Settings   Part of Android Jetpack.

Settings allow users to change the functionality and behavior of an application. Settings can affect background behavior, such as how often the application synchronizes data with the cloud, or they can be more wide-reaching, such as changing the contents and presentation of the user interface.

The recommended way to integrate user configurable settings into your application is to use the AndroidX Preference Library. This library manages the user interface and interacts with storage so that you define only the individual settings that the user can configure. The library comes with a Material theme that provides a consistent user experience across devices and OS versions.

Getting started

A Preference is the basic building block of the Preference Library. A settings screen contains a Preference hierarchy. You can define this hierarchy as an XML resource, or you can build a hierarchy in code.

The sections below describe how to build a simple settings screen using the AndroidX Preference Library.

Create a hierarchy

The following example shows a simple hierarchy that is defined via XML:

<PreferenceScreen
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <SwitchPreferenceCompat
        app:key="notifications"
        app:title="Enable message notifications"/>

    <Preference
        app:key="feedback"
        app:title="Send feedback"
        app:summary="Report technical issues or suggest new features"/>

</PreferenceScreen>

This hierarchy contains two individual Preferences: a SwitchPreferenceCompat that allows a user to toggle a setting on or off, and a basic Preference with no widget.

When building a hierarchy, each Preference should have a unique key.

Inflate the hierarchy

To inflate a hierarchy from an XML attribute, create a PreferenceFragmentCompat, override onCreatePreferences(), and provide the XML resource to inflate, as shown in the example below:

class MySettingsFragment : PreferenceFragmentCompat() {
    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
        setPreferencesFromResource(R.xml.preferences, rootKey)
    }
}

public class MySettingsFragment extends PreferenceFragmentCompat {
    @Override
    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
        setPreferencesFromResource(R.xml.preferences, rootKey);
    }
}

You can then add this Fragment to your Activity as you would with any other Fragment:

class MySettingsActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        supportFragmentManager
                .beginTransaction()
                .replace(R.id.settings_container, MySettingsFragment())
                .commit()
    }
}

public class MySettingsActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getSupportFragmentManager()
                .beginTransaction()
                .replace(R.id.settings_container, new MySettingsFragment())
                .commit();
    }
}