Module system 

“Follow system” appearance: detect the OS dark/light setting and map it to a preset.

Constants

SYSTEM_DARK_INDEX

Preset used while the system is in dark mode (index into THEME_NAMES).

SYSTEM_LIGHT_INDEX

Preset used while the system is in light mode (index into THEME_NAMES).

SYSTEM_THEME_NAME

Persisted theme_name meaning “follow the operating system’s light/dark setting”.

Functions

current_system_theme_index

Preset index matching the current system appearance (dark if undetectable).

detect_system_dark

Is the OS in dark mode? None when it can’t be determined (callers pick a default).

is_system_name

Whether name is the “follow system” pseudo-theme (case-insensitive).

parse_gsettings

Parse gsettings get org.gnome.desktop.interface color-scheme ('prefer-dark', …).

parse_macos

Parse defaults read -g AppleInterfaceStyle output (macOS): prints Dark in dark mode.

parse_windows

Parse reg query … /v AppsUseLightTheme output (Windows): 0x0 means dark.

system_theme_index

The preset index to show for a given system appearance.