Shared SaraSuite settings (theme, font, title bar) with a SaraSuite settings tab

Core.py

@@ -6,6 +6,7 @@ one accent colour (Purple/Mauve) used everywhere, not a mauve+lavender mix.
 """
 
 import shutil
+import subprocess
 from dataclasses import asdict, dataclass, field
 from pathlib import Path
 
@@ -37,7 +38,11 @@ class Palette:
 
 
 AppName = "SaraFem"
-FontFamily = "Fixedsys Excelsior"
+# Bundled in assets/fonts and always registered, so it works as FontFamily
+# without being installed. Any other FontFamily is looked up among the
+# system's installed fonts.
+BundledFontFamily = "Fixedsys Excelsior"
+ActiveFontFamily = BundledFontFamily  # set by ApplyAppearance, read by BuildTheme
 
 CacheDir = Path.home() / ".cache" / "SaraFem"
 ThumbnailCacheDir = CacheDir / "Thumbnails"
@@ -48,6 +53,9 @@ SharedConfigDir = Path.home() / ".config" / "SaraSuite"
 ThemesDir = SharedConfigDir / "Themes"
 ConfigDir = SharedConfigDir / "SaraFem"
 ConfigPath = ConfigDir / "Config.toml"
+# Settings shared by every SaraSuite program. Same key names as the matching
+# fields in each program's own Config.toml.
+SharedConfigPath = SharedConfigDir / "Config.toml"
 BookmarksPath = ConfigDir / ".sfem_bookmarks.toml"
 
 _OldConfigDir = Path.home() / ".config" / "SaraFem"
@@ -152,10 +160,16 @@ class AppConfig:
     (nothing changes visually until the user opts in via Ctrl+B/P/H/T or edits
     Config.toml directly)."""
 
+    # True: Theme, FontFamily and HideWindowTitleBar come from the shared
+    # ~/.config/SaraSuite/Config.toml, like every other SaraSuite program.
+    # False: SaraFem uses its own values below instead.
+    UseSharedSettings: bool = True
     Theme: str = "CatppuccinMocha"  # matches a file in ~/.config/SaraSuite/Themes/
+    FontFamily: str = BundledFontFamily
+    HideWindowTitleBar: bool = False  # the actual OS window title bar, not the toolbar below
+
     ShowDotfiles: bool = True
     ViewMode: str = "list"  # "list" or "grid"
-    HideWindowTitleBar: bool = False  # the actual OS window title bar, not the toolbar below
 
     # Batch-rename pattern for multi-select rename, syntax modeled on
     # SaraSortd's own placeholder characters (see ~/Applications/SaraSortd's
@@ -252,6 +266,68 @@ def LoadConfig() -> AppConfig:
     return AppConfig(**Filtered)
 
 
+@dataclass
+class SharedSettings:
+    """~/.config/SaraSuite/Config.toml: the settings every SaraSuite program
+    shares. A program whose own UseSharedSettings is off reads these same
+    keys from its own Config.toml instead."""
+
+    Theme: str = "CatppuccinMocha"
+    FontFamily: str = BundledFontFamily
+    HideWindowTitleBar: bool = False
+
+    def Save(self) -> None:
+        SharedConfigDir.mkdir(parents=True, exist_ok=True)
+        SharedConfigPath.write_text(toml.dumps(asdict(self)))
+
+
+def _OwnSettings(Config: AppConfig) -> SharedSettings:
+    return SharedSettings(Config.Theme, Config.FontFamily, Config.HideWindowTitleBar)
+
+
+def LoadSharedSettings(Config: AppConfig) -> SharedSettings:
+    """The shared file, created from SaraFem's own values the first time so
+    switching to it doesn't change anything visible."""
+    if not SharedConfigPath.exists():
+        Shared = _OwnSettings(Config)
+        Shared.Save()
+        return Shared
+    Result = _OwnSettings(Config)  # fallback for keys the file doesn't have
+    try:
+        Data = toml.loads(SharedConfigPath.read_text())
+    except toml.TomlDecodeError:
+        return Result
+    for Key in SharedSettings.__dataclass_fields__:
+        if Key in Data:
+            setattr(Result, Key, Data[Key])
+    return Result
+
+
+def EffectiveSettings(Config: AppConfig) -> SharedSettings:
+    """What SaraFem actually uses: the shared settings, or its own."""
+    return LoadSharedSettings(Config) if Config.UseSharedSettings else _OwnSettings(Config)
+
+
+def ApplyAppearance(Settings: SharedSettings) -> None:
+    """Theme colours and font. Must run before anything reads Palette.X or
+    calls BuildTheme(). The window title bar is applied by Main."""
+    global ActiveFontFamily
+    ApplyTheme(Settings.Theme)
+    ActiveFontFamily = Settings.FontFamily or BundledFontFamily
+
+
+def InstalledFontFamilies() -> list[str]:
+    """Font families fontconfig knows about, for the font picker. The
+    bundled font is always first, since it isn't installed system-wide."""
+    try:
+        Result = subprocess.run(["fc-list", ":", "family"], capture_output=True, text=True, timeout=5)
+        Families = {Line.split(",")[0].strip() for Line in Result.stdout.splitlines() if Line.strip()}
+    except (OSError, subprocess.SubprocessError):
+        Families = set()
+    Families.discard(BundledFontFamily)
+    return [BundledFontFamily] + sorted(Families, key=str.lower)
+
+
 def BuildTheme() -> ft.Theme:
     ColorScheme = ft.ColorScheme(
         primary=Palette.Mauve,
@@ -275,7 +351,7 @@ def BuildTheme() -> ft.Theme:
         on_error=Palette.Crust,
     )
     return ft.Theme(
-        font_family=FontFamily,
+        font_family=ActiveFontFamily,
         color_scheme=ColorScheme,
         use_material3=True,
         scaffold_bgcolor=Palette.Base,
@@ -283,7 +359,7 @@ def BuildTheme() -> ft.Theme:
         dialog_theme=ft.DialogTheme(
             bgcolor=Palette.Mantle,
             shape=ft.RoundedRectangleBorder(radius=8, side=ft.BorderSide(1, Palette.Mauve)),
-            title_text_style=ft.TextStyle(color=Palette.Mauve, size=18, font_family=FontFamily),
+            title_text_style=ft.TextStyle(color=Palette.Mauve, size=18, font_family=ActiveFontFamily),
         ),
     )