activity_main.xml

<com.msh_n.myp.customview1.PieView
        android:id="@+id/pieView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:backgroundColor="@color/light_green"
        app:titleText="Foreground color"
        app:viewColor="@color/pink" />


    <com.msh_n.myp.customview1.PieView
        android:id="@+id/pieView2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginTop="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/pieView" />