Preventing AnimationEvent during State Transition by not using State Machine Behavior

✍ Last Updated : September 22, 2022

The 2nd alternative for animation event handling works by setting and checking the state manually.

Case example :

AttackStart Event must be called, but AttackCheck must not get called since the Attack State is already in transition

First, prepare the animationEvent listeners

public class AnimationEventHandler : MonoBehaviour
{
        [HideInInspector] public UnityEvent<object> onAttackStart;
        [HideInInspector] public UnityEvent<object> onAttackCheck;
        [HideInInspector] public UnityEvent<object> onAttackEnd;

        void AttackStart() => onAttackStart?.Invoke();
        void AttackCheck() => onAttackCheck?.Invoke();
        void AttackEnd() => onAttackEnd?.Invoke();
}

Then in the state handler, set state according to triggered event. In this case state = Attacking

public class StateHandler : MonoBehaviour
{
				System.Action state;

				void Awake()
        {
						animationEventHandler = GetComponent<AnimationEventDirectHandler>();
						animationEventHandler.onAttackStart.AddListener(() => OnAttackStart());
						animationEventHandler.onAttackEnd.AddListener(() => OnAttackEnd());
				}
				...
				public System.Action state { get; private set; }
				void OnAttackStart()
        {
            state = Attacking;
        }

        void OnAttackEnd()
        {
            state = Idling;
        }

				public void Attacking()
        {

        }

        public void Idling()
        {

        }
				...
}

Then in the action handler, when OnAttackCheck is triggered, manually check if state is Attacking or not

public class ActionHandler : MonoBehaviour
{
				...
				void Awake()
        {
            stateHandler = GetComponent<StateHandler>();
						animationEventHandler = GetComponent<AnimationEventDirectHandler>();
						animationEventHandler.onAttackCheck.AddListener(() => OnAttackCheck());
				}

				void OnAttackCheck()
        {
            if (stateHandler.state == stateHandler.Attacking)
            {
                hitBox.gameObject.SetActive(true);
                StartCoroutine(DisableHitBox());
            }
        }
				...
}

Pros :

• No need for adding state machine behavior scripts

Cons :

• Script might overlaps with gameplay script
• More context-sensitive, not flexible