Unity toggle sprite swap for on-off sprites

Unity default toggle component doesn’t have ability to just toggle two images for on/off state.
So here my simple component to do this. It is based on Unity.UI.Button.

using System;
using UnityEngine;
using UnityEngine.UI;
[RequireComponent(typeof(Button))]
public class ToggleSpriteSwap: MonoBehaviour
{
[SerializeField] private Image targetImage;
[SerializeField] private Sprite onSprite;
[SerializeField] private Sprite offSprite;
[SerializeField] private bool isOn;
public bool IsOn { get { return isOn; } set { isOn = value; UpdateValue(); }}
public event Action<bool> onValueChanged;
private Button button;
// to set initial value and skip onValueChanged notification
public void Initialize(bool value)
{
isOn = value;
UpdateValue(false);
}
// Use this for initialization
void Start ()
{
button = GetComponent<Button>();
button.transition = Selectable.Transition.None;
button.onClick.AddListener(OnClick);
}
void OnClick()
{
isOn = !isOn;
UpdateValue();
}
private void UpdateValue(bool notifySubscribers = true)
{
if(notifySubscribers && onValueChanged != null)
onValueChanged(isOn);
if (targetImage == null)
return;
targetImage.sprite = isOn ? onSprite : offSprite;
}
}