Improve type hints, other minor edits

app/musicmuster.py

@@ -157,8 +157,8 @@ class PreviewManager:
         self.intro: Optional[int] = None
         self.path: str = ""
         self.row_number: Optional[int] = None
-        self.track_id: int = 0
         self.start_time: Optional[dt.datetime] = None
+        self.track_id: int = 0
 
     def back(self, ms: int) -> None:
         """
@@ -220,7 +220,7 @@ class PreviewManager:
         if not mixer.music.get_busy():
             return
 
-        mixer.music.set_pos(0)
+        mixer.music.rewind()
         self.start_time = dt.datetime.now()
 
     def set_intro(self, ms: int) -> None:
@@ -1246,7 +1246,7 @@ class Window(QMainWindow, Ui_MainWindow):
         Create log entry
         """
 
-        log.debug("quicklog")
+        log.debug("quicklog timestamp; entry follows")
 
         # Get log text
         dlg: QInputDialog = QInputDialog(self)

app/trackmanager.py

@@ -19,6 +19,9 @@ from PyQt6.QtCore import (
     QThread,
     QThreadPool,
 )
+from pyqtgraph import PlotWidget
+from pyqtgraph.graphicsItems.PlotDataItem import PlotDataItem  # type: ignore
+from pyqtgraph.graphicsItems.LinearRegionItem import LinearRegionItem  # type: ignore
 
 # App imports
 from classes import MusicMusterSignals
@@ -68,7 +71,7 @@ class _AddFadeCurve(QObject):
 
 
 class _FadeCurve:
-    GraphWidget = None
+    GraphWidget: Optional[PlotWidget] = None
 
     def __init__(
         self, track_path: str, track_fade_at: int, track_silence_at: int
@@ -94,7 +97,8 @@ class _FadeCurve:
         # Calculate the factor to map milliseconds of track to array
         self.ms_to_array_factor = len(self.graph_array) / (self.end_ms - self.start_ms)
 
-        self.region = None
+        self.curve: Optional[PlotDataItem] = None
+        self.region: Optional[LinearRegionItem] = None
 
     def clear(self) -> None:
         """Clear the current graph"""
@@ -105,7 +109,8 @@ class _FadeCurve:
     def plot(self) -> None:
         if self.GraphWidget:
             self.curve = self.GraphWidget.plot(self.graph_array)
-            self.curve.setPen(Config.FADE_CURVE_FOREGROUND)
+            if self.curve:
+                self.curve.setPen(Config.FADE_CURVE_FOREGROUND)
 
     def tick(self, play_time) -> None:
         """Update volume fade curve"""
@@ -124,15 +129,16 @@ class _FadeCurve:
             self.GraphWidget.addItem(self.region)
 
         # Update region position
-        log.debug("issue223: _FadeCurve: update region")
-        self.region.setRegion([0, ms_of_graph * self.ms_to_array_factor])
+        if self.region:
+            log.debug("issue223: _FadeCurve: update region")
+            self.region.setRegion([0, ms_of_graph * self.ms_to_array_factor])
 
 
 class _FadeTrack(QRunnable):
     def __init__(self, player: vlc.MediaPlayer, fade_seconds) -> None:
         super().__init__()
-        self.player = player
-        self.fade_seconds = fade_seconds
+        self.player: vlc.MediaPlayer = player
+        self.fade_seconds: int = fade_seconds
 
     def run(self) -> None:
         """
@@ -168,9 +174,9 @@ class _Music:
     def __init__(self, name) -> None:
         self.VLC = vlc.Instance()
         self.VLC.set_user_agent(name, name)
-        self.player = None
-        self.name = name
-        self.max_volume = Config.VLC_VOLUME_DEFAULT
+        self.player: Optional[vlc.MediaPlayer] = None
+        self.name: str = name
+        self.max_volume: int = Config.VLC_VOLUME_DEFAULT
         self.start_dt: Optional[dt.datetime] = None
 
     def adjust_by_ms(self, ms: int) -> None:
@@ -182,14 +188,17 @@ class _Music:
         elapsed_ms = self.get_playtime()
         position = self.get_position()
         if not position:
-            position = 0
-        new_position = max(0, position + ((position * ms) / elapsed_ms))
+            position = 0.0
+        new_position = max(0.0, position + ((position * ms) / elapsed_ms))
         self.set_position(new_position)
         # Adjus start time so elapsed time calculations are correct
         if new_position == 0:
             self.start_dt = dt.datetime.now()
         else:
-            self.start_dt -= dt.timedelta(milliseconds=ms)
+            if self.start_dt:
+                self.start_dt -= dt.timedelta(milliseconds=ms)
+            else:
+                self.start_dt = dt.datetime.now() - dt.timedelta(milliseconds=ms)
 
     def stop(self) -> None:
         """Immediately stop playing"""
@@ -235,9 +244,12 @@ class _Music:
             self.player = None
 
         pool = QThreadPool.globalInstance()
-        fader = _FadeTrack(p, fade_seconds=fade_seconds)
-        pool.start(fader)
-        self.start_dt = None
+        if pool:
+            fader = _FadeTrack(p, fade_seconds=fade_seconds)
+            pool.start(fader)
+            self.start_dt = None
+        else:
+            log.error("_Music: failed to allocate QThreadPool")
 
     def get_playtime(self) -> int:
         """
@@ -323,7 +335,7 @@ class _Music:
                         log.error(f"Reset from {volume=}")
                 sleep(0.1)
 
-    def set_position(self, position: int) -> None:
+    def set_position(self, position: float) -> None:
         """
         Set player position
         """
@@ -339,7 +351,7 @@ class _Music:
         if not self.player:
             return
 
-        if set_default:
+        if set_default and volume:
             self.max_volume = volume
 
         if volume is None: