Dynamic JMenuItem
Hi,
Does anybody has any idea about dynamic addition and removal of JMenuItems. I am trying to implement an exactly the same functionality as in MSWord, when you open multiple files, a single MenuItem is adding in Windows Menu.
I want when user opens a new file, a JMenuItem is created with the name of that file in Windows Menu. And when user closes that file, that menu item be removed.
Any ideas
Thanks
The JMenu is a container like all others, so just find the particular index from where you would want to start adding your JMenuItem and then add it using the add(Component, index) method of the container. I believe you are trying to implement the Window menu behavior of MSWord.
Here's a general idea, you could also add seperators, above and below the menuitems and use their indexes as starting and ending points for the addition of the menuItems. So the idea is to get the index of the bottom seperator, remove the seperator, add the menuitem at that index and then re-add the seperator at the next index. Something like that, but I also think adding the component at the index of the seperator will move the seperator down to the index.
I haven't tested this idea (as usual) but you can give it a try.
All the best
ICE
Similar Messages
-
How to handle dynamic JMenuItem's actionListener??
I want to implement a function like "Recent File" in "File" menu.
But I don't know how to handle their actionListener?
for (int i=0; i<count; i++)
JMenuItem miNode = new JMenuItem(fileName);
mnuFile.add(miNode);
miNode.addActionListener(...) ///// ----- ????????
}for (int i = 0; i < count; i++) {
final String fileName = ... // the i-th file name
JMenuItem miNode = new JMenuItem(fileName);
mnuFile.add(miNode);
miNode.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// do whatever you want using "fileName" variable
System.out.println("You have selected the '" + fileName + "' file.");
}Alternatively you can create one ActionListener and add it to all menu items. When event is fired you can use ActionEvent.getActionCommand() - it will return the text of the JMenuItem (the file name on your case) that caused the event provided that you set only JMenuItem text (as you do in your example). -
Dynamic addition of JMenuItem in JMenu
I am trying to create a menu for my project. For that i have added the main menus and for each menu there will be menu item. But the problem is i will get the list of menu items for each menu , only at the runtime of my project. i.e. i wabt to add progrramatically add the menu items. Iam really confused with this. I will appriciate if any one help me on this.
And also i want to know ..is that possible to get the mouse listener for menu.
Thank in advance
Regards,
SAthishYou can add and remove menu items from the jmenu dynamically, the only thing you will have to take care of is invoking validate() after each insertion/deletion (it's a bit buggy there). All you have to do is create the items on demand and add (remove) them via the add(JMenuItem) (remove(JMenuItem)) method.
As for your second question, a JMenu is nothing but a JComponent, so you should be able to add a mouse listener like you would with any other component... -
i have a dynamic JMenu on a jframe. The menu is populated by looking up database entries and ptting them into the right place. This is done by a method 'menus()'.
I also have an addingredients class which adds new ingredient entries into the database, problem is when it does this, the JMenu has to be repopulated. The following code shows the main frame
// Recipe Creation GUI
// Written by Michael Emett
// Monday 15th Decemeber 2003
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.JFrame.*;
import java.sql.*;
import java.util.*;
public class TextAreaDemo extends JFrame {
private static JTextArea part1;
private JButton Browse, Enter, Preview, Remove;
public static JList printList, newList;
private JCheckBox pic;
private JLabel namePrompt, title1, title2, title3;
private static JTextField nameInput;
private JPanel jp, jp1, jp2, jp3, jp4, jp5;
private Connection con;
private Statement stmt;
public static JMenu fileMenu;
private static JMenuBar bar;
// additions /////////////////////////////////////////////////////////////////////////
//set up GUI
public TextAreaDemo() {
super( "Recipe Entry Sheet" );
// set up File menu and its menu items
// Menu and button Initialization ////////////////////////////////////////////////////
//myMouse = new MyMouseAdapter();
//final JMenu
fileMenu = new JMenu( "Ingredients");
fileMenu.setMnemonic( 'I' );
fileMenu.add(menus());
bar = new JMenuBar();
setJMenuBar( bar );
JMenu file = new JMenu( "File");
file.setMnemonic( 'F' );
bar.add(file);
JMenuItem Adder = new JMenuItem( "New Ingredient");
Adder.setMnemonic( 'N' );
JMenuItem Subber = new JMenuItem( "New subMenu");
Subber.setMnemonic( 'S' );
// set up About... menu item
JMenuItem aboutItem = new JMenuItem( "About..." );
aboutItem.setMnemonic( 'A' );
namePrompt = new JLabel( "Recipe Name " );
nameInput = new JTextField( 20 );
title1 = new JLabel( "Selected ingredients" );
title3 = new JLabel( "Please enter the Recipe Instructions" );
title2 = new JLabel( "Enter The SubMenu Name " );
pic = new JCheckBox("Add Picture", false);
file.add( Adder );
Adder.addActionListener(
new ActionListener() {
public void actionPerformed( ActionEvent event )
getList f = new getList();
// Add Ingredient menu item //////////////////////////////////////////////////////////
file.add( Subber );
Subber.addActionListener(
new ActionListener() {
public void actionPerformed( ActionEvent event )
AddSubMenu f = new AddSubMenu();
// About menu item ///////////////////////////////////////////////////////////////////
file.add( aboutItem );
aboutItem.addActionListener(
new ActionListener() { // anonymous inner class
// display message dialog when user selects About...
public void actionPerformed( ActionEvent event )
JOptionPane.showMessageDialog( TextAreaDemo.this,
"Developed by Michael Emett, 2004",
"About", JOptionPane.PLAIN_MESSAGE );
} // end anonymous inner class
); // end call to addActionListener
// Exit menu item ////////////////////////////////////////////////////////////////////
JMenuItem exitItem = new JMenuItem( "Exit" );
exitItem.setMnemonic( 'x' );
file.add( exitItem );
exitItem.addActionListener(
new ActionListener() { // anonymous inner class
// terminate application when user clicks exitItem
public void actionPerformed( ActionEvent event )
System.exit( 0 );
} // end anonymous inner class
); // end call to addActionListener
//create Button Enter
Enter = new JButton("Enter");
Enter.addActionListener(
new ActionListener() {
public void actionPerformed( ActionEvent event )
StringBuffer a = new StringBuffer();
StringBuffer b = new StringBuffer();
StringBuffer c = new StringBuffer();
for(int i= 0; i< victor.size(); i++){
b.append(victor.elementAt(i));
b.append("; ");
a.append(nameInput.getText());
c.append(part1.getText());
//System.out.println(a);
//System.out.println(b);
//System.out.println(c);
InsertRecipe f = new InsertRecipe(a,b,c);
//invalidate();
//fileMenu.updateUI();
// fileMenu.revalidate();
//create Button Remove
Remove = new JButton("Remove");
//add Actionlistener
Remove.addActionListener(
new ActionListener() {
public void actionPerformed( ActionEvent event )
int[] arr;
arr = printList.getSelectedIndices();
int counter = 0;
for (int i= 0; i< arr.length; i++){
int n=arr;
victor.remove(n-counter);
counter++;
printList.setListData(victor);
//create Button Remove
Browse = new JButton("Browse");
//create Button Preview
Preview = new JButton("Clear");
Preview.addActionListener(
new ActionListener() { // anonymous inner class
// display message dialog when user selects Preview...
public void actionPerformed( ActionEvent event )
int result = JOptionPane.showConfirmDialog
(null, "Are you sure to want to clear this form", "Clear?", JOptionPane.YES_NO_OPTION, JOptionPane.PLAIN_MESSAGE);
if(result == JOptionPane.YES_OPTION)
{TextAreaDemo.clear();
//System.out.println("Recipe Entered");
}//end of joptionpane
printList = new JList();
printList.setVisibleRowCount(9);
printList.setFixedCellWidth(150);
printList.setFixedCellHeight(15);
printList.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION );
newList = new JList();
newList.setVisibleRowCount(9);
newList.setFixedCellWidth(150);
newList.setFixedCellHeight(15);
newList.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION );
// Initialise Text Areas //
part1 = new JTextArea( 25, 50);
part1.setFont(new Font("Courier", Font.BOLD, 12));
part1.setLineWrap(true);
part1.setWrapStyleWord(true);
// JPanels for Layout //
jp = new JPanel();
jp1 = new JPanel();
jp2 = new JPanel();
jp3 = new JPanel();
jp4 = new JPanel();
jp5 = new JPanel();
final Container c = getContentPane();
GridBagLayout gbl = new GridBagLayout();
GridBagConstraints gbc = new GridBagConstraints();
c.setLayout(gbl);
gbc.weightx = 0.1;
gbc.weighty = 0.5;
gbc.fill = GridBagConstraints.NONE;
gbc.anchor = GridBagConstraints.NORTHWEST;
add(jp1, gbc, 0, 0, 1, 1);
gbc.fill = GridBagConstraints.NONE;
add(jp2, gbc, 0, 1, 1, 1);
add(jp3, gbc, 1, 0, 2, 2);
jp1.add(jp4, BorderLayout.CENTER);
jp2.add(jp, BorderLayout.CENTER);
bar.add( namePrompt );
bar.add( nameInput);
bar.add( fileMenu );
jp4.setLayout(new BorderLayout());
jp4.add(title1, BorderLayout.NORTH);
jp4.add(new JScrollPane( printList), BorderLayout.CENTER);
jp4.add(Remove, BorderLayout.SOUTH);
jp.setLayout(new BorderLayout());
jp.add(pic, BorderLayout.NORTH);
jp.add(new JScrollPane (newList), BorderLayout.CENTER);
jp.add(Browse, BorderLayout.SOUTH);
jp3.setLayout(new BorderLayout());
jp3.add (title3, BorderLayout.NORTH);
jp3.add (new JScrollPane(part1), BorderLayout.CENTER);
//c.addMouseListener(myMouse);
gbc.anchor = GridBagConstraints.LAST_LINE_END;
add(jp5, gbc, 2, 3, 1, 1);
jp5.setLayout(new FlowLayout());
jp5.add(Preview);
jp5.add(Enter);
setSize(770, 620);
pack();
setVisible(true);
setResizable(false);
private static Vector victor = new Vector();
public static void printListset(String t) {
victor.add(t);
for(int i = 0; i<victor.size(); i++)
printList.setListData(victor);
public void add(Component ce, GridBagConstraints constraints, int x, int y, int w, int h) {
constraints.gridx = x;
constraints.gridy = y;
constraints.gridwidth = w;
constraints.gridheight = h;
getContentPane().add(ce, constraints);
public static JMenu menus() {
// Map Created to Handle JMenuItem Addition //
Map labelToMenu = new HashMap();
Map labelToMenu2 = new HashMap();
Map labelToMenu3 = new HashMap();
String url = "jdbc:odbc:database";
Connection con;
Statement stmt;
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
catch(ClassNotFoundException e) {
System.err.print("Class Not found");
String query = "select baseIngred.IngredientType, baseIngred.PrimaryKey FROM baseIngred";
String query2 = "select baseIngred.IngredientType, baseIngred.PrimaryKey,"
+ "subMenu.menuNumber, subMenu.subMenu FROM baseIngred, "
+ "subMenu WHERE baseIngred.PrimaryKey = subMenu.menuNumber ORDER BY submenu";
String query3 = "select subMenu.subMenu, subMenu.PrimaryNumber,"
+ "Ingredient.Ingredient, Ingredient.MenuNumber FROM subMenu, Ingredient"
+ " WHERE Ingredient.MenuNumber = subMenu.PrimaryNumber ORDER BY PrimaryNumber";
String query4 = "select Ingredient.Ingredient, Ingredient.MenuNumber FROM Ingredient";
try {
con = DriverManager.getConnection(url, "myLogin", "myPassword");
stmt = con.createStatement();
// Initial Jmenu added ///////////////////////////////////////////////////////////////
ResultSet rs = stmt.executeQuery(query);
String[] arr = new String[100];
int[] num = new int[200];
int[] num2 = new int[200];
int counter = 0;
int counter2 = 0;
while (rs.next()) {
//String t is set to the value contained in ingredient type
String t = rs.getString("IngredientType");
//map labelToMenu has String t and a new JMenu with the menu
//name contained in t stored in it
labelToMenu.put(t, fileMenu.add(new JMenu(t)));
//an array containing values of the priamry key is produced
num[counter] = rs.getInt("PrimaryKey");
//a counter is incremeted so that upon further
//interations it is stored in a new array field
counter++;
// Second Jmenu added ////////////////////////////////////////////////////////////////
ResultSet rs2 = stmt.executeQuery(query2);
while (rs2.next()) {
//String first is set to the value contained in ingredient type
String first = rs2.getString("IngredientType");
//String second is set to the value contained in subMenu
String second = rs2.getString("subMenu");
//firstlevel looks up item t in the map, and creates a jmenu name as it.
JMenu firstLevel = (JMenu)labelToMenu.get(first);
//handles menu placement by comparing PrimaryKeys with MenuNumbers
// f = rs2.getInt("menuNumber");
num2[counter2] = rs2.getInt("menuNumber");
for (int nm = 0; nm<num.length; nm++){
if (num[nm] == num2[counter2]
//adds the second value to the jmenu with th name stored in t.
labelToMenu2.put(second, (firstLevel.add(new JMenu (second))));
}counter2++;
// Third JMenu added /////////////////////////////////////////////////////////////////
ResultSet rs3 = stmt.executeQuery(query3);
while (rs3.next()) {
//String next is set to the value contained in subMenu
String next = rs3.getString("subMenu");
//String third is set to the value contained in ingredient
String third = rs3.getString("Ingredient");
JMenu secondLevel = (JMenu)labelToMenu2.get(next);
int f2 = rs3.getInt("MenuNumber");
//System.out.println(f2);
int f3 = rs3.getInt("PrimaryNumber");
if (f3 == f2){
labelToMenu3.put(third, secondLevel.add(new JMenuItem(third)));
// Add AtionListeners ////////////////////////////////////////////////////////////////
ResultSet rs4 = stmt.executeQuery(query4);
while (rs4.next()) {
String third2 = rs4.getString("Ingredient");
JMenuItem thirdLevel = (JMenuItem)labelToMenu3.get(third2);
thirdLevel.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JMenuItem source = (JMenuItem)(e.getSource());
String actionText = source.getText();
PopUp pop = new PopUp(actionText);
stmt.close();
con.close();
}catch(SQLException ex) {
System.err.println(ex);
return (fileMenu);
// End Of Connection //
// Add subMenu menu item /////////////////////////////////////////////////////////////
public static void clear() {
nameInput.setText("");
victor.removeAllElements();
printList.setListData(victor);
part1.setText("");
public static void rebuild() {
fileMenu.removeAll();
fileMenu.add(menus());
bar.add( fileMenu );
public static void main(String args[]) {
TextAreaDemo t = new TextAreaDemo();
t.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE);
the code inside the method 'rebuild()' will work from inside the main JFrame body if assigned to a button (such as the example position denoted by HERE in the code), but that is undesirable as it requires the user to refresh manually every time they add a new ingredient. what i need is a method that can be called from another class/method/whatever.
thankyou for any help you can offer, it is much appreciatedThe code you offered did not solve my problem. I have since entered the followinginto the actionlistener of a button on the JFrame,
refreshMenu = new JButton("Refresh Menu");
refreshMenu.addActionListener(
new ActionListener() {
// display message dialog when user selects Preview...
public void actionPerformed( ActionEvent event )
fileMenu.removeAll();
fileMenu.add(menus());
bar.add( fileMenu );
);This does what i need, but i need these statements to be made from an external class, not a JButton, -
Runtime dynamic filtering TreeModel
Hello,
Changing a tree during runtime seems to be a problem. I've looked at different threads and now I have the following class which filters a delegated DefaultTreeModel (see SimpleFilteredTreeModel and the corresponding TestFilteredTreeModel classes below). Notice, that the commented lines in the isShown-method do filter out alternaitve objects behind the tree at startup of the application correctly.
I used the following two steps to extend the SimpleFilteredTreeModel to make it refreshing dynamically:
1. Step: ViewFilter Interface
First I enabled the SimpleFilteredTreeModel to set filter roules dynamically by introducing an interface (ViewFilter) and three implementions according to the alternatives shown in the isShown method. The filter is set by a method setViewFilter(ViewFilter).
2. Step: Update the Model
The method setViewFilter(ViewFilter) basically sets the new filter and tries to update the model so it shows up under the new behaviour.
public void setViewFilter(ViewFilter filter) {
this.filter = filter;
// Notify the model
final TreeNode root = (TreeNode) getRoot();
final int childCount = root.getChildCount();
final int[] indices = new int[childCount];
final Object[] children = new Object[childCount];
for (int i = 0; i < childCount; i++) {
indices[i] = i;
children[i] = getChild(root, i);
fireTreeStructureChanged(this, new Object[]{root}, indices, children);
}However, the view does not move at all. I tried also reload() and nodeChange(root) of the filter model and its delegate. No success.
If somebody knows how to extend this example to work dynamically, I would appreciate it highly.
-- Thanks
-- Daniel Frey
// File: SimpleFilteredTreeModel.java
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeNode;
public class SimpleFilteredTreeModel extends DefaultTreeModel {
private DefaultTreeModel delegate;
public SimpleFilteredTreeModel(DefaultTreeModel delegate) {
super((TreeNode) delegate.getRoot());
this.delegate = delegate;
public Object getChild(Object parent, int index) {
int count = 0;
for (int i = 0; i < delegate.getChildCount(parent); i++) {
final Object child = delegate.getChild(parent, i);
if (isShown(child)) {
if (count++ == index) {
return child;
else {
final Object child2 = getChild(child, index - count);
if (child2 != null) {
return child2;
count += getChildCount(child);
return null;
public int getIndexOfChild(Object parent, Object child) {
return delegate.getIndexOfChild(parent, child);
public int getChildCount(Object parent) {
int count = 0;
for (int i = 0; i < delegate.getChildCount(parent); i++) {
final Object child = delegate.getChild(parent, i);
if (isShown(child)) {
count++;
else {
count += getChildCount(child);
return count;
public boolean isLeaf(Object node) {
return delegate.isLeaf(node);
private boolean isShown(Object node) {
final DefaultMutableTreeNode treeNode = (DefaultMutableTreeNode) node;
final Object obj = treeNode.getUserObject();
//return obj instanceof TestFilteredTreeModel.Datum1 || obj instanceof TestFilteredTreeModel.Datum2;
//return obj instanceof TestFilteredTreeModel.Datum1;
return obj instanceof TestFilteredTreeModel.Datum2;
// File: TestFilteredTreeModel
import java.util.Arrays;
import java.util.List;
import java.util.Random;
import java.util.ArrayList;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.MutableTreeNode;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreeModel;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.JTree;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
public class TestFilteredTreeModel {
private DefaultMutableTreeNode[] nodes = new DefaultMutableTreeNode[0];
public static void main(String[] args) {
new TestFilteredTreeModel();
public TestFilteredTreeModel() {
final TreeNode root = createRootNode();
final TreeModel model = new SimpleFilteredTreeModel(new DefaultTreeModel(root));
final JTree tree = new JTree(model);
final JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(new JScrollPane(tree));
f.setSize(200, 300);
f.setVisible(true);
// Random tree generation
private Random random = new Random();
private TreeNode createRootNode() {
final MutableTreeNode rootNode = createRandomNode();
updateCache(rootNode);
for (int i = 0; i < 30; i++) {
final DefaultMutableTreeNode childNode = createRandomNode();
pickRandom(nodes).add(childNode);
updateCache(childNode);
return rootNode;
private void updateCache(MutableTreeNode childNode) {
final List list = new ArrayList(Arrays.asList(nodes));
list.add(childNode);
nodes = (DefaultMutableTreeNode[]) list.toArray(new DefaultMutableTreeNode[0]);
private DefaultMutableTreeNode createRandomNode() {
final Datum[] data = new Datum[]{new Datum2(), new Datum1()};
return new DefaultMutableTreeNode(data[random.nextInt(2)]);
private DefaultMutableTreeNode pickRandom(DefaultMutableTreeNode[] nodes) {
return nodes[random.nextInt(nodes.length)];
public static class Datum {
private static int counter = 0;
protected int thisCounter = 0;
public Datum() {
thisCounter = counter++;
public static class Datum2 extends Datum {
public String toString() {
return "Datum2 " + thisCounter;
public static class Datum1 extends Datum {
public String toString() {
return "Datum1 " + thisCounter;
// file: ViewFilter.java
import javax.swing.tree.DefaultMutableTreeNode;
public interface ViewFilter {
boolean isShown(DefaultMutableTreeNode node);
// file: Data1Filter.java
import javax.swing.tree.DefaultMutableTreeNode;
public class Data1Filter implements ViewFilter {
public boolean isShown(DefaultMutableTreeNode node) {
final Object obj = node.getUserObject();
return obj instanceof TestFilteredTreeModel.Datum1;
// file: Data2Filter.java
import javax.swing.tree.DefaultMutableTreeNode;
public class Data2Filter implements ViewFilter {
public boolean isShown(DefaultMutableTreeNode node) {
final Object obj = node.getUserObject();
return obj instanceof TestFilteredTreeModel.Datum2;
// file: Data12Filter.java
import javax.swing.tree.DefaultMutableTreeNode;
public class Data12Filter implements ViewFilter {
public boolean isShown(DefaultMutableTreeNode node) {
final Object obj = node.getUserObject();
return obj instanceof TestFilteredTreeModel.Datum1 || obj instanceof TestFilteredTreeModel.Datum2;
}The filtering works (after a fasion). Please clarify your problem.
I extended SimpleFitleredTreeModel as you described, along with changing isLeaf to use the filter
if (filter != null) return filter.isShown( treeNode );I extended TestFiltredTreeModel constructor as follows, add the member
import javax.swing.*;
import java.awt.event.*;
private SimpleFilteredTreeModel model;Altered TestFilteredTreeModel constructor as follows:
JMenuBar bar = new JMenuBar();
JMenu menu = new JMenu("Filters");
JMenuItem item;
item = new JMenuItem( "Data1Filter" );
item.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ev ) {
model.setViewFilter( new Data1Filter() );
menu.add( item );
item = new JMenuItem( "Data2Filter" );
item.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ev ) {
model.setViewFilter( new Data2Filter() );
menu.add( item );
item = new JMenuItem( "Data12Filter" );
item.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ev ) {
model.setViewFilter( new Data12Filter() );
menu.add( item );
bar.add( menu );
f.setJMenuBar( bar ); -
Hi,
I have painting problem with adding the JMenuItems dynamically. In the screen1 figure shown below, Menu 2 has has total 10 items, but initially we will show only three items. When the user clicks on the menu item ">>" all the Ten Items in Menu 2 are shown. But, All the 10 items are inserted in a compressed manner as shown in screen 2. When i click on the Menu 2 again, is shows properly as shown in screen 3.
screen 1:
<img src="http://img.photobucket.com/albums/v652/petz/Technical/screen1.jpg" border="0" alt="Screen 1"/>
screen 2:
<img src="http://img.photobucket.com/albums/v652/petz/Technical/screen2.jpg" border="0" alt="Screen 2"/>
screen 3:
<img src="http://img.photobucket.com/albums/v652/petz/Technical/screen3.jpg" border="0" alt="Screen 3"/>
Here is the code:
import java.awt.GridLayout;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
public class MenuUI implements MouseListener
JFrame frame;
JMenuBar menubar;
JMenu menu1,menu2;
JMenuItem menuItem;
JMenuItem lastMenuItem;
String MENU1_ITEMS[] = {"ONE","TWO","THREE","FOUR","FIVE"};
String MENU2_ITEMS[] = {"ONE","TWO","THREE","FOUR","FIVE","SIX","SEVEN","EIGHT","NINE","TEN"};
int MIN_MENU = 3;
public MenuUI()
menubar = new JMenuBar();
/*menu1 = new JMenu("Menu 1");
menu1.setMnemonic(KeyEvent.VK_1);
menu1.getPopupMenu().setLayout(new GridLayout(5,1));
menu2 = new JMenu("Menu 2");
menu2.setMnemonic(KeyEvent.VK_2);
menu2.getPopupMenu().setLayout(new GridLayout(5,2));*/
menu1 = new JMenu("Menu 1");
menu1.setMnemonic(KeyEvent.VK_1);
menu2 = new JMenu("Menu 2");
menu2.setMnemonic(KeyEvent.VK_2);
menubar.add(menu1);
menubar.add(menu2);
createMinMenuItems();
frame = new JFrame("MenuDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setJMenuBar(menubar);
frame.setSize(500, 300);
frame.setVisible(true);
public void createMinMenuItems()
for (int i = 0; i < MIN_MENU; i++)
menuItem = new JMenuItem(MENU1_ITEMS);
menu1.add(menuItem);
lastMenuItem = new JMenuItem(">>");
lastMenuItem.addMouseListener(this);
menu1.add(lastMenuItem);
for (int i = 0; i < MIN_MENU; i++)
menuItem = new JMenuItem(MENU2_ITEMS[i]);
menu2.add(menuItem);
lastMenuItem = new JMenuItem(">>");
lastMenuItem.addMouseListener(this);
menu2.add(lastMenuItem);
private void showAllMenuItems(int menuNo)
if(menuNo == 1)
menu1.remove(MIN_MENU);
for (int i = MIN_MENU; i < MENU1_ITEMS.length; i++)
menuItem = new JMenuItem(MENU1_ITEMS[i]);
menu1.add(menuItem);
menu1.updateUI();
else if(menuNo == 2)
menu2.removeAll();
menu2.getPopupMenu().setLayout(new GridLayout((MENU2_ITEMS.length),1));
for (int i = 0; i < MENU2_ITEMS.length; i++)
menuItem = new JMenuItem(MENU2_ITEMS[i]);
//menuItem.setMinimumSize(new Dimension(35,20));
menu2.add(menuItem);
menu2.updateUI();
//menu2.getPopupMenu().invalidate();
//menu2.getPopupMenu().repaint();
//menubar.repaint();
//menubar.invalidate();
//menubar.getParent().repaint();
/* (non-Javadoc)
* @see java.awt.event.MouseListener#mousePressed(java.awt.event.MouseEvent)
public void mousePressed(MouseEvent arg0)
System.out.println("mousePressed: Menu 1 selected: "+menu1.isSelected());
System.out.println("mousePressed: Menu 2 selected: "+menu2.isSelected());
if(menu1.isSelected())
System.out.println("mousePressed: Menu 1: Show All Items");
showAllMenuItems(1);
else if(menu2.isSelected())
System.out.println("mousePressed: Menu 2: Show All Items");
showAllMenuItems(2);
/* (non-Javadoc)
* @see java.awt.event.MouseListener#mouseClicked(java.awt.event.MouseEvent)
public void mouseClicked(MouseEvent evt)
/* (non-Javadoc)
* @see java.awt.event.MouseListener#mouseEntered(java.awt.event.MouseEvent)
public void mouseEntered(MouseEvent arg0)
/* (non-Javadoc)
* @see java.awt.event.MouseListener#mouseExited(java.awt.event.MouseEvent)
public void mouseExited(MouseEvent arg0)
/* (non-Javadoc)
* @see java.awt.event.MouseListener#mouseReleased(java.awt.event.MouseEvent)
public void mouseReleased(MouseEvent arg0)
public static void main(String[] args)
MenuUI ui = new MenuUI();// menu2.updateUI();
menu2.getPopupMenu().setVisible(false);
menu2.getPopupMenu().setVisible(true); -
Dynamic Type Checking... Is this possible?
I want to do a dynamic check for objec types in a datastructure. Something very similar to instanceof but using dynamic type parameter.
Syntactically speaking...
Instead of writing several methods like
public boolean isOfTypeXYZ( )
return ( this instanceof XYZ);
public boolean isOfTypeABC()
return ( this instanceof ABC);
...I want one single method like
public isOfType ( Class a_type)
return (this ***isoftype**** a_type);
}Where isoftype can somehow dynamically figure out if the object is of given type (class)
For those who want to know why I'd need this kind of contrived behaviour let me give a simple example (similar to my real issue).
Suppose I have a swing GUI application which has several laid out components like Containers, JPanels, JToolBars, JMenuItems, JButtons, JToggleButtons, JRadioButtons etc.
Now starting from the JFrame in this containment hierarchy, I want to find all instances of JButtons or say all instances of JRadioButtons or say all instances of JMenuItem or all instances of JComponents ...
I do not want to write a special method for each possible type I might encounter.
I want a more generic method like
searchComponents( Class a_class) that I can invoke by just changing its argument to convey the type.
Unfortunately getClassName() will not work as that gives the most derived type of the object. I want something very much like instanceof wherein I can check for an intermediate super class as well. (eg. All RadioButtons are AbstractButton and should return true for either type).
I tried to search for this in the forums but couldn't find something close to this. (There are several discussions about dynamic type casting which are different).Is this what you want?
searchComponents( Class a_class) {
// browse components
if (a_class.isInstance(component)) {
// do something
} -
Help with loading dynamic classes ..need help please
i'm trying to design a program where by i can load dynamic classes
the problem i'm getting is that only one class is loading.
classes are loaded by their names,and index numbers of public methods from a linklist
.When the program runs only the first class is ever loaded and only the methods of that class ..
help please
//class loader
import java.lang.reflect.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;
public class Test2 extends Thread
public Class c;
public Class Ray;
public Class[] x;
public static Object object = null;
public Method[] theMethods;
public static Method[] method,usemethod;
public int methodcount;
public static int MethodCt;
public static JList list;
public Method[] startClass(String SetMethodName)
try
c = Class.forName(SetMethodName);
object = c.newInstance();
theMethods = c.getDeclaredMethods();
// number of methods
//methodcount = theMethods.length;
catch (Exception e)
e.printStackTrace();
// return the array then invoke the particular method later
return theMethods ;
public void RunMethod(Method[] SomeMethod, int methodcount)
try
SomeMethod[methodcount].invoke( object,null );
catch (Exception e)
e.printStackTrace();
// end class loader
//main calling program
import java.awt.*;
import java.awt.event.*;
import javax.swing .*;
import java.lang.reflect.*;
public class JFMenu extends JFrame
public static JMenu pluginMenu;
public static JMenuBar bar;
public static final Test2 w = new Test2();
public static Method[] setmethod;
private static ClassLinkList startRef = null;
private static ClassLinkList linkRef3 = null;
private static ClassLinkList startRef2 = null;
private String ClassName,ShortCut;
private int MethodNumber;
private JMenuItem PluginItem;
JFMenu()
super (" JFluro ");
JMenu fileMenu = new JMenu("File");
fileMenu.setMnemonic('F');
JMenuItem exitItem = new JMenuItem("Exit");
exitItem.setMnemonic('X');
fileMenu.add(exitItem);
exitItem.addActionListener
new ActionListener()
public void actionPerformed(ActionEvent event )
System.exit(0);
JMenu pluginMenu = new JMenu("Plugins");
pluginMenu.setMnemonic('P');
startRef = new ClassLinkList ("Hello","Hello ",2,1926,"Painter");
addToList("Foo","Foo ",0,1930,"Author");
while (startRef.linkRef5 != null)
//pluginMenu.addSeparator();
ClassName = startRef.linkRef5.className;
ShortCut = startRef.linkRef5.shortcutName;
MethodNumber = startRef.linkRef5.methodNumber;
AddMenuItem(pluginMenu,ShortCut,ClassName,MethodNumber);
startRef.linkRef5 = startRef.linkRef5.next;
// create menu bar and add JFMenu window to it
JMenuBar bar = new JMenuBar();
setJMenuBar(bar);
bar.add(fileMenu);
bar.add(pluginMenu);
//attributes for JFMenu frame
setSize(500,200);
setVisible(true);
}// end JFMenu constructor
public void AddMenuItem(JMenu MainMenu, String shortcut,String className, final int methodCount )
if (MainMenu==null)
return;
//JMenuItem item;
JMenuItem item = new JMenuItem(shortcut);
MainMenu.add(item);
setmethod = w.startClass(className);
item.addActionListener
new ActionListener()
public void actionPerformed(ActionEvent event )
w.RunMethod(setmethod,methodCount);
//item.addActionListener(ij);
public JMenuItem AddMenuItem2(JMenu MainMenu, String shortcut)
//if (MainMenu==null)
// return Main;
//JMenuItem item;
JMenuItem item = new JMenuItem(shortcut);
MainMenu.add(item);
//setmethod = w.startClass(className);
//item.addActionListener(this);
new ActionListener()
public void actionPerformed(ActionEvent event )
w.RunMethod(setmethod,methodCount);
//item.addActionListener(ij);
return item;
public void ReloadMenu(JMenuBar Bar, JMenu PluginMenu)
if (Bar==null)
return;
// setJMenuBar(Bar);
Bar.add(PluginMenu);
//item.addActionListener(ij);
public static void main (String args[])
JFMenu menapp = new JFMenu();
public static void addToList(String clname, String shcutname, int metnumber, int year2,
String description) {
// Create instance of class ClassLinkList
ClassLinkList newRef = new ClassLinkList(clname,shcutname,metnumber,year2,
description);
// Add to linked list;
startRef = startRef.addRecordToLinkedList(newRef);
// end main calling program
class Hello extends Thread
public int getNum()
System.out.println("I can be ");
return 5;
public void rayshowName()
System.out.println("anything i want ");
public void rayshowName3()
System.out.println("to be ");
class Foo extends Thread
public int getNum()
System.out.println("IMHOFF");
return 5;
public void rayshowName()
System.out.println("raYMOND");
// FAMOUS PERSONS LINKED LIST EXAMPLE
// Frans Coenen
// Saturday 15 January 2000
// Depaertment of Computer Science, University of Liverpool
class ClassLinkList {
/* FIELDS */
public String className;
public String shortcutName;
public int methodNumber;
public int yearOfDeath;
public String occupation;
public ClassLinkList next = null;
public ClassLinkList linkRef5 = this;
public ClassLinkList startRef = null;
/* CONSTRUCTORS */
/* FamousPerson constructor */
public ClassLinkList(String classname, String shortcutname, int methodnumber, int year2,
String description) {
className = classname;
shortcutName = shortcutname;
methodNumber = methodnumber;
yearOfDeath = year2;
occupation = description;
next = null;
/* METHODS */
/* Output famous person linked list */
public void outputClassLinkedList()
//public ClassLinkList outputClassLinkedList() {
ClassLinkList linkRef = this;
// Loop through linked list till end outputting each record in turn
while (linkRef != null)
//System.out.println(linkRef5);
System.out.println(linkRef.className + ", " + linkRef.shortcutName +
" (" + linkRef.methodNumber + "-" + linkRef.methodNumber +
"): " + linkRef.occupation);
linkRef = linkRef.next;
//return linkRef;
//public String ShowCasname()
//return String ;
/* Add a new record to the linked list */
public ClassLinkList addRecordToLinkedList(ClassLinkList newRef) {
ClassLinkList tempRef, linkRef;
// Test if new person is to be added to start of list if so return
if (newRef.testRecord(this) ) {
newRef.next = this;
return(newRef);
// Loop through remainder of linked list
tempRef = this;
linkRef = this.next;
while (linkRef != null) {
if (newRef.testRecord(linkRef)) {
tempRef.next = newRef;
newRef.next = linkRef;
return(this);
tempRef = linkRef;
linkRef = linkRef.next;
// Add to end
tempRef.next = newRef;
return(this);
/* Delete a record from the linked list given the first and last name. Four
posibilities:
1) Record to be deleted is at front of list
2) Record to be deleted is at end of list
3) Record to be deleted is in middle of list
4) Record not found. */
public ClassLinkList deleteRecord(String lName, String fName) {
ClassLinkList tempRef, linkRef;
// Record at start of list
if ((this.className == lName) & (this.shortcutName == fName))
return(this.next);
// Loop through linked list to discover if record is in middle of list.
tempRef = this;
linkRef = this.next;
while (linkRef != null) {
if ((linkRef.className == lName) & (linkRef.shortcutName == fName)) {
tempRef.next = linkRef.next;
return(this);
tempRef = linkRef;
linkRef = linkRef.next;
// Record at end of list, or not found
if ((linkRef.className == lName) & (linkRef.shortcutName == fName))
linkRef = null;
else System.out.println("Record: " + lName + " " + fName + " not found!");
return(this);
/* TEST METHODS */
/* Test whether new record comes before existing record or not. If so return
true, false otherwise. */
private boolean testRecord(ClassLinkList existingRef) {
int testResult = className.compareTo(existingRef.className);
if (testResult < 0) return(true);
else {
if ((testResult == 0) & (shortcutName.compareTo(existingRef.shortcutName) < 0 ))
return(true);
// Return false
return(false);
public void addToList(String clname, String shcutname, int metnumber, int year2,
String description)
// Create instance of class Famous Person
ClassLinkList newRef = new ClassLinkList(clname,shcutname,metnumber,year2,
description);
// Add to linked list;
startRef = startRef.addRecordToLinkedList(newRef);I have a similar problem. I am writing a program to read the class names from database and instantiate several classes which extends from ServiceThread (an abstract class extending from Thread).
rs = pStmt.executeQuery();
while(rs.next()) {
String threadclassname = rs.getString("classname").trim();
try{
ServiceThread threadinstance = (ServiceThread)Class.forName(threadclassname).newInstance();
}catch ...
So far, only the first class is ever instantiated and runs fine. But subsequent classes do not even get pass the "... ... Class.forName(...).newInstance();" line.
Funny thing is that there are also no exceptions. The JVM just seem to hang there. -
How to create dynamic menuitems?
I have built a GUI program which read a text file to create menuItems.
for example, following is the text file.
component1
component2
component3
component4
then, my program should read the text file. to built four menuItems and add it to my another JMenu "capactor".
i have read the text file and put it to a array myList[].
i have read all the contructor of JMenuItem... but still don't know how to do it...
any expert can help?
thx.Hi,
my appllication SimplyHTML does exactly that. You can download it including sources and extensive documentation at http://www.lightdev.com/dev/sh.htm
The description of how to do it is in a separate PDF document at http://www.lightdev.com/doc/shtm/rel/Help.pdf
Chapter 'Inside SimplyHTML -> Stage2: Resource bundles and common edit functions -> Creating a dynamic menu'
Have fun
Ulrich -
Well guys, voil� my problem...
I've a Person class, who has some methods to get the person information, like getName(), getAge(), getAdresse(), etc... I would display the information of all the persons in the diary in a JTable... Ok, it's all right, i made a class who extends AbstractModelTable, overriding the getValueAt(int, int) with a switch:
// private static final int COLUMN_NAME = 0;
// private static final int COLUMN_NAME = 1;
switch (column) {
case COLUMN_NAME:
return cols[rowIndex].getName();
case COLUMN_AGE:
return cols[rowIndex].getAge();
default:
return;
}The code it's something like that... I'm sorry i don't show the code, i've not the source here!
It works very fine!... But now, i want to let the user choose witch columns to display...
I made a lot of tries, but i could not get the solution... The only one thing I could, was to eliminate the columns with zero value in the conf file, but the headers were not in the correct order!... And there's another problem too, when I switch the columnIndex, if it equals to COLUMN_EMAIL = 15 means that JTree is getting the value of the 15th column, but if the user had removed the 2 column for example, the 15th column is not more the email column, it's the 15+1 columns :S... is it clair? I think it's a little difficult to explain, and as you see, i don't speak english very well :P...
Summary: I would create a class extending JTable with columns configurables, i mean, let the user choose witch columns should be showed... Any idea ?... I can avoid the JTable component, so If you've another solution, it will be ok...
Greetings and thank you guys...Your requirement is very general so we can't give you an exact solution, but I can try explaining how JTable works.
The TableModel is used to store the data. The JTable is used to display the data. When a table is first created using a TableModel a TableColumnModel is created. Each TableColumn in the TableColumnModel maps directly to a column in the TableModel.
Now what happens if the user moves column 15 to the first column in the table? The data hasn't changed, only the view of the data has changed. So even though the column is in column 0 of the table, the data must still come from column 15 in the TableModel. The TableColumns of the TableColumnModel do the mapping for you so you don't need to worry about the reordering of columns.
However, if you have some code in your program that accesses the data directly, then you need to be aware of this situation. Fortunately JTable has some methods to make this mapping easy.
table.getValueAt(...) will get data from the requested column in the view of the table
table.getModel().getValueAt(...) will get data form the requested column in the TableModel.
You can also do the mapping between "view" and "model" columns using the methods:
table.convertColumnIndexToModel(...)
table.convertColumnIndexToView(...) So what does this mean with dynamic columns? Well, you would build your table normally, then you would remove the TableColumns from the TableColumnModel that the user does not want to see.
The following example is so code I wrote a while ago that will help in manipulating the TableColumnModel. Right click on the TableHeader to see the visible/hidden status of each column:
import java.awt.*;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
public class TableColumnManager implements MouseListener, ActionListener
private static final String HIDDEN_COLUMN = "HiddenColumn:";
// Reference to the Singleton instance of this class
private static TableColumnManager singleton;
* Use a private constructor so we can create a Singleton.
private TableColumnManager()
* Get the Singleton instance of the <code>TableColumnManager</code>.
* @return the Singlton instance of <code>TableColumnManager</code>
private static TableColumnManager getInstance()
if (singleton == null)
singleton = new TableColumnManager();
return singleton;
* Add support for the management of visible <code>TableColumns</code>
* for a given <code>JTable</code>.
* @param table the table to provide support for
public static void install(JTable table)
table.getTableHeader().addMouseListener( getInstance() );
* Remove support for the management of visible <code>TableColumns</code>
* for a given <code>JTable</code>.
* @param table the table to remove support from
public static void uninstall(JTable table)
table.getTableHeader().removeMouseListener( getInstance() );
* Hide a column from view in the table.
* @param table the table from which the column is removed
* @param modelColumn the column index from the TableModel
* of the column to be removed
public static void hideColumn(JTable table, int modelColumn)
int viewColumn = table.convertColumnIndexToView( modelColumn );
if (viewColumn != -1)
TableColumn column = table.getColumnModel().getColumn(viewColumn);
hideColumn(table, column);
* Hide a column from view in the table.
* @param table the table from which the column is removed
* @param columnName the column name of the column to be removed
public static void hideColumn(JTable table, String columnName)
try
TableColumnModel tcm = table.getColumnModel();
int index = tcm.getColumnIndex( columnName );
TableColumn column = tcm.getColumn( index );
hideColumn(table, column);
catch(IllegalArgumentException e) {}
* Hide a column from view in the table.
* @param table the table from which the column is removed
* @param column the TableColumn to be removed from the
* TableColumnModel of the specified table
public static void hideColumn(JTable table, TableColumn column)
table.getColumnModel().removeColumn( column );
// Save the column so it can be redisplayed
ArrayList list = (ArrayList)table.getClientProperty(HIDDEN_COLUMN);
if (list == null)
list = new ArrayList();
table.putClientProperty(HIDDEN_COLUMN, list);
list.add(column);
* Show a hidden column in the table.
* @param table the table to which the column is added
* @param modelColumn the column index from the <code>TableModel</code>
* of the column to be added
public static void showColumn(JTable table, int modelColumn)
ArrayList list = (ArrayList)table.getClientProperty(HIDDEN_COLUMN);
if (list == null) return;
ListIterator it = list.listIterator();
while (it.hasNext())
TableColumn column = (TableColumn)it.next();
if (column.getModelIndex() == modelColumn)
table.getColumnModel().addColumn( column );
it.remove();
break;
* Show a hidden column in the table.
* @param table the table to which the column is added
* @param columnName the column name from the <code>TableModel</code>
* of the column to be added
public static void showColumn(JTable table, String columnName)
ArrayList list = (ArrayList)table.getClientProperty(HIDDEN_COLUMN);
if (list == null) return;
ListIterator it = list.listIterator();
while (it.hasNext())
TableColumn column = (TableColumn)it.next();
if (column.getHeaderValue().equals(columnName))
table.getColumnModel().addColumn( column );
it.remove();
break;
// Implement the MouseListener
public void mousePressed(MouseEvent e)
checkForPopup( e );
public void mouseReleased(MouseEvent e)
checkForPopup( e );
public void mouseClicked(MouseEvent e) {}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
private void checkForPopup(MouseEvent e)
if (e.isPopupTrigger())
JTableHeader header = (JTableHeader)e.getComponent();
int column = header.columnAtPoint( e.getPoint() );
showPopup(header.getTable(), column);
* Show a hidden column in the table.
* @param table the table to which the column is added
* @param columnName the column name from the <code>TableModel</code>
* of the column to be added
public static void showPopup(JTable table, int tableColumn)
int columns = table.getModel().getColumnCount();
JCheckBoxMenuItem[] items = new JCheckBoxMenuItem[columns];
// Create menu items for hidden columns
ArrayList list = (ArrayList)table.getClientProperty(HIDDEN_COLUMN);
if (list != null)
ListIterator it = list.listIterator();
while (it.hasNext())
TableColumn column = (TableColumn)it.next();
String columnName = column.getHeaderValue().toString();
JCheckBoxMenuItem item = new JCheckBoxMenuItem( columnName );
item.setSelected( false );
item.addActionListener(getInstance());
items[column.getModelIndex()] = item;
// Create menu items for visible columns
TableColumnModel columnModel = table.getColumnModel();
int columnCount = columnModel.getColumnCount();
for (int i = 0; i < columnCount; i++)
TableColumn column = columnModel.getColumn(i);
String columnName = column.getHeaderValue().toString();
JCheckBoxMenuItem item = new JCheckBoxMenuItem( columnName );
item.setSelected( true );
item.addActionListener(getInstance());
items[column.getModelIndex()] = item;
// Create popup menu from array of menu items.
// Override the setSelected method to select the
// specified menu item. (ie. this is a bug fix)
JPopupMenu popup = new JPopupMenu()
public void setSelected(Component sel)
int index = getComponentIndex( sel );
getSelectionModel().setSelectedIndex(index);
final MenuElement me[] = new MenuElement[2];
me[0]=(MenuElement)this;
me[1]=getSubElements()[index];
SwingUtilities.invokeLater(new Runnable()
public void run()
MenuSelectionManager.defaultManager()
.setSelectedPath(me);
for (int i = 0; i < items.length; i++)
if (items[i] != null)
popup.add( items[i] );
// Display the popup below the TableHeader
JTableHeader header = table.getTableHeader();
Rectangle r = header.getHeaderRect( tableColumn );
popup.show(header, r.x, r.height);
int modelColumn = table.convertColumnIndexToModel( tableColumn );
popup.setSelected( items[modelColumn] );
* Responsible for processing the ActionEvent. A column will either be
* added to the table or removed from the table depending on the state
* of the menu item that was clicked.
* @param event the ActionEvent.
public void actionPerformed(ActionEvent event)
JMenuItem item = (JMenuItem)event.getSource();
JPopupMenu popup = (JPopupMenu)item.getParent();
JTableHeader header = (JTableHeader)popup.getInvoker();
JTable table = header.getTable();
if (item.isSelected())
showColumn(table, item.getText());
else
hideColumn(table, item.getText());
public static void main(String[] args)
JTable table = new JTable( new DefaultTableModel(5, 10) );
TableColumnManager.install(table);
TableColumnManager.hideColumn(table, 2);
TableColumnManager.hideColumn(table, "E");
JFrame frame = new JFrame();
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.getContentPane().add( new JScrollPane(table) );
frame.pack();
frame.setVisible( true );
}Hopefully I've made some sense. -
Hi guys,
had a small problem while associating dynamic ActionListeners to JPopupMenus.
Here is my code
ArrayList feedList = CityTVStartUp.getOperatorSession().getCameraFeeds();
CameraFeedDO cf;
for (int f = 0; f < feedList.size(); f++) {
cf = (CameraFeedDO) feedList.get(f);
jPopupMenuItemFeeds = new JMenuItem();
jPopupMenuItemFeeds.setText(cf.getTitle());
jPopupMenuItemFeeds.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println(cf.getTitle() + cf.getIPAddress());
System.out.println(jPopupMenuItemFeeds.getName());
jPopupMenu1.add(jPopupMenuItemFeeds);What I am doing here is, creating a popup menus on the basis of number of records in a database and try to add ActionListener on that. But when I run it, it always prints the last record, any ideas how to fix it?It compiles and works fine, The only problem is, whenever I clicked on PopUp Menu, it always access the last one, thats because its in FOR loop....
I dont have two variables with similar names.
private JMenuItem jPopupMenuItemFeeds; // This is my global variable
CameraFeedDO cf = null; // This is also my global variableI call initComponents() from constructor, and initComponents runs that routine above... I had done similar dynamic anonymous listerners with JButtons and that worked fine, anything special with JPopupMenuItems?? -
NEED HELP... Creating dynamic table from data file...
Hi
I'm writing an application for data visualization. The user can press the "open file" button and a FileChooser window will come up where the user can select any data file. I would like to take that data file and display it as a table with rows and columns. The user needs to be able to select the coliumns to create a graph. I have tried many ways to create a table, but nothing seems to work! Can anyone help me?! I just want to read from the data file and create a spreadsheet type table... I won't know how many rows and columns I'll need in advance, so the table needs to be dynamic!
If you have ANY tips, I'd REALLY appreciated.....Thank you for your help. I tried to use some of the code in the examples... I'm really new at this, so I'm not sure how to set it up. I added the code, but when I open a file, nothing happens. Here's the code I have so far...
package awt;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.util.*;
import javax.swing.*;
import javax.swing.event.*;
import java.text.*;
import javax.swing.border.*;
import javax.swing.table.*;
* @author
public class Main {
public static void main(String[] args) {
JFrame frame = new ScatterPlotApp();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.show();
class ScatterPlotApp extends JFrame implements ActionListener{
private JButton openButton, exitButton, scatButton, refreshButton;
private JMenuBar menuBar;
private JMenuItem openItem, exitItem;
private JFileChooser chooser;
private JMenu fileMenu;
private JTextPane pane;
private JTable table;
private DefaultTableModel model;
private JScrollPane scrollPane;
private Container contentPane;
/** Creates a new instance of ScatterPlotApp */
public ScatterPlotApp() {
setTitle("Data Visualizer");
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension d = tk.getScreenSize();
int width = 867;
int height = 800;
setBounds((d.width - width)/2, (d.height - height)/2, width, height);
contentPane = getContentPane();
JPanel panel = new JPanel();
//pane = new JTextPane();
panel.setLayout(new FlowLayout(FlowLayout.CENTER));
contentPane.add(panel, BorderLayout.SOUTH);
//contentPane.add(pane, BorderLayout.NORTH);
scatButton = new JButton("Create ScatterPlot");
scatButton.addActionListener(this);
openButton= new JButton ("Open File");
openButton.addActionListener(this);
exitButton = new JButton ("Exit");
exitButton.addActionListener(this);
refreshButton = new JButton ("Reload Data");
refreshButton.addActionListener(this);
panel.add(openButton);
panel.add(scatButton);
panel.add(refreshButton);
panel.add(exitButton);
fileMenu = new JMenu("File");
openItem = fileMenu.add(new JMenuItem ("Open", 'O'));
openItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, Event.CTRL_MASK));
openItem.addActionListener(this);
exitItem = fileMenu.add(new JMenuItem ("Exit", 'X'));
exitItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X, Event.CTRL_MASK));
exitItem.addActionListener(this);
JMenuBar menuBar = new JMenuBar();
fileMenu.setMnemonic('F');
menuBar.add(fileMenu);
setJMenuBar(menuBar);
public void actionPerformed(ActionEvent e){
Vector columnNames = new Vector();
Vector data = new Vector();
try{
Object source = e.getSource();
if (source == openButton || e.getActionCommand().equals("Open")){
chooser = new JFileChooser(".");
int status =chooser.showOpenDialog(this);
if (status ==JFileChooser.APPROVE_OPTION)
File file = chooser.getSelectedFile();
FileInputStream fin = new FileInputStream(file);
BufferedReader br = new BufferedReader(new InputStreamReader(fin));
String line;
//StringBuffer bf = new StringBuffer();
StringTokenizer st1 = new StringTokenizer(br.readLine(), ";");
while( st1.hasMoreTokens() )
columnNames.addElement(st1.nextToken());
// extract data
while ((line = br.readLine()) != null)
StringTokenizer st2 = new StringTokenizer(line, ";");
Vector row = new Vector();
while(st2.hasMoreTokens())
row.addElement(st2.nextToken());
data.addElement( row );
br.close();
model = new DefaultTableModel(data, columnNames);
table = new JTable(model);
scrollPane = new JScrollPane( table );
getContentPane().add( scrollPane, BorderLayout.NORTH );
while((line=br.readLine())!=null)
bf.append(line+"\n");
pane.setText(bf.toString());
//pane.setText(bf.toString());
else if (source == scatButton){
else if (source == exitButton || e.getActionCommand().equals("Exit")){
System.exit(0);
else if (source == refreshButton){
catch (Exception ex){
ex.printStackTrace();
} -
Problem in showing dynamically created popup menus in MacOs.
I have problem with dynamically popup menus. When the menu item is selected, below method is calling:
public JPopupMenu getPopupMenu(){
JPopupMenu r = super.getPopupMenu(); // My class extends JMenu.
r.removeAll();
String[] remoteEngines = SimulationManager.getRemoteEngines();
try {
for (int i = 0; i < remoteEngines.length; i++) {
JMenuItem item = new JMenuItem(remoteEngines);
item.addActionListener(this);
r.add(item);
} catch (Exception ex) {}
return r;
On windows and linux I get menu populated by servers' names, but under MacOS popup menus don�t appear.
I have MacOs 10.4 and Java 1.5.0.5The problems with the portlet provider. Edit it and do the following:
Uncheck "Web provider in same cookie domain as the portal" and also for the User/Session Information, choose either "Always" or "Once per user session" NOT "never".
Its bug no 4118067 in metalink, the above is a workaround!! -
I'm now trying to make a menu from my application. This menu is generated using plain text file to generate the JMenu, JMenuItem objects. That's not difficult but the problem comes when I want this objects to instantiate objects dynamically. See the example below.
public MasterForm generate (String classname)
//Dynamic generation of objects
}The objects are not always from the same class, that's the reason I pass my method an argument to make my classes. All classes must have some methods so I'm using inheritance. I've been reading the documentation about class Class but the newInstance method doesn't allow you to pass arguments. What should I use?I had a similar problem and I created an instance every object that was supposed to be generated dynamically had to implement. Then you can instantiate them using something like:
Plugin plugin;
// System.out.println("Plugin: " + name);
Class c;
try
c = Class.forName(entrypoint);
plugin = (Plugin)c.newInstance();
//do whatever you want with the interface...
catch (Exception e)
e.printStackTrace();
}Where entrypoint in this case is the path to the implementing class inside a jar file and Plugin is the name of the interface. -
Unable to capture data in an editable dynamic ALV.
Hi ,
I have created a dynamic editable ALV whose displayed structure can be changed at runtime based on the selection in a drop down list value selector.
Im trying to capture the values entered in the ALV into an internal table before the user changes the structure of the ALV to a different structure.
In the ON_SELECT event handler of the drop down list box , im rasing a data_check event to capture the ALV data.
The problem is that the control is not entering the event handler for the data_check event.
If i raise the data_check event in my save event handler or any other event handler , it works fine.
Can someone please suggest a solution.
Regards,
Newton.Hi ,
I have figured out that the problem is local to my machine , because the code works fine on other machines.
I guess my internet explorer has some bug.
Regards,
Newton.
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