*/
boolean operationInProgress();
+ /**
+ * Adds a progress bar for the given id if it doesn't exist displaying the
+ * provided message. Subsequent calls do nothing.
+ *
+ * @param id
+ * progress bar identifier
+ * @param message
+ * displayed message
+ */
+ void addProgressBar(long id, String message);
+
+ /**
+ * Removes a progress bar for the given id if it exists. Subsequent calls do
+ * nothing.
+ *
+ * @param id
+ * id of the progress bar to be removed
+ */
+ void removeProgressBar(long id);
+
+
}