Restore Accessibility for Dropdown (#16576)

* Restore #10096/#8638 and re-fix #15172

This PR restores the vendored and patched dropdow from #8638. It
however, abandons the calls to `click()` using instead the default
dropdown click calls instead. This prevents the issue of the dropdown
grabbing focus permanently however, this may have negative effects on
the effect of focus on the dropdowns.

Of note, the behaviour of the template selector dropdown on the repo
creation page is slightly odd - I don't believe that this odd behaviour
is caused by this PR but rather by the feed source for this. I suspect
that the dropdown should be adding a delete button to its selection.

Fix #15172
References: #7057

Signed-off-by: Andrew Thornton <art27@cantab.net>

* leverage fomantic-build instead

Signed-off-by: Andrew Thornton <art27@cantab.net>

* as per jookia

Signed-off-by: Andrew Thornton <art27@cantab.net>

.eslintrc

@@ -2,6 +2,7 @@ root: true
 reportUnusedDisableDirectives: true
 
 ignorePatterns:
+  - /web_src/js/vendor
   - /templates/base/head.tmpl
   - /templates/repo/activity.tmpl
   - /templates/repo/view_file.tmpl

Makefile

@@ -699,6 +699,7 @@ fomantic:
 	cd $(FOMANTIC_WORK_DIR) && npm install --no-save
 	cp -f $(FOMANTIC_WORK_DIR)/theme.config.less $(FOMANTIC_WORK_DIR)/node_modules/fomantic-ui/src/theme.config
 	cp -rf $(FOMANTIC_WORK_DIR)/_site $(FOMANTIC_WORK_DIR)/node_modules/fomantic-ui/src/
+	cp -f web_src/js/vendor/dropdown.js $(FOMANTIC_WORK_DIR)/node_modules/fomantic-ui/src/definitions/modules
 	cd $(FOMANTIC_WORK_DIR) && npx gulp -f node_modules/fomantic-ui/gulpfile.js build
 
 .PHONY: webpack

web_src/fomantic/build/semantic.css

@@ -30873,7 +30873,7 @@ ol.ui.suffixed.list li:before,
      List
 ---------------*/
 
-/* Menu divider shouldn't apply */
+/* Menu divider shouldnt apply */
 
 .ui.menu .list .item:before {
   background: none !important;
@@ -31802,7 +31802,7 @@ Floated Menu / Item
   opacity: 1;
 }
 
-/* Icon Glyph */
+/* Icon Gylph */
 
 .ui.icon.menu i.icon:before {
   opacity: 1;

web_src/fomantic/build/semantic.js

@@ -142,7 +142,7 @@ $.api = $.fn.api = function(parameters) {
                response = JSON.parse(response);
               }
               catch(e) {
-                // isn't json string
+                // isnt json string
               }
             }
             return response;
@@ -2220,7 +2220,7 @@ $.fn.dimmer = function(parameters) {
 
         event: {
           click: function(event) {
-            module.verbose('Determining if event occurred on dimmer', event);
+            module.verbose('Determining if event occured on dimmer', event);
             if( $dimmer.find(event.target).length === 0 || $(event.target).is(selector.content) ) {
               module.hide();
               event.stopImmediatePropagation();
@@ -2827,6 +2827,13 @@ $.fn.dimmer.settings = {
  *
  */
 
+/*
+ * 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';
@@ -2860,6 +2867,7 @@ $.fn.dropdown = function(parameters) {
     query          = arguments[0],
     methodInvoked  = (typeof query == 'string'),
     queryArguments = [].slice.call(arguments, 1),
+    lastAriaID = 1,
     returnedValue
   ;
 
@@ -2952,6 +2960,8 @@ $.fn.dropdown = function(parameters) {
 
             module.observeChanges();
             module.instantiate();
+
+            module.aria.setup();
           }
 
         },
@@ -3152,6 +3162,86 @@ $.fn.dropdown = function(parameters) {
           }
         },
 
+        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
@@ -3198,6 +3288,7 @@ $.fn.dropdown = function(parameters) {
             if(settings.allowTab) {
               module.set.tabbable();
             }
+            $item.attr('tabindex', '-1');
           },
           select: function() {
             var
@@ -3344,6 +3435,8 @@ $.fn.dropdown = function(parameters) {
               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();
@@ -3366,9 +3459,11 @@ $.fn.dropdown = function(parameters) {
           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();
-                // hiding search focus
+                // hidding search focus
                 if ( module.is.focusedOnSearch() && preventBlur !== true ) {
                   $search.blur();
                 }
@@ -4319,7 +4414,7 @@ $.fn.dropdown = function(parameters) {
               // 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();
                 }
@@ -4339,7 +4434,7 @@ $.fn.dropdown = function(parameters) {
                   }
                   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()) {
@@ -4367,6 +4462,7 @@ $.fn.dropdown = function(parameters) {
                         .closest(selector.item)
                           .addClass(className.selected)
                       ;
+                      module.aria.refreshDescendant();
                       event.preventDefault();
                     }
                   }
@@ -4383,6 +4479,7 @@ $.fn.dropdown = function(parameters) {
                         .find(selector.item).eq(0)
                           .addClass(className.selected)
                       ;
+                      module.aria.refreshDescendant();
                       event.preventDefault();
                     }
                   }
@@ -4407,6 +4504,7 @@ $.fn.dropdown = function(parameters) {
                     $nextItem
                       .addClass(className.selected)
                     ;
+                    module.aria.refreshDescendant();
                     module.set.scrollPosition($nextItem);
                     if(settings.selectOnKeydown && module.is.single()) {
                       module.set.selectedItem($nextItem);
@@ -4434,6 +4532,7 @@ $.fn.dropdown = function(parameters) {
                     $nextItem
                       .addClass(className.selected)
                     ;
+                    module.aria.refreshDescendant();
                     module.set.scrollPosition($nextItem);
                     if(settings.selectOnKeydown && module.is.single()) {
                       module.set.selectedItem($nextItem);
@@ -5403,6 +5502,7 @@ $.fn.dropdown = function(parameters) {
               module.set.scrollPosition($nextValue);
               $selectedItem.removeClass(className.selected);
               $nextValue.addClass(className.selected);
+              module.aria.refreshDescendant();
               if(settings.selectOnKeydown && module.is.single()) {
                 module.set.selectedItem($nextValue);
               }
@@ -11937,7 +12037,7 @@ $.fn.progress = function(parameters) {
            *
            * @param min A minimum value within multiple values
            * @param total A total amount of multiple values
-           * @returns {number} A precision. Could be 1, 10, 100, ... 1e+10.
+           * @returns {number} A precison. Could be 1, 10, 100, ... 1e+10.
            */
           derivePrecision: function(min, total) {
             var precisionPower = 0
@@ -12837,7 +12937,7 @@ $.fn.progress.settings = {
     nonNumeric      : 'Progress value is non numeric',
     tooHigh         : 'Value specified is above 100%',
     tooLow          : 'Value specified is below 0%',
-    sumExceedsTotal : 'Sum of multiple values exceed total',
+    sumExceedsTotal : 'Sum of multple values exceed total',
   },
 
   regExp: {
@@ -18076,7 +18176,7 @@ $.fn.transition.settings = {
 
   // possible errors
   error: {
-    noAnimation : 'Element is no longer attached to DOM. Unable to animate.  Use silent setting to suppress this warning in production.',
+    noAnimation : 'Element is no longer attached to DOM. Unable to animate.  Use silent setting to surpress this warning in production.',
     repeated    : 'That animation is already occurring, cancelling repeated animation',
     method      : 'The method you called is not defined',
     support     : 'This browser does not support CSS animations'