Quelle  preference_calls.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
    android:key="pref_key_voip_settings"
    android:persistent="true"
    android:title="@string/prefs_title_calls">

    <PreferenceCategory
        android:key="@string/preferences__voip"
        android:title="@string/prefs_title_voip">

        <ch.threema.app.preference.SynchronizedCheckBoxPreference
            android:defaultValue="true"
            android:key="@string/preferences__voip_enable"
            android:icon="@drawable/ic_phone_locked_outline"
            android:widgetLayout="@layout/preference_switch_layout"
            android:title="@string/prefs_title_voip_enable" />

        <ch.threema.app.preference.SynchronizedCheckBoxPreference
            android:defaultValue="true"
            android:key="@string/preferences__voip_video_enable"
            android:icon="@drawable/ic_camera_locked"
            android:title="@string/prefs_title_voip_video_enable"
            android:dependency="@string/preferences__voip_enable"
            android:widgetLayout="@layout/preference_switch_layout" />

        <ch.threema.app.preference.SynchronizedCheckBoxPreference
            android:widgetLayout="@layout/preference_switch_layout"
            android:defaultValue="false"
            android:key="@string/preferences__voip_force_turn"
            android:summaryOn="@string/prefs_summary_force_turn_on"
            android:summaryOff="@string/prefs_summary_force_turn_off"
            android:dependency="@string/preferences__voip_enable"
            android:title="@string/prefs_title_force_turn" />

        <CheckBoxPreference
            android:widgetLayout="@layout/preference_switch_layout"
            android:defaultValue="false"
            android:key="@string/preferences__voip_reject_mobile_calls"
            android:title="@string/prefs_voip_reject_incoming_calls_title"
            android:summary="@string/prefs_voip_reject_incoming_calls_summary"
            android:dependency="@string/preferences__voip_enable" />

        <CheckBoxPreference
            android:widgetLayout="@layout/preference_switch_layout"
            android:defaultValue="true"
            android:key="@string/preferences__voip_abort_on_bluetooth_disconnect"
            android:title="@string/prefs_voip_abort_on_bluetooth_disconnect_title"
            android:summaryOn="@string/prefs_voip_abort_on_bluetooth_disconnect_summary_on"
            android:summaryOff="@string/prefs_voip_abort_on_bluetooth_disconnect_summary_off"
            android:dependency="@string/preferences__voip_enable" />

        <DropDownPreference
            android:defaultValue="0"
            android:entries="@array/list_videocall_profile"
            android:entryValues="@array/list_videocall_profile_values"
            android:key="@string/preferences__voip_video_profile"
            android:title="@string/prefs_videocall_profile"
            android:dependency="@string/preferences__voip_video_enable"
            android:summary="%s" />

        <Preference
            android:key="@string/preferences__videocall_profile_explain"
            android:summary="@string/prefs_videocall_profile_explain"
            android:icon="@drawable/ic_info_outline"
            android:dependency="@string/preferences__voip_video_enable"
            android:selectable="false" />

    </PreferenceCategory>

    <PreferenceCategory
        android:key="pref_key_group_calls_settings"
        android:title="@string/group_calls">

        <ch.threema.app.preference.SynchronizedCheckBoxPreference
            android:defaultValue="true"
            android:key="@string/preferences__group_calls_enable"
            android:icon="@drawable/ic_phone_locked_outline"
            android:title="@string/prefs_title_group_calls_enable"
            android:widgetLayout="@layout/preference_switch_layout" />

    </PreferenceCategory>

</PreferenceScreen>