Programmatically set focus to confirmation dialog.

HFJ-1572

js/h5p-confirmation-dialog.js

@@ -176,7 +176,10 @@ H5P.ConfirmationDialog = (function (EventDispatcher) {
       fitToContainer();
       popupBackground.classList.remove('hiding');
       popup.classList.remove('hidden');
-      cancelButton.focus();
+
+      // Programmatically focus popup
+      popup.setAttribute('tabindex', '-1');
+      popup.focus();
 
       return this;
     };

styles/h5p-confirmation-dialog.css

@@ -25,6 +25,10 @@
   transition: opacity 0.1s linear 0s, visibility 0s linear 0.1s;
 }
 
+.h5p-confirmation-dialog-popup:focus {
+  outline: none;
+}
+
 .h5p-confirmation-dialog-popup {
   position: absolute;
   display: flex;