FSM example: FSM

fsm

public class FSM {
 
    public Robot entity;
    public State currentState;
 
    public FSM( Robot entity ) {
        this.entity = entity;
    }
 
    public void Update() {
        if ( currentState != null ) {
            currentState.Execute( entity );
        }
    }
 
    public void ChangeState( Robot newState ) {
        currentState.Exit( entity );
        currentState = newState;
        currentState.Enter( entity );
        currentState.Execute( entity );
    }
 
}