using UnityEngine;

using UnityEngine.EventSystems;

namespace Michsky.DreamOS

{

public class WindowDragger : UIBehaviour, IBeginDragHandler, IDragHandler

{

[Header("Resources")]

public RectTransform dragArea;

public RectTransform dragObject;

private Vector2 originalLocalPointerPosition;

private Vector3 originalPanelLocalPosition;

public new void Start()

{

if (dragArea == null)

{

try

{

dragArea = GetComponent<RectTransform>();

}

catch { Debug.LogWarning("<b>[Window Dragger]</b> Drag Area is missing.", this); }

}

}

public void OnBeginDrag(PointerEventData data)

{

originalPanelLocalPosition = dragObject.localPosition;

RectTransformUtility.ScreenPointToLocalPointInRectangle(dragArea, data.position, data.pressEventCamera, out originalLocalPointerPosition);

}

public void OnDrag(PointerEventData data)

{

Vector2 localPointerPosition;

if (RectTransformUtility.ScreenPointToLocalPointInRectangle(dragArea, data.position, data.pressEventCamera, out localPointerPosition))

{

Vector3 offsetToOriginal = localPointerPosition - originalLocalPointerPosition;

dragObject.localPosition = originalPanelLocalPosition + offsetToOriginal;

}

ClampToArea();

}

public void ClampToArea()

{

Vector3 pos = dragObject.localPosition;

Vector3 minPosition = dragArea.rect.min - dragObject.rect.min;

Vector3 maxPosition = dragArea.rect.max - dragObject.rect.max;

pos.x = Mathf.Clamp(dragObject.localPosition.x, minPosition.x, maxPosition.x);

pos.y = Mathf.Clamp(dragObject.localPosition.y, minPosition.y, maxPosition.y);

dragObject.localPosition = pos;

}

}

}