Update song.py

Groundwork for piano charts keeping LH and RH designations intact, but seperated, so they can be toggled via menu options etc in future

(cherry picked from commit 606b69a75eb5202c6fb2978f496bf97db0ec65e4)

lib/song.py

@@ -37,6 +37,7 @@ class Note:
     right_hand: int = -1
     pick_direction: int = -1
     ignore: bool = False
+    staff: int = -1  # Piano staff: -1=absent, 0=LH/bass clef, 1=RH/treble clef
 
 
 @dataclass
@@ -217,6 +218,8 @@ def note_to_wire(n: Note) -> dict:
         out["pkd"] = n.pick_direction
     if n.ignore:
         out["ig"] = True
+    if n.staff != -1:
+        out["stf"] = n.staff
     return out
 
 
@@ -307,6 +310,7 @@ def note_from_wire(d: dict, time: float | None = None) -> Note:
         right_hand=_wire_int_optional(d.get("rh"), -1),
         pick_direction=_wire_int_optional(d.get("pkd"), -1),
         ignore=bool(d.get("ig", False)),
+        staff=int(d.get("stf", -1)),
     )
 
 
@@ -762,6 +766,7 @@ def _parse_note(n) -> Note:
         right_hand=_int_optional(n, "rightHand", -1),
         pick_direction=_int_optional(n, "pickDirection", -1),
         ignore=_bool(n, "ignore"),
+        staff=_int_optional(n, "staff", -1),
     )