antoniogermano/starlight

Automatic macOS Dark/Light shift based on surrounding ambient light.

Starlight

Starlight is the system dark/light appearance manager for macOS Mojave and later. It does measure time and ambient light periodically and then performs system-wide and specific changes of themes for you. For the time being it can change the system appearance, wallpapers, and vscode themes.

How to build it?

You must be using macOS mojave or later (to even have the light/dark possibility) and then you must have Xcode installed (in a version that supports Swift 4.1+). This build system only uses Swift compiler so if you have swiftc in such way that it supports 4.1+ you can use it. You also have to have GNU Make installed.

% make install

This will install starlight to your /usr/local/bin and the starlight-daemon.plist to your ~/Library/LaunchAgents

How to use it?

Starlight runs with a factory preset, but you can change its settings by overriding the settings at ~/.starlight.json. All the settings are optional, but for the settings that have dark/light objects, you should provide both the dark and light keys.

{
                                                // IMPORTANT
                                                // JSON does not accept comments. So do not
                                                // copy this as is.



    "intervals":            10,                 // The time interval in seconds that starlight
                                                // performs changes.


    "minimumLux":           75000,              // Minimum lux amount to be in the light mode.
                                                // if the amount that is measured is under the
                                                // minimumLux amount, then it will change to
                                                // dark mode and in other cases back to light.

    "samples":              10,                 // The rate of samples that each interval does
                                                // For example in an interval of 30 with the
                                                // sample rate of 10, Starlight measures the
                                                // light in every 3 seconds and in the end of
                                                // intervals performs the changes based on the
                                                // average of the 10 measurements.


    "sunset":               "18:00",            // By setting these two times, from sunset to
    "sunrise":              "06:00",            // sunrise, starlight forces dark mode.
                                                // Please notice the HH:mm format of the time
                                                // any other format is ignored
                                                //
    "location": {                               // Starlight can also compute the sunrise or
        "latitude":         12.3456,            // sunset for you. To do so you can set the
        "longitude":        65.7890             // sunrise and/or sunset to value "auto" and
    },                                          // specify your location as in the "location"
                                                // property. You can use services like Google
                                                // Maps, Apple Maps, OpenStreet Maps, et cetera
                                                // to find out your location.
                                                //
                                                // FYI: Your location can be computed by mac's
                                                // CoreLocation API, however this API needs
                                                // app signing and therefore is not suitable
                                                // for open source nature of starlight. Also
                                                // this location is only needed to determine
                                                // timezone location which if you don't travel
                                                // in such way that needs to change your time-
                                                // zone that much; is probably a one time setup.
                                                // and so not using location APIs is a lot better
                                                // for the battery performance.


    "wallpapers": {                             // By setting this, starlight changes the
        "light":            "~/light.png",      // wallpaper. You have to specify the path of
        "dark":             "~/dark.png"        // the light and dark theme.
    },                                          //
                                                // NOTE: Remember that this changes "all" the
                                                // wallpapers of all the screens and monitors.
                                                // so use it with caution.


    "vscode": {                                 // this setting changes the theme of Visual
        "light":            "Light Theme",      // Studio Code by changing the value of the
        "dark":             "Dark Theme"        // "workbench.colorTheme"
    }
}

Starting and Stopping?

To start and stop Starlight you can use tho following system commands

% launchctl start us.kary.starlight
% launchctl stop  us.kary.starlight

Thanks a lot to

• Jeroen Wesbeek for his gist on accessing mac's ambient light sensor which is the how Starlight reads the surrounding ambient light.

• Chris Howell for his Solar Library that made it possible to have automatic sunrise/sunset scheduling in Starlight.