ExitAction.java

package pipe.actions.gui;

import pipe.controllers.application.PipeApplicationController;

import javax.swing.*;
import java.awt.Frame;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;

public class ExitAction extends GuiAction {

    private final PipeApplicationController pipeApplicationController;

    private Frame application;

    public ExitAction(Frame application, PipeApplicationController pipeApplicationController) {
        super("Exit", "Close the program", KeyEvent.VK_Q, Toolkit.getDefaultToolkit().getMenuShortcutKeyMask());
        this.application = application;
        this.pipeApplicationController = pipeApplicationController;
    }

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

    public void tryToExit() {
        boolean safeToExit = !pipeApplicationController.anyNetsChanged();
        tryToExit(safeToExit);
    }

    /**
     * Tries to exit. If it is not safe to immediately exit then a warning comes up
     * asking the user if they wish to exit. The result is then published and the relevant action
     * is performed (e.g. exit or cancel).
     *
     * @param safeExit boolean determines if it safe to quit immediately
     */
    private void tryToExit(boolean safeExit) {
        if (safeExit) {
            application.dispose();
            System.exit(0);
        } else {
            int result = JOptionPane.showConfirmDialog(application,
                    "Do you really want to exit? Some unsaved Petri nets have changed.", "Confirm Exit",
                    JOptionPane.YES_NO_CANCEL_OPTION, JOptionPane.WARNING_MESSAGE);
            switch (result) {
                case JOptionPane.YES_OPTION:
                    tryToExit(true);
                    break;
                case JOptionPane.CLOSED_OPTION:
                case JOptionPane.CANCEL_OPTION:
                    break;
                default:
                    break;
            }
        }
    }

    public String changedNamesMessage(Iterable<String> changedNames) {
        StringBuilder buffer = new StringBuilder("The following Petri nets have changed. Do you still want to exit?");
        for (String name : changedNames) {
            buffer.append("\n");
            buffer.append(name);
        }
        return buffer.toString();
    }
}