csharp TouchInputModule（b19）

Posted 2021-05-12

using System.Text;

namespace UnityEngine.EventSystems
{
	[AddComponentMenu("Event/Touch Input Module")]
	public class TouchInputModule : PointerInputModule
	{
		protected TouchInputModule()
		{}

		private Vector2 m_LastMousePosition;
		private Vector2 m_MousePosition;
		
		[SerializeField]
		private bool m_AllowActivationOnStandalone;

		public bool allowActivationOnStandalone
		{
			get { return m_AllowActivationOnStandalone; }
			set { m_AllowActivationOnStandalone = value; }
		}

		public override void UpdateModule()
		{
			m_LastMousePosition = m_MousePosition;
			m_MousePosition = Input.mousePosition;
		}

		public override bool IsModuleSupported()
		{
			return m_AllowActivationOnStandalone || Application.isMobilePlatform;
		}

		public override bool ShouldActivateModule()
		{
			if (!base.ShouldActivateModule ())
				return false;

			if (UseFakeInput ())
			{
				bool wantsEnable = Input.GetMouseButtonDown (0);

				wantsEnable |= (m_MousePosition - m_LastMousePosition).sqrMagnitude > 0.0f;
				return wantsEnable;
			}

			for (int i = 0; i < Input.touchCount; ++i)
			{
				Touch input = Input.GetTouch (i);

				if (input.phase == TouchPhase.Began 
					|| input.phase == TouchPhase.Moved
					|| input.phase == TouchPhase.Stationary)
					return true;
			}
			return false;
		}

		private bool UseFakeInput()
		{
			return !Application.isMobilePlatform;
		}

		public override void Process()
		{
			if (UseFakeInput ())
				FakeTouches ();
			else
				ProcessTouchEvents ();
		}

		/// <summary>
		/// For debugging touch-based devices using the mouse.
		/// </summary>
		private void FakeTouches()
		{
			bool pressed = Input.GetMouseButtonDown (0);
			bool released = Input.GetMouseButtonUp (0);

			var pointerData = GetMousePointerEventData ();

			// fake touches... on press clear delta
			if (pressed)
				pointerData.delta = Vector2.zero;

			ProcessTouchPress (pointerData, pressed, released);

			// only process move if we are pressed...
			if (Input.GetMouseButton (0))
				ProcessMove (pointerData);
		}

		/// <summary>
		/// Process all touch events.
		/// </summary>
		private void ProcessTouchEvents()
		{
			for (int i = 0; i < Input.touchCount; ++i)
			{
				Touch input = Input.GetTouch (i);

				bool released;
				bool pressed;
				var pointer = GetTouchPointerEventData (input, out pressed, out released);

				ProcessTouchPress (pointer, pressed, released);
							
				if (!released)
					ProcessMove (pointer);
				else
					RemovePointerData (pointer);
			}
		}

		private void ProcessTouchPress(PointerEventData pointerEvent, bool pressed, bool released)
		{
			var currentOverGo = pointerEvent.pointerCurrentRaycast.go;

			// PointerDown notification
			if (pressed)
			{
				pointerEvent.eligibleForClick = true;
				pointerEvent.delta = Vector2.zero;
				pointerEvent.pressPosition = pointerEvent.position;
				pointerEvent.pointerPressRaycast = pointerEvent.pointerCurrentRaycast;

				if (pointerEvent.pointerEnter != currentOverGo)
				{
					// send a pointer enter to the touched element if it isn't the one to select...
					HandlePointerExitAndEnter (pointerEvent, currentOverGo);
					pointerEvent.pointerEnter = currentOverGo;
				}

				// search for the control that will receive the press
				// if we can't find a press handler set the press 
				// handler to be what would receive a click.
				var newPressed = ExecuteEvents.ExecuteHierarchy (currentOverGo, pointerEvent, ExecuteEvents.pointerDownHandler);

				// didnt find a press handler... search for a click handler
				if (newPressed == null)
					newPressed = ExecuteEvents.GetEventHandler<IPointerClickHandler> (currentOverGo);

				//Debug.Log("Pressed: " + newPressed);

				if (newPressed != pointerEvent.pointerPress)
				{
					pointerEvent.pointerPress = newPressed;
					pointerEvent.rawPointerPress = currentOverGo;
					pointerEvent.clickCount = 0;
				}

				// Save the drag handler as well
				pointerEvent.pointerDrag = ExecuteEvents.GetEventHandler<IDragHandler> (currentOverGo);

				if (pointerEvent.pointerDrag != null)
					ExecuteEvents.Execute<IBeginDragHandler> (pointerEvent.pointerDrag, pointerEvent, ExecuteEvents.beginDragHandler);

				//	Debug.Log("Setting Drag Handler to: " + pointer.pointerDrag);

				// Selection tracking
				var selectHandlerGO = ExecuteEvents.GetEventHandler<ISelectHandler> (currentOverGo);
				eventSystem.SetSelectedGameObject (selectHandlerGO, pointerEvent);
			}

			// PointerUp notification
			if (released)
			{
				//Debug.Log("Executing pressup on: " + pointer.pointerPress);
				ExecuteEvents.Execute (pointerEvent.pointerPress, pointerEvent, ExecuteEvents.pointerUpHandler);

				//Debug.Log("KeyCode: " + pointer.eventData.keyCode);

				// see if we mouse up on the same element that we clicked on...
				var pointerUpHandler = ExecuteEvents.GetEventHandler<IPointerClickHandler> (currentOverGo);

				// PointerClick and Drop events
				if (pointerEvent.pointerPress == pointerUpHandler && pointerEvent.eligibleForClick)
				{
					float time = Time.unscaledTime;

					if (time - pointerEvent.clickTime < 0.3f)
						++pointerEvent.clickCount;
					else
						pointerEvent.clickCount = 1;
					pointerEvent.clickTime = time;

					ExecuteEvents.Execute (pointerEvent.pointerPress, pointerEvent, ExecuteEvents.pointerClickHandler);
				}
				else if (pointerEvent.pointerDrag != null)
				{
					ExecuteEvents.ExecuteHierarchy (currentOverGo, pointerEvent, ExecuteEvents.dropHandler);
				}

				pointerEvent.eligibleForClick = false;
				pointerEvent.pointerPress = null;
				pointerEvent.rawPointerPress = null;

				if (pointerEvent.pointerDrag != null)
					ExecuteEvents.Execute (pointerEvent.pointerDrag, pointerEvent, ExecuteEvents.endDragHandler);

				pointerEvent.pointerDrag = null;

				// send exit events as we need to simulate this on touch up on touch device
				ExecuteEvents.ExecuteHierarchy (pointerEvent.pointerEnter, pointerEvent, ExecuteEvents.pointerExitHandler);
				pointerEvent.pointerEnter = null;
			}
		}
		
		public override void DeactivateModule()
		{
			base.DeactivateModule ();
			ClearSelection ();
		}

		public override string ToString()
		{
			var sb = new StringBuilder ();
			sb.AppendLine (UseFakeInput () ? "Input: Faked" : "Input: Touch");
			if (UseFakeInput ())
			{
				var pointerData = GetLastPointerEventData (kMouseId);
				if (pointerData != null)
					sb.AppendLine (pointerData.ToString ());
			}
			else
			{
				foreach (var pointerEventData in m_PointerData)
					sb.AppendLine (pointerEventData.ToString ());
			}
			return sb.ToString ();
		}
	}
}