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JTabbedPane tab border removal

JTabbedPane - tab border is being shown even after using BasicTabbedPaneUI. Please let me know how can I change such that no border is shown between the tabs? Is there any method to remove the border completely ?
Please Send me the code snippet. Thanks in advance.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.SwingUtilities;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.plaf.basic.BasicTabbedPaneUI;
public class TabbedPaneTest implements Runnable {
#Override
public void run() {
final JTabbedPane pane = new JTabbedPane();
pane.addTab("A", createTab(Color.RED));
pane.addTab("B", createTab(Color.YELLOW));
pane.addTab("C", createTab(Color.BLUE));
pane.setUI(new BasicTabbedPaneUI() {
#Override
protected void paintContentBorder(Graphics g, int tabPlacement, int selectedIndex) {
}
});
pane.setBackground(Color.WHITE);
pane.addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent arg0) {
pane.setForegroundAt(pane.getSelectedIndex(), Color.GREEN);
}
});
final JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(pane);
frame.pack();
//frame.setSize(500, 200);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private JPanel createTab(Color color) {
JPanel p = new JPanel(new BorderLayout()) {
private static final long serialVersionUID = 1L;
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 300);
}
};
p.setBorder(BorderFactory.createLineBorder(color, 2));
p.setBackground(Color.WHITE);
return p;
}
public static void main(String[] args) throws Exception {
SwingUtilities.invokeLater(new TabbedPaneTest());
}
}

// Remove the white line under a tab button
Insets insets = UIManager.getInsets("TabbedPane.contentBorderInsets");
insets.top = -1;
UIManager.put("TabbedPane.contentBorderInsets", insets);

Reinitialise a jframe

I've a main frame on which there is a side panel with some buttons, and central panel used to display the tables and data generated from buttons on the side panel and its sub-panels
On the start my central panel is blank and I want it to always return to its initial state( blank ) after each click on a button before generating any data
I've use some sort of observer pattern (I'm not so experienced) but my problem is that the central panel must display data after clicks on some buttons that are on panels that also need a click on the side panel before to be generated
I've tried to make an executable example on the following classes, my real application displays some tables on the central panel and i send the models via the update method of the observers
hope its clear for you and I hope if you can really help me
1 - the main frame:
package tests;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class MainFrame extends JFrame implements MyObserver{
private SidePanel sidePanel;
private JPanel centralPanel;
private JFrame frame;
private JLabel title;
public MainFrame(){
frame = new JFrame("TEST");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setLayout(new BorderLayout());
sidePanel = new SidePanel();
sidePanel.addObserver(this);
centralPanel = new JPanel();
title = new JLabel();
initialise(0);
frame.pack();
frame.setVisible(true);
frame.setLocationRelativeTo(null);
}
private void initialise(int i) {
if( i == 0){
centralPanel.setPreferredSize(new Dimension(400,300));
centralPanel.setBackground(Color.green);
title.setText("GREEN");
centralPanel.add(title, BorderLayout.CENTER);
frame.add(sidePanel, BorderLayout.WEST);
frame.add(centralPanel, BorderLayout.CENTER);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new MainFrame();
}
});
}
#Override
public void update(int color) {
if(color == 0){
centralPanel.setBackground(Color.yellow);
title.setText("YELLOW");
}else{
centralPanel.setBackground(Color.pink);
title.setText("PINK");
}
}
}
2 - The side Panel
package tests;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JPanel;
public class SidePanel extends JPanel implements MyObserver,MyObservable{
private JPanel panel;
private JButton test;
private MyObserver observer;
private ButtonPanel buttonPanel;
public SidePanel(){
panel = new JPanel();
panel.setPreferredSize(new Dimension(140, 300));
panel.setBackground(Color.blue);
panel.setLayout(new BoxLayout(panel, 0));
test = new JButton("Lunch buttons");
test.setPreferredSize(new Dimension(80,30));
buttonPanel = new ButtonPanel();
buttonPanel.addObserver(this);
test.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
buttonPanel.setVisible(true);
}
});
panel.add(Box.createVerticalGlue());
panel.add(test);
panel.add(Box.createVerticalGlue());
panel.setVisible(true);
this.add(panel, BorderLayout.CENTER);
}
#Override
public void addObserver(MyObserver obs) {
this.observer = obs;
}
#Override
public void updateObserver(MyObserver obs, int color) {
obs.update(color);
}
#Override
public void update(int color) {
updateObserver(observer, color);
}
}
3 - the buttons panel, generally the source of any data to be displayed on the central panel
package tests;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JPanel;
public class ButtonPanel extends JDialog implements MyObservable{
private JButton yellow;
private JButton orange;
private JPanel panel;
private MyObserver observer;
public ButtonPanel(){
panel = new JPanel();
panel.setPreferredSize(new Dimension(300, 40));
panel.setLayout(new FlowLayout());
this.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
this.setContentPane(panel);
yellow = new JButton("YELLOW");
yellow.setPreferredSize(new Dimension(100,30));
yellow.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
updateObserver(observer, 0);
}
});
orange = new JButton("ORANGE");
orange.setPreferredSize(new Dimension(100,30));
orange.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
updateObserver(observer, 1);
}
});
panel.add(yellow);
panel.add(orange);
pack();
setLocationRelativeTo(null);
}
#Override
public void addObserver(MyObserver obs) {
this.observer = obs;
}
#Override
public void updateObserver(MyObserver obs, int color) {
obs.update(color);
}
}
Finally, the customized observer and observable interfaces, note in the real app i use a table model not just an int - I'm not sure it's a good way -
package tests;
public interface MyObservable {
public void addObserver(MyObserver obs);
public void updateObserver(MyObserver obs, int color);
}
package tests;
public interface MyObserver {
public void update(int color);
}

CHANGED ANSWER:
In SidePanel.java add:
private MainFrame frame;
Then make your constructor take a MyFrame object as parameter. Do this:
public SidePanel(MainFrame frame){
this.frame = frame;
//rest not changed
//
}
Change the actionPerformed() of test button to:
test.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
buttonPanel.setVisible(true);
frame.initialise(0); // this line is added
}
});
In MainFrame.java:
Change sidePanel = new SidePanel(); to sidePanel = new SidePanel(this);
AND
Change private void initialise(int i) to public void initialise(int i)
This does what you are trying to achieve.

How to paint on a Jpanel?

i am trying to add 2 different panels in a Frame. one panel adds few buttons in the frame. others frame will add a chess board into the frame. i am confused, how to draw this board on a panel. my Frame will have a board on the top and buttons at the bottom. Moreover, let me know if i am somewhere wrong in the given code can anybody help me? my Code is
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Test {
private JFrame main;
private JPanel board;
private JPanel buttons;
private JButton add;
private JButton delete;
public Test()
{
main=new JFrame();
board=new JPanel();
buttons=new JPanel();
add=new JButton("Add");
delete=new JButton("Delete");
init();
addButtons();
}
public void init()
{
main.setSize(700,700);
main.setVisible(true);
main.setDefaultCloseOperation(main.EXIT_ON_CLOSE);
}
public void addButtons()
{
buttons.setSize(700,40);
buttons.setLayout(new FlowLayout());
buttons.add(add);
buttons.add(delete);
main.add(buttons,BorderLayout.SOUTH);
}
public void addBoxes()
{
// what should be my code here...??
}
public static void main(String[] args) {
// TODO Auto-generated method stub
new Test();
}
}

You need a component to paint on, like a JPanel.
You need to #Override its paintComponent method
You can use a loop to paint using Graphics context
Use a flag to alternate between colors.
Take a look at some Painting Graphics tutorials
In the mean time, give this a whirl
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Board extends JPanel {
private static final int DIM_WIDTH = 640;
private static final int DIM_HEIGHT = 640;
private static final int SQ_SIZE = 80;
boolean black = true;
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (int i = 0; i < DIM_HEIGHT; i += SQ_SIZE) {
if (black) {
black = false;
} else {
black = true;
}
for (int j = 0; j < DIM_WIDTH; j += SQ_SIZE) {
if (black) {
g.setColor(Color.WHITE);
g.fillRect(j, i, SQ_SIZE, SQ_SIZE);
black = false;
} else {
g.setColor(Color.BLACK);
g.fillRect(j, i, SQ_SIZE, SQ_SIZE);
black = true;
}
}
}
}
public static void createAndShowGui() {
JFrame frame = new JFrame();
frame.add(new Board());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
frame.pack();
frame.setVisible(true);
}
public Dimension getPreferredSize() {
return new Dimension(DIM_WIDTH, DIM_HEIGHT);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

Why can this code note be run as a JFrame?

I am trying to make an applet run as a JFrame. The code I have below is simple but should work. It will run as an JApplet but when I go to RUN AS --> nothing appears.
import java.awt.*;
import java.applet.Applet;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class LifeCycle extends Applet
{
private static final long serialVersionUID = 1L;
String output = "test";
String event;
public void init()
{
gui(); //I am not certain if this needs to be there.
event = "\nInitializing...";
printOutput();
}
public void start()
{
event = "\nStarting...";
printOutput();
}
public void stop()
{
event = "\nStopping...";
printOutput();
}
public void destroy()
{
event = "\nDestroying...";
printOutput();
}
private void printOutput()
{
System.out.println(event);
output += event;
repaint();
}
private void gui() {
JFrame f = new JFrame("Not resizable");
JPanel d = new JPanel();
// LifeCycle a = new LifeCycle();
// a.init();//not working
d.setLayout(new BorderLayout());
d.add(new JButton("a"));
d.add(new JButton("b"));
d.setBackground(Color.RED);
//f.add(new LifeCycle());
f.add(d);
f.setSize(545,340);
f.setResizable(false);
f.setLocationRelativeTo(null);
f.setTitle("Test");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//a.destroy();
}
public void paint(Graphics g)
{
System.out.println("Graphics Paint Method!");
g.drawString(output, 100, 100);
}
public static void main(String[] args) {
LifeCycle l = new LifeCycle();
l.gui();
}
}
I would like to see the code that should be changed, but I cannot seem to find why this will not work. I have added to buttons to the panel to be displayed.

Don't mix AWT (Applet) with Swing components. Stick with just Swing.
Gear your class towards creating JPanels. Then you can place it in a JApplet if you want an applet or a JFrame if you want a JFrame.
Read up on use of BorderLayout -- you're adding multiple components to the default BorderLayout.CENTER position, and only one component, the last one added, will show.
For example ...
LifeCycle2.java
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JPanel;
class LifeCycle2 {
private static final int GAP = 5;
private static final int PREF_W = 545;
private static final int PREF_H = 340;
private JPanel mainPanel = new JPanel() {
#Override
public Dimension getPreferredSize() {
return LifeCycle2.this.getPreferredSize();
}
};
public LifeCycle2() {
JPanel buttonPanel = new JPanel(new GridLayout(1, 0, GAP, 0));
buttonPanel.add(new JButton("A"));
buttonPanel.add(new JButton("B"));
buttonPanel.setOpaque(false);
JPanel flowLayoutPanel = new JPanel();
flowLayoutPanel.setOpaque(false);
flowLayoutPanel.add(buttonPanel);
mainPanel.setLayout(new BorderLayout());
mainPanel.setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
mainPanel.setBackground(Color.red);
mainPanel.add(flowLayoutPanel, BorderLayout.NORTH);
}
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
public JComponent getMainPanel() {
return mainPanel;
}
}
Show as a JFrame,
LifeCycleFrame.java
import javax.swing.*;
public class LifeCycleFrame {
private static void createAndShowGui() {
LifeCycle2 lifeCycle2 = new LifeCycle2();
JFrame frame = new JFrame("LifeCycleTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(lifeCycle2.getMainPanel());
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Show as an applet,
LifeCycleApplet.java
import java.lang.reflect.InvocationTargetException;
import javax.swing.JApplet;
import javax.swing.SwingUtilities;
public class LifeCycleApplet extends JApplet {
#Override
public void init() {
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
LifeCycle2 lifeCycle2 = new LifeCycle2();
getContentPane().add(lifeCycle2.getMainPanel());
}
});
} catch (InvocationTargetException | InterruptedException e) {
e.printStackTrace();
}
}
}

Add f.setVisible(true); to the end of the gui() method. Without this call your frame won't be shown.
Please read the "How to Make Frames" Tutorial

JPopupMenu.show shows popupmenu with strange behaviour (sometimes appears as grey box)

I have a JFrame containing a JTabbedPane containing a JPanel in a Tab.
In this JPanel, I want a JPopupMenu to show at Mouse Position when clicking the right mouse button.
To do this, I use the show(invoker, x, y) method.
My Problem: The JPopupMenu has a very strange behaviour; sometimes it displays without containing everything (just a grey box) and sometimes it displays in the top left corner of the Panel, behaving completely as expected.
Code:
import javax.swing.JFrame;
import javax.swing.JTabbedPane;
class Testframe extends JFrame {
public static JFrame frame;
private static final long serialVersionUID = 1L;
public Testframe(String string) {
setDefaultCloseOperation(EXIT_ON_CLOSE);
setTitle(string);
setSize(200,200);
setVisible(true);
}
public static void main(String[] args) {
frame = new Testframe("Title");
JTabbedPane tabpane = new JTabbedPane(JTabbedPane.TOP);
tabpane.addTab("title", new TestPanel());
frame.add(tabpane);
tabpane.setVisible(true);
}
}
import java.awt.Color;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.SwingUtilities;
public class TestPanel extends JPanel implements MouseListener {
private static final long serialVersionUID = 1L;
JPopupMenu activeDropdown;
TestPanel() {
setBackground(Color.GREEN);
setVisible(true);
addMouseListener(this);
}
private void dropdown(MouseEvent e) {
activeDropdown = new JPopupMenu();
JMenuItem item = new JMenuItem("Eintrag 0");
activeDropdown.add(item);
activeDropdown.show(Testframe.frame, e.getX(), e.getY());
this.add(activeDropdown);
}
#Override
public void mouseClicked(MouseEvent e) {
if(SwingUtilities.isRightMouseButton(e)) {
if (activeDropdown != null)
this.remove(activeDropdown);
dropdown(e);
}
}
#Override
public void mouseEntered(MouseEvent e) {}
#Override
public void mouseExited(MouseEvent e) {}
#Override
public void mousePressed(MouseEvent e) {}
#Override
public void mouseReleased(MouseEvent e) {}
}
If I try to put the JTabbedPane into a separate Class, the JPopupMenu appears anywhere (seems to be a fixed position) on the screen, completely independent from the window position.

Change your dropdown method as below. That should work as expected.
private void dropdown(MouseEvent e) {
activeDropdown = new JPopupMenu();
JMenuItem item = new JMenuItem("Eintrag 0");
activeDropdown.add(item);
this.add(activeDropdown);
activeDropdown.show(this, e.getX(), e.getY());
}
However, I don't understand why you are removing the existing JPopMenu and adding a new one on every right-mouse click.

You can simply use JComponent.setComponentPopupMenu to handle righ-click popup-menus. This is much simpler and will handle all the wiring code for you.
Small example with your code:
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JTabbedPane;
import javax.swing.SwingUtilities;
public class TestPanel extends JPanel {
private static final long serialVersionUID = 1L;
JPopupMenu activeDropdown;
TestPanel() {
setBackground(Color.GREEN);
activeDropdown = new JPopupMenu();
JMenuItem item = new JMenuItem("Eintrag 0");
activeDropdown.add(item);
setComponentPopupMenu(activeDropdown);
}
protected void initUI() {
JFrame frame = new JFrame("Title");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTabbedPane tabpane = new JTabbedPane(JTabbedPane.TOP);
tabpane.addTab("title", this);
frame.add(tabpane);
frame.setSize(200, 200);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new TestPanel().initUI();
}
});
}
}
NB: Avoid using static variables!