Java SwingUtilities.invokeLater

Question

.addActionListener(new ActionListener(){
        public void actionPerformed (ActionEvent e){
            try{
                ta.append("Searching Initiated at: "+datetime()+"\n");
                gui.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
                task.execute();
                javax.swing.SwingUtilities.invokeLater(new Runnable() {
                    public void run() {
                        gui.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
                    }
                });
                //Enable the next stage in the YD process and disable the previously executed functions
                clusAn.setEnabled(true);
                open.setEnabled(false);
                statCl.setEnabled(false);
            }catch (Exception IOE){
                }
        }
    });

Hi there, having a bit of a pain with the last stage of this application I've designed.

Basically, when the user clicks the button, I'd like it so the cursor becomes a 'waiting' version and then once the background process (task.execute) has completed, the cursor returns to normal.

The task.execute isn't in the same class so I can't just do a straight call of the "gui.setCursor" because it doesn't recognise GUI as the variable.

Not sure what to do so any advice would be great

Thanks :D

Answer 1

Modify the task's class so that it takes your GUI as a constructor argument. This way, when the task is completed, it can invoke the setCursor method.

You should use a SwingWorker for this kind of thing.

EDIT :

Here's how the code of the task should be :

public class MySwingWorker extends SwingWorker<Void, Void> {

    /**
     * The frame which must have the default cursor set 
     * at the end of the background task
     */
    private JFrame gui;

    public MySwingWorker(JFrame gui) {
        this.gui = gui;
    }

    // ...

    @Override
    protected void done() {
        // the done method is called in the EDT. 
        // No need for SwingUtilities.invokeLater here
        gui.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
    }
}