public void OnBeginDrag(PointerEventData data)
{
dragID = data.pointerId;
dragLock = DragLockDirection.None;
dragStart = data.position;
dragPrevious = data.position;
// don't forward the BeginDrag event until the user leaves the deadzone
}
public void OnEndDrag(PointerEventData data)
{
if (dragID != data.pointerId)
{
return;
}
else if (dragLock != DragLockDirection.None)
{
ForwardEndDrag(data);
}
dragLock = DragLockDirection.None;
dragStart = Vector2.zero;
dragPrevious = Vector2.zero;
}
public void OnDrag(PointerEventData data)
{
// Forwarding the drag events mutates the event data position, but we
// need the original value to assign it to the dragPrevious position
// after evaluating this drag event.
Vector2 originalPosition = data.position;
if (dragID != data.pointerId)
{
return;
}
else if (dragLock == DragLockDirection.None)
{
Vector2 delta = data.position - dragStart;
// start locking the drag if the user has dragged further than the deadzone radius
if ((deadzone * deadzone) < delta.sqrMagnitude)
{
float absx = Mathf.Abs(delta.x);
float absy = Mathf.Abs(delta.y);
dragLock = (absx < absy) ? DragLockDirection.Vertical : DragLockDirection.Horizontal;
if (Debug.isDebugBuild)
{
string direction = (dragLock == DragLockDirection.Vertical) ? "vertical" : "horizontal";
Debug.Log("Locking drag to " + direction);
}
// keep a cast reference to the event handler for this direction
dragEventReceiver = (dragLock == DragLockDirection.Horizontal ? horizontalEventReceiver : verticalEventReceiver) as ILockedDragReceiver;
// forward the BeginDrag event now that we're locked to one direction
ForwardBeginDrag(data);
}
}
else
{
ForwardDragEvent(data);
}
dragPrevious = originalPosition;
}
