package org.trinet.util.graphics.task;
import javax.swing.*;
import javax.swing.SwingUtilities;

class Example2 extends Example1 {

    Example2() {
        super("Example 2");
    }

    /**
     * Popup a modal confirm dialog and block until the user responds.
     * Return true unless the user selects "NO".
     */
    boolean waitForUserConfirmation() throws InterruptedException {

        /* We're going to show the modal dialog on the event dispatching
         * thread with SwingUtilities.invokeLater(), so we create a 
         * Runnable class that shows the dialog and stores the user's
         * response.
         */
        class DoShowDialog implements Runnable {
            boolean proceedConfirmed;
            public void run() {
                Object[] options = {"Continue", "Cancel"};
                int n = JOptionPane.showOptionDialog(Example2.this, 
                                            "Example2: Continue?",
                                            "Example2",
                                            JOptionPane.YES_NO_OPTION,
                                            JOptionPane.QUESTION_MESSAGE,
                                            null,
                                            options,
                                            "Continue");
                proceedConfirmed = (n == JOptionPane.YES_OPTION);
            }
        }
        DoShowDialog doShowDialog = new DoShowDialog();

        /* The invokeAndWait utility can throw an InterruptedException,
         * which we don't bother with, and an InvocationException.
         * The latter occurs if our Runnable throws - which would indicate
         * a bug in DoShowDialog.  The invokeAndWait() call will not return 
         * until the user has dismissed the modal confirm dialog.
         */
        try {
            SwingUtilities.invokeAndWait(doShowDialog);
        }
        catch (java.lang.reflect.InvocationTargetException e) {
            e.printStackTrace();
        }
        return doShowDialog.proceedConfirmed;
    }


    /**
     * This is just a copy of Example1.doWork() with one extra wrinkle.
     * After about two seconds we ask the user to confirm with
     * a modal dialog (see waitForUserConfirmation()); if the answer
     * is NO then we short circuit.
     */
    Object doWork() {
        try {
            for(int i = 0; i < NUMLOOPS; i++) {
                updateStatus(i);
                if (i == 4) {
                    if (!waitForUserConfirmation()) {
                        updateStatus(0);
                        return "Not Confirmed";
                    }
                }
                if (Thread.interrupted()) {
                    throw new InterruptedException();
                }
                Thread.sleep(500);
            }
        }
        catch (InterruptedException e) {
            updateStatus(0);
            return "Interrupted";  // SwingWorker.get() returns this
        }
        return "All Done";         // or this
    }
}