SwingWorker, done() method not called

java, multithreading, swing, swingworker

Solution

All swing events are run inside the Event Dispatch Thread. So the `ChangeListener` that you have added to the `mainTabs` runs in the Event Dispatch Thread.

In the event listener you instantiate the `GuiWorker` and in that constructor you open the dialog by calling `dialog.setVisible(true);`.

Your JDialog instance is `modal` and calling `setVislbe(true)` on a modal dialog will block the calling thread, in your case the Event Dispatch Thread. So until the dialog is closed, the `gw.execute();` is not called. That is why your `done` method is not called until you close the dialog.

For your code to work, you can try not calling `setVisible(true)` in the constructor but provide a method from the `GuiWorker` to set the dialog's visibility. Then after calling `gw.execute();` call `gw.setVisible(true)`.

To clarify, try

class GuiWorker extends SwingWorker<Integer, Integer> {
    private JFrame frame = new JFrame();
    private JDialog dialog = new JDialog(frame, "Loadin data", true);
    private JProgressBar progressBar = new JProgressBar();

    private Statistics st = new Statistics();

    public GuiWorker(GraphEditor editor, Statistics st) {
        this.st = st;

        Window mainWindow = SwingUtilities.windowForComponent(editor
                .getGraphComponent().getParent());
        dialog.setSize(400, 200);

        int x = mainWindow.getX() + (mainWindow.getWidth() - dialog.getWidth())
                / 2;
        int y = mainWindow.getY()
                + (mainWindow.getHeight() - dialog.getHeight()) / 2;
        progressBar.setString("Have fun to wait some time...");
        progressBar.setStringPainted(true);
        progressBar.setIndeterminate(true);
        dialog.add(progressBar);
        dialog.setModal(true);
        dialog.setLocation(x, y);
    }

    @Override
    protected Integer doInBackground() throws Exception {
        st.loadInitialData();
        return 0;
    }

    @Override
    protected void done() {
        dialog.setVisible(false);
        JLabel label = new JLabel("Task Complete");
        dialog.getContentPane().remove(progressBar);
        dialog.getContentPane().add(label);
        dialog.getContentPane().validate();
        dialog.setVisible(false);
    }

   public void setVisible(boolean visible) {
        dialog.setVisible(visible);
   }
}

and

mainTabs.addChangeListener(new ChangeListener() {
                @Override
                public void stateChanged(ChangeEvent e) {
                    switch (mainTabs.getSelectedIndex()) {
                    case 0:
                    case 1:
                    case 2: // stats tab
                        GuiWorker gw = new GuiWorker(editor,st);
                        gw.execute();
                        gw.setVisible(true);
                        break;
                    default:
                        break;
                    }
                }
            });

Problem

Original source