fixes #4091

Closes #4091

Merge request studip/studip!3071

resources/vue/components/blubber/Composer.vue

 <template>
     <div class="writer" :style="composerStyle">
         <studip-icon shape="blubber" :size="30" role="info"></studip-icon>
+        <label for="blubber-placeholder" class="sr-only">
+            {{ placeholder || $gettext('Schreib was, frag was. Enter zum Abschicken.') }}
+        </label>
         <textarea
             :placeholder="placeholder || $gettext('Schreib was, frag was. Enter zum Abschicken.')"
             v-model="localText"
@@ -10,6 +13,7 @@
             @keyup.up.exact="editPreviousComment"
             @keyup="saveCommentToSession"
             ref="textarea"
+            id="blubber-placeholder"
         ></textarea>
         <a class="send" @click="submit" :title="$gettext('Abschicken')">
             <studip-icon shape="arr_2up" :size="30"></studip-icon>

templates/sidebar/search-widget.php

@@ -12,7 +12,7 @@
         <? $hash = md5($url . '|' . $needle['name']) ?>
         <li <? if ($needle['quick_search'] && $needle['quick_search']->hasExtendedLayout()) echo 'class="extendedLayout" id="' . $needle['quick_search']->getId() . '_frame"'; ?>>
             <div class="input-group files-search">
-                <label for="needle-<?= $hash ?>" <? if ($needle['placeholder']) echo 'style="display:none;"'; ?>>
+                <label for="needle-<?= $hash ?>" <? if ($needle['placeholder']) echo 'class="sr-only"'; ?>>
                     <?= htmlReady($needle['label']) ?>
                 </label>
                 <? if ($needle['quick_search']): ?>