Implement track rescanning

Fixes #29

app/playlists.py

@@ -22,6 +22,7 @@ from log import DEBUG, ERROR
 from model import (
     Notes, Playdates, Playlists, PlaylistTracks, Session, Settings, Tracks
 )
+from songdb import create_track_from_file
 
 
 class PlaylistTab(QTableWidget):
@@ -158,6 +159,8 @@ class PlaylistTab(QTableWidget):
                     act_copypath = self.menu.addAction("Copy track path")
                     act_copypath.triggered.connect(
                         lambda: self._copy_path(row))
+                    act_rescan = self.menu.addAction("Rescan track")
+                    act_rescan.triggered.connect(lambda: self._rescan(row))
                     self.menu.addSeparator()
                 act_delete = self.menu.addAction('Delete')
                 act_delete.triggered.connect(lambda: self._delete_row(row))
@@ -954,6 +957,24 @@ class PlaylistTab(QTableWidget):
                         # Don't dim unplayed tracks
                         self._set_row_bold(row)
 
+    def _rescan(self, row):
+        """
+        If passed row is track row, rescan it.
+        Otherwise return None.
+        """
+
+        DEBUG(f"_rescan({row})")
+
+        if row in self._meta_get_notes():
+            return None
+
+        track_id = self._get_row_id(row)
+        if track_id:
+            with Session() as session:
+                track = Tracks.get_track(session, track_id)
+                create_track_from_file(session, track.path)
+                self._update_row(row, track)
+
     def _save_playlist(self, session):
         """
         Save playlist to database.
@@ -1099,3 +1120,28 @@ class PlaylistTab(QTableWidget):
 
         with Session() as session:
             return os.access(Tracks.get_path(session, track_id), os.R_OK)
+
+    def _update_row(self, row, track):
+        """
+        Update the passed row with info from the passed track.
+        """
+
+        DEBUG(f"_update_row({row=}, {track=}")
+
+        item_startgap = self.item(row, self.COL_MSS)
+        item_startgap.setText(str(track.start_gap))
+        if track.start_gap >= 500:
+            item_startgap.setBackground(QColor(Config.COLOUR_LONG_START))
+        else:
+            item_startgap.setBackground(QColor("white"))
+
+        item_title = self.item(row, self.COL_TITLE)
+        item_title.setText(track.title)
+
+        item_artist = self.item(row, self.COL_ARTIST)
+        item_artist.setText(track.artist)
+
+        item_duration = self.item(row, self.COL_DURATION)
+        item_duration.setText(helpers.ms_to_mmss(track.duration))
+
+        self._repaint()