Question How to identify which element was clicked?

I am trying to create a dynamic list of options for runtime menu, but have trouble identifying which of the options was clicked ...

First I instantiate multiple items and .Add(item) them to some parent VisualElement ...
then I customize the items (for example change label/icon) ...
then I register a ClickEvent callback method to each of those items ...

when I receive the callback, how do I know which one was clicked? Is there some special identifier? I tried googling and reading the manual but couldn't find a straightforward way.

I managed to make it work by storing a dictionary of item.GetHashCode and a custom string identifier, and looking up the identifier in callback via clickEvent.target.GetHashCode ... but I'm sure I'm missing something and there are actually elegant ways of doing this?

Thanks for any info!

 

Heya, I think you're basically on the money here, I use dictionaries and event.currentTarget

Code (CSharp):

1.        
2.  
3. private readonly Dictionary<VisualElement, Object> itemClickLink =
4.     new Dictionary<VisualElement, Object>();
5. //Populate items somehow
6.  
7.  private void OnItemClicked(ClickEvent evt)
8.         {
9.             if (!(evt.currentTarget is VisualElement ve)
10.                 || !itemClickLink.TryGetValue(ve, out var obj))
11.                 return;
12.  
13.             if (evt.clickCount == 1) onItemSelected?.Invoke(obj);
14.         }
15.  

 

if you use one callback action for all elements - try this:

Code (CSharp):

1. private void Start()
2.         {
3.             VisualElement element = new VisualElement();
4.  
5.             element.RegisterCallback<ClickEvent>(ev => CallbackMethod(element));
6.         }
7.  
8.         private void CallbackMethod(VisualElement elem)
9.         {
10.             //do stuff
11.         }

 

Great! This allows me to use VisualElement.userData! I set the data when creating the element, then read it when the element is passed via callback.

Also, can anything be done with the closure allocations? Rider suggests that "Closure can be eliminated: Method has overload to avoid closure creation" for RegisterCallback method, but I am unable to find or utilize it.

 

May be ev argument have link to target.