Hi , can anyone help or at least give me an idea of how this swipe event in grid works …
Thanks in advance here the screenshot of the event that I was talking about 
Here you go . Its using swiping with mouse and sweep test & also iTween. iTween script is attached. Place it in your Standard Assets and you are good to go.[57178-itweencs.zip|57178]
using UnityEngine;
using UnityEngine.UI;
using System.Collections;
public class Grid : MonoBehaviour
{
Vector2 firstPressPos;
Vector2 secondPressPos;
Vector2 currentSwipe;
GameObject selected_Object;
Vector3 pos1;
Vector3 pos2;
GameObject item1;
GameObject item2;
GameObject yup;
GameObject ydown;
GameObject xleft;
GameObject xright;
private bool touchdetection ;
void Update()
{
Swipe ();
}
void SwapTwoItems(GameObject a, GameObject b)
{
if(a!=null && b!= null )
{
touchdetection = true;
iTween.Defaults.easeType = iTween.EaseType.easeOutBack;
iTween.MoveTo(a, pos2, 0.2f);
iTween.MoveTo(b, pos1, 0.2f);
}
else
{
xleft = null;
yup = null;
ydown = null;
xright = null;
item1 = null;
item2 = null;
pos1 = Vector3.zero;
pos2 = Vector3.zero;
selected_Object = null;
touchdetection = false;
skip_Swiping = false;
}
}
public void Swipe()
{
if (Input.GetMouseButtonDown (0) && !touchdetection )
{
RaycastHit hitInfo = new RaycastHit();
bool hit = Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), out hitInfo);
if (hit)
{
print("selected object"+hitInfo.transform.gameObject);
selected_Object = hitInfo.transform.gameObject;
item1 = selected_Object;
}
else
{
print ("No selected object");
}
firstPressPos = new Vector2(Input.mousePosition.x,Input.mousePosition.y);
}
if(Input.GetMouseButtonUp(0)&& !touchdetection)
{
//save ended touch 2d point
if(selected_Object!= null)
{
secondPressPos = new Vector2(Input.mousePosition.x,Input.mousePosition.y);
//create vector from the two points
currentSwipe = new Vector2(secondPressPos.x - firstPressPos.x, secondPressPos.y - firstPressPos.y);
//normalize the 2d vector
currentSwipe.Normalize();
//swipe upwards
if(currentSwipe.y > 0 && currentSwipe.x > -0.5f && currentSwipe.x < 0.5f)
{
Debug.Log("up swipe");
RaycastHit hit1;
if (selected_Object.GetComponent<Rigidbody>().SweepTest(transform.up, out hit1, 2)) {
yup = hit1.collider.gameObject;
}
if(yup!= null)
{
item2 =yup;
pos1 = selected_Object.transform.position;
pos2 = item2.transform.position;
SwapTwoItems( item1, item2);
}
}
//swipe down
if(currentSwipe.y < 0 && currentSwipe.x > -0.5f && currentSwipe.x < 0.5f)
{
Debug.Log("down swipe");
RaycastHit hit2;
if (selected_Object.GetComponent<Rigidbody>().SweepTest(-transform.up, out hit2, 2)) {
ydown = hit2.collider.gameObject;
}
if(ydown!= null)
{
item2 = ydown;
pos1 = selected_Object.transform.position;
pos2 = item2.transform.position;
SwapTwoItems( item1, item2);
}
}
//swipe left
else if(currentSwipe.x < 0 && currentSwipe.y > -0.5f && currentSwipe.y < 0.5f)
{
Debug.Log("left swipe");
RaycastHit hit3;
if (selected_Object.GetComponent<Rigidbody>().SweepTest(-transform.right, out hit3, 2)) {
xleft = hit3.collider.gameObject;
}
if(xleft!= null)
{
item2 = xleft;
pos1 = selected_Object.transform.position;
pos2 = item2.transform.position;
SwapTwoItems( item1, item2);
}
}
//swipe right
else if(currentSwipe.x > 0 && currentSwipe.y > -0.5f && currentSwipe.y < 0.5f)
{
RaycastHit hit4;
if (selected_Object.GetComponent<Rigidbody>().SweepTest(transform.right, out hit4, 2)) {
xright = hit4.collider.gameObject;
}
if(xright!= null)
{
Debug.Log("right swipe");
item2 = xright;
pos1 = selected_Object.transform.position;
pos2 = item2.transform.position;
SwapTwoItems( item1, item2);
}
}
}
}
}
Its a very simple code for swiping with mouse . If any problem do ask me 
Hi,
Try using sweep test. Link shared below: