fixed errors, removed unused code

resources/assets/javascripts/bootstrap/tooltip.js

@@ -7,29 +7,3 @@
 var timeout = null;
 
 STUDIP.Tooltip.threshold = 6;
-/*
-$(document).on('mouseenter mouseleave focusin focusout', '[data-tooltip],.tooltip:has(.tooltip-content)', function(event) {
-    let data = $(this).data();
-    const visible = event.type === 'mouseenter' || event.type === 'focusin';
-    const offset = $(this).offset();
-    const x = offset.left + $(this).outerWidth(true) / 2;
-    const y = offset.top;
-    const delay = data.tooltipDelay ?? 300;
-
-    if (!data.tooltipObject) {
-        data.tooltipObject = new STUDIP.Tooltip(x, y, $(this).children('.tooltip-content').first().html());
-    }
-
-    if (visible) {
-        // If tooltip has already been created, update its position.
-        // This is necessary if the surrounding content is scrollable AND has
-        // been scrolled. Otherwise, the tooltip would appear at its previous
-        // and now wrong location.
-        data.tooltipObject.position(x, y);
-    }
-}).on('mouseenter focusin', '.studip-tooltip', () => {
-    clearTimeout(timeout);
-}).on('mouseleave focusout', '.studip-tooltip', function() {
-    $(this).hide();
-});
-*/

resources/assets/stylesheets/scss/tooltip.scss

@@ -43,7 +43,7 @@
         bottom: 100%;
         display: inline-block;
         left: 50%;
-        margin-left: -($grid-element-width) / 2 - 10px;
+        margin-left: - calc($grid-element-width / 2) - 10px;
         width: $grid-element-width;
     }
 }

templates/shared/tooltip.php

 <span class="tooltip tooltip-icon <? if ($important) echo 'tooltip-important'; ?>"
-      tabindex="0">
+      tabindex="0" aria-label="<?= $html ? kill_format($text) : htmlReady($text) ?>">
     <span class="tooltip-content"><?= $html ? $text : htmlReady($text) ?></span>
 </span>