Android Dark Theme

Rishabh Sharma

25 July 2019

A dark theme is a low-light UI that displays mostly dark surfaces.

Dark theme has many benefits:

Can reduce power usage by a significant amount (depending on the device’s screen technology).
Improves visibility for users with low vision and those who are sensitive to bright light.
Makes it easier for anyone to use a device in a low-light environment.

To support dark theme you need to inherit DayNight theme:

<style name="AppTheme" parent="Theme.AppCompat.DayNight">

1	<style name="AppTheme" parent="Theme.AppCompat.DayNight">

You can also use MaterialComponents’ dark theming:

<style name="AppTheme" parent="Theme.MaterialComponents.DayNight">

1	<style name="AppTheme" parent="Theme.MaterialComponents.DayNight">

Here are the two most important theme attributes to know about:

?android:attr/textColorPrimary This is a general purpose text color. It is near-black in Light theme and near-white on Dark themes. It contains a disabled state.
?attr/colorControlNormal A general-purpose icon color. It contains a disabled state.

On devices running Android 9 or earlier, the recommended theme options are:

Light
Dark
Set by Battery Saver (the recommended default option)

When running on Android Q, the recommended options are different, to allow the user to override the system default:

Light
Dark
System default (the recommended default option)

Note that if the user selects Light, then Battery Saver will not change that setting.

Each of the options map directly to one of the AppCompat.DayNight modes:

Light – MODE_NIGHT_NO
Dark – MODE_NIGHT_YES
Set by Battery Saver – MODE_NIGHT_AUTO_BATTERY
System default – MODE_NIGHT_FOLLOW_SYSTEM

To switch the theme, call AppCompatDelegate.setDefaultNightMode().

You can create a helper class like below to toggle the Dark Mode :

public class ThemeHelper {

    public static final String LIGHT_MODE = "light";
    public static final String DARK_MODE = "dark";
    public static final String DEFAULT_MODE = "default";

    public static void applyTheme(@NonNull String themePref) {
        switch (themePref) {
            case LIGHT_MODE: {
                AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
                break;
            }
            case DARK_MODE: {
                AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
                break;
            }
            default: {
                if (BuildCompat.isAtLeastQ()) {
                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM);
                } else {
                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_AUTO_BATTERY);
                }
                break;
            }
        }
    }
}

public class ThemeHelper {

public static final String LIGHT_MODE = "light";

public static final String DARK_MODE = "dark";

public static final String DEFAULT_MODE = "default";

public static void applyTheme(@NonNull String themePref) {

switch (themePref) {

case LIGHT_MODE: {

AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);

break;

}

case DARK_MODE: {

AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);

break;

}

default: {

if (BuildCompat.isAtLeastQ()) {

AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM);

} else {

AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_AUTO_BATTERY);

}

break;

}

References: