JScrollPane Auto Scrolling for Teleprompter

Question

I am working on a piece of software to scroll text for a teleprompter. I have a class that scrolls the text that is in a JEditorPane nested in a JScrollPane. Here is the class that scrolls the text:
package teleprompter;
import javax.swing.JScrollPane;
public class Scroll extends Thread
    JScrollPane scrlMain;
    public Scroll(JScrollPane scrlMain)
        this.scrlMain = scrlMain;
    public void run()
        int iPos = scrlMain.getVerticalScrollBar().getValue();
        for (;;)
            iPos += 5;
            scrlMain.getVerticalScrollBar().setValue(iPos);
}My problem is that it is not a consistent, smooth scroll so that someone can read it. It is real jumpy, sometimes it will jump an entire page. For now, the speed of the scroll can be changed by making the 5 in "iPos += 5" a higher number.
Is there a better way to do an auto scroll that is not so inconsistent and jumpy that anyone can think of?
Edited by: 879705 on Aug 18, 2011 1:40 PM

Answer 1

879705 wrote:
I am working on a piece of software to scroll text for a teleprompter. I have a class that scrolls the text that is in a JEditorPane nested in a JScrollPane.One possibility occurred to me, although I'm no GUI expert and it maybe totally the wrong approach.
One of the characteristics of a teleprompter (at least in most Western languages) is that new text is always likely to appear at the bottom so, rather than worrying about scrolling, why not either:
(a) Set the scroll value to 100% and add new lines to the end as and when required, or
(b) Maintain the text array yourself and simply display it in a fixed area.
It seems to me that the same technique could also be combined with text animation to display a line at a time.
However, as I say, I'm no GUI expert, so feel free to laugh...
Winston