[BUG] AtomBaseReferenceDrawer fails if the reference is in a List

Describe the bug

When stored in a list, the reference drawer will exhibit strange behavior.

1. clicking on the kebab menu will open the menu normally, but on selection a drag-event will have been started on the list item. This drag event does not stop until a different object is selected in the inspector

1. sometimes (probably due to the same effect) one of the references in the list becomes invisible

1. sometimes while the object reference field is visible, clicking on it has no effect

All these problems last until a different object is selected. Folding the list field does not resolve it. Folding the behaviour inspector doesn’t either.

To Reproduce Steps to reproduce the behavior:

1. create a script with [SerializeField] List<FloatReference> inputs;
2. Open the script inspector in unity
3. Add a new list item
4. Click ⁝
5. Move mouse

Expected behavior Clicking on the kebab menu should just work

Environment

• OS: Windows
• Unity Version: 2022.2.4f1
• Version of Unity Atoms: 4.4.5

[lgarczyn]

This appears to be due to a hotControl issue.

It appears that using the custom styles on the kebab menu breaks the Popup event handling system.

Unity Atoms should try to set a hotControl id when opening the popup, or use a different type of menu, such as a context menu maybe.

You can detect clicks by hand using this type of calls

      // Don't capture event if array drag/drop is active
      if (GUIUtility.hotControl != 0) return;
      if (Event.current.type == EventType.MouseDown
          && Event.current.button == 0
          && GUILayoutUtility.GetLastRect().Contains(Event.current.mousePosition))
      {
        DrawModifierContextMenu(modifier);
        Event.current.Use();
      }

[lgarczyn]

Confirmed fixed on 2022.2.21