How to call Update function's code by button click - function

Question

How can I call the codes, inside the Update function using a public method?
What I need to archive is, calling Update using another function.
So that Update triggers using that other method.
One more thing, code should run only when a button long press.
Many Thanks four help
using UnityEngine;
using System.Collections;
public class CarController : MonoBehaviour
{
public float speed = 1500f;
public float rotationSpeed = 15f;
public WheelJoint2D backWheel;
public WheelJoint2D frontWheel;
public Rigidbody2D rb;
private float movement = 0f;
private float rotation = 0f;
void Update()
{
rotation = Input.GetAxisRaw("Horizontal");
movement = -Input.GetAxisRaw("Vertical") * speed;
}
void FixedUpdate()
{
if (movement == 0f)
{
backWheel.useMotor = false;
frontWheel.useMotor = false;
}
else
{
backWheel.useMotor = true;
frontWheel.useMotor = true;
JointMotor2D motor = new JointMotor2D { motorSpeed = movement, maxMotorTorque = 10000 };
backWheel.motor = motor;
frontWheel.motor = motor;
}
rb.AddTorque(-rotation * rotationSpeed * Time.fixedDeltaTime);
}
//public void Rotate()
//{
// rotate = true;
// print("aa");
//}
//public void Move()
//{
// rotation = Input.GetAxisRaw("Horizontal");
// movement = -Input.GetAxisRaw("Vertical") * speed;
//}
}

Answer 1

Those are actually two questions.
1. A long press button
The Unity UI.Button hasn't per se a method for a long press but you can use the IPointerXHandler interfaces for implementing that on your own:
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;
using UnityEngine.UI;
// RequireComponent makes sure there is Button on the GameObject
[RequireComponent(typeof(Button))]
public class LongPressButton : MonoBehaviour, IPointerDownHandler, IPointerUpHandler, IPointerExitHandler
{
private void Awake()
{
ResetButton();
}
// set the long press duration in the editor (in seconds)
public float LongPressDuration = 0.5f;
// Here you reference method just like in onClick
public UnityEvent onLongPress;
private float _timer;
private bool _isPressed;
private bool _pressInvoked;
private void Update()
{
// prevent multiple calls if button stays pressed
if (_pressInvoked) return;
// if button is not pressed do nothing
if (!_isPressed) return;
// reduce the timer by the time passed since last frame
_timer -= Time.deltaTime;
// if timeout not reached do nothing
if (!(_timer <= 0)) return;
// Invoke the onLongPress event -> call all referenced callback methods
onLongPress.Invoke();
_pressInvoked = true;
}
// reset all flags and timer
private void ResetButton()
{
_isPressed = false;
_timer = LongPressDuration;
_pressInvoked = false;
}
/* IPointer Callbacks */
// enable the timer
public void OnPointerDown(PointerEventData eventData)
{
_isPressed = true;
}
// reset if button is released before timeout
public void OnPointerUp(PointerEventData eventData)
{
ResetButton()
}
// reset if cursor leaves button before timeout
public void OnPointerExit(PointerEventData eventData)
{
ResetButton();
}
}
This script has to be placed next to the Button component.
You don't reference the callback method(s) in the Button's
onClick but instead in this LongPressButton's onLongPress
and don't forget to adjust LongPressDuration also in the inspector.
Example
2. Calling CarController's Update
I don't know why you want this (I guess you disabled the component but want to call Update anyway)
Solution A
In order to be able to reference that method in the Inspector there are a few options:
Simply make your Update method public
public void Update()
{
rotation = Input.GetAxisRaw("Horizontal");
movement = -Input.GetAxisRaw("Vertical") * speed;
}
wrap the content of Update in another public method and use that one instead:
private void Update()
{
DoUpdateStuff();
}
public void DoUpdateStuff()
{
rotation = Input.GetAxisRaw("Horizontal");
movement = -Input.GetAxisRaw("Vertical") * speed;
}
the other way round (how you requested it) - call Update from another public method:
private void Update()
{
rotation = Input.GetAxisRaw("Horizontal");
movement = -Input.GetAxisRaw("Vertical") * speed;
}
public void DoUpdateStuff()
{
Update();
}
So all that's left is referencing the CarController's Update or DoUpdateStuff method in the LongPressButton's onLongPress event.
Solution B
Alternatively you could add that callback directly on runtime without referencing anything nor making the callback method public so you could directly use private void Update without a wrapper method.
Drawback: For this method you somehow have to get the reference to that LongPressButton in your CarController script instead
public class CarController : MonoBehaviour
{
// Somehow get the reference for this either by referencing it or finding it on runtime etc
// I will asume this is already set
public LongPressButton longPressButton;
private void Awake()
{
// make sure listener is only added once
longPressButton.onLongPress.RemoveListener(Update);
longPressButton.onLongPress.AddListener(Update);
}
private void Update()
{
rotation = Input.GetAxisRaw("Horizontal");
movement = -Input.GetAxisRaw("Vertical") * speed;
}
private void OnDestroy()
{
// clean up the listener
longPressButton.onLongPress.RemoveListener(Update);
}
//...
}

Answer 2

Thanks for your descriptive reply. What I did was change my script to following and added Event Trigger component. Then call the public functions accordingly.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class CarMve : MonoBehaviour
{
bool move = false;
bool moveR = false;
public Rigidbody2D rb;
public float speed = 20f;
public float rotationSpeed = 2f;
private void FixedUpdate()
{
if (move == true)
{
rb.AddForce(transform.right * speed * Time.fixedDeltaTime * 100f, ForceMode2D.Force);
}
if (moveR == true)
{
rb.AddForce(transform.right *- speed * Time.fixedDeltaTime * 100f, ForceMode2D.Force);
}
}
/* Will be used on the UI Button */
public void MoveCar(bool _move)
{
move = _move;
}
public void MoveCarR(bool _moveR)
{
moveR = _moveR;
}
}