Pausing Swing GUI

Question

Hy! So I'm starting with netbeans java gui development and I have run into this problem:

I have made a window with a button and a text field. When the user clicks the button I want the text field to start typing itself with a delay. So for example:

textfield.text=h
wait(1) sec
textfield.text=he
wait(1) sec
textfield.text=hel
wait(1) sec
textfield.text=hell
wait(1) sec
textfield.text=hello

I have already tried with Thread.sleep(), but in the example above it waits 4 seconds or so and after that displays the whole text (so it's not giving me the typo effect that I would want).

Can somebody help me with this?

Answer 1

If you use Thread.sleep(...) or any other code that delays the Swing event thread, you'll end up putting the entire Swing event thread to sleep, and with it your application. The key here is to instead use a Swing Timer. In the Timer's ActionListener's actionPerformed method, add a letter and increment your index, and then use that index to decide what letter to next add.

i.e.,

String helloString = "hello";

// in the Timer's ActionListener's actionPerformed method:
if (index >= helloString.length()) {
  // stop the Timer here
} else {
  String currentText = textField.getText();
  currentText += helloString.charAt(index);
  textField.setText(currentText);
  index++;
}

Answer 2

Got it working by using something like this:

Timer a,b,c

Timer c=new Timer(500, new ActionListener(){public void actionPerformed(ActionEvent e){textfield.setText(abc)}})

Timer b=new Timer(500, new ActionListener(){public void actionPerformed(ActionEvent e){textfield.setText(ab);c.start()}})

Timer a=new Timer(500, new ActionListener(){public void actionPerformed(ActionEvent e){textfield.setText(a);b.start()}})

a.setRepeats(false);
b.setRepeats(false);
c.setRepeats(false);

a.start()

Does anybody know a more simple method with the same effect maybe?