using System;
using System.Collections.Generic;
using UnityEngine.EventSystems;

namespace UnityEngine.UI
{
    [Obsolete("Use BaseMeshEffect instead", true)]
    public abstract class BaseVertexEffect
    {
        [Obsolete("Use BaseMeshEffect.ModifyMeshes instead", true)] //We can't upgrade automatically since the signature changed.
        public abstract void ModifyVertices(List<UIVertex> vertices);
    }

    // 关键在于实现IMeshModifier接口，自己写效果，不一定要继承这个类
    [ExecuteInEditMode]
    public abstract class BaseMeshEffect : UIBehaviour, IMeshModifier
    {
        [NonSerialized]
        private Graphic m_Graphic;

        protected Graphic graphic
        {
            get
            {
                if (m_Graphic == null)
                    m_Graphic = GetComponent<Graphic>();

                return m_Graphic;
            }
        }

        protected override void OnEnable()
        {
            base.OnEnable();
            if (graphic != null)
                graphic.SetVerticesDirty();
        }

        protected override void OnDisable()
        {
            if (graphic != null)
                graphic.SetVerticesDirty();
            base.OnDisable();
        }

        protected override void OnDidApplyAnimationProperties()
        {
            if (graphic != null)
                graphic.SetVerticesDirty();
            base.OnDidApplyAnimationProperties();
        }

#if UNITY_EDITOR
        protected override void OnValidate()
        {
            base.OnValidate();
            if (graphic != null)
                graphic.SetVerticesDirty();
        }

#endif

        public virtual void ModifyMesh(Mesh mesh)
        {
            using (var vh = new VertexHelper(mesh))
            {
                ModifyMesh(vh);
                vh.FillMesh(mesh);
            }
        }

        public abstract void ModifyMesh(VertexHelper vh);
    }
}