Develop Reference

Adding a JInternalFrame to a JTabbedPane holding a JScrollPane holding a JPanel with Gridbag layout

Can't figure out why this wont work, I get a blank panel added to my gridbag panel.
I added a JLabel("test") between the frames I'm trying to add just to see that something IS getting added, it just isn't visible?
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Label;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
public class Workspace extends JTabbedPane {
static JFrame frame = new JFrame();
private JPanel grid;
private String text = new String("testing.");
Workspace() {
this.addTab("title", growPanel());
}
public static void main(String[] args) throws IOException {
createAndShowGUI();
}
private JPanel growPanel() {
JPanel gp = new JPanel(false);
gp.setPreferredSize(new Dimension(800,600));
//Add a button that adds my frame
JButton addComponentBtn = new JButton("Add Component");
addComponentBtn.addActionListener(e-> {
try {
addComponent();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
});
gp.add(addComponentBtn, BorderLayout.PAGE_START);
grid = new JPanel(new GridLayout(0, 2, 10, 10)); //any number of rows, 2 columns, H and V gap
JScrollPane sp = new JScrollPane(grid);
sp.setPreferredSize(new Dimension(800,600));
gp.add(sp, BorderLayout.CENTER);
this.setVisible(true);
return gp;
}
void addComponent() throws IOException {
System.out.println("adding");
grid.add(new JLabel("test"));
grid.add(new intf());
this.repaint();
frame.pack();
}
private static void createAndShowGUI() throws IOException {
//Create and set up the window.
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Add content to the window.
frame.add(new Workspace(), BorderLayout.CENTER);
//Display the window.
frame.pack();
frame.setVisible(true);
}
}
And the intf.java class for the JInternalFrame:
import javax.swing.JInternalFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class intf extends JInternalFrame {
public intf () {
super("Document",
true, //resizable
true, //closable
true, //maximizable
true);//iconifiable
JPanel jp = new JPanel();
JLabel jl = new JLabel("Hi I'm a label");
jp.add(jl);
this.add(jp);
this.pack();
this.repaint();
}
}
Edit:
The JPanel is used to hold the Layout, I don't think I can assign one to the TabbedPane?
Users will load in images which will appear on the left side of the GridLayout (I will upgrade this to a GridBag). After selecting regions on said images, graphs will appear on the right side. This is also why we use a scrollPane so that there is no limit to the number of images loaded. The TabbedPane will be used to split the load if a user loads in too many images (this is all not in the demo code shown here and not relevant to the problem).
The code I posted is for testing why the JInternalFrame doesn't show, so it only shows what is relevant to getting that to work.

Thank you all for your input.
It turned out to be a simple mistake of not having a necessary .setVisible(true)
Under the addComponent() method, the problem is solved when I replace
grid.add(new intf());
with
intf a = new intf();
a.setVisible(true);
grid.add(a);

JPanel created on click not appearing

The below code is not my actual code but a concise, runnable remake of what I am trying to achieve. I want the JPanel CP, an instance of clickPanel, to appear when the user clicks on the image in JPanel hasAnImage. I can see in the Netbeans console that the is executing because of the Sys.out.print, but nothing appears on the screen. I have tried setting visible to false then true again and revalidate() in the mousePressed event; the image moves to the left, but nothing appears on the screen. The goal is for CP to appear. What am I missing? Hope my question is clear.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Testo extends JFrame{
public Testo(){
BufferedImage image = null;
try {
image = ImageIO.read(new File("C:\\Users\\someimage.jpg"));
} catch (IOException ex) {
ex.printStackTrace();
}
;
final JLabel label = new JLabel(new ImageIcon(image));
JPanel hasAnImage = new JPanel();
hasAnImage.addMouseListener(new MouseAdapter(){
#Override //I override only one method for presentation
public void mousePressed(MouseEvent e) {
clickPanel CP = new clickPanel();
hasAnImage.add(CP);
revalidate();
//setVisible(false);
//setVisible(true);
}
});
hasAnImage.add(label);
add(hasAnImage);
setVisible(true);
}
public static void main(String[] args) {
Testo frame = new Testo();
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.getContentPane().setBackground(Color.WHITE);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public class clickPanel extends JPanel{
public clickPanel() {
setPreferredSize(new Dimension(100,60));
setMaximumSize(new Dimension(100,60));
setBackground(new Color(1.0f,1.0f,1.0f,0.1f));
setBorder(BorderFactory.createMatteBorder(2,2,2,2,Color.GREEN));
System.out.println("This is being executed...");
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setFont(new Font("Arial", Font.PLAIN, 12));
g.setColor(Color.GREEN);
g.drawString("CLICK", 2, 2);
}
}
}

Beyond revalidate();ing the pane, you also need to repaint(); it. Thus your mousePressed method should become:
public void mousePressed(MouseEvent e) {
clickPanel CP = new clickPanel();
hasAnImage.add(CP);
revalidate();
repaint();
}
For further reading: http://docs.oracle.com/javase/7/docs/api/java/awt/Component.html#repaint()

Select text in 2 JTextarea at the same time

I am trying to do a small app that compares two similar texts contained in 2 JTextarea. I am wondering if it's possible to select text from the first JTextarea and automatically select the text on the second JTeaxtarea (lets consider that it's guarantee that the 2 JTextarea will have the same text for now) ?
Should I share events or listeners ?
Thank you

This would be so much easier if JTextComponent supported a selection model...
Basically, what you can do is attach a ChangeListener to the JTextArea's Caret and monitor for changes to the Caret, changing the selection of the other JTextArea in response...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.CaretEvent;
import javax.swing.event.CaretListener;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.DefaultHighlighter;
public class MirrorTextSelection {
public static void main(String[] args) {
new MirrorTextSelection();
}
public MirrorTextSelection() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JTextArea left;
private JTextArea right;
private DefaultHighlighter.DefaultHighlightPainter highlightPainter;
public TestPane() {
highlightPainter = new DefaultHighlighter.DefaultHighlightPainter(UIManager.getColor("TextArea.selectionBackground"));
left = new JTextArea(20, 20);
left.setWrapStyleWord(true);
left.setLineWrap(true);
right = new JTextArea(20, 20);
right.setWrapStyleWord(true);
right.setLineWrap(true);
left.setText("I am trying to do a small app that compares two similar texts contained in 2 JTextarea. I am wondering if it's possible to select text from the first JTextarea and automatically select the text on the second JTeaxtarea (lets consider that it's guarantee that the 2 JTextarea will have the same text for now) ? Should I share events or listeners ? Thank you");
right.setText("I am trying to do a small app that compares two similar texts contained in 2 JTextarea. I am wondering if it's possible to select text from the first JTextarea and automatically select the text on the second JTeaxtarea (lets consider that it's guarantee that the 2 JTextarea will have the same text for now) ? Should I share events or listeners ? Thank you");
setLayout(new GridLayout(0, 2));
add(new JScrollPane(left));
add(new JScrollPane(right));
left.getCaret().addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
int dot = left.getCaret().getDot();
int mark = left.getCaret().getMark();
right.setCaretPosition(mark);
right.moveCaretPosition(dot);
}
});
}
}
}
Now, when you run this, you will find that the right side doesn't seem to get highlighted...what?!
The selection is changing, it's just not been rendered because the component doesn't have focus...
Instead, you could use a Highlighter to highlight the text...
private DefaultHighlighter.DefaultHighlightPainter highlightPainter;
//...
highlightPainter = new DefaultHighlighter.DefaultHighlightPainter(UIManager.getColor("TextArea.selectionBackground"));
left.getCaret().addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
int dot = left.getCaret().getDot();
int mark = left.getCaret().getMark();
right.getHighlighter().removeAllHighlights();
try {
int start = Math.min(dot, mark);
int end = Math.max(dot, mark);
right.getHighlighter().addHighlight(start, end, highlightPainter);
} catch (BadLocationException ex) {
ex.printStackTrace();
}
}
});
Okay, this is now working and you can control the background color of the highlight...
There is another alternative...We can replace the Caret of the right JTextArea with one that doesn't hide the selection when focus is lost...
public class HighlightCaret extends DefaultCaret {
#Override
public void install(JTextComponent c) {
super.install(c);
setSelectionVisible(true);
}
#Override
public void focusGained(FocusEvent e) {
JTextComponent component = getComponent();
if (component.isEnabled()) {
if (component.isEditable()) {
setVisible(true);
}
setSelectionVisible(true);
}
}
#Override
public void focusLost(FocusEvent e) {
setVisible(false);
}
}
Then we set the Caret to right...
right.setCaret(nwe HighlightCaret());
This means we don't need the Highlighter code, we can stick with the original and we get control over not only the background selection color but also the foreground selection color as well...

Why isn't mouselistener working?

Here's the code. It prints out the mouse location when it's in the panel but not the JTextArea. I added the mouse listener to the text area as well? The problem is that the coordinates are not consistent throughout the JFrame. Is there a way to just have one mouselistener that covers the entire jframe?
Is there a way to disable the mouse listener in the textarea?
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
public class test extends JFrame {
public test(){
setPreferredSize(new Dimension(600,400));
JPanel p = new JPanel();
p.setBackground(Color.blue);
p.setPreferredSize(new Dimension(600,200));
JTextArea t = new JTextArea();
t.setPreferredSize(new Dimension(600,200));
add(p,BorderLayout.NORTH);
add(t,BorderLayout.SOUTH);
pack();
MouseInput m = new MouseInput();
addMouseMotionListener(m);
t.addMouseMotionListener(m);
setVisible(true);
}
public static void main(String[] args){
new test();
}
public class MouseInput implements MouseMotionListener{
#Override
public void mouseDragged(MouseEvent e) {
}
#Override
public void mouseMoved(MouseEvent e) {
int mx = e.getX();
int my = e.getY();
System.out.println(mx + "," + my);
}
}
}

Think of your mouse events like rain. They fall from the top of your component hierarchy down until something stops them.
Once stopped, they will no long notify other listeners lower in the hierarchy.
In you program you have and JPanel and JTextField sitting on top of another component (the content pane) sitting on a JLayeredPane sitting on top of the frame. Any one of these may be consuming the mouse event.
Try adding the MouseInput to your JPanel, p instead
Updated
This is an example of a global mouse listener (as suggested by #Hovercraft Full Of Eels, it WILL get hammered, as every mouse event will pass through it.
It also demonstrates how to translate a mouse point from it's local context to another context.
import java.awt.AWTEvent;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.AWTEventListener;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class GloablMouseListener {
public static void main(String[] args) {
new GloablMouseListener();
}
public GloablMouseListener() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new BorderLayout());
JPanel panel = new JPanel();
panel.setBackground(Color.BLUE);
JTextArea ta = new JTextArea(10, 20);
add(panel, BorderLayout.NORTH);
add(new JScrollPane(ta), BorderLayout.SOUTH);
Toolkit.getDefaultToolkit().addAWTEventListener(new AWTEventListener() {
#Override
public void eventDispatched(AWTEvent event) {
if (event instanceof MouseEvent) {
MouseEvent e = (MouseEvent) event;
System.out.println("Local point = " + e.getPoint());
Point p = e.getPoint();
Window window = SwingUtilities.getWindowAncestor(e.getComponent());
if (window != e.getSource() && window != null) {
p = SwingUtilities.convertPoint(e.getComponent(), e.getPoint(), window);
}
System.out.println("Global point = " + p);
}
}
}, AWTEvent.MOUSE_EVENT_MASK | AWTEvent.MOUSE_MOTION_EVENT_MASK);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
}

The JTextArea has its own MouseListener/MouseMotionListener that grabs the mouse information before any underlying class with a MouseListener or motion listener can.
This may be fixable by using an AWTEventListener, but I have not tried this myself yet.
Edit
OK, I have tried this as a for instance:
import java.awt.AWTEvent;
import java.awt.Color;
import java.awt.Component;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.AWTEventListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class Test2 extends JPanel {
JTextArea textarea = new JTextArea(15, 60);
public Test2() {
JPanel topPanel = new JPanel();
topPanel.setBackground(Color.blue);
setLayout(new GridLayout(0, 1));
add(topPanel);
add(new JScrollPane(textarea));
addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseMoved(MouseEvent e) {
int x = e.getX();
int y = e.getY();
System.out.printf("%20s [%03d, %03d]%n", "From MouseAdapter:", x, y);
}
});
long eventMask = AWTEvent.MOUSE_MOTION_EVENT_MASK;
Toolkit.getDefaultToolkit().addAWTEventListener(new AWTEventListener() {
#Override
public void eventDispatched(AWTEvent awtEvent) {
MouseEvent mouseEvent = (MouseEvent) awtEvent;
Component component = (Component) awtEvent.getSource();
Point location = component.getLocationOnScreen();
Point test2Location = Test2.this.getLocationOnScreen();
// Normalized to find the mouse location relative to the main JPanel,
// the Test2 "this" JPanel.
int x = mouseEvent.getX() + location.x - test2Location.x;
int y = mouseEvent.getY() + location.y - test2Location.y;
System.out.printf("%20s [%03d, %03d]%n", "From AWTEvent:", x, y);
}
}, eventMask );
}
private static void createAndShowGui() {
JFrame frame = new JFrame("Test2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new Test2());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

Try adding a MouseListener to your application's GlassPane.
See these following link. It includes a Java Web Start demo of something similar to what you want to do.
How to Use Root Panes

Java tabbed panes within internal frame

I am trying to get an internal frame to contain tabbed panes. However, my code does not seem to be loading the panes into the internal frame. I have my code in the java files, called InternalFrame.java and TabbedPaneSample.java. The code for both files is included below. Can anyone show me how to fix the code below so that it loads the tabbed panes when I run InternalFrame.java?
Here is my code:
The code for InternalFrame.java is:
package test;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Panel;
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.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JLayeredPane;
public class InternalFrame extends JFrame {
JButton openButton;
JLayeredPane desktop;
JInternalFrame internalFrame;
TabbedPaneSample myTabbedPaneSample = new TabbedPaneSample();
public InternalFrame() {
super("Click button to open internal frame with two panels.");
setSize(500, 400);
openButton = new JButton("Open");
Panel p = new Panel();
p.add(openButton);
add(p, BorderLayout.SOUTH);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
openButton.addActionListener(new OpenListener());
desktop = new JDesktopPane();
desktop.setOpaque(true);
add(desktop, BorderLayout.CENTER);
}
class OpenListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
if ((internalFrame == null) || (internalFrame.isClosed())) {
internalFrame = new JInternalFrame("Internal Frame", true, true, true, true);
internalFrame.setBounds(50, 50, 200, 100);
internalFrame.add(myTabbedPaneSample, BorderLayout.CENTER);
internalFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
internalFrame.pack();
internalFrame.setMinimumSize(new Dimension(300, 300));
desktop.add(internalFrame, new Integer(1));
internalFrame.setVisible(true);
}
}
}
public static void main(String args[]) {
InternalFrame myInternalFrame = new InternalFrame();
myInternalFrame.setVisible(true);
}
}
And the code for TabbedPaneSample.java is:
package test;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
public class TabbedPaneSample extends JTabbedPane {
private JTabbedPane tabbedPane = new JTabbedPane();
private ImageIcon closeImage = new ImageIcon("C:/test/shipIcon.gif");
private Dimension closeButtonSize;
private int tabCounter = 0;
public TabbedPaneSample() {
closeButtonSize = new Dimension(closeImage.getIconWidth() + 2, closeImage.getIconHeight() + 2);
}
public void add() {
final JPanel content = new JPanel();
JPanel tab = new JPanel();
tab.setOpaque(false);
JLabel tabLabel = new JLabel("Tab " + (++tabCounter));
JButton tabCloseButton = new JButton(closeImage);
tabCloseButton.setPreferredSize(closeButtonSize);
tabCloseButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int closeTabNumber = tabbedPane.indexOfComponent(content);
tabbedPane.removeTabAt(closeTabNumber);
}
});
tab.add(tabLabel, BorderLayout.WEST);
tab.add(tabCloseButton, BorderLayout.EAST);
this.addTab(null, content);
this.setTabComponentAt(this.getTabCount() - 1, tab);
}
public static void main(String[] args) {
TabbedPaneSample main = new TabbedPaneSample();
main.add();
main.add();
}
}

Here's one approach, shown below. A more flexible approach using Action is referenced here.
Addendum: Reviewing your code, you should let the various layout managers and component preferred sizes do more of the work, as shown. In particular, this.setPreferredSize() is done for demonstration purposes. In a real application, you would restore user size and location preferences.
package overflow;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
/** #see https://stackoverflow.com/posts/6514889 */
public class InternalFrame extends JFrame {
JButton openButton;
JLayeredPane desktop;
JInternalFrame internalFrame;
public InternalFrame() {
super("Click button to open internal frame with two tabs.");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setPreferredSize(new Dimension(400, 400));
openButton = new JButton("Open");
JPanel p = new JPanel();
p.add(openButton);
this.add(p, BorderLayout.SOUTH);
openButton.addActionListener(new OpenListener());
desktop = new JDesktopPane();
this.add(desktop, BorderLayout.CENTER);
this.pack();
this.setLocationRelativeTo(null);
}
class OpenListener implements ActionListener {
private static final int DELTA = 40;
private int offset = DELTA;
public void actionPerformed(ActionEvent e) {
internalFrame = new JInternalFrame(
"Internal Frame", true, true, true, true);
internalFrame.setLocation(offset, offset);
offset += DELTA;
internalFrame.add(createTabbedPane());
desktop.add(internalFrame);
internalFrame.pack();
internalFrame.setVisible(true);
}
}
private JTabbedPane createTabbedPane() {
JTabbedPane jtp = new JTabbedPane();
createTab(jtp, "One");
createTab(jtp, "Two");
return jtp;
}
private void createTab(JTabbedPane jtp, String s) {
jtp.add(s, new JLabel("TabbedPane " + s, JLabel.CENTER));
}
public static void main(String args[]) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
InternalFrame myInternalFrame = new InternalFrame();
myInternalFrame.setVisible(true);
}
});
}
}

First of all, I think Finally, I think you shouldn't use desktop.add(internalFrame, new Integer(1)) but rather desktop.add(internalFrame) instead, the reason is that JDesktopPane uses its layers (it is a JLayeredPane subclass) internally, and I don't think you should play with layers yourself.
Then, following this problem I had once with JInternalFrame, I would advise you call pack() after adding the internal frame to the desktop pane.
Hence, you should try with your OpenListener class looking like this:
class OpenListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
if ((internalFrame == null) || (internalFrame.isClosed())) {
internalFrame = new JInternalFrame("Internal Frame", true, true, true, true);
internalFrame.setBounds(50, 50, 200, 100);
internalFrame.add(myTabbedPaneSample, BorderLayout.CENTER);
internalFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// internalFrame.pack();
internalFrame.setMinimumSize(new Dimension(300, 300));
// desktop.add(internalFrame, new Integer(1));
desktop.add(internalFrame);
internalFrame.pack();
internalFrame.setVisible(true);
}
}
}
Besides, I also agree with trashgod comments on Action of course and the simplifying rework he has done on your snippet.

I preferred to create in my Main Frame class (which extends JFrame) the following function:
private void showIntFrame(Class intFrameClass) {
JInternalFrame targetFrame = null;
int xoff = 0, yoff = 0;
for(JInternalFrame jif : jdp.getAllFrames()) {
if(jif.getClass().equals(intFrameClass))
targetFrame = jif;
if(jif.getLocation().x > xoff)
xoff = jif.getLocation().x;
if(jif.getLocation().y > yoff)
yoff = jif.getLocation().y;
}
if(targetFrame == null) {
try {
Constructor<JInternalFrame> c = intFrameClass.getConstructor(MainFrame.class);
targetFrame = c.newInstance(MainFrame.this);
} catch (Exception ex) {
System.err.println("Exception in MainFrame.showIntFrame() while creating new JInternalFrame instance. " + ex.getLocalizedMessage());
ex.printStackTrace();
return;
}
jdp.add(targetFrame);
targetFrame.setLocation(xoff + 30, yoff + 30);
}
targetFrame.setVisible(true);
try {
targetFrame.setSelected(true);
} catch (PropertyVetoException ex) {
System.err.println("PropertyVetoException in MainFrame.showIntFrame() while activating JInternalFrame instance. " + ex.getLocalizedMessage());
}
}
Here jdp is instance of JDesktopPane, which previously was set as ContentPane of my main JFrame.
Because my programs often contain numbers of different classes, inherited from JInternalFrame, it is easier to call this function from event handlers to show new subclass of JInternalFrame.
Every subclass of JInternalFrame in my programs have one constructor with one parameter - MainFrame (main JFrame).