Add onselect

[iliakap]

No description provided.

[josdejong]

Thanks @iliakap for your PR, I'll look into it after the holidays

[josdejong]

Thanks again for your PR @iliakap .

For reference: this PR will resolve #163.

Two questions:

1. Right now, the onSelect will work for tree and table mode, but not for text mode. I think we need to at least have a clear plan on how to implement support for selection for text mode: either a different method, or via an extra parameter or so. What are your thoughts on that?
2. Besides listening for changes in the selection, we'll also need a way to change the selection, like I describe in Feature-Request: onSelect #163 (comment). What do you think?

[josdejong]

Closing this PR now due to lack of response. Feel free to reopen if needed.

[iliakap]

@josdejong, just saw ur comments, sorry for the late response :)
I wont reopen now since I'll only have time to look at it in a few weeks.
with regards to your questions:

1. having hard time to remember, but I recall the text mode is just free text, I think it can be implemented using the web selection api, but it felt out of scope.
2. I agree it's a nice addition, LMK if you wanna add this to this PR, not sure what the timeline will be though :)

[josdejong]

Thanks for getting back @iliakap, no problem at all. Let's continue the discussion in #163