Implement "remove comments"

Fixes #185

app/playlistmodel.py

@@ -40,6 +40,7 @@ from classes import (
 )
 from config import Config
 from helpers import (
+    ask_yes_no,
     file_is_unreadable,
     get_embedded_time,
     get_relative_date,
@@ -67,7 +68,7 @@ class PlaylistModel(QAbstractTableModel):
     database
 
     refresh_data() will repopulate all of playlist_rows from the
-    database
+    database.
     """
 
     def __init__(
@@ -993,10 +994,17 @@ class PlaylistModel(QAbstractTableModel):
 
     @line_profiler.profile
     def refresh_data(self, session: db.session, dummy_for_profiling=None) -> None:
-        """Populate self.playlist_rows with playlist data"""
+        """
+        Populate self.playlist_rows with playlist data
+
+        We used to clear self.playlist_rows each time but that's
+        expensive and slow on big playlists. Instead we track where rows
+        are in database versus self.playlist_rows and fixup the latter.
+        This works well for news rows added and for rows moved, but
+        doesn't work for changed comments so they must be handled using
+        refresh_row().
+        """
 
-        # We used to clear self.playlist_rows each time but that's
-        # expensive and slow on big playlists
 
         # Note where each playlist_id is
         plid_to_row: dict[int, int] = {}
@@ -1016,12 +1024,13 @@ class PlaylistModel(QAbstractTableModel):
         # Copy to self.playlist_rows
         self.playlist_rows = new_playlist_rows
 
-    # Same as refresh data, but only used when creating playslit.
-    # Distinguishes profile time between initial load and other
-    # refreshes.
     def load_data(self, session: db.session, dummy_for_profiling=None) -> None:
         """Populate self.playlist_rows with playlist data"""
 
+        # Same as refresh data, but only used when creating playslit.
+        # Distinguishes profile time between initial load and other
+        # refreshes.
+
         # We used to clear self.playlist_rows each time but that's
         # expensive and slow on big playlists
 
@@ -1107,6 +1116,38 @@ class PlaylistModel(QAbstractTableModel):
 
         self.update_track_times()
 
+    def remove_comments(self, row_numbers: list[int]) -> None:
+        """
+        Remove comments from passed rows
+        """
+
+        if not row_numbers:
+            return
+
+        # Safety check
+        if not ask_yes_no(
+            title="Remove comments",
+            question=f"Remove comments from {len(row_numbers)} rows?"
+        ):
+            return
+
+        with db.Session() as session:
+            for row_number in row_numbers:
+                playlist_row = session.get(
+                    PlaylistRows, self.playlist_rows[row_number].playlistrow_id
+                )
+                if playlist_row.track_id:
+                    playlist_row.note = ""
+                    # We can't use refresh_data() because its
+                    # optimisations mean it won't update comments in
+                    # self.playlist_rows
+                    # The "correct" approach would be to re-read from the
+                    # database but we optimise here by simply updating
+                    # self.playlist_rows directly.
+                    self.playlist_rows[row_number].note = ""
+            session.commit()
+        self.invalidate_rows(row_numbers)
+
     def _reversed_contiguous_row_groups(
         self, row_numbers: list[int]
     ) -> list[list[int]]:

app/playlists.py

@@ -505,6 +505,9 @@ class PlaylistTab(QTableView):
                 lambda: proxy_model.remove_track(model_row_number),
             )
 
+        # Remove comments
+        self._add_context_menu("Remove comments", lambda: self._remove_comments())
+
         # Add track to section header (ie, make this a track row)
         if header_row:
             self._add_context_menu("Add a track", lambda: self._add_track())
@@ -778,6 +781,17 @@ class PlaylistTab(QTableView):
         except ApplicationError as e:
             show_warning(self.musicmuster, "Audacity error", str(e))
 
+    def _remove_comments(self) -> None:
+        """
+        Remove comments from selected rows
+        """
+
+        row_numbers = self.selected_model_row_numbers()
+        if not row_numbers:
+            return
+
+        self.source_model.remove_comments(row_numbers)
+
     def _rescan(self, row_number: int) -> None:
         """Rescan track"""