Media controls (MPRIS, Windows SMTC); stop old tracks when switching

Covers.py

@@ -31,18 +31,33 @@ def Thumbnail(Data: bytes, Size: int) -> Optional[bytes]:
 _Memory: dict[tuple[str, int], bytes] = {}
 
 
+def _CachePath(FilePath: str, Size: int) -> Optional[Path]:
+    try:
+        Stamp = Path(FilePath).stat().st_mtime_ns
+    except OSError:
+        return None
+    Name = hashlib.sha1(f"{FilePath}|{Size}|{Stamp}".encode("utf-8", "surrogateescape")).hexdigest()
+    return CoversDir / f"{Name}.jpg"
+
+
+def CoverPath(FilePath: str, Size: int) -> Optional[Path]:
+    """The cached thumbnail's file (made if needed), for the system media
+    controls, which want a picture file rather than bytes. Blocking."""
+    if not CoverFor(FilePath, Size):
+        return None
+    CachePath = _CachePath(FilePath, Size)
+    return CachePath if CachePath and CachePath.exists() else None
+
+
 def CoverFor(FilePath: str, Size: int) -> Optional[bytes]:
     """FilePath's cover at most Size pixels wide. Blocking (run it in a
     thread). Cached on disk by path, size and the file's mtime."""
     Key = (FilePath, Size)
     if Key in _Memory:
         return _Memory[Key] or None
-    try:
-        Stamp = Path(FilePath).stat().st_mtime_ns
-    except OSError:
+    CachePath = _CachePath(FilePath, Size)
+    if CachePath is None:
         return None
-    Name = hashlib.sha1(f"{FilePath}|{Size}|{Stamp}".encode("utf-8", "surrogateescape")).hexdigest()
-    CachePath = CoversDir / f"{Name}.jpg"
     if CachePath.exists():
         Data = CachePath.read_bytes()
     else: