using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Events;

using System.Collections;

public static class ExtensionButton
{
    public static void SetButtonEvent(this Button button, UnityAction onClick)
    {
        button.onClick = new Button.ButtonClickedEvent();

        button.onClick.AddListener(onClick);
    }

    public static void AddButtonEvent(this Button button, UnityAction onClick)
    {
        button.onClick.AddListener(onClick);
    }

    public static void PushButtonEvent(this Button button, UnityAction onClick)
    {
        Button.ButtonClickedEvent click = button.onClick;

        button.onClick = new Button.ButtonClickedEvent();

        button.onClick.AddListener(onClick);
        button.onClick.AddListener(click.Invoke);
    }

    public static void AddButtonEventOnetime(this Button button, UnityAction onClick)
    {
        onClick += () =>
        {
            button.onClick.RemoveListener(onClick);
        };

        button.onClick.AddListener(onClick);
    }

    public static void PushButtonEventOnetime(this Button button, UnityAction onClick)
    {
        onClick += () =>
        {
            button.onClick.RemoveListener(onClick);
        };

        Button.ButtonClickedEvent click = button.onClick;

        button.onClick = new Button.ButtonClickedEvent();

        button.onClick.AddListener(onClick);
        button.onClick.AddListener(click.Invoke);
    }
}