Touch Input with Event Trigger. How to handle with it properly.

Hello Community,

Since this is my first post I wanted to say hello.

As every beginner developer I have a lot of problems. Below one of them:

I wrote simple script to control my 'Player' object:

 using UnityEngine;
 using System.Collections;
 
 public class PlayerMovement : MonoBehaviour {
 
     public float jumpVelocity = 10;
 
     private Transform groundCheck;
     private Animator anim;
     private Rigidbody2D rigidbody2D;
     private bool grounded;
     private Physics2D gravity;
 
     [SerializeField] private LayerMask whatIsGround;
 
     const float groundedRadius = .2f;
 
 
     void Awake () {
 
         // Setting up references.
         groundCheck = transform.Find("GroundCheck");
         anim = GetComponent<Animator>();
         rigidbody2D = GetComponent<Rigidbody2D>();
         
     }
 
     // Use it for Graphic & Input
     void Update () {
         
     }
     
     //Physics and ground check
     void FixedUpdate () {
 
         grounded = false;
 
         Collider2D[] colliders = Physics2D.OverlapCircleAll(groundCheck.position, groundedRadius, whatIsGround);
         for (int i = 0; i < colliders.Length; i++)
         {
             if (colliders[i].gameObject != gameObject)
                 grounded = true;
         }
 
     }
 
     //Jump function
     public void Jump () {
 
         if (grounded) 
             rigidbody2D.velocity = jumpVelocity * Vector2.up;    
     }
 
     //Gliding function
     public void GlideON () {
     
         rigidbody2D.gravityScale = 1;
         Debug.Log ("Graviti is on");
     }
 
     public void GlideOFF () {
 
         rigidbody2D.gravityScale = 0;
         Debug.Log ("Graviti is off");
 
         if (!grounded) {
             rigidbody2D.velocity = ( -jumpVelocity / 10 ) * Vector2.up;
         }
     }
 
 }

To operate touch screen I used GUI function like this:

What I want to achieve:

• One click - Player jump

• Hold button - Player starts glide.

• Player can not glide when he's grounded.

• It does not matter whether I start from 'PointerClick' or 'PointerDown'. If player is grounded the first action should be 'Jump' always.

• If we start with 'PointerDown', Player should jump and after reaching the maximum height he starts glide.

• If we start with 'PointerClick' Player should jump.

• If Player is not grounded and we want to start glide - we have to touch screen and hold it.

Where is the problem:

• When I start with 'PointerDown', my Player begins infinite jump until 'PointerUp'.

I would be grateful for your help and suggestions.