foomantic accessibility patch - working copy from #8638

dropdown.patch

--- web_src/fomantic/build/components/dropdown.js	1985-10-26 09:15:00.000000000 +0100
+++ web_src/js/vendor/dropdown.js	2021-07-29 21:53:25.769541139 +0100
@@ -8,6 +8,13 @@
  *
  */
 
+/*
+ * Copyright 2019 The Gitea Authors
+ * Released under the MIT license
+ * http://opensource.org/licenses/MIT
+ * This version has been modified by Gitea to improve accessibility.
+ */
+
 ;(function ($, window, document, undefined) {
 
 'use strict';
@@ -41,6 +48,7 @@
     query          = arguments[0],
     methodInvoked  = (typeof query == 'string'),
     queryArguments = [].slice.call(arguments, 1),
+    lastAriaID = 1,
     returnedValue
   ;
 
@@ -133,6 +141,8 @@
 
             module.observeChanges();
             module.instantiate();
+
+            module.aria.setup();
           }
 
         },
@@ -333,6 +343,86 @@
           }
         },
 
+        aria: {
+          setup: function() {
+            var role = module.aria.guessRole();
+            if( role !== 'menu' ) {
+              return;
+            }
+            $module.attr('aria-busy', 'true');
+            $module.attr('role', 'menu');
+            $module.attr('aria-haspopup', 'menu');
+            $module.attr('aria-expanded', 'false');
+            $menu.find('.divider').attr('role', 'separator');
+            $item.attr('role', 'menuitem');
+            $item.each(function (index, item) {
+              if( !item.id ) {
+                item.id = module.aria.nextID('menuitem');
+              }
+            });
+            $text = $module
+              .find('> .text')
+              .eq(0)
+            ;
+            if( $module.data('content') ) {
+              $text.attr('aria-hidden');
+              $module.attr('aria-label', $module.data('content'));
+            }
+            else {
+              $text.attr('id', module.aria.nextID('menutext'));
+              $module.attr('aria-labelledby', $text.attr('id'));
+            }
+            $module.attr('aria-busy', 'false');
+          },
+          nextID: function(prefix) {
+            var nextID;
+            do {
+              nextID = prefix + '_' + lastAriaID++;
+            } while( document.getElementById(nextID) );
+            return nextID;
+          },
+          setExpanded: function(expanded) {
+            if( $module.attr('aria-haspopup') ) {
+              $module.attr('aria-expanded', expanded);
+            }
+          },
+          refreshDescendant: function() {
+            if( $module.attr('aria-haspopup') !== 'menu' ) {
+              return;
+            }
+            var
+              $currentlySelected = $item.not(selector.unselectable).filter('.' + className.selected).eq(0),
+              $activeItem        = $menu.children('.' + className.active).eq(0),
+              $selectedItem      = ($currentlySelected.length > 0)
+                ? $currentlySelected
+                : $activeItem
+            ;
+            if( $selectedItem ) {
+              $module.attr('aria-activedescendant', $selectedItem.attr('id'));
+            }
+            else {
+              module.aria.removeDescendant();
+            }
+          },
+          removeDescendant: function() {
+            if( $module.attr('aria-haspopup') == 'menu' ) {
+              $module.removeAttr('aria-activedescendant');
+            }
+          },
+          guessRole: function() {
+            var
+              isIcon = $module.hasClass('icon'),
+              hasSearch = module.has.search(),
+              hasInput = ($input.length > 0),
+              isMultiple = module.is.multiple()
+            ;
+            if ( !isIcon && !hasSearch && !hasInput && !isMultiple ) {
+              return 'menu';
+            }
+            return 'unknown';
+          }
+        },
+
         setup: {
           api: function() {
             var
@@ -379,6 +469,7 @@
             if(settings.allowTab) {
               module.set.tabbable();
             }
+            $item.attr('tabindex', '-1');
           },
           select: function() {
             var
@@ -525,6 +616,8 @@
               return true;
             }
             if(settings.onShow.call(element) !== false) {
+              module.aria.setExpanded(true);
+              module.aria.refreshDescendant();
               module.animate.show(function() {
                 if( module.can.click() ) {
                   module.bind.intent();
@@ -547,6 +640,8 @@
           if( module.is.active() && !module.is.animatingOutward() ) {
             module.debug('Hiding dropdown');
             if(settings.onHide.call(element) !== false) {
+              module.aria.setExpanded(false);
+              module.aria.removeDescendant();
               module.animate.hide(function() {
                 module.remove.visible();
                 // hidding search focus
@@ -995,7 +1090,7 @@
           ;
           if(settings.allowAdditions || (hasSelected && !module.is.multiple())) {
             module.debug('Forcing partial selection to selected item', $selectedItem);
-            module.event.item.click.call($selectedItem, {}, true);
+            $selectedItem[0].click();
           }
           else {
             module.remove.searchTerm();
@@ -1500,7 +1595,7 @@
               // allow selection with menu closed
               if(isAdditionWithoutMenu) {
                 module.verbose('Selecting item from keyboard shortcut', $selectedItem);
-                module.event.item.click.call($selectedItem, event);
+                $selectedItem[0].click();
                 if(module.is.searchSelection()) {
                   module.remove.searchTerm();
                 }
@@ -1520,7 +1615,7 @@
                   }
                   else if(selectedIsSelectable) {
                     module.verbose('Selecting item from keyboard shortcut', $selectedItem);
-                    module.event.item.click.call($selectedItem, event);
+                    $selectedItem[0].click();
                     if(module.is.searchSelection()) {
                       module.remove.searchTerm();
                       if(module.is.multiple()) {
@@ -1548,6 +1643,7 @@
                         .closest(selector.item)
                           .addClass(className.selected)
                       ;
+                      module.aria.refreshDescendant();
                       event.preventDefault();
                     }
                   }
@@ -1564,6 +1660,7 @@
                         .find(selector.item).eq(0)
                           .addClass(className.selected)
                       ;
+                      module.aria.refreshDescendant();
                       event.preventDefault();
                     }
                   }
@@ -1588,6 +1685,7 @@
                     $nextItem
                       .addClass(className.selected)
                     ;
+                    module.aria.refreshDescendant();
                     module.set.scrollPosition($nextItem);
                     if(settings.selectOnKeydown && module.is.single()) {
                       module.set.selectedItem($nextItem);
@@ -1615,6 +1713,7 @@
                     $nextItem
                       .addClass(className.selected)
                     ;
+                    module.aria.refreshDescendant();
                     module.set.scrollPosition($nextItem);
                     if(settings.selectOnKeydown && module.is.single()) {
                       module.set.selectedItem($nextItem);
@@ -2584,6 +2683,7 @@
               module.set.scrollPosition($nextValue);
               $selectedItem.removeClass(className.selected);
               $nextValue.addClass(className.selected);
+              module.aria.refreshDescendant();
               if(settings.selectOnKeydown && module.is.single()) {
                 module.set.selectedItem($nextValue);
               }