Java – Show / hide JPopupMenu from JButton; Focuslistener is not working properly?

I need a JButton with an additional drop-down style menu So I took a JPopupMenu and attached it to JButton in the way you see in the code below What it needs to do is:

>Show popup when clicked > hide it if clicked again > hide an item if it is selected in the popup > hide it if the user clicks elsewhere in the screen

These four things are valid, but because of the boolean flag I'm using, if the user clicks elsewhere or selects an item, I have to click twice on the button to display it again That's why I tried to add a focuslistener (absolutely unresponsive) to fix it and set the flag to false in these cases

Editor: last attempt to answer the post

The following is the listener: (it is in a class that extends JButton, so the second listener is on JButton.)

// Show popup on left click.
menu.addFocusListener(new FocusListener() {
 @Override
 public void focusLost(FocusEvent e) {
  System.out.println("LOST FOCUS");
  isShowingPopup = false;
 }

 @Override
 public void focusGained(FocusEvent e) {
  System.out.println("GAINED FOCUS");
 }
});

addActionListener(new ActionListener() {
 @Override
 public void actionPerformed(ActionEvent e) {
  System.out.println("isShowingPopup: " + isShowingPopup);
  if (isShowingPopup) {
   isShowingPopup = false;
  } else {
   Component c = (Component) e.getSource();
   menu.show(c,-1,c.getHeight());
   isShowingPopup = true;
  }
 }
});

I've been using this for too long now It would be great if someone could give me a clue about this problem!

thank you!

Code:

public class Button extends JButton {

    // Icon.
    private static final ImageIcon ARROW_SOUTH = new ImageIcon("ArrowSouth.png");

    // Unit popup menu.
    private final jpopupmenu menu;

    // Is the popup showing or not?
    private boolean isShowingPopup = false;

    public Button(int height) {
        super(ARROW_SOUTH);
        menu = new jpopupmenu(); // menu is populated somewhere else

        // FocusListener on the jpopupmenu
        menu.addFocusListener(new FocusListener() {
            @Override
            public void focusLost(FocusEvent e) {
                System.out.println("LOST FOCUS");
                isShowingPopup = false;
            }

            @Override
            public void focusGained(FocusEvent e) {
                System.out.println("GAINED FOCUS");
            }
        });

        // ComponentListener on the jpopupmenu
        menu.addComponentListener(new ComponentListener() {
            @Override
            public void componentShown(ComponentEvent e) {
                System.out.println("SHOWN");
            }

            @Override
            public void componentResized(ComponentEvent e) {
                System.out.println("RESIZED");
            }

            @Override
            public void componentMoved(ComponentEvent e) {
                System.out.println("MOVED");
            }

            @Override
            public void componentHidden(ComponentEvent e) {
                System.out.println("HIDDEN");
            }
        });

        // ActionListener on the JButton
        addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println("isShowingPopup: " + isShowingPopup);
                if (isShowingPopup) {
                    menu.requestFocus();
                    isShowingPopup = false;
                } else {
                    Component c = (Component) e.getSource();
                    menu.show(c,c.getHeight());
                    isShowingPopup = true;
                }
            }
        });

        // Skip when navigating with TAB.
        setFocusable(true); // Was false first and should be false in the end.

        menu.setFocusable(true);
    }

}

Solution

This is another way, if not elegant, it's not too bad, and as far as I know, it can work First, at the top, I added a second Boolean named showpopup

Focuslistener must be as follows:

menu.addFocusListener(new FocusListener() {
        @Override
        public void focusLost(FocusEvent e) {
            System.out.println("LOST FOCUS");
            isShowingPopup = false;
        }

        @Override
        public void focusGained(FocusEvent e) {
            System.out.println("GAINED FOCUS");
            isShowingPopup = true;
        }
    });

The isshowingpopup Boolean does not change anywhere else - if it gets focus, it assumes it is already displayed, and if it loses focus, it assumes it is not

Next, the actionlistener on the button is different:

addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            System.out.println("isShowingPopup: " + isShowingPopup);
            if (showPopup) {
                Component c = (Component) e.getSource();
                menu.show(c,c.getHeight());
                menu.requestFocus();
            } else {
                showPopup = true;
            }
        }
    });

Now is really a new point It is the mouselistener on the button:

addMouseListener(new MouseAdapter() {
        @Override
        public void mousePressed(MouseEvent e) {
            System.out.println("ispopup?: " + isShowingPopup);
            if (isShowingPopup) {
                showPopup = false;
            }
        }

        @Override
        public void mouseReleased(MouseEvent e) {
            showPopup = true;
        }
    });

Basically, mousePressed is called before the menu loses focus, so isshowingpopup reflects whether a pop-up window is displayed before the button is pressed Then, if the menu is there, we just set showpopup to false, so that once the actionperformed method is called, the menu will not be displayed (after releasing the mouse)

This situation behaves as expected in each case, but only in one case: if the menu is displayed and the user presses the mouse on the button but releases it outside, actionperformed. Is never called This means that showpopup is still false and the menu is not displayed the next time the button is pressed To fix this problem, the mousereleased method resets showpopup As far as I know, the mouseReleased method is called after actionPerformed.

I played with the result button, made all the buttons I could think of, and it worked as expected However, I am not 100% sure that events will always occur in the same order

In the end, I think it's at least worth trying