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import $ from 'jquery';
import {generateAriaId} from './base.js';
const ariaPatchKey = '_giteaAriaPatchDropdown';
const fomanticDropdownFn = $.fn.dropdown;
// use our own `$().dropdown` function to patch Fomantic's dropdown module
export function initAriaDropdownPatch() {
if ($.fn.dropdown === ariaDropdownFn) throw new Error('initAriaDropdownPatch could only be called once');
$.fn.dropdown = ariaDropdownFn;
ariaDropdownFn.settings = fomanticDropdownFn.settings;
}
// the patched `$.fn.dropdown` function, it passes the arguments to Fomantic's `$.fn.dropdown` function, and:
// * it does the one-time attaching on the first call
// * it delegates the `onLabelCreate` to the patched `onLabelCreate` to add necessary aria attributes
function ariaDropdownFn(...args) {
const ret = fomanticDropdownFn.apply(this, args);
// if the `$().dropdown()` call is without arguments, or it has non-string (object) argument,
// it means that this call will reset the dropdown internal settings, then we need to re-delegate the callbacks.
const needDelegate = (!args.length || typeof args[0] !== 'string');
for (const el of this) {
const $dropdown = $(el);
if (!el[ariaPatchKey]) {
attachInit($dropdown);
}
if (needDelegate) {
delegateOne($dropdown);
}
}
return ret;
}
// make the item has role=option/menuitem, add an id if there wasn't one yet, make items as non-focusable
// the elements inside the dropdown menu item should not be focusable, the focus should always be on the dropdown primary element.
function updateMenuItem(dropdown, item) {
if (!item.id) item.id = generateAriaId();
item.setAttribute('role', dropdown[ariaPatchKey].listItemRole);
item.setAttribute('tabindex', '-1');
for (const a of item.querySelectorAll('a')) a.setAttribute('tabindex', '-1');
}
// make the label item and its "delete icon" has correct aria attributes
function updateSelectionLabel($label) {
// the "label" is like this: "<a|div class="ui label" data-value="1">the-label-name <i|svg class="delete icon"/></a>"
if (!$label.attr('id')) $label.attr('id', generateAriaId());
$label.attr('tabindex', '-1');
$label.find('.delete.icon').attr({
'aria-hidden': 'false',
'aria-label': window.config.i18n.remove_label_str.replace('%s', $label.attr('data-value')),
'role': 'button',
});
}
// delegate the dropdown's template functions and callback functions to add aria attributes.
function delegateOne($dropdown) {
const dropdownCall = fomanticDropdownFn.bind($dropdown);
// the "template" functions are used for dynamic creation (eg: AJAX)
const dropdownTemplates = {...dropdownCall('setting', 'templates'), t: performance.now()};
const dropdownTemplatesMenuOld = dropdownTemplates.menu;
dropdownTemplates.menu = function(response, fields, preserveHTML, className) {
// when the dropdown menu items are loaded from AJAX requests, the items are created dynamically
const menuItems = dropdownTemplatesMenuOld(response, fields, preserveHTML, className);
const $wrapper = $('<div>').append(menuItems);
const $items = $wrapper.find('> .item');
$items.each((_, item) => updateMenuItem($dropdown[0], item));
$dropdown[0][ariaPatchKey].deferredRefreshAriaActiveItem();
return $wrapper.html();
};
dropdownCall('setting', 'templates', dropdownTemplates);
// the `onLabelCreate` is used to add necessary aria attributes for dynamically created selection labels
const dropdownOnLabelCreateOld = dropdownCall('setting', 'onLabelCreate');
dropdownCall('setting', 'onLabelCreate', function(value, text) {
const $label = dropdownOnLabelCreateOld.call(this, value, text);
updateSelectionLabel($label);
return $label;
});
}
// for static dropdown elements (generated by server-side template), prepare them with necessary aria attributes
function attachStaticElements($dropdown, $focusable, $menu) {
const dropdown = $dropdown[0];
// prepare static dropdown menu list popup
if (!$menu.attr('id')) $menu.attr('id', generateAriaId());
$menu.find('> .item').each((_, item) => updateMenuItem(dropdown, item));
// this role could only be changed after its content is ready, otherwise some browsers+readers (like Chrome+AppleVoice) crash
$menu.attr('role', dropdown[ariaPatchKey].listPopupRole);
// prepare selection label items
$dropdown.find('.ui.label').each((_, label) => updateSelectionLabel($(label)));
// make the primary element (focusable) aria-friendly
$focusable.attr({
'role': $focusable.attr('role') ?? dropdown[ariaPatchKey].focusableRole,
'aria-haspopup': dropdown[ariaPatchKey].listPopupRole,
'aria-controls': $menu.attr('id'),
'aria-expanded': 'false',
});
// use tooltip's content as aria-label if there is no aria-label
if ($dropdown.hasClass('tooltip') && $dropdown.attr('data-content') && !$dropdown.attr('aria-label')) {
$dropdown.attr('aria-label', $dropdown.attr('data-content'));
}
}
function attachInit($dropdown) {
const dropdown = $dropdown[0];
dropdown[ariaPatchKey] = {};
if ($dropdown.hasClass('custom')) return;
// Dropdown has 2 different focusing behaviors
// * with search input: the input is focused, and it works with aria-activedescendant pointing another sibling element.
// * without search input (but the readonly text), the dropdown itself is focused. then the aria-activedescendant points to the element inside dropdown
// Some desktop screen readers may change the focus, but dropdown requires that the focus must be on its primary element, then they don't work well.
// Expected user interactions for dropdown with aria support:
// * user can use Tab to focus in the dropdown, then the dropdown menu (list) will be shown
// * user presses Tab on the focused dropdown to move focus to next sibling focusable element (but not the menu item)
// * user can use arrow key Up/Down to navigate between menu items
// * when user presses Enter:
// - if the menu item is clickable (eg: <a>), then trigger the click event
// - otherwise, the dropdown control (low-level code) handles the Enter event, hides the dropdown menu
// TODO: multiple selection is only partially supported. Check and test them one by one in the future.
const $textSearch = $dropdown.find('input.search').eq(0);
const $focusable = $textSearch.length ? $textSearch : $dropdown; // the primary element for focus, see comment above
if (!$focusable.length) return;
let $menu = $dropdown.find('> .menu');
if (!$menu.length) {
// some "multiple selection" dropdowns don't have a static menu element in HTML, we need to pre-create it to make it have correct aria attributes
$menu = $('<div class="menu"></div>').appendTo($dropdown);
}
// There are 2 possible solutions about the role: combobox or menu.
// The idea is that if there is an input, then it's a combobox, otherwise it's a menu.
// Since #19861 we have prepared the "combobox" solution, but didn't get enough time to put it into practice and test before.
const isComboBox = $dropdown.find('input').length > 0;
dropdown[ariaPatchKey].focusableRole = isComboBox ? 'combobox' : 'button';
dropdown[ariaPatchKey].listPopupRole = isComboBox ? 'listbox' : 'menu';
dropdown[ariaPatchKey].listItemRole = isComboBox ? 'option' : 'menuitem';
attachDomEvents($dropdown, $focusable, $menu);
attachStaticElements($dropdown, $focusable, $menu);
}
function attachDomEvents($dropdown, $focusable, $menu) {
const dropdown = $dropdown[0];
// when showing, it has class: ".animating.in"
// when hiding, it has class: ".visible.animating.out"
const isMenuVisible = () => ($menu.hasClass('visible') && !$menu.hasClass('out')) || $menu.hasClass('in');
// update aria attributes according to current active/selected item
const refreshAriaActiveItem = () => {
const menuVisible = isMenuVisible();
$focusable.attr('aria-expanded', menuVisible ? 'true' : 'false');
// if there is an active item, use it (the user is navigating between items)
// otherwise use the "selected" for combobox (for the last selected item)
const $active = $menu.find('> .item.active, > .item.selected');
// if the popup is visible and has an active/selected item, use its id as aria-activedescendant
if (menuVisible) {
$focusable.attr('aria-activedescendant', $active.attr('id'));
} else if (dropdown[ariaPatchKey].listPopupRole === 'menu') {
// for menu, when the popup is hidden, no need to keep the aria-activedescendant, and clear the active/selected item
$focusable.removeAttr('aria-activedescendant');
$active.removeClass('active').removeClass('selected');
}
};
$dropdown.on('keydown', (e) => {
// here it must use keydown event before dropdown's keyup handler, otherwise there is no Enter event in our keyup handler
if (e.key === 'Enter') {
const dropdownCall = fomanticDropdownFn.bind($dropdown);
let $item = dropdownCall('get item', dropdownCall('get value'));
if (!$item) $item = $menu.find('> .item.selected'); // when dropdown filters items by input, there is no "value", so query the "selected" item
// if the selected item is clickable, then trigger the click event.
// we can not click any item without check, because Fomantic code might also handle the Enter event. that would result in double click.
if ($item && ($item.is('a') || $item.hasClass('js-aria-clickable'))) $item[0].click();
}
});
// use setTimeout to run the refreshAria in next tick (to make sure the Fomantic UI code has finished its work)
// do not return any value, jQuery has return-value related behaviors.
// when the popup is hiding, it's better to have a small "delay", because there is a Fomantic UI animation
// without the delay for hiding, the UI will be somewhat laggy and sometimes may get stuck in the animation.
const deferredRefreshAriaActiveItem = (delay = 0) => { setTimeout(refreshAriaActiveItem, delay) };
dropdown[ariaPatchKey].deferredRefreshAriaActiveItem = deferredRefreshAriaActiveItem;
$dropdown.on('keyup', (e) => { if (e.key.startsWith('Arrow')) deferredRefreshAriaActiveItem(); });
// if the dropdown has been opened by focus, do not trigger the next click event again.
// otherwise the dropdown will be closed immediately, especially on Android with TalkBack
// * desktop event sequence: mousedown -> focus -> mouseup -> click
// * mobile event sequence: focus -> mousedown -> mouseup -> click
// Fomantic may stop propagation of blur event, use capture to make sure we can still get the event
let ignoreClickPreEvents = 0, ignoreClickPreVisible = 0;
dropdown.addEventListener('mousedown', () => {
ignoreClickPreVisible += isMenuVisible() ? 1 : 0;
ignoreClickPreEvents++;
}, true);
dropdown.addEventListener('focus', () => {
ignoreClickPreVisible += isMenuVisible() ? 1 : 0;
ignoreClickPreEvents++;
deferredRefreshAriaActiveItem();
}, true);
dropdown.addEventListener('blur', () => {
ignoreClickPreVisible = ignoreClickPreEvents = 0;
deferredRefreshAriaActiveItem(100);
}, true);
dropdown.addEventListener('mouseup', () => {
setTimeout(() => {
ignoreClickPreVisible = ignoreClickPreEvents = 0;
deferredRefreshAriaActiveItem(100);
}, 0);
}, true);
dropdown.addEventListener('click', (e) => {
if (isMenuVisible() &&
ignoreClickPreVisible !== 2 && // dropdown is switch from invisible to visible
ignoreClickPreEvents === 2 // the click event is related to mousedown+focus
) {
e.stopPropagation(); // if the dropdown menu has been opened by focus, do not trigger the next click event again
}
ignoreClickPreEvents = ignoreClickPreVisible = 0;
}, true);
}
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