1

How can you call a function from a script when a button is moused over?

I tried OnMouseEnter/Exit, even WITH a collider attached to the button. I also dont see any way to make it work like on CLICK does in the inspector, although that would be very convenient!

2

Method:

  1. Add an Event Trigger component to your button game object.
  2. Click on Add New button and select PointerEnter.
  3. Now click on ‘+’ button to add a new item to the list of event of type PointerEnter(BaseEventData).
  4. Select the object containing your script.
  5. Now select the function to be called from the list of functions.
4

var EventSystem : UnityEngine.EventSystems.EventSystem;

function Start () {
	EventSystem = GameObject.Find("EventSystem").GetComponent(UnityEngine.EventSystems.EventSystem);
}

function MyClickFunction () {
	if (EventSystem.IsPointerOverGameObject())
		return;
	else
		DoAnythingInTheWorld();
}
3

Here is my solution. I fire a ray throught the UI and see what it hits. If it is
a button etc. then I am in “Entering Text” mode which also covers hovering over a buttone and such. I also check the EventSystem.current.currentSelectedGameObject in case they are entering text in a field and have moved the mouse out of the field.

I also have a canvas called BackgroundEventCatcher which catches button click that get through the UI. I also have a class for showing notifications on the bottom edge of the screen.

So here it is, (Unity3d 4.6 rev 20) …

        PointerEventData pe = new PointerEventData(EventSystem.current);
		pe.position =  Input.mousePosition;
	
		List<RaycastResult> hits = new List<RaycastResult>();
		EventSystem.current.RaycastAll( pe, hits );

		bool hit = false;
		GameObject hgo = null;
		string gos = "gos: ";
		foreach(RaycastResult h in hits)
		{
			GameObject g = h.go;
			gos += g + "  ";
			hit = ( g.name != "BackgroundEventCatcher" &&
			        (g.GetComponent<Button>() ||
			         g.GetComponent<Canvas>() ||
			         g.GetComponent<InputField>())
			       );
			if(hit)
			{
				break;
			}
		}

		if( hit ||
		    EventSystem.current.currentSelectedGameObject != null &&
		    EventSystem.current.currentSelectedGameObject.name != "BackgroundEventCatcher" &&
		   (EventSystem.current.currentSelectedGameObject.GetComponent<Button>() != null ||
		    EventSystem.current.currentSelectedGameObject.GetComponent<Canvas>() != null ||
		    EventSystem.current.currentSelectedGameObject.GetComponent<InputField>() != null) )
		{
			keyMode = eKeyInputMode.EnteringText;
		}
		else
		{
			keyMode = eKeyInputMode.KeysAreCommands;
		}

		Notifications.ShowNotification("hit : " + hit + " of " + hits.Count + " :  " + keyMode + " :  gos " + gos);