app/src/main/res/xml/preferences_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.preference.PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<android.support.v7.preference.PreferenceCategory android:title="@string/preference_category_ui">
<android.support.v7.preference.ListPreference
android:defaultValue="0"
android:entries="@array/theme_entries"
android:entryValues="@array/theme_entries_values"
android:key="THEME"
android:title="@string/preference_theme" />
<android.support.v7.preference.SwitchPreferenceCompat
android:defaultValue="false"
android:key="COLORED_CARDS"
android:summary="@string/preference_show_colored_cards_summary"
android:title="@string/preference_show_colored_cards" />
</android.support.v7.preference.PreferenceCategory>
<android.support.v7.preference.PreferenceCategory android:title="@string/preference_category_converter">
<android.support.v7.preference.SwitchPreferenceCompat
android:defaultValue="false"
android:key="DECIMAL_PLACES"
android:summary="@string/preference_show_3_decimal_places_summary"
android:title="@string/preference_show_3_decimal_places" />
</android.support.v7.preference.PreferenceCategory>
</android.support.v7.preference.PreferenceScreen>