PointerInputModule.cs

using System.Collections.Generic;
using System.Text;

namespace UnityEngine.EventSystems
{
	public abstract class PointerInputModule : BaseInputModule
	{
		public const int kMouseId = -1;
		public const int kFakeTouchesId = -2;

		protected Dictionary<int, PointerEventData> m_PointerData = new Dictionary<int, PointerEventData> ();

		private bool GetPointerData(int id, out PointerEventData data, bool create)
		{
			if (!m_PointerData.TryGetValue (id, out data) && create)
			{
				data = new PointerEventData (eventSystem)
				{
					pointerId = id,
				};
				m_PointerData.Add (id, data);
				return true;
			}
			return false;
		}

		protected void RemovePointerData(PointerEventData data)
		{
			m_PointerData.Remove (data.pointerId);
		}

		protected PointerEventData GetTouchPointerEventData(Touch input, out bool pressed, out bool released)
		{
			PointerEventData pointerData;
			var created = GetPointerData (input.fingerId, out pointerData, true);

			pointerData.Reset ();

			pressed = created || (input.phase == TouchPhase.Began);
			released = (input.phase == TouchPhase.Canceled) || (input.phase == TouchPhase.Ended);

			if (created)
				pointerData.position = input.position;

			if (pressed)
				pointerData.delta = Vector2.zero;
			else
				pointerData.delta = input.position - pointerData.position;

			pointerData.position = input.position;

			eventSystem.RaycastAll (pointerData, m_RaycastResultCache);

			var raycast = FindFirstRaycast (m_RaycastResultCache);
			pointerData.pointerCurrentRaycast = raycast;
			m_RaycastResultCache.Clear ();
			return pointerData;
		}

		protected virtual PointerEventData GetMousePointerEventData()
		{
			PointerEventData pointerData;
			var created = GetPointerData (kMouseId, out pointerData, true);

			pointerData.Reset ();

			if (created)
				pointerData.position = Input.mousePosition;

			Vector2 pos = Input.mousePosition;
			pointerData.delta = pos - pointerData.position;
			pointerData.position = pos;

			eventSystem.RaycastAll (pointerData, m_RaycastResultCache);
			var raycast = FindFirstRaycast (m_RaycastResultCache);
			pointerData.pointerCurrentRaycast = raycast;
			m_RaycastResultCache.Clear ();
			return pointerData;
		}

		protected PointerEventData GetLastPointerEventData(int id)
		{
			PointerEventData data;
			GetPointerData (id, out data, false);
			return data;
		}

		protected virtual void ProcessMove(PointerEventData pointerEvent)
		{
			bool moving = pointerEvent.IsPointerMoving ();

			// Drag notification
			if (moving && pointerEvent.pointerDrag != null)
			{
				// Before doing drag we should cancel any pointer down state
				// And clear selection!
				if (pointerEvent.pointerPress != pointerEvent.pointerDrag)
				{
					ExecuteEvents.Execute (pointerEvent.pointerPress, pointerEvent, ExecuteEvents.pointerUpHandler);

					pointerEvent.eligibleForClick = false;
					pointerEvent.pointerPress = null;
					pointerEvent.rawPointerPress = null;
				}
				ExecuteEvents.Execute (pointerEvent.pointerDrag, pointerEvent, ExecuteEvents.dragHandler);
			}
		}

		public override bool IsPointerOverEventSystemObject(int pointerId)
		{
			var lastPointer = GetLastPointerEventData (pointerId);
			if (lastPointer != null)
				return lastPointer.pointerEnter != null;
			return false;
		}

		protected void ClearSelection()
		{
			var baseEventData = GetBaseEventData ();

			foreach (var pointer in m_PointerData.Values)
			{
				// clear all selection
				HandlePointerExitAndEnter (pointer, null);
			}

			m_PointerData.Clear ();
			eventSystem.SetSelectedGameObject (null, baseEventData);
		}

		public override string ToString()
		{
			var sb = new StringBuilder("<b>Pointer Input Module of type: </b>" + GetType ());
			foreach (var pointer in m_PointerData)
			{
				if (pointer.Value == null)
					continue;
				sb.AppendLine ("<B>Pointer:</b> " + pointer.Key);
				sb.AppendLine (pointer.Value.ToString ());
			}
			return sb.ToString ();
		}
	}
}