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

public class ContextMenuExample : EditorWindow
{
    [MenuItem("ContextMenuExample/Open Window")]
    static void Open()
    {
        GetWindow<ContextMenuExample>().Show();
    }

    private void OnGUI()
    {
        if(GUILayout.Button("DropDown", EditorStyles.popup))
        {
            DropDownMenu();
        }
    }

    void DropDownMenu()
    {
        GenericMenu menu = new GenericMenu();

        menu.AddDisabledItem(new GUIContent("Do Nothing"));
        menu.AddSeparator("");
        menu.AddItem(new GUIContent("SubMenu/Hello World"), false, HelloWorld);
        menu.AddItem(new GUIContent("SubMenu/Hello Parameters"), false, HelloParameters, new int[] { 1, 2, 3 });
        menu.ShowAsContext();
    }

    void HelloWorld()
    {
        Debug.Log("Hello World");
    }

    void HelloParameters(object obj)
    {
        int[] parameters = (int[])obj;

        foreach (int i in parameters)
            Debug.Log("Parameter: " + i);
    }
}