It was the conclusion I was coming to

You could also fire a rename event from my string converter

that it must be inside my Cell class

@carlw Can you easily handle a rename failure that way?

I'd expected to wrap the rename function in a try/catch. If it exists already or an exception is thrown, just leave alone and return the value in the tree back to last value

The failure has to be captured in a runasync failed wherever it lives

I'd then want to fire an event for a popup

Task is a try catch

Never do I/O on the fx thread with just a try catch

Ah I see what you are saying. Yes, to keep it off the main thread

I probably should have stuck to Swing for my current client

so much more to catch up on

@carlw - I agree with runAsync but don't understand how an event for the rename would propogate the failure back to the event producer (ie, the TreeCell).

It wouldn’t . You’d delegate the operation and the errror handling elsewhere

It would be optimistic in that way

@sp33dy - you shouldn't need to return the value back to the last value if the rename fails - you should just be able to cancel the edit (which results in the same behaviour)

..but I couldnt' find a cancel method?

I know that's a dumb statement. I had a hunt around and couldn't see how to trigger the cancel

remember I'm very new to Kotlin/JFX. Coming in from Java/Swing

...Ah, cancelEdit "inside" the cell class

I've been trying to do it from the onEditCommit method of the Tree itself

so I am working in the wrong object

Thanks @carlw and @gtnarg this is exactly what I wanted to know. I've stuffed all the File handling alongside the ViewTree. However, the renaming event needs to move into the TreeCell class that I've extended. Instead of that being a String, I should use my own class (i.e. like FSItem in Carl's example)

Gotcha

You could even use an actual File object. FSItem was for a demo

Yep, I can now see File would work

too

this is the missing link in my knowledge that I had to have the pain in

A more idiomatic tfx way to do this would be with a TreeCellFragment (I think) - but I would recommend continuing on your current path because I think you are close to what you want... If you post your code again once it's working I will try to convert it for you.

So, I've already been using Fragments