parent_node_is_shadow_root(&self) -> bool;
/// The host of the containing shadow root, if any.
fn containing_shadow_host(&self) -> Option<Self>;
/// The parent of a given pseudo-element, after matching a pseudo-element
/// selector.
/// This is guaranteed to be called in a pseudo-element.
fn pseudo_element_originating_element(&self) -> Option<Self> {
/// Whether we're matching on a pseudo-element.
fn is_pseudo_element(&self) -> bool;
/// Skips non-element nodes
fn prev_sibling_element(&self) -> Option<Self>;
/// Skips non-element nodes
fn next_sibling_element(&self) -> Option<Self>;
/// Skips non-element nodes
fn first_element_child(&self) -> Option<Self>;
fn is_html_element_in_html_document(&self) -> bool;
fn has_local_name(&self, local_name: &<Self::Impl as SelectorImpl>::BorrowedLocalName) -> bool;
/// Empty string for no namespace
fn has_namespace(&self, ns: &<Self::Impl as SelectorImpl>::BorrowedNamespaceUrl) -> bool;
/// Whether this element and the `other` element have the same local name and namespace.
fn is_same_type(&self, other: &Self) -> bool;
fn attr_matches(
ns: &NamespaceConstraint<&<Self::Impl as SelectorImpl>::NamespaceUrl>,
local_name: &<Self::Impl as SelectorImpl>::LocalName,
operation: &AttrSelectorOperation<&<Self::Impl as SelectorImpl>::AttrValue>,
) -> bool;
fn has_attr_in_no_namespace(
local_name: &<Self::Impl as SelectorImpl>::LocalName,
) -> bool {
fn match_non_ts_pseudo_class(
pc: &<Self::Impl as SelectorImpl>::NonTSPseudoClass,
context: &mut MatchingContext<Self::Impl>,
) -> bool;
fn match_pseudo_element(
pe: &<Self::Impl as SelectorImpl>::PseudoElement,
context: &mut MatchingContext<Self::Impl>,
) -> bool;
/// Sets selector flags on the elemnt itself or the parent, depending on the
/// flags, which indicate what kind of work may need to be performed when
/// DOM state changes.
fn apply_selector_flags(&self, flags: ElementSelectorFlags);
/// Whether this element is a `link`.
fn is_link(&self) -> bool;
/// Returns whether the element is an HTML <slot> element.
fn is_html_slot_element(&self) -> bool;
/// Returns the assigned <slot> element this element is assigned to.
/// Necessary for the `::slotted` pseudo-class.
fn assigned_slot(&self) -> Option<Self> {
fn has_id(
id: &<Self::Impl as SelectorImpl>::Identifier,
case_sensitivity: CaseSensitivity,
) -> bool;
fn has_class(
name: &<Self::Impl as SelectorImpl>::Identifier,
case_sensitivity: CaseSensitivity,
) -> bool;
/// Returns the mapping from the `exportparts` attribute in the reverse
/// direction, that is, in an outer-tree -> inner-tree direction.
fn imported_part(
name: &<Self::Impl as SelectorImpl>::Identifier,
) -> Option<<Self::Impl as SelectorImpl>::Identifier>;
fn is_part(&self, name: &<Self::Impl as SelectorImpl>::Identifier) -> bool;
/// Returns whether this element matches `:empty`.
/// That is, whether it does not contain any child element or any non-zero-length text node.
fn is_empty(&self) -> bool;
/// Returns whether this element matches `:root`,
/// i.e. whether it is the root element of a document.
/// Note: this can be false even if `.parent_element()` is `None`
/// if the parent node is a `DocumentFragment`.
fn is_root(&self) -> bool;
/// Returns whether this element should ignore matching nth child
/// selector.
fn ignores_nth_child_selectors(&self) -> bool {
/// Add hashes unique to this element to the given filter, returning true
/// if any got added.
fn add_element_unique_hashes(&self, filter: &mut BloomFilter) -> bool;