Update notification dismissal system a bit

notification/src/main/java/de/staropensource/engine/notification/NotificationManager.java

@@ -105,8 +105,9 @@ public final class NotificationManager {
      * Does nothing if it is already dismissed.
      * <p>
      * Note: Dismissing a notification does not
-     * necessarily mean it removes it. Depending
+     * necessarily mean removing it. Check
-     * on the {@link Notification#}
+     * {@link Notification#getDismissalAction()}
+     * first or you might get a surprise.
      *
      * @param notification notification to update
      * @since v1-alpha6
@@ -119,13 +120,37 @@ public final class NotificationManager {
                 case UNREGISTER -> updateNotification(notification, notifications.get(notification), true);
                 case EXECUTE -> notification.dismiss();
                 case EXECUTE_UNREGISTER -> {
+                    updateNotification(notification, NotificationState.DISMISSED_ACTIVE, false);
                     notification.dismiss();
-                    updateNotification(notification, notifications.get(notification), true);
+                    updateNotification(notification, NotificationState.DISMISSED, true);
                 }
             }
         }
     }
 
+    /**
+     * Frees the specified notification,
+     * or all if {@code notifications} is empty.
+     * <p>
+     * Only works for dismissed notifications
+     * which require manual freeing. See
+     * {@link #dismiss(Notification)} for more information.
+     *
+     * @param notifications notifications to free, or all if empty
+     * @since v1-alpha6
+     */
+    public static void freeDismissed(@NotNull Notification @NotNull... notifications) {
+        if (notifications.length == 0)
+            notifications = NotificationManager.getNotifications().keySet().toArray(new Notification[0]);
+
+        for (Notification notification : notifications)
+            if (
+                    NotificationManager.getNotifications().containsKey(notification)
+                    && NotificationManager.getNotifications().get(notification) == NotificationState.DISMISSED
+            )
+                updateNotification(notification, NotificationState.DISMISSED, true);
+    }
+
     /**
      * Adds or updates the specified notification
      * in the {@link #notifications} map.

notification/src/main/java/de/staropensource/engine/notification/type/Notification.java

@@ -237,6 +237,7 @@ public class Notification {
      * @return linked button map
      * @since v1-alpha6
      */
+    @Setter(value = AccessLevel.NONE)
     private @NotNull LinkedHashMap<@NotNull String, @NotNull Runnable> buttons = new LinkedHashMap<>();
 
     /**

notification/src/main/java/de/staropensource/engine/notification/type/NotificationState.java

@@ -39,6 +39,14 @@ public enum NotificationState {
      */
     HIDDEN,
 
+    /**
+     * A dismissed notification which
+     * is still executing code.
+     *
+     * @since v1-alpha6
+     */
+    DISMISSED_ACTIVE,
+
     /**
      * A dismissed notification.
      *