JTextArea scroll to bottom only if text is appended

Question

I am trying to create a JTextArea which scrolls to bottom every time a text is appended to that text area. Otherwise, the user should be able to scroll top and see

Answer 1

Check out Smart Scrolling.

If the scrollbar is at the bottom, then as text is appended you will see the new text.

If the user has scrolled to a different position, then the viewport will stay there until the user scrolls back to the bottom.