[Accessibility] fix: Set focus to form when applying filters

components/ILIAS/Mail/classes/Folder/MailFilterUI.php

@@ -41,7 +41,8 @@ public function __construct(
         private readonly Factory $ui_factory,
         private readonly ilUIFilterService $filter_service,
         private readonly ilLanguage $lng,
-        private readonly DateTimeZone $user_time_zone
+        private readonly DateTimeZone $user_time_zone,
+        private readonly bool $focus_first_filter_input_after_apply = false
     ) {
         $inputs = [];
         if ($this->folder->hasIncomingMails()) {
@@ -81,6 +82,24 @@ public function __construct(
             false,
             false
         );
+
+        if ($this->focus_first_filter_input_after_apply) {
+            $this->filter = $this->filter->withAdditionalOnLoadCode(
+                static fn(string $id): string => <<<JS
+window.setTimeout(function() {
+    const filterSection = document.getElementById('section_inputs_{$id}');
+    if (!filterSection) {
+        return;
+    }
+
+    const firstFocusable = filterSection.querySelector('input:not([type="hidden"]):not([disabled]), select:not([disabled]), textarea:not([disabled]), button:not([disabled]), [tabindex]:not([tabindex="-1"])');
+    if (firstFocusable instanceof HTMLElement) {
+        firstFocusable.focus();
+    }
+}, 25);
+JS
+            );
+        }
     }
 
     /**

components/ILIAS/Mail/classes/class.ilMailFolderGUI.php

@@ -622,9 +622,17 @@ protected function getFilterUI(): MailFilterUI
             $this->ui_service->filter(),
             $this->lng,
             new DateTimeZone($this->user->getTimeZone()),
+            $this->shouldFocusFirstFilterInputAfterApply(),
         );
     }
 
+    protected function shouldFocusFirstFilterInputAfterApply(): bool
+    {
+        $query_params = $this->http->request()->getQueryParams();
+
+        return ($query_params[ilUIFilterRequestAdapter::CMD_PARAMETER] ?? '') === ilUIFilterService::CMD_APPLY;
+    }
+
     /**
      * Searcher for mails in the folder, initialized with the current filter values
      * needed for table display and actions for the whole table