I164 warning if no data

sohstationviewer/model/data_loader.py

@@ -57,8 +57,11 @@ class DataLoaderWorker(QtCore.QObject):
         # the main thread.
         self.notification.connect(display_tracking_info)
         self.end_msg = None
+        # to change display tracking info to error when failed
+        self.process_failed: bool = False
 
     def run(self):
+        self.process_failed = False
         folders = (self.list_of_rt130_paths
                    if self.list_of_dir == [''] else self.list_of_dir)
         folders_str = ', '.join([dir.name for dir in folders])
@@ -98,10 +101,17 @@ class DataLoaderWorker(QtCore.QObject):
             fmt = traceback.format_exc()
             self.end_msg = (f"Some in {folders_str} can't be read "
                             f"due to error: {str(fmt)}")
+            self.process_failed = True
             self.failed.emit()
         else:
-            self.end_msg = f'Finished loading data stored in {folders_str}'
-            self.finished.emit(data_object)
+            if data_object.selected_key is None:
+                self.process_failed = True
+                self.end_msg = ("No data was found. Please check the selected "
+                                "time range and channel list.")
+                self.failed.emit()
+            else:
+                self.end_msg = f'Finished loading data stored in {folders_str}'
+                self.finished.emit(data_object)
 
 
 class DataLoader(QtCore.QObject):
@@ -210,8 +220,11 @@ class DataLoader(QtCore.QObject):
         Currently does the following:
             - Set running state of self to False
         """
+        log_type = LogType.INFO
+        if self.worker.process_failed:
+            log_type = LogType.ERROR
         display_tracking_info(self.worker.tracking_box,
-                              self.worker.end_msg, LogType.INFO)
+                              self.worker.end_msg, log_type)
         self.running = False
 
     @QtCore.Slot()