How to configure JMenu for the behavior of a JMenuBar button

Question

I tried to get JMenu to behave like JButton, but I have problems, and hopefully someone here can help!

I added a MenuListener to the JMenu element with this, but I can’t get the popup menu / focus to allow me to press JMenu repeatedly to call this function, and I was hoping someone would tell me what I’m doing wrong . Thank.

public void menuSelected(MenuEvent e)
        {
            ... // do stuff here code
            JMenu source = (JMenu)e.getSource();
            source.setSelected(false);
            source.setPopupMenuVisible(false);

        }

Answer 1

Not quite sure what you are asking ...

But it JMenuBarinherits from Container- if you prefer to add to it JButton, than JMenu, you can just call -

JMenuBar menuBar = ....
JButton myButton = ....
menuBar.add(myButton);

Answer 2

eclipse, , ?

public class MyMenuFrame extends JFrame {


    public MyMenuFrame() throws HeadlessException {
        super("My Frame");
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setSize(400, 300);
        Container pane = this.getContentPane();
        pane.setLayout(new BorderLayout());
        pane.add(new JLabel("Hi there"), BorderLayout.PAGE_START);
        this.setVisible(true);
        JMenuBar menubar = new JMenuBar();
        JMenu menu = new JMenu("File");

        menu.addMenuListener(new MenuListener() {

            @Override
            public void menuSelected(MenuEvent e) {
                System.out.println("a");

            }

            @Override
            public void menuDeselected(MenuEvent e) {
                System.out.println("a");

            }

            @Override
            public void menuCanceled(MenuEvent e) {
                System.out.println("a");

            }
        });
        menubar.add(menu);
        this.setJMenuBar(menubar );
    }

    public static void main(String[] args) {
        new MyMenuFrame();
    }
}

Answer 3

, , , . . JMenuItem JMenu. L & F JMenu, JMenuBar. , , "button", ( ) :

http://www.javaworld.com/javaworld/jw-09-2000/jw-0922-javatraps.html

( , google "setize does not work" - ). , "button" JMenuBar.

:

menuItem.setMinimumSize(someMenu.getSize());
menuItem.setPreferredSize(someMenu.getSize());
menuItem.setMaximumSize(someMenu.getSize());
menuItem.setActionCommand("ActionText");

setActionCommand() , , "button", , action- , :

public void actionPerformed(ActionEvent e) {
    System.out.println(e.getActionCommand());
}

, !

Answer 4

, . , JMenu.

A JMenu - , . (JMenuBar) (JMenuItem). JMenuBar JMenus (File, Edit ..), , , JMenuItems (New, Open, Close). JMenuItems - , " " .

, . :

JMenu fileMenu = new JMenu("File");
JMenuItem newChoice = new JMenuItem("New");
newChoice.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent evt) {
        newHasBeenSelected();
    }
});
fileMenu.add(newChoice);

, JPopupMenu JMenu, JMenuBar. Java : http://java.sun.com/docs/books/tutorial/uiswing/components/menu.html

Java JMenuBar, JMenu, JPopupMenu JMenuItem.

, , .

Answer 5

Well, I decided to explore it a little more. Below is a cut and it seems to act like JButton, but appears as jmenu on jmenubar. The code is below. (note that just adding actionListener to JMenu does not work correctly, which is the reason for mouselistener. You add actionListener to the menu, just like a regular button, and until you add any menu items to the menu (which technically you could ) it will appear as JMenu on the JMenuBar, but it will behave like a button.

import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.lang.reflect.Method;
import java.util.EventListener;   
import javax.swing.ImageIcon;
import javax.swing.JMenu;

public class MenuButton extends JMenu {

private boolean startedIn = false;
private ActionListener action;

public MenuButton(String title) {
    super(title);
    removeListeners(this);
    this.addMouseListener(new MenuButtonListener());

}

public MenuButton(ImageIcon icon) {
    super();
    removeListeners(this);
    this.addMouseListener(new MenuButtonListener());
    this.setIcon(icon);
}

public void addActionListener(ActionListener a) {
    action = a;
}
    //we need to remove all the listeners already associated with a JMenu. If we do
//not do this, then it will not behave as expected because some mouseclicks are eaten 
//by these listeners. There is no easy way to do that, the following method is a 
//workaroundprovided in the java bug database. 
static private void removeListeners(Component comp) {
    Method[] methods = comp.getClass().getMethods();
    for (int i = 0; i < methods.length; i++) {
        Method method = methods[i];
        String name = method.getName();
        if (name.startsWith("remove") && name.endsWith("Listener")) {

            Class[] params = method.getParameterTypes();
            if (params.length == 1) {
                EventListener[] listeners = null;
                try {
                    listeners = comp.getListeners(params[0]);
                } catch (Exception e) {
                    // It is possible that someone could create a listener
                    // that doesn't extend from EventListener. If so, ignore
                    // it
                    System.out.println("Listener " + params[0]
                            + " does not extend EventListener");
                    continue;
                }
                for (int j = 0; j < listeners.length; j++) {
                    try {
                        method.invoke(comp, new Object[] { listeners[j] });
                        // System.out.println("removed Listener " + name +
                        // " for comp " + comp + "\n");
                    } catch (Exception e) {
                        System.out
                                .println("Cannot invoke removeListener method "
                                        + e);
                        // Continue on. The reason for removing all
                        // listeners is to
                        // make sure that we don't have a listener holding
                        // on to something
                        // which will keep it from being garbage collected.
                        // We want to
                        // continue freeing listeners to make sure we can
                        // free as much
                        // memory has possible
                    }
                }
            } else {
                // The only Listener method that I know of that has more
                // than
                // one argument is removePropertyChangeListener. If it is
                // something other than that, flag it and move on.
                if (!name.equals("removePropertyChangeListener"))
                    System.out.println("    Wrong number of Args " + name);
            }
        }
    }
}

public class MenuButtonListener extends MouseAdapter {

    boolean within = false;
    boolean pressed = false;


    public void mousePressed(MouseEvent e) {
        MenuButton.this.setSelected(true);
        pressed = true;
        //System.out.println("pressed");
    }

    public void mouseReleased(MouseEvent e) {
        //System.out.println("released");
        MenuButton.this.setSelected(false);
        if (action != null && within && pressed) {
            action.actionPerformed(new ActionEvent(this,
                    ActionEvent.ACTION_PERFORMED, null));
            MenuButton.this.setSelected(false);
        }
        pressed = false;
    }

    @Override
    public void mouseEntered(MouseEvent e) {
        within = true;
    }

    @Override
    public void mouseExited(MouseEvent e) {
        within = false;
    }
}
}