fix: rapid seek with fade in-out enabled may set volume to 0 (#768)

feeluown/player/mpvplayer.py

@@ -160,9 +160,7 @@ def set_play_range(self, start=None, end=None):
             self.seeked.emit(start)
         _mpv_set_option_string(self._mpv.handle, b'end', bytes(end_str, 'utf-8'))
 
-    def fade(self, fade_in: bool, max_volume=None, callback=None):
-        self.fade_lock.acquire()
-
+    def fade(self, fade_in: bool, callback=None):
         # k: factor between 0 and 1, to represent tick/fade_time
         def fade_curve(k: float, fade_in: bool) -> float:
             if fade_in:
@@ -186,35 +184,26 @@ def set_volume(max_volume: int, fade_in: bool):
                 self.volume = new_volume
                 time.sleep(interval)
 
-        if max_volume:
-            volume = max_volume
-        else:
-            volume = self.volume
-
-        set_volume(volume, fade_in=fade_in)
+        with self.fade_lock:
+            max_volume = self.volume
+            set_volume(max_volume, fade_in=fade_in)
 
-        if callback is not None:
-            callback()
+            if callback is not None:
+                callback()
 
-        self.volume = volume
-        self.fade_lock.release()
+            self.volume = max_volume
 
     def resume(self):
-        if self.do_fade:
-            _volume = self.volume
-            self.volume = 0
-
-        self._mpv.pause = False
-        self.state = State.playing
-
         if self.do_fade:
             fade_thread = Thread(
                 target=self.fade,
-                kwargs={"fade_in": True,
-                        "max_volume": _volume}
+                kwargs={"fade_in": True}
             )
             fade_thread.start()
 
+        self._mpv.pause = False
+        self.state = State.playing
+
     def _pause(self):
         self._mpv.pause = True
         self.state = State.paused