Sending custom event from child to parent

Unity Engine
1

First of all, it that possible to create custom event and use it in Register/Unregister callback?
And second question, how to send event from child visual element to parent visual element?

What I am trying to create - some generic editor window that accepts content VisualElement as a content and add it to Window.rootVisualElement. I want my button located in VisualElement send some CloseEditorWindowEvent and add callback for this event to Window.rootVisualElement in order to intercept it and close actual editor window. I want to do this in order to encapsulate content from knowing anything about where its located.

Thanks in advance.

2

I was not able to route my custom message until this reflection magic added.

    public class CloseWindowEvent : EventBase<CloseWindowEvent>
    {
        public CloseWindowEvent()
        {

        }

        protected override void Init()
        {
            base.Init();
            PropertyInfo propagation = typeof(EventBase).GetProperty("propagation", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public);
            propagation.GetSetMethod(true).Invoke(this, new object[] { 1 | 2 | 4 });
        }
    }

Internal unity code checks for propagation flag(which is 0 by default) and do nothing in case of 0. Not sure how to set it without reflection, since property is internal. Maybe Unity guys can help with this.

1 Like
3

Also, another solution without reflection:

                            var closeWindowEvent = ChangeEvent<WhateverUniqueType>.GetPooled();
                            closeWindowEvent.target = item;
                           
                            item.SendEvent(closeWindowEvent);

Ensure to replace WhateverUniqueType to something unique to your event type. Use ChangeEvent in callbacks.

2 Likes
4

The EventBase class has the tricklesDown and bubbles protected properties that are accessible proxies to the propatagion internal property.

5

But how to set them without reflection? None of that properties has setters, that is why I used reflection.

6

Oh you’re right, the setters were introduced in 2020.2. If you’re on 2020.1 you can install the com.unity.ui package, otherwise I guess you’re stuck with reflection.

1 Like
7

Ha, I am on 2019.4. Anyway, thanks for replies, thats make sense now.