Connection checker

NetworkConnectionChecker.cs

using System;
using System.Collections;
using UnityEngine;
using UnityEngine.Networking;

public class NetworkConnectionChecker : MonoBehaviour
{
    [Header("Settings")]
    public bool RunOnStart = true;
    public string DefaultChekingServer = "https://google.com";
    public float CheckPeriod = 5;
    public float ErrorRetryDelay = 15;

    [Header("Debug")]
    public bool IsDebugOnInDevBuild = true;
    public Color GUIColorConnected = Color.green;
    public Color GUIColorNotConnected = Color.red;

    [SerializeField]
    private bool m_IsConnected;
    public bool IsConnected
    {
        get => m_IsConnected;
        private set
        {
            if (m_IsConnected != value)
            {
                m_IsConnected = value;
                OnNetworkConnectivityChanged?.Invoke(m_IsConnected);
            }
        }
    }

    public Action<bool> OnNetworkConnectivityChanged;

    #region Unity

    private void Start()
    {
        if (RunOnStart)
            RunCheckerProcess();
    }

    private void OnGUI()
    {
        if (Debug.isDebugBuild)
        {
            GUI.matrix = Matrix4x4.Scale(new Vector3(3.5f, 3.5f, 3.5f));
            GUI.color = IsConnected ? GUIColorConnected : GUIColorNotConnected;
            GUI.Label(new Rect(0, 0, 200, 50), IsConnected ? "Connected" : "Not connected");
        }
    }

    #endregion

    #region Public

    public void RunCheckerProcess() => StartCoroutine(CheckerProcess());
    public void CheckInternetConnection(Action<bool> result) => CheckInternetConnectionForServer(DefaultChekingServer, result);
    public void CheckInternetConnectionForServer(string server, Action<bool> result) => StartCoroutine(CheckInternetConnectionCoroutine(server, result));

    #endregion

    #region Private

    private IEnumerator CheckerProcess()
    {
        bool connection = false;
        yield return StartCoroutine(CheckInternetConnectionCoroutine(DefaultChekingServer, (result) => connection = result));

        IsConnected = connection;
        if (IsConnected)
        {
            yield return new WaitForSeconds(CheckPeriod);
            RunCheckerProcess();
        }
        else
        {
            yield return new WaitForSeconds(ErrorRetryDelay);
            RunCheckerProcess();
        }
    }

    private IEnumerator CheckInternetConnectionCoroutine(string server, Action<bool> syncResult)
    {
        bool result;
        using (var request = UnityWebRequest.Head(server))
        {
            request.timeout = 5;
            yield return request.SendWebRequest();
            result = !request.isNetworkError && !request.isHttpError && request.responseCode == 200;
        }
        syncResult(result);
    }

    #endregion
}