Adding a background image to my JTextField

How do I add a background image to my JTextField?

Make sure the opaqueness property of your JTextField component is false. You can then override the paintComponent method that draws the background image and calls super.paintComponent. Here’s an example: 

import javax.swing.*;
import java.awt.*;
 
public class Main {
   public static void main(String args[]) {
      JFrame frame = new JFrame("JTextField Background Demonstration");
      final ImageIcon imageIcon = new ImageIcon("bluebg.jpg");
 
      JTextField textField = new JTextField() {
         Image image = imageIcon.getImage();
         { 
            setOpaque(false);
         }
         public void paintComponent (Graphics g) {
            g.drawImage(image, 0, 0, this);
            setForeground(Color.yellow);
            super.paintComponent(g);
         }
      };
      textField.setFont(new Font("Helvetica", Font.BOLD, 16));
 
      frame.getContentPane().add(BorderLayout.CENTER, textField);
      frame.setDefaultCloseOperation(3);
      frame.setSize(200, 50);
      frame.setVisible(true);
      frame.setResizable(false);
   }
}

Embedding a clickable HTML image in a JLabel

A JLabel is able to render HTML but it does not respond to clicks on anchor tags. You could do something simple like add a MouseListener to your JLabel and respond to mouse events like a normal browser would.

Main.java: 

import java.awt.event.*;
import java.awt.font.*; 
import javax.swing.*;
import java.util.*;
import java.text.*;
import java.awt.*;
   
public class Main extends JFrame {
   public Main() {
      getContentPane().setLayout(new FlowLayout());
 
      final JLabel label = new JLabel("<html><a href="dummy"><img src="file:c:\esuslogo.gif"></a></html>");
      getContentPane().add(label);
 
      label.addMouseListener(new MouseAdapter() {
         public void mouseEntered(MouseEvent me) {
            label.setCursor(new Cursor(Cursor.HAND_CURSOR));
         }
         public void mouseExited(MouseEvent me) {
            label.setCursor(Cursor.getDefaultCursor());
         }
         public void mouseClicked(MouseEvent me) {
            System.out.println("Clicked on JLabel image");
         }
      });
  
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent event) {
            System.exit(0);   
         }      
      });
 
      pack();
   }
 
   public static void main(String[] args) {
      (new Main()).show();
   }
}

Setting the JProgressBar colors

You can set the progress rectangle color and remaining area color with setForeground and setBackground.
To set the color of the string drawn inside the progress bar, you have two choices (there is no trivial API method to set these colors, look at bug http://developer.java.sun.com/developer/bugParade/bugs/4226498.html.

  • Set the UIManager property values ProgressBar.selectionForeground and ProgressBar.selectionBackground before creating the JProgressBar. Beware that all your JProgressBar components will take on this color.
  • Extend the JProgressBar UI class to provide a method setSelectionForeground and setSelectionBackground

Main.java: 

import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.awt.*;
 
public class Main extends JFrame {
   public Main() {
      super("JProgressBar Color Demonstration");
 
      // sets the color of the string painted inside the progressbar
      // selectionForeground is the color of the string that appears
      //    in the rectangle that shows the progress
      // selectionBackground is the color of the string that appears
      //    in the rectangle that shows the remaining area
      UIManager.put("ProgressBar.selectionForeground", Color.red);
      UIManager.put("ProgressBar.selectionBackground", Color.green);
 
      JProgressBar pb = new JProgressBar(0, 100);
      pb.setValue(50); 
      pb.setStringPainted(true);
 
      // sets the foreground color, but only the 
      // rectangle that shows the progress, not the text  
      pb.setForeground(Color.green);
 
      // sets the background color, the rectangle that  
      // shows the remaining area
      pb.setBackground(Color.red);
 
      // add the scroll pane to this window.
      getContentPane().add(pb);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent e) {
            System.exit(0);
         }
      });
   }
 
   public static void main(String[] args) {
      Main main = new Main();
      main.pack();
      main.setVisible(true);
   }
}

Creating a directory chooser

Set the file selection mode in JFileChooser to JFileChooser.DIRECTORIES_ONLY. A directory
can then be selected by not navigating into the directory but by selecting it when you’re a level
higher.

Main.java: 

import javax.swing.filechooser.*;
import javax.swing.event.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
import java.io.*;
 
public class Main extends JFrame {
   public Main() {
      super("JFileChooser Directory Chooser Demonstration");
 
      getContentPane().setLayout(new FlowLayout()); 
      JButton button = new JButton("Show JFileChooser and select directory");
      button.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent ae) {
            JFileChooser fc = new JFileChooser();
            fc.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
            int r = fc.showOpenDialog(Main.this); 
            while (r != JFileChooser.APPROVE_OPTION) {
               JOptionPane.showMessageDialog(Main.this,"Try again, select a directory.", 
                  "ERROR", JOptionPane.ERROR_MESSAGE); 
               r = fc.showOpenDialog(Main.this); 
            }
  
            System.out.println("Selected directory: " + fc.getSelectedFile());
         }
      });
 
      getContentPane().add(button); 
  
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent e) {
            System.exit(0);
         }
      });
   }
 
   public static void main(String[] args) {
      Main main = new Main();
      main.pack();
      main.setVisible(true);
   }
}

Setting the width of a JTable column

you should do something like this: 

   TableColumn column=jTable1.getColumnModel().getColumn(1);
   column.setMinWidth(0);
   column.setMaxWidth(300);
   column.setPreferredWidth(15);

Setting

column.setMinWidth(0);
column.setMaxWidth(300);

is not nessesary, but you’ll be sure that desired width fits in this range.

Creating a JTable with row headers

Courtesy of Nobuo Tamemasa (http://www2.gol.com/users/tame/swing/examples/JTableExamples1.html)



import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
 
 
/**
 * @version 1.0 11/09/98
 */
  
class RowHeaderRenderer extends JLabel implements ListCellRenderer {
   
  RowHeaderRenderer(JTable table) {
    JTableHeader header = table.getTableHeader();
    setOpaque(true);
    setBorder(UIManager.getBorder("TableHeader.cellBorder"));
    setHorizontalAlignment(CENTER);
    setForeground(header.getForeground());
    setBackground(header.getBackground());
    setFont(header.getFont());
  }
  
  public Component getListCellRendererComponent( JList list, 
         Object value, int index, boolean isSelected, boolean cellHasFocus) {
    setText((value == null) ? "" : value.toString());
    return this;
  }
}
 
public class RowHeaderExample extends JFrame {
 
  public RowHeaderExample() {
    super( "Row Header Example" );
    setSize( 300, 150 );
        
    ListModel lm = new AbstractListModel() {
      String headers[] = {"a", "b", "c", "d", "e", "f", "g", "h", "i"};
      public int getSize() { return headers.length; }
      public Object getElementAt(int index) {
        return headers[index];
      }
    };
 
    DefaultTableModel dm = new DefaultTableModel(lm.getSize(),10);
    JTable table = new JTable( dm );
    table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
    
    JList rowHeader = new JList(lm);    
    rowHeader.setFixedCellWidth(50);
    
    rowHeader.setFixedCellHeight(table.getRowHeight()
                               + table.getRowMargin());
//                             + table.getIntercellSpacing().height);
    rowHeader.setCellRenderer(new RowHeaderRenderer(table));
 
    JScrollPane scroll = new JScrollPane( table );
    scroll.setRowHeaderView(rowHeader);
    getContentPane().add(scroll, BorderLayout.CENTER);
  }
 
  public static void main(String[] args) {
    RowHeaderExample frame = new RowHeaderExample();
    frame.addWindowListener( new WindowAdapter() {
      public void windowClosing( WindowEvent e ) {
        System.exit(0);
      }
    });
    frame.setVisible(true);
  }
}

Displaying a popup-menu when right-clicking on a JTable header

Main.java: 

import javax.swing.table.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.awt.*;
 
public class Main extends JFrame {
   public Main() {
      super("TableModel Demonstration");
 
      // create our own custom TableModel
      WineTableModel wineModel = new WineTableModel();
      final JTable table = new JTable(wineModel);
 
      // add rows to our TableModel, each row is represented as a Wine object
      wineModel.addWine(new Wine("Chateau Meyney, St. Estephe", "1994", 18.75f, true));
      wineModel.addWine(new Wine("Chateau Montrose, St. Estephe", "1975", 54.25f, true));
      wineModel.addWine(new Wine("Chateau Gloria, St. Julien", "1993", 22.99f, false));
      wineModel.addWine(new Wine("Chateau Beychevelle, St. Julien", "1970", 61.63f, false));
      wineModel.addWine(new Wine("Chateau La Tour de Mons, Margeaux", "1975", 57.03f, true));
      wineModel.addWine(new Wine("Chateau Brane-Cantenac, Margeaux", "1978", 49.92f, false));

      final JPopupMenu popupMenu = new JPopupMenu();
      popupMenu.add(new JMenuItem("PopupItem 1"));
      popupMenu.add(new JMenuItem("PopupItem 2"));
      popupMenu.add(new JPopupMenu.Separator());
      popupMenu.add(new JMenuItem("PopupItem 3"));

      final JTableHeader header = table.getTableHeader();
      header.addMouseListener(new MouseAdapter() {
         public void mouseClicked(MouseEvent me) {
            if (SwingUtilities.isRightMouseButton(me))
               popupMenu.show(header, me.getX(), me.getY());
         }
      });
 
      // create the scroll pane and add the table to it. 
      JScrollPane scrollPane = new JScrollPane(table);
 
      // add the scroll pane to this window.
      getContentPane().add(scrollPane, BorderLayout.CENTER);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent e) {
            System.exit(0);
         }
      });
   }
 
   public static void main(String[] args) {
      Main main = new Main();
      main.pack();
      main.setVisible(true);
   }
}
 
// a simple object that holds data about a particular wine
class Wine {
   private String  name;
   private String  vintage;
   private float   price;
   private boolean inStock;
 
   public Wine(String name, String vintage, float price, boolean inStock) {
      this.name = name;
      this.vintage = vintage;
      this.price = price;
      this.inStock = inStock;
   }
 
   public String getName()     { return name; }
   public String getVintage()  { return vintage; }
   public float  getPrice()    { return price; } 
   public boolean getInStock() { return inStock; }
 
   public String toString() { 
      return "[" + name + ", " + vintage + ", " + price + ", " + inStock + "]"; }
}
 
class WineTableModel extends AbstractTableModel {
   // holds the strings to be displayed in the column headers of our table
   final String[] columnNames = {"Name", "Vintage", "Price", "In stock?"};
 
   // holds the data types for all our columns
   final Class[] columnClasses = {String.class, String.class, Float.class, Boolean.class};
 
   // holds our data
   final Vector data = new Vector();
  
   // adds a row
   public void addWine(Wine w) {
      data.addElement(w);
      fireTableRowsInserted(data.size()-1, data.size()-1);
   }
 
   public int getColumnCount() {
      return columnNames.length;
   }
         
   public int getRowCount() {
      return data.size();
   }
 
   public String getColumnName(int col) {
      return columnNames[col];
   }
 
   public Class getColumnClass(int c) {
      return columnClasses1;
   }
 
   public Object getValueAt(int row, int col) {
      Wine wine = (Wine) data.elementAt(row);
      if (col == 0)      return wine.getName();
      else if (col == 1) return wine.getVintage();
      else if (col == 2) return new Float(wine.getPrice());
      else if (col == 3) return new Boolean(wine.getInStock());
      else return null;
   }
 
   public boolean isCellEditable(int row, int col) {
      return false;
   }
}

Handling Hyperlink events on a JEditorPane

Add a HyperlinkListener to your JEditorPane, as shown in the following example.
Note that a distinction is made between a normal hyperlink and a hyperlink activated
in a frame. In the latter case, a HTMLFrameHyperlinkEvent will be posted. 

import javax.swing.text.html.*;
import javax.swing.event.*;
import javax.swing.text.*;
import java.awt.event.*;
import javax.swing.*;
import java.net.*;
import java.awt.*;
import java.io.*;
 
public class Main extends JFrame
{
   // need to be final to allow the inner class to access it!
   final JTextField urlTextField = new JTextField();
   final JEditorPane htmlPane = new JEditorPane();
   JButton urlButton = new JButton("Go!");
 
   public static void main(String []args) {
      Main main = new Main();
      main.show();
   }
 
   public Main() { 
      htmlPane.setEditable(false);
      urlTextField.setText("http://www.yahoo.com");
  
      urlButton.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent ae) {
            loadPage(urlTextField.getText());
         }
      });

      htmlPane.addHyperlinkListener(new HyperlinkListener() {
         public void hyperlinkUpdate (HyperlinkEvent event) {
            if (event.getEventType() == HyperlinkEvent.EventType.ACTIVATED) {
               urlTextField.setText(event.getURL().toString());

               if (event instanceof HTMLFrameHyperlinkEvent) {
                  HTMLDocument doc = (HTMLDocument) htmlPane.getDocument();
                  doc.processHTMLFrameHyperlinkEvent ((HTMLFrameHyperlinkEvent) event);
               }
               else {
                  loadPage(urlTextField.getText());
               }
            }
         }
      });
 
      getContentPane().setLayout(new BorderLayout());
      JPanel topPanel = new JPanel(new BorderLayout());
      topPanel.add(BorderLayout.CENTER, urlTextField);
      topPanel.add(BorderLayout.EAST, urlButton);
 
      getContentPane().add(BorderLayout.NORTH, topPanel);
      getContentPane().add(BorderLayout.CENTER, new JScrollPane(htmlPane));
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent e) {
            System.exit(0);
         }
      });
 
      setSize(400, 400);
   }

   public void loadPage(String url) {
      try {
         htmlPane.setPage(new URL(urlTextField.getText()));
      }
      catch(Exception e) {
         System.out.println(e);
      }
   }
}

Change to a Mac Look and Feel on a Windows Machine

There are two ways to implement Mac L&F on Windows. The first consists of modifying the main L&F class to return true when the isSupportedLookAndFeel is called. This is against the Swing/JDK license agreement, though.

Another way is to use a 3rd party Mac look & feel. Check out the website in the related URLs section for more information. Remember that you can dynamically load a look and feel without having to modify a properties file.

Turn off copy/paste in a JTextArea

Main.java: 

import javax.swing.event.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
 
public class Main extends JFrame
{
   public Main() {
      JTextArea ta = new JTextArea();
      getContentPane().add(new JScrollPane(ta));
 
      ta.getInputMap().put(KeyStroke.getKeyStroke("control C"), "none");
      ta.getInputMap().put(KeyStroke.getKeyStroke("control V"), "none");
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(1);
         }
      });
   }
 
   public static void main(String []args) {
      Main main = new Main();
      main.setSize(400, 400);
      main.setVisible(true);
   }
}