HeavenStudio/Assets/Scripts/Util/UiScrollRectEventBubbling.cs
2022-06-28 18:51:19 -04:00

94 lines
3.1 KiB
C#

using UnityEngine;
using UnityEngine.EventSystems;
using static UnityEngine.EventSystems.ExecuteEvents;
namespace kamgam
{
/// <summary>
/// Bubbles events to the parent. Use this to overcome EventTriggers which stop scroll and drag events from bubbling.
///
/// If an EventTrigger component is attached and other code is listening for
/// onPointer events then these will NOT be triggered while dragging if DisableEventTriggerWhileDragging
/// is true.
/// </summary>
public class UiScrollRectEventBubbling : MonoBehaviour,
IBeginDragHandler,
IDragHandler,
IEndDragHandler,
IScrollHandler
{
[Tooltip("Should the scroll and drag events be forwarded (bubble up) to the parent?")]
public bool Bubble = true;
[Tooltip("Stop EventTriggers from executing events while dragging?")]
public bool DisableEventTriggerWhileDragging = true;
protected EventTrigger eventTrigger;
public EventTrigger EventTrigger
{
get
{
if (eventTrigger == null)
{
eventTrigger = this.GetComponent<EventTrigger>();
}
return eventTrigger;
}
}
protected bool dragging = false;
protected void HandleEventPropagation<T>(Transform goTransform, BaseEventData eventData, EventFunction<T> callbackFunction) where T : IEventSystemHandler
{
if (Bubble && goTransform.parent != null)
{
ExecuteEvents.ExecuteHierarchy(goTransform.parent.gameObject, eventData, callbackFunction);
}
}
public void OnScroll(PointerEventData eventData)
{
HandleEventPropagation(transform, eventData, ExecuteEvents.scrollHandler);
}
public void OnBeginDrag(PointerEventData eventData)
{
HandleEventPropagation(transform, eventData, ExecuteEvents.beginDragHandler);
dragging = true;
if (DisableEventTriggerWhileDragging && EventTrigger != null)
{
EventTrigger.enabled = false;
}
}
public void OnDrag(PointerEventData eventData)
{
HandleEventPropagation(transform, eventData, ExecuteEvents.dragHandler);
}
public void OnEndDrag(PointerEventData eventData)
{
HandleEventPropagation(transform, eventData, ExecuteEvents.endDragHandler);
dragging = false;
if (DisableEventTriggerWhileDragging && EventTrigger != null)
{
EventTrigger.enabled = true;
}
}
/// <summary>
/// If the object is disabled while being dragged then the EventTrigger would remain disabled.
/// </summary>
public void OnDisable()
{
if (DisableEventTriggerWhileDragging && dragging && EventTrigger != null)
{
dragging = false;
EventTrigger.enabled = true;
}
}
}
}