Add OnBeforeClose Event

[hendrik244]

Would be great to also have events like:

• OnBeforeOpen
• OnAfterOpen
• OnBeforeClose
• OnAfterClose

In my case I'm assigning the selectable not until the list is opening. By using the "onOpen" Event I always have a small delay between the point of time of the opening of it and the point of time of the item(s), which need to get selected.