java - 如何编写一个 [递归？] 函数来迭代 JMenu 层次结构中的(子)MenuElements？

Question

我有一个应用程序，它实现了带有子 JMenu 和 JCheckBoxMenuItem 的子菜单项的 JMenu:

       JMenuBar menuBar = new JMenuBar();
        menuBar.setEnabled(true);

        JMenu toolsMenu = new JMenu("Tools");
        toolsMenu.setEnabled(true);
        menuBar.add(toolsMenu);

        JMenu checkMenu = new JMenu("Checks");
        checkMenu.setEnabled(true);
        toolsMenu.add(checkMenu);

        JMenu checkOneMenu = new JMenu("Check One");
        checkOneMenu.setEnabled(true);
        checkMenu.add(checkOneMenu);

        JMenu checkTwoMenu = new JMenu("Check Two");
        checkTwoMenu.setEnabled(true);
        checkMenu.add(checkTwoMenu);

        JMenu checkThreeMenu = new JMenu("Check Three");
        checkThreeMenu.setEnabled(true);
        checkMenu.add(checkThreeMenu);

每个检查[One,Two,Three]菜单都有子JCheckBoxMenuItem:

        checkOneMenu.add(new JCheckBoxMenuItem("One-one"));
        checkOneMenu.add(new JCheckBoxMenuItem("One-two"));
        checkOneMenu.add(new JCheckBoxMenuItem("One-three"));

        checkTwoMenu.add(new JCheckBoxMenuItem("Two-one"));
        checkTwoMenu.add(new JCheckBoxMenuItem("Two-two"));
        checkTwoMenu.add(new JCheckBoxMenuItem("Two-three"));

        checkThreeMenu.add(new JCheckBoxMenuItem("Three-one"));
        checkThreeMenu.add(new JCheckBoxMenuItem("Three-two"));
        checkThreeMenu.add(new JCheckBoxMenuItem("Three-three"));

所有这些都按预期在应用程序内运行:我可以选择(/[取消]检查)任何一个 JCheckBoxMenuItem。

作为一名优秀程序员，我现在想编写适当的 JUnit4 测试:

    @Test
    public void testCheckOneMenu() {
        Assume.assumeFalse(GraphicsEnvironment.isHeadless());
        efo = new EditorFrameOperator(myJFrame);
        JMenuOperator toolsJMO = new JMenuOperator(efo, toolsMenuTitle);
        //this populates the checkOneMenu sub-JCheckBoxMenuItem's
        toolsJMO.pushMenuNoBlock("Tools/Checks/Check One", "/");
        new QueueTool().waitEmpty();

        JPopupMenu toolsPopupMenu = toolsJMO.getPopupMenu();
        //TODO:validate results
        dumpMenuElement(toolsPopupMenu);
        JMenuItem checkMenuItem = (JMenuItem) toolsPopupMenu.getComponent(0);
        dumpMenuElement(checkMenuItem);

在“TODO:”步骤中，我需要迭代工具菜单的所有子菜单。我编写了一个递归函数来执行此操作:

    private int tab_level = 1;
    private void dumpMenuElement(MenuElement jMenuElement) {
        System.out.println(StringUtils.leftPad(((JMenuItem) jMenuElement).getText(), tab_level, " "));
        tab_level += 4;
        for (MenuElement subMenuElement : jMenuElement.getSubElements()) {
            dumpMenuElement(subMenuElement);
        }
        tab_level -= 4;
    }

当我运行它时，我在工具菜单中得到了这个:

 Tools
     Tools
         Tools
             Tools

这是检查菜单:

 Checks
     Checks
         Checks

我希望看到这个(对于工具菜单):

 Tools
     Checks
         Check One
             One-One
             One-Two
             One-Three
         Check Two
             Two-One
             Two-Two
             Two-Three
         Check Three
             Three-One
             Three-Two
             Three-Three

有什么线索吗？提示？侮辱？(注意:我目前只是在调试 JUnit4 代码时转储标题。最终代码将仅访问标题并将它们与预期内容进行比较(无输出)。)

这是一个minimal reproducible example .

package dumpmenuelementtestapp;

import java.awt.BorderLayout;
import java.awt.Container;
import javax.swing.*;

/**
 *
 * @author geowar
 */
public class DumpMenuElementTestApp {

    /**
     * @param args the command line arguments
     */
    public static JMenuBar createMenuBar() {
        JMenuBar menuBar = new JMenuBar();
        menuBar.setEnabled(true);

        JMenu toolsMenu = new JMenu("Tools");
        toolsMenu.setEnabled(true);
        menuBar.add(toolsMenu);

        JMenu checkMenu = new JMenu("Checks");
        checkMenu.setEnabled(true);
        toolsMenu.add(checkMenu);

        JMenu checkOneMenu = new JMenu("Check One");
        checkOneMenu.setEnabled(true);
        checkMenu.add(checkOneMenu);

        JMenu checkTwoMenu = new JMenu("Check Two");
        checkTwoMenu.setEnabled(true);
        checkMenu.add(checkTwoMenu);

        JMenu checkThreeMenu = new JMenu("Check Three");
        checkThreeMenu.setEnabled(true);
        checkMenu.add(checkThreeMenu);

        checkOneMenu.add(new JCheckBoxMenuItem("One-one"));
        checkOneMenu.add(new JCheckBoxMenuItem("One-two"));
        checkOneMenu.add(new JCheckBoxMenuItem("One-three"));

        checkTwoMenu.add(new JCheckBoxMenuItem("Two-one"));
        checkTwoMenu.add(new JCheckBoxMenuItem("Two-two"));
        checkTwoMenu.add(new JCheckBoxMenuItem("Two-three"));

        checkThreeMenu.add(new JCheckBoxMenuItem("Three-one"));
        checkThreeMenu.add(new JCheckBoxMenuItem("Three-two"));
        checkThreeMenu.add(new JCheckBoxMenuItem("Three-three"));

        return menuBar;
    }

    public static Container createContentPane() {
        //Create the content-pane-to-be.
        JPanel contentPane = new JPanel(new BorderLayout());
        contentPane.setOpaque(true);

        //Create a scrolled text area.
        JTextArea output = new JTextArea(5, 30);
        output.setEditable(false);
        JScrollPane scrollPane = new JScrollPane(output);

        //Add the text area to the content pane.
        contentPane.add(scrollPane, BorderLayout.CENTER);

        return contentPane;
    }

    /**
     * Create the GUI and show it. For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("PopupMenuDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create/set menu bar and content pane.
        frame.setJMenuBar(createMenuBar());
        frame.setContentPane(createContentPane());

        //Display the window.
        frame.setSize(450, 260);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

Answer 1

为了转储菜单栏的所有元素，我这样做了:

private static void dumpMenuBar(JMenuBar menuBar)
{
    for (MenuElement element : menuBar.getSubElements())
    {
        JMenuItem menuItem = (JMenuItem)element;
        System.out.println( menuItem.getText() );
        dumpMenuElement( element );
    }
}

private static void dumpMenuElement(MenuElement subElement)
{
    for (MenuElement element : subElement.getSubElements())
    {
        if (element instanceof JMenuItem)
        {
            System.out.println( ((JMenuItem)element).getText() );
        }

        dumpMenuElement( element );
    }
}

我明白了:

Tools
Checks
Check One
One-one
One-two
One-three
Check Two
Two-one
Two-two
Two-three
Check Three
Three-one
Three-two
Three-three

我无法访问StringUtils，因此我将让您找出正确的对齐方式。