Develop Reference

How to add ScrollBar on Textarea or JFrame in Java Swing?

Hi everyone ,i`m beginner in programmation and i wanted to make a text editor interface by using java Eclipse and i get problem each time i add scrollbar , the text area disappear ... How can i fix my code to continue on it ?... i saw many tutorials but nothing work>
import java.awt.*;
import java.awt.color.*;
import javax.swing.*;
public class Fenetre extends JFrame {
JMenuBar Menubar = new JMenuBar();
JMenu MenuFichier = new JMenu("Fichier");
JMenuItem MenuFichier1 = new JMenuItem("Nouveau");
JMenuItem MenuFichier2 = new JMenuItem("Ouvrir");
JMenuItem MenuFichier3 = new JMenuItem("Enregister");
JMenuItem MenuFichier4 = new JMenuItem("Enregister sous");
JMenuItem MenuFichier5 = new JMenuItem("Quitter");
JMenu MenuEdition = new JMenu("Edition");
JMenuItem MenuEdition1 = new JMenuItem("Couper");
JMenuItem MenuEdition2 = new JMenuItem("Copier");
JMenuItem MenuEdition3 = new JMenuItem("Coller");
JMenu MenuAide = new JMenu("Aide");
JMenuItem MenuAide1 = new JMenuItem("A propos");
JPanel p=new JPanel();
JScrollPane sp = new JScrollPane ();
JTextArea jt = new JTextArea (90,90);
public Fenetre() {
add(p);
setTitle("Text Editor");
setBounds(100,100, 500, 500);
//setExtendedState(JFrame.MAXIMIZED_BOTH);
sp.add(jt);
jt.setText(null);
jt.setLineWrap(true);
jt.setWrapStyleWord(true);
jt.setVisible(true);
sp.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
sp.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
p.add(sp);
sp.setVisible(true);
Menubar.add(MenuFichier);
Menubar.add(MenuEdition);
Menubar.add(MenuAide);
MenuFichier.add(MenuFichier1);
MenuFichier.add(MenuFichier2);
MenuFichier.addSeparator();
MenuFichier.add(MenuFichier3);
MenuFichier.add(MenuFichier4);
MenuFichier.addSeparator();
MenuFichier.add(MenuFichier5);
MenuEdition.add(MenuEdition1);
MenuEdition.add(MenuEdition2);
MenuAide.add(MenuAide1);
Menubar.setBackground(Color.PINK);
getContentPane().add(sp);
setJMenuBar(Menubar);
setVisible(true);
setAlwaysOnTop(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}}
and this is the main of the code
import java.awt.*;
import javax.swing.*;
import java.awt.Color;
public class CreationEditor {
public static void main(String[] args) {
JFrame f = new Fenetre();
}
}

Is it possible to open a Jmenu on button click in swing?

Is it possible to open a Jmenu on button click ? I have a button in Jtable and my requirement is that when user presses this button, a Jmenu should appear. So is this possible ?

Yes it is possible. You can by default hide the menus by menu.setVisible(false); method. And on click of button make it menu.setVisible(true);
JFrame frame = new JFrame("List of Metrics used");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(new ListModelExample());
frame.setSize(260, 200);
frame.setVisible(true);
First thing,these are not necessarily written in main method. And your problem of hiding menu doesn't affect by location of these lines. You can keep it as it is. Also render Jmenu at a required place only, but keep it invisible by default.

Do you want to display menuitem on a button click? Then use this code:
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JMenuBar;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JButton;
public class TestFrame extends JFrame {
private JPanel contentPane;
JMenu mnFile;
JMenuItem mntmExit;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
TestFrame frame = new TestFrame();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public TestFrame() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
JMenuBar menuBar = new JMenuBar();
setJMenuBar(menuBar);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
JButton btnNewButton = new JButton("Click me");
contentPane.add(btnNewButton, BorderLayout.SOUTH);
mnFile = new JMenu("file");
menuBar.add(mnFile);
mntmExit = new JMenuItem("exit");
mnFile.add(mntmExit);
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
mnFile.doClick();
}
});
}
}

hidden labels/panels in java

Basically, i am trying to make it so there are 3 buttons on the bottom of the screen and then have a label which has words in it in the middle of the screen. However, i cant seem to have both buttons and the label in the GUI at the same time. I am a beginner and dont know much about layouts (even though i have read into them) so any help/guidance would be helpful on why i cannot see both the label and the buttons.enter code here
import java.awt.Dimension;
import java.awt.Insets;
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.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
public class AWorldPanel implements ActionListener {
/** Declaring all the menu items within the GUI **/
private JMenuItem Fileitem1 = new JMenuItem("New configuration");
private JMenuItem Fileitem2 = new JMenuItem("Open configuration file ");
private JMenuItem Fileitem3 = new JMenuItem("Save");
private JMenuItem Fileitem4 = new JMenuItem("Save As");
private JMenuItem Fileitem5 = new JMenuItem("Exit");
private JMenuItem Viewitem1 = new JMenuItem("Display configuration");
private JMenuItem Viewitem2 = new JMenuItem("Edit configuration");
private JMenuItem Viewitem3 = new JMenuItem("Info about Bugs");
private JMenuItem Viewitem4 = new JMenuItem("Info about Map");
private JMenuItem Edititem1 = new JMenuItem("Remove");
private JMenuItem Edititem2 = new JMenuItem("Add");
private JMenuItem Simulationitem1 = new JMenuItem("Simulation");
private JMenuItem Helpitem1 = new JMenuItem("Info about application");
private JMenuItem Helpitem2 = new JMenuItem("Info about author");
private JLabel theLabel;
private JPanel thePanel;
JButton Run, Pause, Reset;
JFrame GUI = new JFrame("Graphical User Interface");
private static AWorld guiworld;
public AWorldPanel() {
/** Creating the menu **/
JMenuBar menubar = new JMenuBar();
JMenu File = new JMenu("File");
JMenu View = new JMenu("View");
JMenu Edit = new JMenu("Edit");
JMenu Help = new JMenu("Help");
/** welcome label **/
theLabel = new JLabel("Hello ", JLabel.CENTER);
theLabel.setVisible(true);
theLabel.setVerticalTextPosition(JLabel.TOP);
theLabel.setHorizontalTextPosition(JLabel.CENTER);
/** file sub menus **/
menubar.add(File);
File.add(Fileitem1);
File.add(Fileitem2);
File.add(Fileitem3);
File.add(Fileitem4);
File.add(Fileitem5);
menubar.add(View);
View.add(Viewitem1);
View.add(Viewitem2);
View.add(Viewitem3);
View.add(Viewitem4);
menubar.add(Edit);
Edit.add(Edititem1);
Edit.add(Edititem2);
menubar.add(Help);
Help.add(Helpitem1);
Help.add(Helpitem2);
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.X_AXIS));
panel.setBorder(new EmptyBorder(new Insets(300, 125, 100, 100)));
Run = new JButton("Run");
Pause = new JButton("Pause");
Reset = new JButton("Reset");
panel.add(Run);
panel.add(Box.createRigidArea(new Dimension(0, 5)));
panel.add(Pause);
panel.add(Box.createRigidArea(new Dimension(0, 5)));
panel.add(Reset);
GUI.add(panel);
GUI.add(theLabel);
GUI.setJMenuBar(menubar);
}
private static void createAndShowGUI() {
AWorldPanel newworld = new AWorldPanel();
// Create the container
JFrame frame = new JFrame("Graphical User Interface");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// changing the menu settings
newworld.GUI.setLocation(300, 100);
newworld.GUI.setSize(500, 500);
newworld.GUI.setVisible(true);// Now the frame will appear on screen
}
public static void main(String args[]) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}

The default layout manager for a JFrame is a BorderLayout. If you don't specify a constraint then the component will be added to the BorderLayout.CENTER. You can't add multiple components to the same location in the layout. Try something like:
GUI.add(panel, BorderLayout.SOUTH);
GUI.add(theLabel, BorderLayout.CENTER);
Also, learn standard Java naming conventions. Every book, tutorial or example you will read uses these standards so don't make up your own conventions. Variable names do not start with an upper case character.

MenuBar appears of the left of the JFrame. how to make it appear on the top of JFrame?

import javax.swing.*;
import java.awt.event.*;
//import java.awt.event.ActionListener;
class Test extends JFrame
{
JButton qb=new JButton("quit");
JPanel p1=new JPanel();
JMenuBar menubar = new JMenuBar();
JMenu file = new JMenu("File");
JMenuItem eMenuItem = new JMenuItem("Exit");
public Test()
{
//setLayout();
setTitle("this is a test");
setSize(300,300);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setAlwaysOnTop(true);
setResizable(true);
setExtendedState( this.getExtendedState()|JFrame.MAXIMIZED_BOTH );//to set initial state of frame as minimized
menubar.add(file);
add(menubar);
file.add(eMenuItem);
}
public static void main (String[] args)
{
new Test();
}
}
i have written the above code and tried to find out the reason of why does the menu bar appears on the left of the frame but failed. also layoutmanager doesnt works in the test constructor. i also tried to insert a button in the code but it didnt appear as well. so what are the poosible reasons of such a behaviour of the frame and what are the solutions?

You can try to call setJMenuBar(..)
Change you code from
menubar.add(file);
add(menubar);
file.add(eMenuItem);
to
menubar.add(file);
file.add(eMenuItem);
this.setJMenuBar(menubar);
It will work fine then.

You add your menu to container with BorderLayout(it's default) with next code:
add(menubar);
But for adding menu to JFrame you can use next line instead yours.
setJMenuBar(menubar);
output:

simply you put like this
add(menubar,BorderLayout.NORTH);

This is what you are looking for
import javax.swing.*;
import java.awt.GridBagLayout;
import java.awt.event.*;
//import java.awt.event.ActionListener;
class Test extends JFrame
{
JButton qb=new JButton("quit");
JPanel p1=new JPanel();
JMenuBar menubar = new JMenuBar();
JMenu file = new JMenu("File");
JMenuItem eMenuItem = new JMenuItem("Exit");
public Test()
{
setTitle("this is a test");
setSize(300,300);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setAlwaysOnTop(true);
setResizable(true);
setExtendedState( this.getExtendedState()|JFrame.MAXIMIZED_BOTH );//to set initial state of frame as minimized
menubar.add(file);
setJMenuBar(menubar);
file.add(eMenuItem);
}
public static void main (String[] args)
{
new Test();
}
}

JButtons fail to appear in the JFrame

I have code that displays a menu and 4 JButtons in a JFrame. I tested the code last night and everything was working fine. Now the JButtons do not appear in the JFrame today in the morning. I tried doing in Eclipse and still I got the same result.
The output I am getting :
My code:
import java.awt.Color;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JSeparator;
public class Control {
//JFrame
JFrame main = new JFrame();
//MenuBar
JMenuBar menuBar = new JMenuBar();
//Adding the menu
JMenu fileMenu = new JMenu("File");
JMenu functionMenu = new JMenu("Function");
JMenu helpMenu = new JMenu("Help");
//Adding the Menu Item
JMenuItem addFlight = new JMenuItem("Add Flight");
JMenuItem exit = new JMenuItem("Exit");
JMenuItem landFlight = new JMenuItem("Land Flight");
JMenuItem virtualPath = new JMenuItem("Virtual Path");
JMenuItem flightDetails = new JMenuItem("Flight Details");
JMenuItem about = new JMenuItem("About ...");
//JPanel
JPanel pnlButton = new JPanel();
//Buttons
JButton btnAddFlight = new JButton("Add Flight");
JButton btnLandFlight = new JButton("Land Flight");
JButton btnVirtualPath = new JButton("Virtual Path");
JButton btnFlightDetails = new JButton("Flight Details");
public Control() {
//Adding to the file menu
fileMenu.add(addFlight);
fileMenu.add(exit);
//Adding to the function menu
functionMenu.add(landFlight);
functionMenu.add(virtualPath);
functionMenu.add(flightDetails);
//Adding to the help menu
helpMenu.add(about);
exit.add(new JSeparator());
flightDetails.add(new JSeparator());
//Adding the Menus to the Menu Bar
menuBar.add(fileMenu);
menuBar.add(functionMenu);
menuBar.add(helpMenu);
//FlightInfo setbounds
btnAddFlight.setBounds(30, 30, 120, 30);
btnLandFlight.setBounds(30, 80, 120, 30);
btnVirtualPath.setBounds(30, 130, 120, 30);
btnFlightDetails.setBounds(30, 180, 120, 30);
//JPanel bounds
pnlButton.setLayout(null);
//Adding to JFrame
pnlButton.add(btnAddFlight);
pnlButton.add(btnLandFlight);
pnlButton.add(btnVirtualPath);
pnlButton.add(btnFlightDetails);
main.add(pnlButton);
// JFrame properties
main.setJMenuBar(menuBar);
main.setLayout(null);
main.setBackground(Color.red);
main.setSize(800, 300);
main.setTitle("Air Traffic Control");
main.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
main.setVisible(true);
//Adding the actionlistener
//btnAddFlight.addActionListener(new AddFlight());
//btnLandFlight.addActionListener(new LandFlight());
}
public static void main(String[] args) {
new Control();
}
}
I want to make the JButtons appear on the JFrame.
Many Thanks

You shouldn't add widgets (pnlButton) directly to the JFrame, you need to add them to a sub panel that is automatically created for you called the content pane. To get the content pane do
Container cp = main.getContentPane();
so then do
cp.add(pnlButton);
It's typically a bad idea to use a null layout with absolute positioning, btw.

Use GridBagLayout instead of null layout.
visit the following links for reference
http://www.java2s.com/Code/Java/Swing-JFC/WorkGridBagConstraints3.htm
http://download.oracle.com/docs/cd/E17409_01/javase/tutorial/uiswing/layout/gridbag.html