app/classes.py

@@ -93,6 +93,13 @@ class MusicMusterSignals(QObject):
         super().__init__()
 
 
+@singleton
+@dataclass
+class Selection:
+    playlist_id: int = 0
+    rows: list[int] = field(default_factory=list)
+
+
 class Tags(NamedTuple):
     artist: str
     title: str

app/musicmuster.py

@@ -49,6 +49,7 @@ import stackprinter  # type: ignore
 # App imports
 from classes import (
     MusicMusterSignals,
+    Selection,
     TrackInfo,
 )
 from config import Config
@@ -80,17 +81,13 @@ class DownloadCSV(QDialog):
         self.ui.buttonBox.rejected.connect(self.reject)
 
 
-class Current:
+@dataclass
+class PlaylistData:
     base_model: PlaylistModel
     proxy_model: PlaylistProxyModel
-    playlist_id: int = 0
-    selected_rows: list[int] = field(default_factory=list)
 
-    def __repr__(self):
+    def __post_init__(self):
-        return (
+        self.proxy_model.setSourceModel(self.base_model)
-            f"<Current(base_model={self.base_model}, proxy_model={self.proxy_model}, "
-            f"playlist_id={self.playlist_id}, selected_rows={self.selected_rows}>"
-        )
 
 
 class PreviewManager:
@@ -289,7 +286,8 @@ class Window(QMainWindow, Ui_MainWindow):
         self.connect_signals_slots()
         self.catch_return_key = False
         self.importer: Optional[FileImporter] = None
-        self.current = Current()
+        self.selection = Selection()
+        self.playlists: dict[int, PlaylistData] = {}
 
         if not Config.USE_INTERNAL_BROWSER:
             webbrowser.register(
@@ -326,12 +324,12 @@ class Window(QMainWindow, Ui_MainWindow):
             QMessageBox.StandardButton.Ok,
         )
 
-    def active_base_model(self) -> PlaylistModel:
-        return self.current.base_model
-
     def active_tab(self) -> PlaylistTab:
         return self.tabPlaylist.currentWidget()
 
+    def active_proxy_model(self) -> PlaylistProxyModel:
+        return self.tabPlaylist.currentWidget().model()
+
     def clear_next(self) -> None:
         """
         Clear next track
@@ -553,21 +551,24 @@ class Window(QMainWindow, Ui_MainWindow):
         log.debug(f"create_playlist_tab({playlist=})")
 
         # Create model and proxy model
-        base_model = PlaylistModel(playlist.id)
+        self.playlists[playlist.id] = PlaylistData(
-        proxy_model = PlaylistProxyModel()
+            base_model=PlaylistModel(playlist.id), proxy_model=PlaylistProxyModel()
-        proxy_model.setSourceModel(base_model)
+        )
 
         # Create tab
-        playlist_tab = PlaylistTab(musicmuster=self, model=proxy_model)
+        playlist_tab = PlaylistTab(
+            musicmuster=self, model=self.playlists[playlist.id].proxy_model
+        )
         idx = self.tabPlaylist.addTab(playlist_tab, playlist.name)
 
         log.debug(f"create_playlist_tab() returned: {idx=}")
-
         return idx
 
     def debug(self):
         """Invoke debugger"""
 
+        visible_playlist_id = self.active_tab().playlist_id
+        print(f"Active playlist id={visible_playlist_id}")
         import ipdb  # type: ignore
 
         ipdb.set_trace()
@@ -578,7 +579,7 @@ class Window(QMainWindow, Ui_MainWindow):
         """
 
         with db.Session() as session:
-            playlist_id = self.current.playlist_id
+            playlist_id = self.active_tab().playlist_id
             playlist = session.get(Playlists, playlist_id)
             if playlist:
                 if helpers.ask_yes_no(
@@ -654,7 +655,7 @@ class Window(QMainWindow, Ui_MainWindow):
             track_sequence.current = None
 
         # Tell playlist previous track has finished
-        self.current.base_model.previous_track_ended()
+        self.active_tab().previous_track_ended()
 
         # Reset clocks
         self.frame_fade.setStyleSheet("")
@@ -676,7 +677,10 @@ class Window(QMainWindow, Ui_MainWindow):
     def export_playlist_tab(self) -> None:
         """Export the current playlist to an m3u file"""
 
-        playlist_id = self.current.playlist_id
+        if not self.active_tab():
+            return
+
+        playlist_id = self.active_tab().playlist_id
 
         with db.Session() as session:
             # Get output filename
@@ -720,20 +724,26 @@ class Window(QMainWindow, Ui_MainWindow):
         if track_sequence.current:
             track_sequence.current.fade()
 
+    def get_active_base_model(self) -> PlaylistModel:
+        """
+        Return the model for the current tab
+        """
+
+        return self.playlists[self.selection.playlist_id].base_model
+
     def hide_played(self):
         """Toggle hide played tracks"""
 
         if self.hide_played_tracks:
             self.hide_played_tracks = False
-            self.current.base_model.hide_played_tracks(False)
+            self.active_proxy_model().hide_played_tracks(False)
             self.btnHidePlayed.setText("Hide played")
         else:
             self.hide_played_tracks = True
+            self.active_proxy_model().hide_played_tracks(True)
             self.btnHidePlayed.setText("Show played")
             if Config.HIDE_PLAYED_MODE == Config.HIDE_PLAYED_MODE_SECTIONS:
                 self.active_tab().hide_played_sections()
-            else:
-                self.current.base_model.hide_played_tracks(True)
 
         # Reset row heights
         self.active_tab().resize_rows()
@@ -743,11 +753,11 @@ class Window(QMainWindow, Ui_MainWindow):
         Pass import files call to file_importer module
         """
 
-        # We need to keep a reference to the FileImporter else it will be
+        # We need to keep a referent to the FileImporter else it will be
         # garbage collected while import threads are still running
         self.importer = FileImporter(
-            self.current.base_model,
+            self.get_active_base_model(),
-            self.current.selected_rows[0],
+            self.active_tab().source_model_selected_row_number(),
         )
         self.importer.do_import()
 
@@ -761,24 +771,24 @@ class Window(QMainWindow, Ui_MainWindow):
         dlg.resize(500, 100)
         ok = dlg.exec()
         if ok:
-            self.current.base_model.insert_row(
+            self.get_active_base_model().insert_row(
-                proposed_row_number=self.current.selected_rows[0],
+                proposed_row_number=self.active_tab().source_model_selected_row_number(),
                 note=dlg.textValue(),
             )
 
     def insert_track(self) -> None:
         """Show dialog box to select and add track from database"""
 
-        if self.current.selected_rows:
+        new_row_number = (
-            new_row_number = self.current.selected_rows[0]
+            self.active_tab().source_model_selected_row_number()
-        else:
+            or self.active_proxy_model().rowCount()
-            new_row_number = self.current.base_model.rowCount()
+        )
         with db.Session() as session:
             dlg = TrackSelectDialog(
                 parent=self,
                 session=session,
                 new_row_number=new_row_number,
-                base_model=self.current.base_model,
+                base_model=self.get_active_base_model(),
             )
             dlg.exec()
             session.commit()
@@ -835,8 +845,8 @@ class Window(QMainWindow, Ui_MainWindow):
 
         # Save the selected PlaylistRows items ready for a later
         # paste
-        self.move_source_rows = self.current.selected_rows
+        self.move_source_rows = self.active_tab().get_selected_rows()
-        self.move_source_model = self.current.base_model
+        self.move_source_model = self.get_active_base_model()
 
         log.debug(
             f"mark_rows_for_moving(): {self.move_source_rows=} {self.move_source_model=}"
@@ -849,7 +859,8 @@ class Window(QMainWindow, Ui_MainWindow):
 
         # Identify destination playlist
         playlists = []
-        source_playlist_id = self.current.playlist_id
+        visible_tab = self.active_tab()
+        source_playlist_id = visible_tab.playlist_id
 
         with db.Session() as session:
             for playlist in Playlists.get_all(session):
@@ -872,7 +883,7 @@ class Window(QMainWindow, Ui_MainWindow):
                 to_row = 0
 
         # Move rows
-        self.current.base_model.move_rows_between_playlists(
+        self.get_active_base_model().move_rows_between_playlists(
             row_numbers, to_row, to_playlist_id
         )
 
@@ -891,7 +902,7 @@ class Window(QMainWindow, Ui_MainWindow):
         Move selected rows to another playlist
         """
 
-        selected_rows = self.current.selected_rows
+        selected_rows = self.active_tab().get_selected_rows()
         if not selected_rows:
             return
 
@@ -902,7 +913,7 @@ class Window(QMainWindow, Ui_MainWindow):
         Move unplayed rows to another playlist
         """
 
-        unplayed_rows = self.current.base_model.get_unplayed_rows()
+        unplayed_rows = self.get_active_base_model().get_unplayed_rows()
         if not unplayed_rows:
             return
         # We can get a race condition as selected rows change while
@@ -985,12 +996,12 @@ class Window(QMainWindow, Ui_MainWindow):
         if not self.move_source_rows or not self.move_source_model:
             return
 
-        to_playlist_model = self.current.base_model
+        to_playlist_model = self.get_active_base_model()
-        selected_rows = self.current.selected_rows
+        selected_rows = self.active_tab().get_selected_rows()
         if selected_rows:
             destination_row = selected_rows[0]
         else:
-            destination_row = self.current.base_model.rowCount()
+            destination_row = self.active_proxy_model().rowCount()
 
         # If we move a row to immediately under the current track, make
         # that moved row the next track
@@ -1175,8 +1186,8 @@ class Window(QMainWindow, Ui_MainWindow):
                     track.intro = intro
                     session.commit()
                     self.preview_manager.set_intro(intro)
-                    self.current.base_model.refresh_row(session, row_number)
+                    self.get_active_base_model().refresh_row(session, row_number)
-                    self.current.base_model.invalidate_row(row_number)
+                    self.get_active_base_model().invalidate_row(row_number)
 
     def preview_start(self) -> None:
         """Restart preview"""
@@ -1205,7 +1216,7 @@ class Window(QMainWindow, Ui_MainWindow):
         """
 
         with db.Session() as session:
-            playlist_id = self.current.playlist_id
+            playlist_id = self.active_tab().playlist_id
             playlist = session.get(Playlists, playlist_id)
             if playlist:
                 new_name = self.solicit_playlist_name(session, playlist.name)
@@ -1319,7 +1330,7 @@ class Window(QMainWindow, Ui_MainWindow):
                     self, "Duplicate template", "Template name already in use"
                 )
             Playlists.save_as_template(
-                session, self.current.playlist_id, template_name
+                session, self.active_tab().playlist_id, template_name
             )
             session.commit()
             helpers.show_OK(self, "Template", "Template saved")
@@ -1347,7 +1358,7 @@ class Window(QMainWindow, Ui_MainWindow):
         Incremental search of playlist
         """
 
-        self.current.proxy_model.set_incremental_search(self.txtSearch.text())
+        self.active_proxy_model().set_incremental_search(self.txtSearch.text())
 
     def selected_or_next_track_info(self) -> Optional[RowAndTrack]:
         """
@@ -1355,7 +1366,7 @@ class Window(QMainWindow, Ui_MainWindow):
         next track. If no next track, return None.
         """
 
-        row_number = self.current.selected_rows[0]
+        row_number = self.active_tab().source_model_selected_row_number()
         if row_number is None:
             if track_sequence.next:
                 if track_sequence.next.track_id:
@@ -1363,7 +1374,7 @@ class Window(QMainWindow, Ui_MainWindow):
         if row_number is None:
             return None
 
-        track_info = self.current.base_model.get_row_info(row_number)
+        track_info = self.get_active_base_model().get_row_info(row_number)
         if track_info is None:
             return None
 
@@ -1445,14 +1456,20 @@ class Window(QMainWindow, Ui_MainWindow):
             # No playlist
             return
 
-        # Switch to correct tab
+        if playlist_id != self.active_tab().playlist_id:
-        if playlist_id != self.current.playlist_id:
             for idx in range(self.tabPlaylist.count()):
                 if self.tabPlaylist.widget(idx).playlist_id == playlist_id:
                     self.tabPlaylist.setCurrentIndex(idx)
                     break
 
-        self.active_tab().scroll_to_top(playlist_track.row_number)
+        display_row = (
+            self.active_proxy_model()
+            .mapFromSource(
+                self.get_active_base_model().index(playlist_track.row_number, 0)
+            )
+            .row()
+        )
+        self.tabPlaylist.currentWidget().scroll_to_top(display_row)
 
     def solicit_playlist_name(
         self, session: Session, default: str = ""

app/playlistmodel.py

@@ -1671,7 +1671,7 @@ class PlaylistProxyModel(QSortFilterProxyModel):
         self.setFilterKeyColumn(-1)
 
     def __repr__(self) -> str:
-        return f"<PlaylistProxyModel: sourceModel={self.sourceModel()}>"
+        return f"<PlaylistProxyModel: sourceModel={self.sourceModel}>"
 
     def filterAcceptsRow(self, source_row: int, source_parent: QModelIndex) -> bool:
         """

app/playlists.py

@@ -37,7 +37,7 @@ import line_profiler
 
 # App imports
 from audacity_controller import AudacityController
-from classes import ApplicationError, Col, MusicMusterSignals, TrackInfo
+from classes import ApplicationError, Col, MusicMusterSignals, Selection, TrackInfo
 from config import Config
 from dialogs import TrackSelectDialog
 from helpers import (
@@ -295,8 +295,9 @@ class PlaylistTab(QTableView):
         super().__init__()
 
         # Save passed settings
-        self.musicmuster = musicmuster
+        self.musicmuster = (
-
+            musicmuster  # TODO: do we need to keep a reference to musicmuster?
+        )
         self.playlist_id = model.sourceModel().playlist_id
 
         # Set up widget
@@ -328,6 +329,9 @@ class PlaylistTab(QTableView):
         self.setSelectionMode(QAbstractItemView.SelectionMode.ExtendedSelection)
         self.setSelectionBehavior(QAbstractItemView.SelectionBehavior.SelectRows)
 
+        # Singleton object to store selection
+        self.selection = Selection()
+
         # Set up for Audacity
         try:
             self.ac: Optional[AudacityController] = AudacityController()
@@ -483,7 +487,7 @@ class PlaylistTab(QTableView):
         """
 
         selected_rows = self.get_selected_rows()
-        self.musicmuster.current.selected_rows = selected_rows
+        self.selection.rows = selected_rows
 
         # If no rows are selected, we have nothing to do
         if len(selected_rows) == 0:
@@ -926,6 +930,14 @@ class PlaylistTab(QTableView):
         except ApplicationError as e:
             show_warning(self.musicmuster, "Audacity error", str(e))
 
+    def previous_track_ended(self) -> None:
+        """
+        Called when track ends
+        """
+
+        # Let the model know
+        self.get_base_model().previous_track_ended()
+
     def _remove_comments(self) -> None:
         """
         Remove comments from selected rows
@@ -1037,7 +1049,7 @@ class PlaylistTab(QTableView):
 
     def _selected_row_indexes(self) -> List[QModelIndex]:
         """
-        Return a list of indexes of column 0 of selected rows
+        Return a list of indexes of column 1 of selected rows
         """
 
         sm = self.selectionModel()
@@ -1111,11 +1123,8 @@ class PlaylistTab(QTableView):
         Called when tab gets focus
         """
 
-        # Update musicmuster
+        self.selection.playlist_id = self.playlist_id
-        self.musicmuster.current.playlist_id = self.playlist_id
+        self.selection.rows = self.get_selected_rows()
-        self.musicmuster.current.selected_rows = self.get_selected_rows()
-        self.musicmuster.current.base_model = self.get_base_model()
-        self.musicmuster.current.proxy_model = self.model()
 
         self.resize_rows()