trail-into-darkness/Packages/com.jovian.popup-system/Runtime/UI/PopupTrigger.cs

using System;
using UnityEngine;
using UnityEngine.EventSystems;

namespace Jovian.PopupSystem.UI {
    public class PopupTrigger : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler {
        [SerializeField] PopupCategory category;
        [SerializeField] AnchorSide anchorSide = AnchorSide.Below;
        [SerializeField] PopupPositionMode positionMode = PopupPositionMode.AnchorToElement;

        IPopupSystem popupSystem;
        Action<PopupContentBuilder> contentCallback;
        bool initialized;

        public PopupCategory Category => category;

        public void Initialize(IPopupSystem popupSystem, Action<PopupContentBuilder> contentCallback) {
            this.popupSystem = popupSystem;
            this.contentCallback = contentCallback;
            initialized = true;
        }

        public void Initialize(IPopupSystem popupSystem, PopupCategory category, Action<PopupContentBuilder> contentCallback) {
            this.popupSystem = popupSystem;
            this.category = category;
            this.contentCallback = contentCallback;
            initialized = true;
        }

        public void UpdateContent(Action<PopupContentBuilder> contentCallback) {
            this.contentCallback = contentCallback;
        }

        public void OnPointerEnter(PointerEventData eventData) {
            if(!initialized || popupSystem == null || contentCallback == null) {
                return;
            }

            if(positionMode == PopupPositionMode.AnchorToElement) {
                popupSystem.Show(category, contentCallback, (RectTransform)transform, anchorSide);
            }
            else {
                popupSystem.Show(category, contentCallback);
            }
        }

        public void OnPointerExit(PointerEventData eventData) {
            if(!initialized || popupSystem == null) {
                return;
            }
            popupSystem.Hide(category);
        }
    }
}