Merge branch 'i227_TPS_not_plotted' into 'master'

fix TPS not plotted

Closes #227

See merge request !257

sohstationviewer/view/plotting/time_power_square/time_power_squared_widget.py

@@ -239,12 +239,13 @@ class TimePowerSquaredWidget(plotting_widget.PlottingWidget):
         :param chan_id: channel name in str or None if no data, '' if stop
         """
         if chan_id is None:
-            self.done()
-            msg = None
+            msg = f'{self.get_plot_name()} has no data.'
         elif chan_id == '':
             msg = f'{self.get_plot_name()} stopped.'
         else:
             msg = f'{self.get_plot_name()} finished.'
+            self.done()
+
         if msg:
             self.parent.processing_log_msg += msg + "\n"
             display_tracking_info(