Handle the "default" desktop color scheme setting gracefully

README.md

@@ -14,8 +14,10 @@ Fix auto dark mode for sublime v4 on Linux. Sublime text 4 supposedly has such a
 - Edit your preferences and configure the following keys:
     - `dark_color_scheme`
     - `light_color_scheme`
+    - `default_color scheme` (`dark`, `light`, or a color scheme name)
     - `dark_theme`
     - `light_theme`
+    - `default_theme` (`dark`, `light`, or a theme name)
 - Either from the context menu (under View), or from the command pallet (search for AutoDark)
     - `System`: Sublime follows the system settings
     - `Light`: Sublime sticks to only light mode

helpers.py

@@ -1,6 +1,6 @@
 import sublime
 
-from typing import Callable, Any, Literal, TypeVar, cast
+from typing import Callable, Any, Final, Literal, Sequence, TypeVar, cast
 from functools import wraps, reduce
 from types import MappingProxyType
 import operator
@@ -44,18 +44,20 @@ def wrapper():
     return decorator
 
 
-colorSchemeMap = MappingProxyType({1: "dark", 2: "light"})
+ColorScheme = Literal["default", "dark", "light"]
+colorSchemeMap: Final[Sequence[ColorScheme]] = ColorScheme.__args__
+ColorSchemeEnum = Literal[range(len(colorSchemeMap))]
 
 
-def parse_dbus_call(output: str) -> Literal["dark", "light"]:
+def parse_dbus_call(output: str) -> ColorScheme:
     result = json.loads(output)
-    system_scheme: Literal[1, 2] = result["data"][0]["data"]
+    system_scheme: ColorSchemeEnum = result["data"][0]["data"]
     return cast(Any, colorSchemeMap[system_scheme])
 
 
-def parse_dbus_monitor(output: str) -> Literal["dark", "light"]:
+def parse_dbus_monitor(output: str) -> ColorScheme:
     result = json.loads(output)
-    system_scheme: Literal[1, 2] = result["payload"]["data"][2]["data"]
+    system_scheme: ColorSchemeEnum = result["payload"]["data"][2]["data"]
     return cast(Any, colorSchemeMap[system_scheme])
 
 

main.py

@@ -15,7 +15,9 @@
 import contextlib
 import uuid
 
-from .helpers import settings_watcher, read_system_theme, parse_dbus_monitor
+from .helpers import (
+    settings_watcher, read_system_theme, parse_dbus_monitor,
+    ColorScheme)
 from .lifecycle import lifecycle, CycleStage
 from .logger import logger
 
@@ -175,15 +177,25 @@ def unmonitor():
         logger.info("Daemon stopped")
 
 
-def change_color_scheme(new_scheme: str, old_scheme: Optional[str] = None):
+def change_color_scheme(new_scheme: ColorScheme, old_scheme: Optional[ColorScheme] = None):
     settings = sublime.load_settings("Preferences.sublime-settings")
     ui_info = sublime.ui_info()
-    if (theme := settings.get(f"{new_scheme}_theme")) != ui_info.get("theme").get("resolved_value"):
-        settings["theme"] = theme
-    if (color_scheme := settings.get(f"{new_scheme}_color_scheme")) != ui_info.get(
-        "color_scheme"
-    ).get("resolved_value"):
-        settings["color_scheme"] = color_scheme
+    for what in ("color_scheme", "theme"):
+        value = settings.get(f"{new_scheme}_{what}")
+        if new_scheme == "default":
+            # Desktops may ask applications to use "default" UI colors. Let
+            # users choose what to do through configuration.
+            if not value:
+                # ...but if they don't we'll choose for them.
+                # In GNOME and Sublime Text the default would be "light".
+                value = "light"
+            if value in ("light", "dark"):
+                # These special aliases are resolved through their respective
+                # configuration settings.
+                new_scheme = value
+                value = settings.get(f"{new_scheme}_{what}")
+        if value != ui_info.get(what).get("resolved_value"):
+            settings[what] = value
 
     if new_scheme != old_scheme:
         logger.info(f"Color scheme change detected: previous={old_scheme}, new={new_scheme}")