How can I access a script from another script if both scripts not attached to any GameObject?

Question

The first script is EditorWindow: And places in Editor folder:

public class HierarchyEditor : EditorWindow

The second script is MonoBehaviour but with attibute: [InitializeOnLoad]

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

[InitializeOnLoad]
public class CustomHierarchy : MonoBehaviour
{
    private static Vector2 offset = new Vector2(0, 2);
    public static Color gameObjectFontColor = Color.black;
    public static Color prefabOrgFontColor = Color.black;
    public static Color prefabModFontColor = Color.white;
    public static Color inActiveColor = new Color(0.01f, 0.4f, 0.25f);
    public static Color meshRendererColor = Color.yellow;

    static CustomHierarchy()
    {
        EditorApplication.hierarchyWindowItemOnGUI += HandleHierarchyWindowItemOnGUI;
    }
    private static void HandleHierarchyWindowItemOnGUI(int instanceID, Rect selectionRect)
    {
        Color fontColor = gameObjectFontColor;
        Color backgroundColor = new Color(.76f, .76f, .76f);
        FontStyle styleFont = FontStyle.Normal;
        var obj = EditorUtility.InstanceIDToObject(instanceID);
        GameObject gameObj = EditorUtility.InstanceIDToObject(instanceID) as GameObject;

        if (Selection.instanceIDs.Contains(instanceID))
        {
            backgroundColor = new Color(0.24f, 0.48f, 0.90f);
        }
        if (obj != null)
        {
            var prefabType = PrefabUtility.GetPrefabType(obj);
            if (gameObj.activeInHierarchy == false)
            {
                backgroundColor = inActiveColor;
            }

            if (prefabType == PrefabType.PrefabInstance)
            {
                styleFont = FontStyle.Bold;
                PropertyModification[] prefabMods = PrefabUtility.GetPropertyModifications(obj);
                foreach (PropertyModification prefabMod in prefabMods)
                {
                    if (prefabMod.propertyPath.ToString() != "m_Name" && prefabMod.propertyPath.ToString() != "m_LocalPosition.x" && prefabMod.propertyPath.ToString() != "m_LocalPosition.y" && prefabMod.propertyPath.ToString() != "m_LocalPosition.z" && prefabMod.propertyPath.ToString() != "m_LocalRotation.x" && prefabMod.propertyPath.ToString() != "m_LocalRotation.y" && prefabMod.propertyPath.ToString() != "m_LocalRotation.z" && prefabMod.propertyPath.ToString() != "m_LocalRotation.w" && prefabMod.propertyPath.ToString() != "m_RootOrder" && prefabMod.propertyPath.ToString() != "m_IsActive")
                    {
                        if (HasAllComponents(gameObj, typeof(MeshRenderer), typeof(BoxCollider)))
                        {
                            fontColor = meshRendererColor;
                        }
                        else
                        {
                            fontColor = prefabModFontColor;
                        }

                        break;
                    }
                }
                if (fontColor != prefabModFontColor)
                {
                    if (HasAllComponents(gameObj, typeof(MeshRenderer), typeof(BoxCollider)))
                    {
                        fontColor = meshRendererColor;
                    }
                    else
                    {
                        fontColor = prefabOrgFontColor;
                    }
                }
            }
            else
            {
                if (HasAllComponents(gameObj, typeof(MeshRenderer), typeof(BoxCollider)))
                {
                    fontColor = meshRendererColor;
                }
            }
            Rect offsetRect = new Rect(selectionRect.position + offset, selectionRect.size);
            EditorGUI.DrawRect(selectionRect, backgroundColor);
            EditorGUI.LabelField(offsetRect, obj.name, new GUIStyle()
            {
                normal = new GUIStyleState() { textColor = fontColor },
                fontStyle = styleFont
            }
            );
        }
    }

    public static bool HasAllComponents(GameObject gameObject, params System.Type[] types)
    {
        for (int i = 0; i < types.Length; i++)
        {
            if (gameObject.GetComponent(types[i]) == null)
                return false;
        }

        return true;
    }
}

I want to access some variables that are in the CustomHierarchy script from the HierarchyEditor script.

In the CustomHierarchy script in all places:

if (HasAllComponents(gameObj, typeof(MeshRenderer), typeof(BoxCollider)))
                    {
                        fontColor = meshRendererColor;
                    }

This gameobjects I want to get and show in the editorwindow script. In the CustomHierarchy script I color the objects in yellow fontColor = meshRendererColor but I also want to display this objects in the editorwindow.

Answer 1

As all the members of your CustomHierarchy class are static you can simply make your class static as well:

public static class CustomHierarchy
{
    // ...
}

HierarchyEditor can simply access your members:

public class HierarchyEditor : EditorWindow
{
    void Test()
    {
        Color someColor = CustomHierarchy.gameObjectFontColor;
        // ...
    }

    // ...
}