How to get ScrollPane vertical positions?

I have a TextArea and a ScrollPane:

private final StyleClassedTextArea textArea = new StyleClassedTextArea();
private final VirtualizedScrollPane scrollPane = new VirtualizedScrollPane(textArea);

And I need to know when my vertical bar is at the highest and the lowest positions. By other words when vertical scroll bar is on top or bottom. Something like this:

if (scrollPane.getVerticalBar().getPosition() == 0) { //0 -> top, 1 -> bottom
...
}

I’ve found several issues related to this problem but still have no solution. Could anyone say how to do it?

[PavelTurkish]

@Jugen Yes, thank you. This is the way I went.

[Jugen]

So maybe try either (totalEstimatedHeight - viewPortHeight - 2) or fractionalPos >= 0.9999 ?