How to get animation to Stop and Start with a key press

Hello, I have a simple movement and animation script that works great except once a key is pressed, the animation never stops. I'm guessing it involves a if statement or a while loop, but I can't seem to implement it right. Any help would be amazing.

 using UnityEngine;
 using System.Collections;
 
 public class rickyMovement : MonoBehaviour 
 {
     private Animator animator;
     public float speed = 4;
     public bool happen = false;
     void Start () 
     {
         animator = this.GetComponent<Animator> ();
     }
     
     // Update is called once per frame
     void Update () 
     {
         animation ();
         motion ();
     }
 
     void motion(bool happen)
     {
         if (Input.GetKey (KeyCode.RightArrow)) 
         {
             transform.Translate(Vector2.right * speed * Time.deltaTime);
         }
         if (Input.GetKey (KeyCode.LeftArrow)) 
         {
             transform.Translate(-Vector2.right * speed * Time.deltaTime);
         }
         if (Input.GetKey (KeyCode.UpArrow)) 
         {
             transform.Translate(Vector2.up * speed * Time.deltaTime);
         }
         if (Input.GetKey (KeyCode.DownArrow)) 
         {
             transform.Translate(-Vector2.up * speed * Time.deltaTime);
         }
     }
 
     void animation()
     {
         var vertical = Input.GetAxis("Vertical");
         var horizontal = Input.GetAxis("Horizontal");
 
 
         if (vertical > 0 )
         {
             animator.SetInteger("Direction", 2);
         }
         else if (vertical < 0)
         {
             animator.SetInteger("Direction", 0);
         }
         else if (horizontal > 0)
         {
             animator.SetInteger("Direction", 3);
         }
         else if (horizontal < 0)
         {
             animator.SetInteger("Direction", 1);
         }    
     }
 }