StemRoller: desktop stem separator, Android stems player, and server daemons

- stemroller/: PySide6/QML desktop app and player for separating music into stems
- android/: Plex music player that plays per-stem mixes, with Android Auto support,
  a graphic + parametric (Equalizer APO-style) EQ, and offline downloads
- server/: stemserve (serves stems to the app) and stemd (separates the library on
  the server's GPU, with "Stem Now" priority requests)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

stemroller/player/sheets.py

@@ -0,0 +1,149 @@
+"""The workbook: every view is a sheet (columns + rows) shown in the Excel grid."""
+
+import time
+import unicodedata
+
+from PySide6.QtCore import QAbstractTableModel, QByteArray, QModelIndex, Qt
+
+# Column formats: how a value is shown, aligned and summed in the status bar.
+#   text, int, year, time (ms -> m:ss), stems (count of stems, shown TRUE/FALSE-ish), date (unix s)
+COLUMNS = {
+    "songs": [
+        ("title", "Title", 300, "text"), ("artist", "Artist", 190, "text"), ("album", "Album", 230, "text"),
+        ("year", "Year", 64, "year"), ("durationMs", "Time", 64, "time"), ("stems", "Stems", 70, "stems"),
+        ("plays", "Plays", 64, "int"),
+    ],
+    "albumSongs": [
+        ("index", "#", 44, "int"), ("title", "Title", 320, "text"), ("artist", "Artist", 200, "text"),
+        ("durationMs", "Time", 64, "time"), ("stems", "Stems", 70, "stems"), ("plays", "Plays", 64, "int"),
+    ],
+    "artists": [
+        ("title", "Artist", 280, "text"), ("albums", "Albums", 70, "int"), ("songs", "Songs", 70, "int"),
+        ("stemSongs", "With stems", 90, "int"), ("genre", "Genre", 200, "text"),
+    ],
+    "albums": [
+        ("title", "Album", 300, "text"), ("artist", "Artist", 200, "text"), ("year", "Year", 64, "year"),
+        ("tracks", "Songs", 64, "int"), ("stemSongs", "With stems", 90, "int"), ("genre", "Genre", 160, "text"),
+        ("addedAt", "Added", 96, "date"),
+    ],
+    "playlists": [
+        ("title", "Playlist", 300, "text"), ("tracks", "Songs", 70, "int"), ("durationMs", "Length", 80, "time"),
+        ("kind", "Type", 80, "text"), ("updatedAt", "Updated", 96, "date"),
+    ],
+    "queue": [
+        ("pos", "#", 44, "int"), ("title", "Title", 300, "text"), ("artist", "Artist", 190, "text"),
+        ("album", "Album", 230, "text"), ("durationMs", "Time", 64, "time"), ("stems", "Stems", 70, "stems"),
+    ],
+    "search": [
+        ("type", "Type", 70, "text"), ("title", "Name", 300, "text"), ("artist", "Artist", 190, "text"),
+        ("album", "Album", 230, "text"), ("year", "Year", 64, "year"), ("durationMs", "Time", 64, "time"),
+        ("stems", "Stems", 70, "stems"),
+    ],
+}
+
+# Plex row kind -> what a double-click does
+SONG, ARTIST, ALBUM, PLAYLIST = "song", "artist", "album", "playlist"
+
+
+def fold(s: str) -> str:
+    """Case- and accent-insensitive form for search and sorting."""
+    s = unicodedata.normalize("NFKD", s or "")
+    return "".join(c for c in s if not unicodedata.combining(c)).casefold()
+
+
+def fmt_time(ms) -> str:
+    s = int(round((ms or 0) / 1000))
+    h, m = divmod(s // 60, 60)
+    return f"{h}:{m:02d}:{s % 60:02d}" if h else f"{m}:{s % 60:02d}"
+
+
+def fmt(value, kind) -> str:
+    if kind == "time":
+        return fmt_time(value) if value else ""
+    if kind == "year":
+        return str(value) if value else ""
+    if kind == "int":
+        return "" if value in (None, "") else str(value)
+    if kind == "stems":
+        return f"{value}" if value else ""
+    if kind == "date":
+        return time.strftime("%Y-%m-%d", time.localtime(value)) if value else ""
+    return "" if value is None else str(value)
+
+
+class Sheet:
+    """A tab: its rows, columns and what the rows are."""
+
+    def __init__(self, title, columns, rows, kind=SONG, sid=None, loading=False):
+        self.title = title
+        self.columns = COLUMNS[columns]
+        self.layout = columns
+        self.rows = rows
+        self.kind = kind
+        self.sid = sid or title
+        self.loading = loading
+        self.sort = None  # (column, descending)
+
+    def row_kind(self, r):
+        return self.rows[r].get("_kind", self.kind)
+
+
+class SheetModel(QAbstractTableModel):
+    """One sheet for the QML TableView. Roles: display, align, style, playing."""
+
+    ROLES = {Qt.ItemDataRole.DisplayRole: b"display", Qt.ItemDataRole.UserRole + 1: b"align",
+             Qt.ItemDataRole.UserRole + 2: b"cellStyle", Qt.ItemDataRole.UserRole + 3: b"playing",
+             Qt.ItemDataRole.UserRole + 4: b"bold"}
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.sheet: Sheet | None = None
+        self.playing_key = ""
+        self.playing_pos = -1  # for the queue sheet, where the same song can appear twice
+
+    def set_sheet(self, sheet):
+        self.beginResetModel()
+        self.sheet = sheet
+        self.endResetModel()
+
+    def refresh(self):
+        self.beginResetModel()
+        self.endResetModel()
+
+    def set_playing(self, key, pos):
+        self.playing_key, self.playing_pos = key, pos
+        if self.sheet and self.sheet.rows:
+            self.dataChanged.emit(self.index(0, 0), self.index(len(self.sheet.rows) - 1, len(self.sheet.columns) - 1),
+                                  [Qt.ItemDataRole.UserRole + 3, Qt.ItemDataRole.UserRole + 4])
+
+    def roleNames(self):
+        return {k: QByteArray(v) for k, v in self.ROLES.items()}
+
+    def rowCount(self, parent=QModelIndex()):
+        return len(self.sheet.rows) if self.sheet else 0
+
+    def columnCount(self, parent=QModelIndex()):
+        return len(self.sheet.columns) if self.sheet else 0
+
+    def data(self, index, role=Qt.ItemDataRole.DisplayRole):
+        s = self.sheet
+        if s is None or not index.isValid():
+            return None
+        row = s.rows[index.row()]
+        key, _, _, kind = s.columns[index.column()]
+        if role == Qt.ItemDataRole.DisplayRole:
+            return fmt(row.get(key), kind)
+        if role == Qt.ItemDataRole.UserRole + 1:
+            return "left" if kind in ("text", "stems") else "right"
+        if role == Qt.ItemDataRole.UserRole + 2:
+            # Conditional formatting: "Good" for songs with stems, a data bar for stem counts.
+            if kind == "stems" and row.get(key):
+                return "good"
+            if key == "stemSongs" and row.get(key):
+                return "bar:%.3f" % (row[key] / max(1, row.get("tracks") or row.get("songs") or row[key]))
+            return ""
+        if role in (Qt.ItemDataRole.UserRole + 3, Qt.ItemDataRole.UserRole + 4):
+            if s.layout == "queue":
+                return row.get("pos") == self.playing_pos + 1
+            return s.row_kind(index.row()) == SONG and row.get("key") == self.playing_key and bool(self.playing_key)
+        return None