Customizing your buttons with code in Unity

Unity has an easy to use built-in Button interface in the Canvas UI. But with many easy to use things, they come with limitations. For instance, if we wanted a method to run when a button is highlighted, we wouldn’t be able to do this unless it is written in some type of code.

In my example, I want an icon to appear next to a button when the user highlights it. We can use the UnityEngine.EventSystems to make the changes we need.

using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;
using UnityEngine.UI;

public class Button : MonoBehaviour, ISelectHandler, IPointerEnterHandler, IPointerExitHandler, IDeselectHandler

We can derive our class from the above parent classes and then use the following methods:

    // When highlighted with mouse.
    public void OnPointerEnter(PointerEventData eventData)
    {
        // Do something.
    }
    // When no longer highlighted with mouse.
    public void OnPointerExit(PointerEventData eventData)
    {
        // Do something.
    }
    // When selected.
    public void OnSelect(BaseEventData eventData)
    {
        // Do something.
    }
    //when deselected
    public void OnDeselect(BaseEventData eventData)
    {
        // Do something.
    }

There are other useful methods we can use with our buttons located within the Unity API here.