myClassEditor

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using System;

[CustomEditor(typeof(myClass))]
public class myClassEditor : Editor
{
    public override void OnInspectorGUI()
    {
        myClass scriptToEdit = (myClass)target;


        //Used to hide all variables instead of greying them out.
        //scriptToEdit.showVariables = EditorGUILayout.Toggle("Show variables", scriptToEdit.showVariables);
        //using (var showVariablesGroup = new EditorGUILayout.FadeGroupScope(Convert.ToSingle(scriptToEdit.showVariables)))
        //{
            //if (showVariablesGroup.visible == true)
            //{
            //}

        using (var showVariablesGroup = new EditorGUILayout.ToggleGroupScope("Show variables", scriptToEdit.showVariables))
        {

            scriptToEdit.showVariables = showVariablesGroup.enabled;

            //Indents the text in the inspector 1 step.
            EditorGUI.indentLevel++;

            //This creates a regular field that takes an integer, just like public or serializeable will do.
            scriptToEdit.myInt = EditorGUILayout.IntField("Here you can add a label to your field", scriptToEdit.myInt);

            //This creates a slider for a floating point between 0 and 10
            scriptToEdit.myFloat = EditorGUILayout.Slider("This is a slider", scriptToEdit.myFloat, 0.0f, 10.0f);

            //This creates a field that tales a game object
            //the last "true" is a bool that allows/disallows objects from the scene to be used.
            scriptToEdit.myGameobject =
                (GameObject)EditorGUILayout.ObjectField("This field lets you add a gameobject", scriptToEdit.myGameobject, typeof(GameObject), true);

            //Creates a small spacing between the last control and the next one.
            EditorGUILayout.Space();

            //This provides a field where the user can select a color from the RGB spectrum.
            scriptToEdit.myColor = EditorGUILayout.ColorField("Here there be colors", scriptToEdit.myColor);

            //Moves the indentation 1 step to the left.
            EditorGUI.indentLevel--;
        }
    }
}