62 lines
1.8 KiB
JavaScript
62 lines
1.8 KiB
JavaScript
import { HEADING_PATTERN, PDF_ROLE_TO_HTML_ROLE } from './constants.js';
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export function isPdfRole(role) {
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return role in PDF_ROLE_TO_HTML_ROLE;
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}
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export function isStructTreeNode(node) {
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return 'children' in node;
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}
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export function isStructTreeNodeWithOnlyContentChild(node) {
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if (!isStructTreeNode(node)) {
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return false;
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}
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return node.children.length === 1 && 0 in node.children && 'id' in node.children[0];
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}
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export function getRoleAttributes(node) {
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const attributes = {};
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if (isStructTreeNode(node)) {
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const { role } = node;
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const matches = role.match(HEADING_PATTERN);
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if (matches) {
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attributes.role = 'heading';
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attributes['aria-level'] = Number(matches[1]);
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}
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else if (isPdfRole(role)) {
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const htmlRole = PDF_ROLE_TO_HTML_ROLE[role];
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if (htmlRole) {
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attributes.role = htmlRole;
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}
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}
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}
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return attributes;
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}
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export function getBaseAttributes(node) {
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const attributes = {};
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if (isStructTreeNode(node)) {
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if (node.alt !== undefined) {
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attributes['aria-label'] = node.alt;
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}
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if (node.lang !== undefined) {
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attributes.lang = node.lang;
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}
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if (isStructTreeNodeWithOnlyContentChild(node)) {
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const [child] = node.children;
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if (child) {
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const childAttributes = getBaseAttributes(child);
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return Object.assign(Object.assign({}, attributes), childAttributes);
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}
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}
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}
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else {
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if ('id' in node) {
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attributes['aria-owns'] = node.id;
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}
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}
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return attributes;
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}
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export function getAttributes(node) {
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if (!node) {
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return null;
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}
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return Object.assign(Object.assign({}, getRoleAttributes(node)), getBaseAttributes(node));
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}
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