SafeKeyboard/app/src/main/res/xml/keyboard_numbers.xml

<?xml version="1.0" encoding="utf-8"?>
<Keyboard xmlns:android="http://schemas.android.com/apk/res/android"
          android:keyWidth="30%p"
          android:horizontalGap="@dimen/keyboard_horizontalGap"
          android:verticalGap="@dimen/keyboard_verticalGap"
          android:keyHeight="47dp">
    <Row>
        <Key android:codes="49" android:keyLabel="1" />
        <Key android:codes="50" android:keyLabel="2" />
        <Key android:codes="51" android:keyLabel="3" />
    </Row>

    <Row>
        <Key android:codes="52" android:keyLabel="4" />
        <Key android:codes="53" android:keyLabel="5" />
        <Key android:codes="54" android:keyLabel="6" />
    </Row>

    <Row>
        <Key android:codes="55" android:keyLabel="7" />
        <Key android:codes="56" android:keyLabel="8" />
        <Key android:codes="57" android:keyLabel="9" />
    </Row>

    <Row>
        <Key android:codes="-2" android:keyLabel="ABC" />
        <Key android:codes="48" android:keyLabel="0" />
        <Key android:codes="-35"
            android:isRepeatable="true"/>
    </Row>
</Keyboard>