TouhouLS/Assets/RealCode/Menu/ButtonS/MainMenuButton.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;

public class MainMenuButton : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler, ISelectHandler, IDeselectHandler, IPointerDownHandler, IPointerUpHandler {

  [Header("References")]
  public Image targetGraphic;
  public RectTransform targetTransform;
  public bool pointerSelected;
  public bool keyboardSelected;
  public bool pressed;

  [Header("Style")]
  public Color baseColor;
  public Color selectedColor;
  public float baseWidth;
  public float selectedWidth;
  public Color tintColor;

  public void OnPointerEnter(PointerEventData eventData) {
    pointerSelected = true;
  }

  public void OnPointerExit(PointerEventData eventData) {
    pointerSelected = false;
  }

  public void OnSelect(BaseEventData eventData) {
    keyboardSelected = true;
  }

  public void OnDeselect(BaseEventData eventData) {
    keyboardSelected = false;
  } 

  public void OnPointerDown(PointerEventData eventData) {
    pressed = true;
  }

  public void OnPointerUp(PointerEventData eventData) {
    pressed = false;
  }

  void Start(){
    var b = GetComponent<Button>();
    if (b){
      b.onClick.RemoveAllListeners();

      var click = GetComponent<ButtonOnClick>();
      if (click)
        b.onClick.AddListener(click.OnClick);
    }
    
  }

  // Update is called once per frame
  void Update() {
    var selected = keyboardSelected || pointerSelected;
    targetGraphic.color = (selected ? selectedColor : baseColor) * (pressed ? tintColor : Color.white);
    targetTransform.sizeDelta = new Vector2(selected ? selectedWidth : baseWidth, targetTransform.sizeDelta.y);
  }

}