CODEWITHSUNDEEP
javaswingtimer
RegularMoments
RegularMoments

Reputation: 9

Swing Timer only works once

For a few days now I have been working on a Timer program in Java. How it works is, you open the program and the JLabel counts up. For some reason it doesn't repeat itself and only works once.

Here's my code.

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.SwingConstants;
import java.awt.Font;

public class TimerC extends JFrame implements ActionListener{

Timer t = new Timer(5, this);
public int intClicked;
public String stringClicked;
public JLabel clicked;
public TimerC() {
    t.start();
    JPanel p1 = new JPanel();
    getContentPane().add(p1);
    p1.setLayout(null);

    JLabel clicked = new JLabel();
    clicked.setFont(new Font("Tahoma", Font.PLAIN, 64));
    clicked.setHorizontalAlignment(SwingConstants.CENTER);
    clicked.setText("0");

    int intClicked = 1;
    String stringClicked = String.valueOf(intClicked);

    clicked.setText(stringClicked);

p1.add(clicked);

clicked.setSize(42, 100);
clicked.setLocation(191, 97);
     }

@Override
public void actionPerformed(ActionEvent e) {
}
}

Upvotes: 0

Views: 214

Answers (3)

James Jithin
James Jithin

Reputation: 10565

For each second update, you would need Timer t = new Timer(1000, this); and use the actionPeformed as below:

public void actionPerformed(ActionEvent e) {
        System.out.println(e);
        clicked.setText(String.valueOf(intClicked++));
}

Upvotes: 0

Johnny Willer
Johnny Willer

Reputation: 3917

that line inside TimerC(), JLabel clicked = new JLabel(); remove JLabel infront clicked, because you have already declared clicked outside, and with this way your are declaring again as a local variable. Read about variable scope.

I don't know if you have noticed, but the size of the font that you use is big, and your JLabel size is not big enough, try change it's size:

clicked.setSize(200, 100);

Define some behavior to actionPerformed

   @Override
    public void actionPerformed(ActionEvent e) {
        clicked.setText(intClicked++ + " ");
       // this.repaint(); it's not necessary
    }

Upvotes: 1

deepak marathe
deepak marathe

Reputation: 408

As a good programming practice, it is always recommended to pass the self reference this to other objects, only after the construction of the object is complete, in the code flow. In the code example, 

    public class TimerC extends JFrame implements ActionListener{

        Timer t = null;
        public JLabel clicked;

        public TimerC() {
            ...
            clicked = new JLabel();
            ...
            intClicked = 1;
            ...
            clicked.setSize(42, 100);
            clicked.setLocation(191, 97);

            t = new Timer(5, this);
            t.start();
        }

         @Override
         public void actionPerformed(ActionEvent e) {
             intClicked = intClicked + 1;
             clicked.setText(String.valueOf(intClicked));
             clicked.repaint();
         }
    }

Upvotes: 1

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