I am pretty new to Swing, any help appreciated.
I have the following situation:
A "Main" Class where I define my main JPanel and default Label text.
A "GUILabel" Class (extends JLabel) where I define the look of the Text Labels.
A "popupmenu" Class (extends JPopupMenu) where I define the content of the popupmenu.
Target:
When I right-click on a panel the popupMenu should appear (this already works).
When I choose a menu item of this popupMenu, the text of the label I clicked on should change.
I guess its currently not working (I am sorry this code isn't complete - this is my 5th attempt), because I create the popup menu Once in the Main Class. Then I am adding this popup menu to each Label. So I guess thats why getInvoker() returns null in the popup menu class.
But do I really have to create a new popupmenu for each JLabel? Cant this single menu just handle all Components assigned to?
Main Frame:
package popupshit;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenuItem;
import javax.swing.border.BevelBorder;
public class Model implements ActionListener {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridLayout(0, 3));
frame.setVisible(true);
GUIPopupMenu popup = new GUIPopupMenu(9);
JLabel label1 = new GUILabel();
label1.setComponentPopupMenu(popup);
JLabel label2 = new GUILabel();
label2.setComponentPopupMenu(popup);
JLabel label3 = new GUILabel();
label3.setComponentPopupMenu(popup);
frame.add(label1);
frame.add(label2);
frame.add(label3);
frame.pack();
}
#Override
public void actionPerformed(ActionEvent e) {
((JLabel) e.getSource()).setText("" + e.getActionCommand());
}
}
PopupMenu:
package popupshit;
import java.awt.event.ActionListener;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
public class GUIPopupMenu extends JPopupMenu {
public GUIPopupMenu(int numbers) {
for (int i = 1; i < numbers; i++) {
JMenuItem popMenuItem = new JMenuItem("" + i);
popMenuItem.addActionListener ((ActionListener) this.getInvoker());
System.out.println(this.getParent());
this.add(new JMenuItem("" + i));
}
this.addSeparator();
this.add(new JMenuItem("remove"));
}
}
GUILabel:
package popupshit;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.border.BevelBorder;
import javax.swing.border.BevelBorder;
public class GUILabel extends JLabel implements ActionListener {
public GUILabel() {
this.setBorder(new BevelBorder(BevelBorder.LOWERED));
this.setVisible(true);
this.setPreferredSize(new Dimension(50, 50));
this.setText("0");
}
#Override
public void actionPerformed(ActionEvent e) {
this.setText((String) e.getActionCommand());
JOptionPane.showMessageDialog(null, "worked!" );
}
}
invoker is null because until the popup menu is a actually invoked, it has no invoker.
Instead, add a simple ActionListener to the menu item which, when invoked, uses the invoker property to determine which should occur.
My personal preference would be to create a new instance of the popup menu for each component separately, passing a reference of the component in question or some other controller as required...but that's me...
Add an ActionListener to the menu item something like:
#Override
public void actionPerformed(ActionEvent e)
{
Component c = (Component)e.getSource();
JPopupMenu popup = (JPopupMenu)c.getParent();
JLabel label = (JLabel)popup.getInvoker();
...
}
Don't extend JPopupMenu just to add a few menu items to the popup.
Related
I'm not sure what exactly I am doing wrong but I keep getting an error with the ButtonHandler. I have a GUI class and a GUI Test class. The GUI class is the first one and the GUI_Test class is at the bottom. I am using NetBeans IDE 11.0. Everything else works on here but the ButtonHandler. I believe I followed the directions wrong or something because it just keeps telling me to create a new class for the ButtonHandler or break it up. But neither of those things are what I want.
The checkboxes also will not appear in the output text area when you run it.
package javaapplication20;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.ButtonGroup;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JTextArea;
public class Week3GUI extends JFrame {`
//variables
private JRadioButton radCoffee, radTea;
private JCheckBox chkFootball, chkBasketball, chkBaseball;
private JTextArea txtMessage;
public Week3GUI()
{
//instantiate the GUI components
// this sets 5 rows, 20 columns as default size
txtMessage = new JTextArea(5,20);
radCoffee =new JRadioButton("Coffee");
radTea =new JRadioButton("Tea");
//instantiate checkboxes
chkFootball =new JCheckBox("football");
chkBasketball =new JCheckBox("basketball");
chkBaseball =new JCheckBox("baseball");
//create panel for the radio buttons
JPanel p1 =new JPanel();
JPanel p2 =new JPanel();
//set layout for the panel and add the components
p1.setLayout(new FlowLayout());
p1.add(radCoffee);
p1.add(radTea);
// set layout for the panel and add the components
p2.setLayout(new FlowLayout());
p2.add(chkFootball);
p2.add(chkBasketball);
p2.add(chkBaseball);
//need to group the buttons together
ButtonGroup b =new ButtonGroup();
b.add(radCoffee);
b.add(radTea);
//add event handlers for radio buttons
RBHandler rb =new RBHandler();
radCoffee.addItemListener(rb);
radTea.addItemListener(rb);
//use grid layout for the frame
//1 column, multiple rows
setLayout(new GridLayout(0,1));
//first "row" of the frame is the label
add(new JLabel("Which do you like?"));
//next "row" is the panel p1 with radio buttons
add(p1);
//third "row" is the textfield
add(p2);
// fourth "row" is the textfield
add(txtMessage);
} //end constructor
private class RBHandler implements ItemListener
{
#Override
public void itemStateChanged(ItemEvent e)
{
if(radCoffee.isSelected())
txtMessage.setText("You like coffee");
else if(radTea.isSelected())
txtMessage.setText("You like tea");
}
private void processChoices()
{
//"read" the radio buttons first
if(radCoffee.isSelected())
txtMessage.setText("You like\ncoffee");
else if (radTea.isSelected())
txtMessage.setText("You like\ntea");
else
{
JOptionPane.showMessageDialog(null,"Must select a beverage",
"Error",JOptionPane.ERROR_MESSAGE);
return; //do NOT continue this method
}
//now read the check boxes and APPEND to textarea
if(chkFootball.isSelected())
txtMessage.append("\nfootball");
if(chkBasketball.isSelected())
txtMessage.append("\nbasketball");
if(chkBaseball.isSelected())
txtMessage.append("\nbaseball");
}
private class ButtonHandler implements ActionListener
{
ButtonHandler h = new ButtonHandler();
#Override
public void actionPerformed(ActionEvent actionEvent)
{
processChoices();
radCoffee.addActionListener(h);
radTea.addActionListener(h);
chkFootball.addActionListener(h);
chkBaseball.addActionListener(h);
chkBasketball.addActionListener(h);
}
}
}
} //end class
package javaapplication20;
import javax.swing.JFrame;
public class Week3GUI_Test {
public static void main(String[] args)
{
Week3GUI g =new Week3GUI();
g.setSize(300,200);
g.setVisible(true);
g.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
Here is the minimal working application :
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import java.awt.Dimension;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
public class JMenuItemReuse {
public static void main(String[] args) {
SwingUtilities.invokeLater(TestFrame::new);
}
}
class TestFrame extends JFrame {
public TestFrame() {
super();
JPanel panel = new JPanel();
JPopupMenu menu1 = new JPopupMenu();
JPopupMenu menu2 = new JPopupMenu();
JMenuItem item1 = new JMenuItem("reused");
JMenuItem item2 = new JMenuItem("not reused");
menu1.add(item1);
menu2.add(item1); // works if this line is commented
menu2.add(item2);
panel.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
super.mouseClicked(e);
if (SwingUtilities.isRightMouseButton(e)) {
menu1.show(panel, e.getX(), e.getY());
} else {
menu2.show(panel, e.getX(), e.getY());
}
}
});
panel.add(new JLabel("popup-test"));
add(panel);
setPreferredSize(new Dimension(400, 400));
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
pack();
setVisible(true);
}
}
The problem is that the popup menus do not work as expected when at least one menu item is reused. It is not a big issue, can be easily avoided by duplicating the reused menu item, but I am still wondering why does it happen. Any ideas?
A JMenuItem belongs to one, and only one, JPopupMenu (or any other menu). You cannot add a Swing component to more than one container; if you do, then the component will automatically be removed from the previous container.
Actaully if you want, you can create Actions. Actions can be shared and added to multiple components (JMenuItems, JButtons etc). You can even enable/disable the Action which will enable/disable all the components at the same time.
I am actually a beginner in Java Programming (on eclipse and without netbeans), and want to clear a JLabel presents in a JFrame by clicking a JButton without removing the JButton present at the top of this frame.
import java.awt.Color;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JOptionPane;
import java.awt.*;
import java.awt.BorderLayout;
import java.awt.event.KeyEvent;
import javax.swing.BoundedRangeModel;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class ButtonTest extends JPanel implements ActionListener {
private JButton ouvrirButton = new JButton("Ouvrir");
private JButton retirerButton = new JButton("Retirer");
private JButton ajouterButton = new JButton("Ajouter");
public ButtonTest() {
add(ouvrirButton);
add(retirerButton);
add(ajouterButton);
ouvrirButton.addActionListener(this);
retirerButton.addActionListener(this);
ajouterButton.addActionListener(this);}
public void actionPerformed(ActionEvent evt) {
Object source = evt.getSource();
Color color = getBackground();
// ACTION Button "OUVRIR"
// I WANT TO REMOVE THIS JLABEL TEXT WHEN I CLICK FOR EXEMPLE ON
// OR "RETIRER"
if (source == ouvrirButton)
{
color = Color.yellow;
JLabel lab1 = new JLabel("Text", JLabel.LEFT);
setLayout(new FlowLayout());
add(lab1 = new JLabel("INVENTAIRE : "));
lab1.setBounds(20, 15, 500, 100);
}
else if (source == retirerButton)
color = Color.red;
else if (source == ajouterButton)
color = Color.red;
setBackground(color);
repaint();
}
// The main
public static void main(String[] args) {
// NOM DE LA FENETRE
JFrame frame = new JFrame("Programme ");
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
Container contentPane = frame.getContentPane();
contentPane.add(new ButtonTest());
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(1300, 700);
frame.setVisible(true);
}
}
I tried .setText("") but it doesn't work... Please help me !
I tried .setText("") but it doesn't work...
Yes it does. The problem is you create the label in the ActionListener so that label reference is only valid in the block of code that created it.
You need to create the label as an instance variable (the way you did for all you buttons) and add the label to the fame at the same time you add the buttons to the panel.
Then you will be able to access the label in the ActionListener and change the text.
I have a window, which is the main window in my app and it contains buttons. On clicking on one of them, a child JFrame appears and if I click again another frame appears and this can be continuous depending on how many clicks are made. What I want, is when I click on the JButton once only one frame should open and since this frame is open no other similar frames can be opened upon clicking on the button for the second time until the first child frame is closed.
This can be done by opening a Modal dialog box instead of a jFrame. See How to Use Modality in Dialogs for more information.
Here is a simple example from A Simple Modal Dialog:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class AboutDialog extends JDialog implements ActionListener {
public AboutDialog(JFrame parent, String title, String message) {
super(parent, title, true);
if (parent != null) {
Dimension parentSize = parent.getSize();
Point p = parent.getLocation();
setLocation(p.x + parentSize.width / 4, p.y + parentSize.height / 4);
}
JPanel messagePane = new JPanel();
messagePane.add(new JLabel(message));
getContentPane().add(messagePane);
JPanel buttonPane = new JPanel();
JButton button = new JButton("OK");
buttonPane.add(button);
button.addActionListener(this);
getContentPane().add(buttonPane, BorderLayout.SOUTH);
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
pack();
setVisible(true);
}
public void actionPerformed(ActionEvent e) {
setVisible(false);
dispose();
}
public static void main(String[] a) {
AboutDialog dlg = new AboutDialog(new JFrame(), "title", "message");
}
}
I am having some problems regarding to the JMenuBar and I cant seem to figure it out.
I will start with an abriviation of the problem: The program consists of a JFrame, a JDialog and a JMenuBar. Initially, you will get to see a JFrame with the JMenuBar in the top. But at some point, the JDialog will pop up where a user can fill in some text fields. The problem that I'm having is that as soon as the focus goes to the JDialog, the JMenuBar disappears. What I want is that the JMenuBar stays in the top of the screen all the time, except if the whole program is NOT in focus. Here are 2 screenshots, in the first screen shot, the JFrame is selected and in the other one the JDialog is selected.
So what i actually want is instead of only seeing the JMenuBar when the focus is on the JFrame, i want to see the JMenuBar all the time. Since a JDialogs can not have the JMenuBar in the top, like a JFrame has, i decided not to have multiple JMenuBars, but just the one that should be visible all the time.
At last i will give a part of the code that is as small as possible (and still working) and also contains the problem:
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JRootPane;
import javax.swing.KeyStroke;
/**
* #author Guus Leijsten
* #created Oct 27, 2012
*/
public class MenuBarProblem extends JFrame {
public MenuBarProblem() {
super("Frame");
this.setMinimumSize(new Dimension(270, 200));
this.setPreferredSize(new Dimension(800, 530));
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
JRootPane root = this.getRootPane();
//Menu
JMenu fileMenu = new JMenu("File");
JMenuItem file_exit = new JMenuItem("Exit");
file_exit.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_W, Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
file_exit.setToolTipText("Exit application");
file_exit.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
fileMenu.add(file_exit);
JMenuBar menu = new JMenuBar();
menu.add(fileMenu);
root.setJMenuBar(menu);
this.setVisible(true);
JDialog d = new JDialog(this, "Dialog");
d.setSize(200, 100);
d.setLocation(0, (int)root.getContentPane().getLocationOnScreen().getY());
d.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
d.setVisible(true);
}
public static void main(String[] args) {
String os = System.getProperty("os.name").toLowerCase();
if(os.indexOf("mac") >= 0) {
System.setProperty("apple.laf.useScreenMenuBar", "true");
}
new MenuBarProblem();
}
}
If I can be honoust, i think that the problem lies in the part of JRootPane. But we'll see ;)
Did anyone else encountered this problem and managed to solve it alrady, or is there anybody that wants to give it a shot?
Thanks in advance!
Added content:
In the following example I will show a version that gives some functionality to the play.
This is the program i'm making:
The second image shows the state in which the right menu is undocked.
Obviously the JMenuBar should still be visible and operational because without it, a lot of functionalities of the program will be disabled.
At this point i'm starting to think that it is impossible for the JMenuBar to stay visible when the dialog (undocked menu) is undocked, and focussed on.
I know that the JMenuBar on a JDialog can not be in the mac osx style (top of screen), so are there any other techniques i can use for undocking, which does give me a mac osx style JMenuBar?
One key to solving this problem, pun intended, is to let a key binding share a common menu action, as shown below. Note how a menu item, your dialog's content and an (otherwise superfluous) button can all use the same Action instance. A few additional notes:
Kudos for using getMenuShortcutKeyMask().
Swing GUI objects should be constructed and manipulated only on the event dispatch thread (EDT).
System properties should be set before starting the EDT.
Make the dialog's setLocation() relative to the frame after its geometry is known.
A common Mac idiom uses the following predicate:
if (System.getProperty("os.name").startsWith("Mac OS X") {…}
See also this example.
For local use in the dialog itself, also consider JToolBar.
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
/**
* #see https://stackoverflow.com/a/13100894/230513
*/
public class MenuBarProblem extends JFrame {
private static final int MASK =
Toolkit.getDefaultToolkit().getMenuShortcutKeyMask();
private static final String exitName = "Exit";
private static final KeyStroke exitKey =
KeyStroke.getKeyStroke(KeyEvent.VK_W, MASK);
private final ExitAction exitAction = new ExitAction(exitName);
public MenuBarProblem() {
super("Frame");
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
JMenu fileMenu = new JMenu("File");
JMenuItem fileExit = new JMenuItem(exitAction);
fileMenu.add(fileExit);
JMenuBar menu = new JMenuBar();
menu.add(fileMenu);
JDialog d = new JDialog(this, "Dialog");
JPanel p = new JPanel();
p.getInputMap().put(exitKey, exitName);
p.getActionMap().put(exitName, exitAction);
p.add(new JButton(exitAction));
d.add(p);
d.pack();
d.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
this.setJMenuBar(menu);
this.pack();
this.setSize(new Dimension(320, 240));
this.setLocationByPlatform(true);
this.setVisible(true);
d.setLocation(this.getRootPane().getContentPane().getLocationOnScreen());
d.setVisible(true);
}
private static class ExitAction extends AbstractAction {
public ExitAction(String name) {
super(name);
this.putValue(Action.MNEMONIC_KEY, exitKey.getKeyCode());
this.putValue(Action.ACCELERATOR_KEY, exitKey);
}
#Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
}
public static void main(String[] args) {
System.setProperty("apple.laf.useScreenMenuBar", "true");
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new MenuBarProblem();
}
});
}
}
Solved!
Using a JFrame with the use of setAlwaysOnTop(true) gives me the desired effect of having a JMenuBar when the focus changes.