From d4f35bd681af0632da988e15306f330e020422b2 Mon Sep 17 00:00:00 2001 From: wxiaoguang Date: Wed, 22 Mar 2023 10:52:01 +0800 Subject: [PATCH] Use a general approch to improve a11y for all checkboxes and dropdowns. (#23542) This PR follows #22599 and #23450 The major improvements: 1. The `aria-*.js` are totally transparent now, no need to call `attachDropdownAria` explicitly anymore. * It hooks the `$.fn.checkbox` and `$.fn.dropdown`, then our patch works. * It makes all dynamically generated checkbox/dropdown work with a11y without any change * eg: the `conversation.find('.dropdown').dropdown();` in `repo-diff.js` 2. Since it's totally transparent now, it could be easier to modify or remove in the future. 3. It handles all selection labels as well (by onLabelCreate), so it supports "multiple selection dropdown" now. * It partially completes one of my TODOs: `TODO: multiple selection is not supported yet.` 4. The code structure is clearer, code blocks are splitted into different functions. * The old `attachOneDropdownAria` was splitted into separate functions. * It makes it easier to add more fine tunes in the future, and co-work with contributors. 6. The code logic is similar as before, only two new parts: 1. the `ariaCheckboxFn` and `ariaDropdownFn` functions 2. the `onLabelCreate` and `updateSelectionLabel` functions In `aria-dropdown.js` I had to mix jQuery and Vanilla JS somewhat, I think the code is still understandable, otherwise the code would be much more complex to read. Thanks to fsologureng for the idea about "improving the 'delete icon' with aria attributes". If there is anything unclear or incorrect, feel free to ask and discuss, or propose new PRs for it. --- options/locale/locale_en-US.ini | 1 + templates/base/head_script.tmpl | 1 + web_src/js/features/common-global.js | 5 +- web_src/js/index.js | 5 + web_src/js/{features => modules/aria}/aria.md | 12 +- web_src/js/modules/aria/base.js | 5 + web_src/js/modules/aria/checkbox.js | 38 +++ .../aria.js => modules/aria/dropdown.js} | 225 +++++++++++------- 8 files changed, 198 insertions(+), 94 deletions(-) rename web_src/js/{features => modules/aria}/aria.md (88%) create mode 100644 web_src/js/modules/aria/base.js create mode 100644 web_src/js/modules/aria/checkbox.js rename web_src/js/{features/aria.js => modules/aria/dropdown.js} (52%) diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini index 818a6bbef1..da4ad47620 100644 --- a/options/locale/locale_en-US.ini +++ b/options/locale/locale_en-US.ini @@ -84,6 +84,7 @@ add = Add add_all = Add All remove = Remove remove_all = Remove All +remove_label_str = Remove item "%s" edit = Edit enabled = Enabled diff --git a/templates/base/head_script.tmpl b/templates/base/head_script.tmpl index ca8c7e6a77..62fb10d89f 100644 --- a/templates/base/head_script.tmpl +++ b/templates/base/head_script.tmpl @@ -41,6 +41,7 @@ If you introduce mistakes in it, Gitea JavaScript code wouldn't run correctly. copy_error: '{{.locale.Tr "copy_error"}}', error_occurred: '{{.locale.Tr "error.occurred"}}', network_error: '{{.locale.Tr "error.network_error"}}', + remove_label_str: '{{.locale.Tr "remove_label_str"}}', }, }; {{/* in case some pages don't render the pageData, we make sure it is an object to prevent null access */}} diff --git a/web_src/js/features/common-global.js b/web_src/js/features/common-global.js index cdb9132805..113ff2e1f1 100644 --- a/web_src/js/features/common-global.js +++ b/web_src/js/features/common-global.js @@ -4,7 +4,6 @@ import {mqBinarySearch} from '../utils.js'; import {createDropzone} from './dropzone.js'; import {initCompColorPicker} from './comp/ColorPicker.js'; import {showGlobalErrorMessage} from '../bootstrap.js'; -import {attachCheckboxAria, attachDropdownAria} from './aria.js'; import {handleGlobalEnterQuickSubmit} from './comp/QuickSubmit.js'; import {initTooltip} from '../modules/tippy.js'; import {svg} from '../svg.js'; @@ -123,9 +122,7 @@ export function initGlobalCommon() { $uiDropdowns.filter('.slide.up').dropdown({transition: 'slide up'}); $uiDropdowns.filter('.upward').dropdown({direction: 'upward'}); - attachDropdownAria($uiDropdowns); - - attachCheckboxAria($('.ui.checkbox')); + $('.ui.checkbox').checkbox(); $('.tabular.menu .item').tab(); $('.tabable.menu .item').tab(); diff --git a/web_src/js/index.js b/web_src/js/index.js index 480661118b..7d74ee6b94 100644 --- a/web_src/js/index.js +++ b/web_src/js/index.js @@ -89,6 +89,8 @@ import {initFormattingReplacements} from './features/formatting.js'; import {initCopyContent} from './features/copycontent.js'; import {initCaptcha} from './features/captcha.js'; import {initRepositoryActionView} from './components/RepoActionView.vue'; +import {initAriaCheckboxPatch} from './modules/aria/checkbox.js'; +import {initAriaDropdownPatch} from './modules/aria/dropdown.js'; // Run time-critical code as soon as possible. This is safe to do because this // script appears at the end of and rendered HTML is accessible at that point. @@ -98,6 +100,9 @@ initFormattingReplacements(); $.fn.tab.settings.silent = true; // Disable the behavior of fomantic to toggle the checkbox when you press enter on a checkbox element. $.fn.checkbox.settings.enableEnterKey = false; +// Use the patches to improve accessibility, these patches are designed to be as independent as possible, make it easy to modify or remove in the future. +initAriaCheckboxPatch(); +initAriaDropdownPatch(); $(document).ready(() => { initGlobalCommon(); diff --git a/web_src/js/features/aria.md b/web_src/js/modules/aria/aria.md similarity index 88% rename from web_src/js/features/aria.md rename to web_src/js/modules/aria/aria.md index 679cec774c..a32d15f46f 100644 --- a/web_src/js/features/aria.md +++ b/web_src/js/modules/aria/aria.md @@ -23,6 +23,14 @@ To test the aria/accessibility with screen readers, developers can use the follo * Double-finger swipe means old single-finger swipe. * TODO: on Windows, on Linux, on iOS +# Known Problems + +* Tested with Apple VoiceOver: If a dropdown menu/combobox is opened by mouse click, then arrow keys don't work. + But if the dropdown is opened by keyboard Tab, then arrow keys work, and from then on, the keys almost work with mouse click too. + The clue: when the dropdown is only opened by mouse click, VoiceOver doesn't send 'keydown' events of arrow keys to the DOM, + VoiceOver expects to use arrow keys to navigate between some elements, but it couldn't. + Users could use Option+ArrowKeys to navigate between menu/combobox items or selection labels if the menu/combobox is opened by mouse click. + # Checkbox ## Accessibility-friendly Checkbox @@ -52,9 +60,7 @@ There is still a problem: Fomantic UI checkbox is not friendly to screen readers so we add IDs to all the Fomantic UI checkboxes automatically by JS. If the `label` part is empty, then the checkbox needs to get the `aria-label` attribute manually. -# Dropdown - -## Fomantic UI Dropdown +# Fomantic Dropdown Fomantic Dropdown is designed to be used for many purposes: diff --git a/web_src/js/modules/aria/base.js b/web_src/js/modules/aria/base.js new file mode 100644 index 0000000000..c4a01038ba --- /dev/null +++ b/web_src/js/modules/aria/base.js @@ -0,0 +1,5 @@ +let ariaIdCounter = 0; + +export function generateAriaId() { + return `_aria_auto_id_${ariaIdCounter++}`; +} diff --git a/web_src/js/modules/aria/checkbox.js b/web_src/js/modules/aria/checkbox.js new file mode 100644 index 0000000000..08af1c2eb6 --- /dev/null +++ b/web_src/js/modules/aria/checkbox.js @@ -0,0 +1,38 @@ +import $ from 'jquery'; +import {generateAriaId} from './base.js'; + +const ariaPatchKey = '_giteaAriaPatchCheckbox'; +const fomanticCheckboxFn = $.fn.checkbox; + +// use our own `$.fn.checkbox` to patch Fomantic's checkbox module +export function initAriaCheckboxPatch() { + if ($.fn.checkbox === ariaCheckboxFn) throw new Error('initAriaCheckboxPatch could only be called once'); + $.fn.checkbox = ariaCheckboxFn; + ariaCheckboxFn.settings = fomanticCheckboxFn.settings; +} + +// the patched `$.fn.checkbox` checkbox function +// * it does the one-time attaching on the first call +function ariaCheckboxFn(...args) { + const ret = fomanticCheckboxFn.apply(this, args); + for (const el of this) { + if (el[ariaPatchKey]) continue; + attachInit(el); + } + return ret; +} + +function attachInit(el) { + // Fomantic UI checkbox needs to be something like:
+ // It doesn't work well with + // To make it work with aria, the "id"/"for" attributes are necessary, so add them automatically if missing. + // In the future, refactor to use native checkbox directly, then this patch could be removed. + el[ariaPatchKey] = {}; // record that this element has been patched + const label = el.querySelector('label'); + const input = el.querySelector('input'); + if (!label || !input || input.getAttribute('id')) return; + + const id = generateAriaId(); + input.setAttribute('id', id); + label.setAttribute('for', id); +} diff --git a/web_src/js/features/aria.js b/web_src/js/modules/aria/dropdown.js similarity index 52% rename from web_src/js/features/aria.js rename to web_src/js/modules/aria/dropdown.js index 676f4cd56c..70d524cfe7 100644 --- a/web_src/js/features/aria.js +++ b/web_src/js/modules/aria/dropdown.js @@ -1,14 +1,116 @@ import $ from 'jquery'; +import {generateAriaId} from './base.js'; -let ariaIdCounter = 0; +const ariaPatchKey = '_giteaAriaPatchDropdown'; +const fomanticDropdownFn = $.fn.dropdown; -function generateAriaId() { - return `_aria_auto_id_${ariaIdCounter++}`; +// 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'); + $.fn.dropdown = ariaDropdownFn; + ariaDropdownFn.settings = fomanticDropdownFn.settings; } -function attachOneDropdownAria($dropdown) { - if ($dropdown.attr('data-aria-attached') || $dropdown.hasClass('custom')) return; - $dropdown.attr('data-aria-attached', 1); +// the patched `$.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: "the-label-name " + 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 = $('
').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. @@ -23,71 +125,39 @@ function attachOneDropdownAria($dropdown) { // - if the menu item is clickable (eg: ), then trigger the click event // - otherwise, the dropdown control (low-level code) handles the Enter event, hides the dropdown menu - // TODO: multiple selection is not supported yet. + // 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 = $('
').appendTo($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 = $dropdown.find('input').length > 0; - const focusableRole = isComboBox ? 'combobox' : 'button'; - const listPopupRole = isComboBox ? 'listbox' : 'menu'; - const listItemRole = isComboBox ? 'option' : 'menuitem'; + dropdown[ariaPatchKey].focusableRole = isComboBox ? 'combobox' : 'button'; + dropdown[ariaPatchKey].listPopupRole = isComboBox ? 'listbox' : 'menu'; + dropdown[ariaPatchKey].listItemRole = isComboBox ? 'option' : 'menuitem'; - // make the item has role=option/menuitem, add an id if there wasn't one yet, make items as non-focusable - // the elements inside the dropdown menu item should not be focusable, the focus should always be on the dropdown primary element. - function prepareMenuItem($item) { - if (!$item.attr('id')) $item.attr('id', generateAriaId()); - $item.attr({'role': listItemRole, 'tabindex': '-1'}); - $item.find('a').attr('tabindex', '-1'); - } - - // delegate the dropdown's template function to add aria attributes. - // the "template" functions are used for dynamic creation (eg: AJAX) - const dropdownTemplates = {...$dropdown.dropdown('setting', 'templates')}; - 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 = $('
').append(menuItems); - const $items = $wrapper.find('> .item'); - $items.each((_, item) => prepareMenuItem($(item))); - return $wrapper.html(); - }; - $dropdown.dropdown('setting', 'templates', dropdownTemplates); - - // use tooltip's content as aria-label if there is no aria-label - if ($dropdown.hasClass('tooltip') && $dropdown.attr('data-content') && !$dropdown.attr('aria-label')) { - $dropdown.attr('aria-label', $dropdown.attr('data-content')); - } - - // prepare dropdown menu list popup - const $menu = $dropdown.find('> .menu'); - if (!$menu.attr('id')) $menu.attr('id', generateAriaId()); - $menu.find('> .item').each((_, item) => { - prepareMenuItem($(item)); - }); - // this role could only be changed after its content is ready, otherwise some browsers+readers (like Chrome+AppleVoice) crash - $menu.attr('role', listPopupRole); - - // make the primary element (focusable) aria-friendly - $focusable.attr({ - 'role': $focusable.attr('role') ?? focusableRole, - 'aria-haspopup': listPopupRole, - 'aria-controls': $menu.attr('id'), - 'aria-expanded': 'false', - }); + attachDomEvents($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 refreshAria = () => { + const refreshAriaActiveItem = () => { const menuVisible = isMenuVisible(); $focusable.attr('aria-expanded', menuVisible ? 'true' : 'false'); @@ -97,7 +167,7 @@ function attachOneDropdownAria($dropdown) { // 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 (!isComboBox) { + } 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'); $active.removeClass('active').removeClass('selected'); @@ -107,7 +177,8 @@ function attachOneDropdownAria($dropdown) { $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') { - let $item = $dropdown.dropdown('get item', $dropdown.dropdown('get value')); + const dropdownCall = fomanticDropdownFn.bind($dropdown); + let $item = dropdownCall('get item', dropdownCall('get value')); if (!$item) $item = $menu.find('> .item.selected'); // when dropdown filters items by input, there is no "value", so query the "selected" item // if the selected item is clickable, then trigger the click event. // we can not click any item without check, because Fomantic code might also handle the Enter event. that would result in double click. @@ -119,8 +190,9 @@ function attachOneDropdownAria($dropdown) { // 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 deferredRefreshAria = (delay = 0) => { setTimeout(refreshAria, delay) }; - $dropdown.on('keyup', (e) => { if (e.key.startsWith('Arrow')) deferredRefreshAria(); }); + const deferredRefreshAriaActiveItem = (delay = 0) => { setTimeout(refreshAriaActiveItem, delay) }; + dropdown[ariaPatchKey].deferredRefreshAriaActiveItem = deferredRefreshAriaActiveItem; + $dropdown.on('keyup', (e) => { if (e.key.startsWith('Arrow')) deferredRefreshAriaActiveItem(); }); // if the dropdown has been opened by focus, do not trigger the next click event again. // otherwise the dropdown will be closed immediately, especially on Android with TalkBack @@ -128,26 +200,26 @@ function attachOneDropdownAria($dropdown) { // * 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[0].addEventListener('mousedown', () => { + dropdown.addEventListener('mousedown', () => { ignoreClickPreVisible += isMenuVisible() ? 1 : 0; ignoreClickPreEvents++; }, true); - $dropdown[0].addEventListener('focus', () => { + dropdown.addEventListener('focus', () => { ignoreClickPreVisible += isMenuVisible() ? 1 : 0; ignoreClickPreEvents++; - deferredRefreshAria(); + deferredRefreshAriaActiveItem(); }, true); - $dropdown[0].addEventListener('blur', () => { + dropdown.addEventListener('blur', () => { ignoreClickPreVisible = ignoreClickPreEvents = 0; - deferredRefreshAria(100); + deferredRefreshAriaActiveItem(100); }, true); - $dropdown[0].addEventListener('mouseup', () => { + dropdown.addEventListener('mouseup', () => { setTimeout(() => { ignoreClickPreVisible = ignoreClickPreEvents = 0; - deferredRefreshAria(100); + deferredRefreshAriaActiveItem(100); }, 0); }, true); - $dropdown[0].addEventListener('click', (e) => { + dropdown.addEventListener('click', (e) => { if (isMenuVisible() && ignoreClickPreVisible !== 2 && // dropdown is switch from invisible to visible ignoreClickPreEvents === 2 // the click event is related to mousedown+focus @@ -157,24 +229,3 @@ function attachOneDropdownAria($dropdown) { ignoreClickPreEvents = ignoreClickPreVisible = 0; }, true); } - -export function attachDropdownAria($dropdowns) { - $dropdowns.each((_, e) => attachOneDropdownAria($(e))); -} - -export function attachCheckboxAria($checkboxes) { - $checkboxes.checkbox(); - - // Fomantic UI checkbox needs to be something like:
- // It doesn't work well with - // To make it work with aria, the "id"/"for" attributes are necessary, so add them automatically if missing. - // In the future, refactor to use native checkbox directly, then this patch could be removed. - for (const el of $checkboxes) { - const label = el.querySelector('label'); - const input = el.querySelector('input'); - if (!label || !input || input.getAttribute('id')) continue; - const id = generateAriaId(); - input.setAttribute('id', id); - label.setAttribute('for', id); - } -}