Android: Low Light Theme Switcher

This helper library will automatically switches your Activity between Dark/Light themes using the device light sensor and DayNight theme from Support Library 23.2.

The DayNight theme available in Support Library is a really neat feature, but functionally it's not that useful. Even though it's night by time definition, I could still be in a well lit room and it would still show me the night theme.

I beleive that this default behaviour is due to a limitation that not all Android devices will have a light sensor. If the target device does not have a light sensor then it simply falls back to the default behaviour of AppCompatDelegate.MODE_NIGHT_AUTO.

Requires API 14+.

Adding it to your project

Add the jitpack repo to your project build.gradle

allprojects {
	repositories {
		...
		maven { url "https://jitpack.io" }
	}
}

Add the library to your module build.gradle

dependencies {
        compile 'com.github.twig:android-low-light-theme-switcher:1.1.0'
}

Usage

public class YourApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();

        // Change between day/night/auto
        DayNightSensor.start(this);
    }

    @Override
    public void onTerminate() {
        DayNightSensor.stop(this);
        super.onTerminate();
    }
}

Options

DayNightSensor.start(this, [settings]);

Parameter settings is an instance of DayNightSensor.Settings.

By default:

Settings.luxThreshold is currently 4.0 lumens. Still trying to figure out a good "dark enough" value.
Settings.samplingDelay checks the light sensor values every 3,000 milliseconds.
Settings.autoRestartActivity will automatically recreate the current activity if darkness levels change. Set to false if you don't want it to cause jitters.

Technical details