Use signals to updates note text after editing

Hypothesis: this stops some kind of database race condition or
similar.

app/musicmuster.py

@@ -258,6 +258,7 @@ class MusicMusterSignals(QObject):
     """
 
     save_playlist_signal = pyqtSignal()
+    update_row_note_signal = pyqtSignal(int)
 
 
 class Window(QMainWindow, Ui_MainWindow):

app/playlists.py

@@ -197,6 +197,7 @@ class PlaylistTab(QTableWidget):
         # Connect signals
         self.horizontalHeader().sectionResized.connect(self._column_resize)
         self.signals.save_playlist_signal.connect(self._deferred_save)
+        self.signals.update_row_note_signal.connect(self._update_row_note)
 
         # Load playlist rows
         self.populate_display(session, self.playlist_id)
@@ -333,24 +334,8 @@ class PlaylistTab(QTableWidget):
 
             if self.edit_cell_type == ROW_NOTES:
                 plr_item.note = new_text
-                # Set/clear row start time accordingly
+                session.flush()
-                start_time = self._get_note_text_time(new_text)
+                self.signals.update_row_note_signal.emit(row)
-                if start_time:
-                    self._set_row_start_time(row, start_time)
-                else:
-                    self._set_row_start_time(row, None)
-                self._set_row_note_colour(session, row, new_text,
-                                          section_header=not bool(track_id))
-                # Update note display
-                # If this is a header row, also calcuate track times in case
-                # note added a start time
-                if track_id:
-                    self._set_row_note_colour(session, row, new_text,
-                                              section_header=False)
-                else:
-                    self._set_row_note_colour(session, row, new_text,
-                                              section_header=True)
-                    self._update_start_end_times()
             else:
                 track = None
                 if track_id:
@@ -2091,6 +2076,26 @@ class PlaylistTab(QTableWidget):
         if not file_is_readable(track.path):
             self._set_row_colour_unreadable(row)
 
+    def _update_row_note(self, row_number: int) -> None:
+        """
+        Called by signal when row note is updated
+        """
+
+        # Set/clear row start time accordingly
+        note_text = self._get_row_note(row_number)
+        start_time = self._get_note_text_time(note_text)
+        if start_time:
+            self._set_row_start_time(row_number, start_time)
+        else:
+            self._set_row_start_time(row_number, None)
+
+        is_section_header = not bool(self._get_row_track_id(row_number))
+        with Session() as session:
+            self._set_row_note_colour(session, row_number, note_text,
+                                      section_header=is_section_header)
+
+        self._update_start_end_times()
+
     def _update_section_headers(self, session: scoped_session) -> None:
         """
         Update section headers with run time of section