CODEWITHSUNDEEP
javaswingtimerdelaytimertask
joey rohan
joey rohan

Reputation: 3566

Issue with TimerTask

Just have a look on this block of code:

public Reminder() {

    a[0]=1000;
    a[1]=3000;
    a[2]=1000;
   a[3]=5000;
    timer = new Timer();

  timer.schedule(new RemindTask(),0,  a[i]);

  }
 //////////////////////
   class RemindTask extends TimerTask  {

    public void run() {

  point =point +arr[i].length();

     doc.setCharacterAttributes(0,point+1, textpane.getStyle("Red"), true);
     i++;

    }
    }

I want delay to be changed after each task,so the timings are stored in an array. When i++ is preformed(pointer to array),the timings are not changed;the subsequent rate of delay is same as the first delay value.Why it dosn't change?

EDIT:

Here's an SSCCE if required:

import java.awt.Color;
import java.lang.reflect.InvocationTargetException;
import java.util.Timer;
import java.util.TimerTask;
import java.awt.Toolkit;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextPane;
import javax.swing.SwingUtilities;
import javax.swing.text.DefaultStyledDocument;
import javax.swing.text.StyleConstants;
import javax.swing.text.StyledDocument;


public class Reminder {
static   JFrame frame;
Toolkit toolkit;
Timer timer;
int point=0;
static   StyledDocument doc;
 static   JTextPane textpane;
 String[] arr={"Tes"," hiiii"," what"," happpn"};
public int i=0;
long[] a=new long[4];
public Reminder() {

    a[0]=1000;
    a[1]=3000;
    a[2]=1000;
   a[3]=5000;
    timer = new Timer();

  timer.schedule(new RemindTask(),0,  a[i]);

 }

 class RemindTask extends TimerTask  {

    public void run() {

  point =point +arr[i].length();

     doc.setCharacterAttributes(0,point+1, textpane.getStyle("Red"), true);
     i++;


    }
  }
 public static void newcompo()
{

    JPanel panel = new JPanel();
    doc = (StyledDocument) new DefaultStyledDocument();
  textpane = new JTextPane(doc);
    textpane.setText("Test hiiii what happpn");
    javax.swing.text.Style style = textpane.addStyle("Red", null);
    StyleConstants.setForeground(style, Color.RED);
           panel.add(textpane);
    frame.add(panel);
    frame.pack();

 }
  public static void main(String args[]) throws InterruptedException,   InvocationTargetException {
      SwingUtilities.invokeAndWait(new Runnable() {

        public void run() {
            frame = new JFrame();
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            frame.setVisible(true);

           newcompo();
        }
    });



 Reminder aa=  new Reminder();

  }
 }

Upvotes: 0

Views: 552

Answers (4)

Reimeus
Reimeus

Reputation: 159784

When using Swing, better to use javax.swing.Timer over javax.util.Timer. That will give you the setDelay method:

timer = new Timer(0, new ActionListener() {

    @Override
    public void actionPerformed(ActionEvent e) {
        if (i > a.length) { // check when to stop
            timer.stop();
            return;
        }

        point = point + arr[i].length();
        doc.setCharacterAttributes(0, point + 1, textpane.getStyle("Red"), true);
        i++;

        // Change delay period
        timer.setDelay(a[i]);
    }
});
timer.setDelay(a[0]);
timer.start();

This will required you to change the type of your delay array a, from

long[] a = new long[4];

to this:

int[] a = new int[4];

Upvotes: 4

SylvainL
SylvainL

Reputation: 3938

Into your run(), you need to cancel the old timer and re-run a new one, something like (untested):

public void run() {
   ...
timer.cancel(); // Terminate the timer thread.
timer = new Timer();
timer.schedule(new RemindTask(), 0, a[i]);
}

And of course, it's probably better to specify the initial delay instead:

timer.schedule(new RemindTask(), a[i]);

Upvotes: 0

SylvainL
SylvainL

Reputation: 3938

A second method would be to schedule your run() every second but return without doing nothing when it's not the time to perform the next action.

Upvotes: 0

SylvainL
SylvainL

Reputation: 3938

Try with declaring the variable i as volatile.

Upvotes: 0

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