Sub-Menus are displaying away from their parent Menu for first time.

Question

Hi All,
I have a problem with sub-menus display location. In my application, I have a JPopupMenu to which several sub-menus (*JMenu*) are added. All the JMenuItems inside JMenu are having an Icon (Image) along with menu item title. I am providing a facility to change the font size of Menu Item names as well as the ImageIcon size dynamically through a dialog box. When the size is changed to larger value than the existing, the menus as well as submenus are getting displayed correctly. But when I change the size of ImageIcon and the font to smaller value than the existing one, then the submenus are getting displayed away from their parent menu for the first time. The location of sub menu display is matching with the location when their size was larger. This problem appears only for the first display of sub menus after their sizes are changed. For the successive display, the locating is resetting automatically to correct location.
So can anybody help me out about how to display submenus at correct location irrespective of font and image size changes for the first time also? Is there any event which gets fired when we change the font size or ImageIcon sizes? Is there any specific method to refresh the menu sizes if any of such properties (such as font size, ImageIcon size) are changed?
If you need any additional information, feel free to ask.

Answer 1

Below is the sample code for the query I placed. Steps to reproduce the problem are:
1. Click on "Increase Font" button.
2. Generate the popup at the right side corner of the screen (using right mouse click) such that the sub menu of edit should appear at left side of "Edit" option.
3. Click on "Decrease Font" button.
4. Generate the popup at the right side corner of the screen (using right mouse click) such that the sub menu of edit should appear at left side of "Edit" option.
You will see that sub menu of edit menu is displayed away from the popup for the first time. The sub menu location matches with previous location when its font size was larger. Location resets automatically for the next successive displays.
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Toolkit;
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 javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
public class JPopupDemo implements ActionListener {
  public static Font newFont=new Font("Times New Roman", Font.BOLD,24);
  JFrame frame = null;
  JPopupMenu popupMenu = null;
  JMenuItem fileMenu = null;
  JMenu editMenu = null;
  JMenuItem cutMenuItem = null;
  JMenuItem copyMenuItem = null;
  JMenuItem pasteMenuItem = null;
  JMenuItem findMenuItem = null;
    JPopupDemo(){
    frame = new JFrame("Popup Example");     
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    popupMenu = new JPopupMenu();
    fileMenu = new JMenuItem("File");
    editMenu = new JMenu("Edit");
    cutMenuItem = new JMenuItem("Cut");
    editMenu.add(cutMenuItem);
    copyMenuItem = new JMenuItem("Copy");
    editMenu.add(copyMenuItem);
    pasteMenuItem = new JMenuItem("Paste");
    pasteMenuItem.setEnabled(false);
    editMenu.add(pasteMenuItem);
    editMenu.addSeparator();
    findMenuItem = new JMenuItem("Find");
    editMenu.add(findMenuItem);
    popupMenu.add(fileMenu);
    popupMenu.add(editMenu);
    MouseListener mouseListener = new JPopupMenuShower(popupMenu);
    frame.addMouseListener(mouseListener);
    //frame.setSize(350, 250);
    Toolkit toolkit = Toolkit.getDefaultToolkit();
    Dimension dim = toolkit.getScreenSize();
    frame.setSize(dim.width,dim.height-100);
    JButton incrButton = new JButton("Increase Size");
    incrButton.setActionCommand("IncreaseSize");
    incrButton.addActionListener(this);
    JButton decrButton = new JButton("Decrease Size");
    decrButton.setActionCommand("DecreaseSize");
    decrButton.addActionListener(this);
    Container cp = frame.getContentPane();
    cp.setLayout(new BorderLayout());
    JPanel jp = new JPanel();
    jp.add(incrButton);
    jp.add(decrButton);
    cp.add(jp,BorderLayout.SOUTH);
    frame.setVisible(true);
public static void main(String args[]) {
     JPopupDemo demo = new JPopupDemo();
  public void actionPerformed(ActionEvent ae)
        if (ae.getActionCommand().equals("IncreaseSize"))
               newFont = new Font("Times New Roman", Font.BOLD,48);
               setNewFont();
          else if (ae.getActionCommand().equals("DecreaseSize"))
               newFont = new Font("Times New Roman", Font.BOLD,12);
               setNewFont();
   public void setNewFont()
        popupMenu.setFont(newFont);
        fileMenu.setFont(newFont);
        editMenu.setFont(newFont);
        cutMenuItem.setFont(newFont);
        copyMenuItem.setFont(newFont);
        pasteMenuItem.setFont(newFont);
        findMenuItem.setFont(newFont);
class JPopupMenuShower extends MouseAdapter {
  private JPopupMenu popup;
  public JPopupMenuShower(JPopupMenu popup) {
    this.popup = popup;
  private void showIfPopupTrigger(MouseEvent mouseEvent) {
    if (popup.isPopupTrigger(mouseEvent)) {
      popup.show(mouseEvent.getComponent(), mouseEvent.getX(), mouseEvent
          .getY());
  public void mousePressed(MouseEvent mouseEvent) {
    showIfPopupTrigger(mouseEvent);
  public void mouseReleased(MouseEvent mouseEvent) {
    showIfPopupTrigger(mouseEvent);
}Edited by: VPKVL on Aug 4, 2008 1:18 AM