Error checking, type annotations, minor edits

app/helpers.py

@@ -370,7 +370,7 @@ def show_OK(parent: QMainWindow, title: str, msg: str) -> None:
     QMessageBox.information(parent, title, msg, buttons=QMessageBox.StandardButton.Ok)
 
 
-def show_warning(parent: QMainWindow, title: str, msg: str) -> None:
+def show_warning(parent: Optional[QMainWindow], title: str, msg: str) -> None:
     """Display a warning to user"""
 
     QMessageBox.warning(parent, title, msg, buttons=QMessageBox.StandardButton.Cancel)

app/musicmuster.py

@@ -1144,12 +1144,12 @@ class Window(QMainWindow, Ui_MainWindow):
 
         # Show closing volume graph
         if track_sequence.current.fade_graph:
-            log.error("issue223: play_next: set up fade_graph")
+            log.debug("issue223: play_next: set up fade_graph")
             track_sequence.current.fade_graph.GraphWidget = self.widgetFadeVolume
             track_sequence.current.fade_graph.clear()
             track_sequence.current.fade_graph.plot()
         else:
-            log.error("issue223: play_next: No fade_graph")
+            log.debug("issue223: play_next: No fade_graph")
 
         # Disable play next controls
         self.catch_return_key = True

app/trackmanager.py

@@ -31,6 +31,7 @@ from models import db, PlaylistRows, Tracks
 from helpers import (
     file_is_unreadable,
     get_audio_segment,
+    show_warning,
 )
 
 lock = threading.Lock()
@@ -312,6 +313,10 @@ class _Music:
             return None
 
         media = self.VLC.media_new_path(path)
+        if media is None:
+            log.error(f"_Music:play: failed to create media ({path=})")
+            show_warning(None, "Error loading file", f"Cannot play file ({path})")
+            return
         self.player = media.player_new_from_media()
         if self.player:
             _ = self.player.play()
@@ -334,6 +339,9 @@ class _Music:
                         self.set_volume(Config.VLC_VOLUME_DEFAULT)
                         log.error(f"Reset from {volume=}")
                 sleep(0.1)
+        else:
+            log.error("_Music:play: failed to create media player")
+            show_warning(None, "Media player", "Unable to create media player")
 
     def set_position(self, position: float) -> None:
         """
@@ -497,19 +505,6 @@ class _TrackManager:
 
         self.player.adjust_by_ms(ms)
 
-    def move_to_intro_end(self, buffer: int = Config.PREVIEW_END_BUFFER_MS) -> None:
-        """
-        Move play position to 'buffer' milliseconds before end of intro.
-
-        If no intro defined, do nothing.
-        """
-
-        if self.intro is None:
-            return
-
-        new_position = max(0, self.intro - Config.PREVIEW_END_BUFFER_MS)
-        self.player.adjust_by_ms(new_position - self.time_playing())
-
     def play(self, position: Optional[float] = None) -> None:
         """Play track"""
 
@@ -519,7 +514,7 @@ class _TrackManager:
 
         self.player.play(self.path, start_time=now, position=position)
 
-        self.end_time = self.start_time + dt.timedelta(milliseconds=self.duration)
+        self.end_time = now + dt.timedelta(milliseconds=self.duration)
 
         # Calculate time fade_graph should start updating
         if self.fade_at:

app/ui/main_window_ui.py

@@ -841,4 +841,4 @@ class Ui_MainWindow(object):
 
 
 from infotabs import InfoTabs
-from pyqtgraph import PlotWidget
+from pyqtgraph import PlotWidget  # type: ignore