mirror of
https://github.com/servo/servo
synced 2026-04-25 17:15:48 +02:00
64041ee394
Co-authored-by: Delan Azabani <dazabani@igalia.com> Signed-off-by: Luke Warlow <lwarlow@igalia.com>
201 lines
8.2 KiB
Rust
201 lines
8.2 KiB
Rust
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
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use std::rc::Rc;
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use std::sync::LazyLock;
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pub(crate) use accessibility_traits::AccessibilityTree;
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use accesskit::{Action, Node as AxNode, NodeId as AxNodeId, Role, Tree as AxTree};
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use html5ever::{LocalName, local_name};
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use layout_api::wrapper_traits::{LayoutNode, ThreadSafeLayoutNode};
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use log::trace;
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use rustc_hash::FxHashMap;
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use script::layout_dom::ServoLayoutDocument;
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use style::dom::{NodeInfo, TDocument, TElement, TNode};
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use crate::FragmentTree;
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// #[derive(MallocSizeOf)]
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pub(crate) struct AccessibilityTreeCalculator {}
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impl AccessibilityTreeCalculator {
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pub(crate) fn construct(
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document: ServoLayoutDocument<'_>,
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fragment_tree: Rc<FragmentTree>,
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) -> AccessibilityTree {
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let mut ax_nodes: FxHashMap<AxNodeId, AxNode> = FxHashMap::default();
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let ax_document_id = AxNodeId(document.as_node().opaque().0 as u64);
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let ax_document = AxNode::new(Role::Document);
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ax_nodes.insert(ax_document_id, ax_document);
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let dom_root = document.root_element().unwrap().as_node();
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let mut dom_queue = vec![dom_root];
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'outer: loop {
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// find the next node in the queue that is not ‘display: none’.
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let dom_next = loop {
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let Some(next) = dom_queue.pop() else {
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break 'outer;
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};
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if next
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.style_data()
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.is_none_or(|style| !style.element_data.borrow().styles.is_display_none())
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{
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break next;
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}
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};
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// push its children for later traversal.
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// reverse order ensures that the first child will get popped first.
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for child in RevDomChildren::of(dom_next) {
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dom_queue.push(child);
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}
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// now process the node.
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trace!("DOM node: {dom_next:?}");
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let dom_parent = dom_next
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.parent_node()
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.expect("Even the root element must have a parent");
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let ax_parent_id = AxNodeId(dom_parent.opaque().0 as u64);
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let ax_next_id = AxNodeId(dom_next.opaque().0 as u64);
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let ax_parent = ax_nodes.get_mut(&ax_parent_id).expect("Guaranteed by us");
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ax_parent.push_child(ax_next_id);
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let mut ax_next = AxNode::default();
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if dom_next.is_text_node() {
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let text_content = dom_next.to_threadsafe().text_content();
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trace!("node text content = {:?}", text_content);
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ax_next.set_value(&*text_content);
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// FIXME: this should take into account editing selection units (grapheme clusters?)
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ax_next.set_character_lengths(
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text_content
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.chars()
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.map(|c| c.len_utf8() as u8)
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.collect::<Box<[u8]>>(),
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);
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ax_next.set_role(Role::TextRun);
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} else if let Some(element) = dom_next.as_element() {
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if element.is_html_element() {
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if let Some(role) = HTML_ELEMENT_ROLE_MAPPINGS.get(element.local_name()) {
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ax_next.set_role(*role);
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}
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}
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}
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ax_next.add_action(Action::Click);
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ax_nodes.insert(ax_next_id, ax_next);
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}
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AccessibilityTree {
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ax_nodes,
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ax_tree: AxTree {
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root: ax_document_id,
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toolkit_name: None,
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toolkit_version: None,
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},
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}
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}
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}
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/// Like [`style::dom::DomChildren`], but reversed.
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///
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/// Do not use the tuple constructor; use [`Self::of`].
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pub(crate) struct RevDomChildren<N>(Option<N>);
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impl<N: TNode> RevDomChildren<N> {
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fn of(node: N) -> Self {
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Self(node.last_child())
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}
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}
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impl<N: TNode> Iterator for RevDomChildren<N> {
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type Item = N;
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fn next(&mut self) -> Option<N> {
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let n = self.0.take()?;
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self.0 = n.prev_sibling();
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Some(n)
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}
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}
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/// <https://www.w3.org/TR/html-aam-1.0/#html-element-role-mappings>
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///
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/// FIXME: converted mechanically for now, so this will have many errors
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static HTML_ELEMENT_ROLE_MAPPINGS: LazyLock<FxHashMap<LocalName, Role>> = LazyLock::new(|| {
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[
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(local_name!("a"), Role::Link),
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(local_name!("address"), Role::Group),
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(local_name!("area"), Role::Link),
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(local_name!("area"), Role::GenericContainer),
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(local_name!("article"), Role::Article),
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(local_name!("aside"), Role::Complementary),
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(local_name!("b"), Role::GenericContainer),
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(local_name!("bdi"), Role::GenericContainer),
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(local_name!("bdo"), Role::GenericContainer),
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(local_name!("blockquote"), Role::Blockquote),
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(local_name!("body"), Role::GenericContainer),
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(local_name!("button"), Role::Button),
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(local_name!("caption"), Role::Caption),
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(local_name!("code"), Role::Code),
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(local_name!("data"), Role::GenericContainer),
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(local_name!("datalist"), Role::ListBox),
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(local_name!("dd"), Role::Definition),
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(local_name!("del"), Role::ContentDeletion),
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(local_name!("details"), Role::Group),
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(local_name!("dfn"), Role::Term),
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(local_name!("dialog"), Role::Dialog),
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(local_name!("dir"), Role::List),
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(local_name!("div"), Role::GenericContainer),
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(local_name!("dl"), Role::List),
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(local_name!("dt"), Role::Term),
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(local_name!("em"), Role::Emphasis),
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(local_name!("fieldset"), Role::Group),
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(local_name!("figcaption"), Role::Caption),
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(local_name!("figure"), Role::Figure),
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(local_name!("footer"), Role::ContentInfo),
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(local_name!("form"), Role::Form),
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(local_name!("h1"), Role::Heading),
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(local_name!("h2"), Role::Heading),
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(local_name!("h3"), Role::Heading),
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(local_name!("h4"), Role::Heading),
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(local_name!("h5"), Role::Heading),
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(local_name!("h6"), Role::Heading),
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(local_name!("header"), Role::Banner),
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(local_name!("hgroup"), Role::Group),
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(local_name!("hr"), Role::Splitter),
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(local_name!("html"), Role::GenericContainer),
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(local_name!("i"), Role::GenericContainer),
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(local_name!("img"), Role::Image),
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(local_name!("ins"), Role::ContentInsertion),
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(local_name!("li"), Role::ListItem),
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(local_name!("main"), Role::Main),
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(local_name!("mark"), Role::Mark),
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(local_name!("menu"), Role::List),
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(local_name!("meter"), Role::Meter),
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(local_name!("nav"), Role::Navigation),
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(local_name!("ol"), Role::List),
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(local_name!("optgroup"), Role::Group),
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(local_name!("option"), Role::ListBoxOption),
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(local_name!("output"), Role::Status),
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(local_name!("p"), Role::Paragraph),
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(local_name!("pre"), Role::GenericContainer),
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(local_name!("progress"), Role::ProgressIndicator),
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(local_name!("q"), Role::GenericContainer),
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(local_name!("s"), Role::ContentDeletion),
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(local_name!("samp"), Role::GenericContainer),
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(local_name!("search"), Role::Search),
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(local_name!("section"), Role::Region),
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(local_name!("select"), Role::ListBox),
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(local_name!("select"), Role::ComboBox),
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(local_name!("small"), Role::GenericContainer),
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(local_name!("span"), Role::GenericContainer),
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(local_name!("strong"), Role::Strong),
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(local_name!("table"), Role::Table),
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(local_name!("tbody"), Role::RowGroup),
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(local_name!("td"), Role::Cell),
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(local_name!("textarea"), Role::TextInput),
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(local_name!("tfoot"), Role::RowGroup),
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(local_name!("th"), Role::Cell),
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(local_name!("th"), Role::ColumnHeader),
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(local_name!("th"), Role::RowHeader),
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(local_name!("thead"), Role::RowGroup),
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(local_name!("time"), Role::Time),
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(local_name!("tr"), Role::Row),
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(local_name!("u"), Role::GenericContainer),
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(local_name!("ul"), Role::List),
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]
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.into_iter()
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.collect()
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});
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