GUI Text disappearing and Coroutines

Questions & Answers
1

I’m new to java scripting and game design in general, so I can’t seem to figure out the issue with this script I wrote.

var clicked = false;
var time = true;
var seconds = 5;

function Start () 
{
    clicked = false;
    time = true;
    if (gameObject.GetComponent(Collider) == null)
    {
       gameObject.AddComponent(typeof(BoxCollider));
    }
}
 
function OnMouseDown()
{
    clicked = true;
}
 
function OnMouseUp()
{
    time = false; 
}
 
function Update() 
{
    if (clicked == true)
    {
       GUI.Label(new Rect(350,250,400,100), "Door seems to be blocked..");
    }

{
    if (time == false) 
    {
    	yield WaitForSeconds(seconds);
    	clicked = false;
    	}
	}
}

I can run the game, and it says that the variable “time” is true when the game loads and then false when the game object I put the script on is clicked. Likewise, the “isClicked” variable is checked in the inspector when the gameobject is clicked, but there is no countdown of the 5 seconds. I’m also getting an error about Update() cannot be used as a Coroutine. I looked on the unity wiki and saw that functions run over a period of a single frame while Coroutines kind of spread the time out, which makes sense because I’m using a script that takes place over a period of time. But I can’t figure out how to use a Coroutine. Any help would be appreciated.

2

You have two major problems here. First, you cannot use ‘yield’ inside of Update(). Second, GUI functions like GUI.Label() must be executed inside of the OnGUI callback function. I had a guess a bit about what you want to happen with this code, but I think you want:

#pragma strict

var clicked = false;
var seconds = 5;

function Start ()  {
    clicked = false;
    
    if (gameObject.GetComponent(Collider) == null) {
       gameObject.AddComponent(typeof(BoxCollider));
    }
}

function OnMouseDown() {
    clicked = true;
}

function OnMouseUp() {
    yield WaitForSeconds(seconds);
    clicked = false;
}

function OnGUI() {
	if (clicked) {
		GUI.Label(new Rect(350,250,400,100), "Door seems to be blocked..");
	}
}