Question

I’m implementing a javax.swing.timer to call a synchronous operation on a GUI. However, that operation takes some time to finish and I’d like to provide an abort option to that timer call. Is that possible?

Thx!

import java.awt.EventQueue;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JMenu;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.Timer;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.File;
import java.io.FilenameFilter;
import java.util.Iterator;
import javax.swing.JLabel;
import javax.swing.ImageIcon;
import javax.swing.JTextField;
import org.omg.CosNaming.IstringHelper;


public class vtm extends JPanel implements ActionListener{

    private JFrame frame;
    private String children[];
    private ConsoleApp hawk[];
    public static String data[][];
    public Timer timer;
    private int count1, count2;
    private int i;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    vtm window = new vtm();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     */
    public vtm() {
        timer = new Timer(25000, this);
        //timer.setInitialDelay(190);
        timer.start();
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {

        frame = new JFrame("VTM");
        frame.setSize(1024, 720);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(null);

        JLabel lblNewLabel_1 = new JLabel("");
        lblNewLabel_1.setIcon(new ImageIcon("config.png"));
        lblNewLabel_1.setBounds(970, 0, 51, 55);
        frame.getContentPane().add(lblNewLabel_1);
        lblNewLabel_1.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent arg0) {
                config x = new config();
                x.main(null);
                timer.stop();
                frame.dispose();
            }
            });

        JLabel lblNewLabel = new JLabel("");
        lblNewLabel.setIcon(new ImageIcon("bg.png"));
        lblNewLabel.setBounds(0, 0, 1024, 720);
        frame.getContentPane().add(lblNewLabel);


        String dir = System.getProperty("user.dir");

        File df = new File(dir);

        FilenameFilter fi = new FilenameFilter(){
            public boolean accept(File df, String name){
                return name.startsWith("D-");
            }
        };

        children = df.list(fi);
        hawk=new ConsoleApp[children.length];

        EventQueue.invokeLater(new Runnable(){
            public void run(){

                int count1 = 0; count2 = 0;

                for(i=0;i<children.length;i++)
                {


                hawk[i]=new ConsoleApp(children[i]);

                Iterator<String> it = hawk[i].p.iterator();

                System.out.println("Hi:"+hawk[i].p.size());

                while(it.hasNext())
                {
                    hawk[i].call(it.next());

                    if(count1 == 3)
                    {
                        count2++;
                        count1=0;
                    }

                    System.out.println("Look: " + hawk[i].l.getText().length());
                    hawk[i].l.setBounds((60 + 270*count1) + ((260-(hawk[i].l.getText().length()*7))/2), (70+(count2*60)), 260, 62);
                    hawk[i].c.setBounds(50 + 270*count1, (70+(count2*60)), 273, 62);
                    frame.getContentPane().add(hawk[i].c,0);
                    frame.getContentPane().add(hawk[i].l,0);

                    count1++;
                }
            }
            }
        });
    }

    public void actionPerformed(ActionEvent arg0) {
        // TODO Auto-generated method stub
        System.out.println("lol");

        EventQueue.invokeLater(new Runnable(){
                public void run(){

                    int count1 = 0; count2 = 0;

                    for(i=0;i<children.length;i++)
                    {


                    hawk[i]=new ConsoleApp(children[i]);

                    Iterator<String> it = hawk[i].p.iterator();

                    System.out.println("Hi:"+hawk[i].p.size());

                    while(it.hasNext())
                    {
                        hawk[i].call(it.next());

                        if(count1 == 3)
                        {
                            count2++;
                            count1=0;
                        }

                        hawk[i].l.setBounds((60 + 270*count1) + ((260-(hawk[i].l.getText().length()*7))/2), (70+(count2*60)), 260, 62);
                        hawk[i].c.setBounds(50 + 270*count1, (70+(count2*60)), 273, 62);
                        frame.getContentPane().add(hawk[i].c,0);
                        frame.getContentPane().add(hawk[i].l,0);

                        count1++;
                    }
                }
                }
            });


    }


}

Answer 1

You actionPerformed triggers a Runnable, which I assume is what takes a long time and what you would like to abort. Inside the Runnable’s run method you have two loops, for(i=0;i<children.length;i++) and while(it.hasNext()). If you add a stopping condition to these loops, you can make the Runnable finish early by controlling that condition from outside.

For example, add a field abort to vtm and change the two loops to for(i=0;i<children.length && !abort;i++) and while(it.hasNext() && !abort) respectively. You can now set abort to true and the Runnable will stop the next time it tries to loop again.