java - Clarification on modifying a Document's contents from a DocumentListener

Question

From the Swing tutorial on text components:

You may want to change the document's text within a document listener. However, you should never modify the contents of a text component from within a document listener. If you do, the program will likely deadlock. Instead, you can use a formatted text field or provide a document filter.

I am confused. So what is the correct way to change the text eg. as a result of a KeyEvent ?

Answer 1

1) using DocumentListener for

• output from JTextComponent to the GUI

• HightLighter or Styled text

2) DocumentFilter for filtering of

• unwanted chars,

• chars sequence(s),

these filtered chars could be

• replaced with another char (or with defined chars sequence)

• removed (never will be displayed in the JTextComponent)

3) similair funcionality to provide JFormattedTextFieldis possible to input to the JTextComponent only chars 0 - 9, decimal separator, negative sing,

4) So what is the correct way to change the text eg. as a result of a KeyEvent ?

use DocumentFilter