CalcJobOutputFollower: Fetch retrieved output file if available (aiid…

…alab#269)

Besides performance reasons, this work better
when the remote folder is cleared.

aiidalab_qe/widgets.py

@@ -296,7 +296,15 @@ def _follow_output(self, calcjob):
 
     def _fetch_output(self, calcjob):
         assert isinstance(calcjob, CalcJobNode)
-        if "remote_folder" in calcjob.outputs:
+        if "retrieved" in calcjob.outputs:
+            try:
+                self.filename = calcjob.attributes["output_filename"]
+                with calcjob.outputs.retrieved.open(self.filename) as f:
+                    return f.read().splitlines()
+            except OSError:
+                return list()
+
+        elif "remote_folder" in calcjob.outputs:
             try:
                 fn_out = calcjob.attributes["output_filename"]
                 self.filename = fn_out