Source Code for UnityEngine.Events?

I want to create my own type of UnityEvent. So I downloaded Unity's UI source code so I could read through and understand how it worked. I wasn't able to find it. I could find references to it like using UnityEngine.Events; but not the source code itself. I found the code for UnityEngine.EventSystems but no UnityEngine.Events. Did I download the wrong repository? Is the UnityEngine.Events source code in a different repository?

 

When you say you want to create your own kind of UnityEvent, do you mean define an event with custom parameters that show up in the inspector? In that case I would suggest to look at the documentation. There is an example on how to use it.

Otherwise take a look at the FAQ; it has tthe following to say about licencing of source code. So I don't think you can download the source code somewhere easily, or it will most likely be illegal.

 

http://docs.unity3d.com/Manual/MessagingSystem.html

There's the documentation for creating a custom event to use with the UI event system.