koobas.hobune.stream
GUI problem: Lack of Events and Listeners.
I have a screen (Empty GameObject) with three buttons (child GameObjects with GUITexture + Script) on my scene. What is an good approach when dealing with buttons? I want to know what button the user clicked without having to add a reference to the Screen in the button class. I am used to Actionscript 3 where you add listeners and dispatch events. Any tips?
- Screen
|- Button1
|- Button2
|- Button3
If you have a button script you can tell which game object it's attached to with the gameObject member variable. To access the parent game object (the screen), use gameObject.transform.parent.gameObject.
You could also look at the use of scripted user interfaces where you implement an OnGUI method and call things like GUI.Button to create your interface.
... and if those suggestions don't help, please share some of your code so we get a clearer idea of what you're trying to do and how.
I'm a little confused because I'm not sure why you want to reference the Screen class, but you can make an event based system.
You have a little bit of choice if you want a global button manager or events fired by individual buttons. Here's an individual button system:
using System;
using UnityEngine;
public class Button : MonoBehaviour {
private GUITexture thisTex;
//Cache a reference to the button.
public event Action onClick;
//Action is a generic delegate in the System namespace.
void Start () {
thisTex = guiTexture;
StartCoroutine( ListenForButton() );
}
//Here's a performance trick. Checking for Input in an infinite coroutine will help performance.
//Update() is called via reflection slowing it down some.
//And we aren't allocating any additional memory in the loop.
private IEnumerator ListenForButton() {
for (;;) {
if(thisTex.HitTest(Input.mousePosition) && Input.GetMouseButtonDown(0) ) {
if(onClick != null)
onClick();
}
yield return null;
}
}
}
Example:
someButtonScript.onClick += buttonListen.SomeMethod();
Now if you want to get fancier, you can write an extension method that gets the event by referencing the guiTexture.
using System;
using UnityEngine;
public static class ExtensionMethods {
public static void AddListener (this GUITexture guiTex, Action listener) {
var buttonScript = guiTex.GetComponent<Button>();
if(buttonScript != null)
buttonScript.onClick += listener;
else
Debug.Log("There is no Button script attached to the Game Object");
}
}
And then you can access it like such:
var guiTex = (GUITexture)FindObjectOfType(GUITexture);
guiTex.AddListener( someScript.Method() );
