ProjectDDD/Packages/SLUnity/SLUI/UIOnOff/SLUIFade.cs

using UnityEngine;
using UnityEngine.UI;

namespace Superlazy.UI
{
    public class SLUIFade : SLUIOnOffTransition
    {
        public float fadeInTime = 1.0f;
        public float fadeOutTime = 1.0f;

        private Graphic[] graphics;
        private float currentAlpha = 0.0f;

        protected override void Validate()
        {
        }

        protected override void Init()
        {
            graphics = GetComponentsInChildren<Graphic>();

            if (currentState) currentAlpha = 1.0f;
            else currentAlpha = 0.0f;

            foreach (var graphic in graphics)
            {
                var c = graphic.color;
                c.a = currentAlpha;
                graphic.color = c;
            }
        }

        protected override bool OnUpdate(bool forceUpdate = false)
        {
            var result = false;
            if (currentState)
            {
                if (fadeInTime != 0) currentAlpha += Time.unscaledDeltaTime / fadeInTime;
                else currentAlpha = 1.0f;
                if (currentAlpha >= 1.0f)
                {
                    currentAlpha = 1.0f;
                    result = true;
                }
            }
            else
            {
                if (fadeOutTime != 0) currentAlpha -= Time.unscaledDeltaTime / fadeOutTime;
                else currentAlpha = 0.0f;
                if (currentAlpha <= 0.0f)
                {
                    currentAlpha = 0.0f;
                    result = true;
                }
            }

            foreach (var graphic in graphics)
            {
                var c = graphic.color;
                c.a = currentAlpha;
                graphic.color = c;
            }

            return result;
        }

        protected override void ForceDisable()
        {
            foreach (var graphic in graphics)
            {
                var c = graphic.color;
                c.a = 0;
                graphic.color = c;
            }
        }
    }
}