Changing the font color of a JLabel

Use the method setForeground.

Main.java:

import javax.swing.border.*;
import java.awt.event.*;
import javax.swing.*;
import java.text.*;
import java.awt.*;
   
public class Main extends JFrame {
   public Main() {
      getContentPane().setLayout(new FlowLayout());
 
      JLabel label = new JLabel("The font and color of this JLabel have been changed!");
      getContentPane().add(label);  
      label.setFont(new Font("Tahoma", Font.ITALIC, 30));
      label.setForeground(Color.red);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent event) {
            System.exit(0);   
         }      
      });
 
      pack();
   }
 
   public static void main(String[] args) {
      (new Main()).show();
   }
}

Creating a multiline JTooltip

An easy way is to have your tooltip text to be HTML:

      label.setToolTipText("<html>This is a two-line<br> tooltip text!</html>");

as in following example:

import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
   
public class Main extends JFrame
{ 
   public Main() {
      getContentPane().setLayout(new FlowLayout());
      JLabel label = new JLabel("Mouse-over me!");
      getContentPane().add(label);
 
      label.setToolTipText("<html>This is a two-line<br> tooltip text!</html>");
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(1);
         }
      });      
   
      setSize(new Dimension(200, 200));
   } 
 
   public static void main(String[] args) throws Exception {
      Main main = new Main();
      main.setVisible(true);
   }
}

Getting rid of the top panel of a JFileChooser

Try this:

   fc.remove(1)

(where fc is a JFileChooser instance)
This example shows you also how to remove only part of the top panel:

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 Demonstration");
 
      getContentPane().setLayout(new FlowLayout()); 
      final JFileChooser fc = new JFileChooser();
 
      // Remove the whole top panel of JFileChooser 
      fc.remove(1);
 
      // Disable the create new folder button 
      //((JPanel)fc.getComponent(1)).getAccessibleContext()
      .getAccessibleChild(9).getAccessibleContext()
      .getAccessibleComponent().setEnabled(false);
 
      // Hide the create new folder button
      //((JPanel)fc.getComponent(1)).getAccessibleContext()
      .getAccessibleChild(9).getAccessibleContext()
      .getAccessibleComponent().setVisible(false); 
 
      JButton button = new JButton("Show JFileChooser");
      button.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent ae) {
            int r = fc.showOpenDialog(Main.this); 
  
            if (r == JFileChooser.APPROVE_OPTION)
               System.out.println("Selected: " + 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);
   }
}

Add a background image to a JTable

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.table.*;
 
public class BackgroundTable 
{ 
   public static void main(String[] args) {
      JFrame frame = new JFrame("Table Example"); 
      frame.addWindowListener( new WindowAdapter() { 
         public void windowClosing(WindowEvent e) 
         { 
            Window w = e.getWindow(); 
            w.setVisible(false); 
            w.dispose(); 
            System.exit(0); 
         } 
      }); 
 
      JTable imTable = new JTable(35, 3) { 
         public Component prepareRenderer(TableCellRenderer renderer, int row, int column) 
         { 
            Component c = super.prepareRenderer( renderer, row, column); 
            // We want renderer component to be 
            //transparent so background image is visible 
            if( c instanceof JComponent ) 
               ((JComponent)c).setOpaque(false); 
            return c; 
         }
   
         public void paint( Graphics g ) 
         { 
            ImageIcon image = new ImageIcon("FIREFALL.gif"); 
            // tile the background image 
            Dimension d = getSize(); 
            for( int x = 0; x < d.width; x += image.getIconWidth() ) 
            for( int y = 0; y < d.height; y += image.getIconHeight() ) 
            g.drawImage( image.getImage(), x, y, null, null ); 
            // Now let the paint do its usual work 
            super.paint(g); 
         } 
      }; 
 
      //make the table transparent 
      imTable.setOpaque(false); 
 
      JScrollPane jsp = new JScrollPane(imTable); 
      frame.getContentPane().add(jsp); 
 
      frame.pack(); 
      frame.show(); 
   } 
}

Freezing the first column of a JTable

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



RowHeaderRenderer.java:

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);
  }
}

Making a JSlider cell editor for my JTable


Note: in JDK1.4, you don’t need to do the setSize() and updateUI in the SliderRenderer.

Main.java:

import javax.swing.event.*;
import javax.swing.table.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.awt.*;
  
public class JSliderTableExample extends JFrame {
 
  public JSliderTableExample() {
    super( "JSliderTableExample Example" );
 
    DefaultTableModel dtm = new DefaultTableModel();
    dtm.setDataVector(new Object[][]{{ "JSlider1", new Integer(10) },
                                     { "JSlider2", new Integer(12) }},
                      new Object[]{ "String","JSlider"});
                     
    JTable table = new JTable(dtm);
    table.getColumn("JSlider").setCellRenderer(new SliderRenderer(JSlider.HORIZONTAL, 0, 20, 10));
    table.getColumn("JSlider").setCellEditor(new SliderEditor(JSlider.HORIZONTAL, 0, 20, 10));
 
    table.setRowHeight(20);
    JScrollPane scroll = new JScrollPane(table);
    getContentPane().add(scroll);
 
    setSize( 400, 100 );
    setVisible(true);
  }
 
  public static void main(String[] args) {
    JSliderTableExample frame = new JSliderTableExample();
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
  }
}
  
class SliderRenderer extends JSlider implements TableCellRenderer
{
   public SliderRenderer(int orientation, int min, int max, int value) {
      super(orientation, min, max, value);
   }
 
   public Component getTableCellRendererComponent(JTable table, Object value,
                                  boolean isSelected, boolean hasFocus,
                                  int row, int column)
   {
      if (isSelected) {
         setForeground(table.getSelectionForeground());
         setBackground(table.getSelectionBackground());
      } else {
         setForeground(table.getForeground());
         setBackground(table.getBackground());
      }
 
      TableColumnModel columnModel = table.getColumnModel();      
      TableColumn selectedColumn = columnModel.getColumn(column);      
      int columnWidth = selectedColumn.getWidth();
      int columnHeight = table.getRowHeight();
      setSize(new Dimension(columnWidth, columnHeight));
 
      setValue(((Integer)value).intValue());
      updateUI();
      return this;
   }
}
 
class SliderEditor extends DefaultCellEditor {
   protected JSlider slider;
 
   public SliderEditor(int orientation, int min, int max, int value) {
      super(new JCheckBox());
      slider = new JSlider(orientation, min, max, value);      
      slider.setOpaque(true);      
   }
 
   public Component getTableCellEditorComponent(JTable table, Object value,
                                   boolean isSelected, int row, int column) {
      if (isSelected) {
         slider.setForeground(table.getSelectionForeground());
         slider.setBackground(table.getSelectionBackground());
      } else {
         slider.setForeground(table.getForeground());
         slider.setBackground(table.getBackground());
      }
      slider.setValue(((Integer) value).intValue());
 
      return slider;
   }
 
   public Object getCellEditorValue() {
      return new Integer(slider.getValue());
   }
 
   public boolean stopCellEditing() {
      return super.stopCellEditing();
   }
 
   protected void fireEditingStopped() {
      super.fireEditingStopped();
   }
}

Changing the icons of a JTree

Just use the methods setOpenIcon, setClosedIcon and setLeafIcon defined in the DefaultCellRenderer class.

Here’s an example.

Main.java:

import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
 
public class Main extends JFrame
{
   public Main() {
      DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
      DefaultMutableTreeNode child1 = new DefaultMutableTreeNode("Child 1");
      root.add(child1);
      DefaultMutableTreeNode child2 = new DefaultMutableTreeNode("Child 2");
      root.add(child2);
      JTree tree = new JTree(root);
 
      DefaultTreeCellRenderer cr = new DefaultTreeCellRenderer();
      cr.setOpenIcon(new ImageIcon("openicon.jpg"));
      cr.setClosedIcon(new ImageIcon("closedicon.jpg"));
      cr.setLeafIcon(new ImageIcon("leaficon.jpg"));
  
      tree.setCellRenderer(cr);
 
      getContentPane().add(new JScrollPane(tree));
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(0);
         }
      });
   }
 
   public static void main(String []args) {
      Main main = new Main();
      main.setSize(400, 400);
      main.setVisible(true);
   }
}

The icons used in this program:


Using a Look and Feel for one component and another Look and Feel for another component

Main.java:

import javax.swing.plaf.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.awt.*;
import java.io.*; 
  
public class Main extends JFrame
{
   public Main() throws Exception {
      getContentPane().setLayout(new BorderLayout(30, 30)); 
 
      Vector v = new Vector();
      v.addElement("item 1");
      v.addElement("item 2");
      v.addElement("item 3");
 
      JPanel panel1 = new JPanel(new FlowLayout(FlowLayout.LEFT));
      panel1.add(new JButton("Button"));
      panel1.add(new JCheckBox("CheckBox"));
      panel1.add(new JTextField(10));
      panel1.add(new JComboBox(v));
 
      JPanel panel2 = new JPanel(new FlowLayout(FlowLayout.LEFT));
      panel2.add(new JButton("Button"));
      panel2.add(new JCheckBox("CheckBox"));
      panel2.add(new JTextField(10));
      panel2.add(new JComboBox(v));
 
      getContentPane().add(BorderLayout.NORTH, panel1);
      getContentPane().add(BorderLayout.SOUTH, panel2);
 
      UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
      SwingUtilities.updateComponentTreeUI(panel1);
 
      UIManager.setLookAndFeel("com.sun.java.swing.plaf.motif.MotifLookAndFeel");
      SwingUtilities.updateComponentTreeUI(panel1);
 
      pack();
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent e) {
            System.exit(0);
         }
      });
   }
 
   public static void main(String args[]) throws Exception {
      Main main = new Main();
      //main.setSize(300, 300);
      main.setVisible(true);
   }
}

Right-aligning a JTable column

Main.java:

import javax.swing.table.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
 
public class Main extends JFrame 
{
   public Main() {
      super("Table example, Wines from Bordeaux");
 
      Object[][] tabledata = {
            { "Chateau Meyney, St. Estephe", 	   new Integer(1994), "$18.75"},
            { "Chateau Montrose, St. Estephe", 	   new Integer(1975), "$54.25" },
            { "Chateau Gloria, St. Julien", 	   new Integer(1993), "$22.99" },
            { "Chateau Beychevelle, St. Julien",   new Integer(1970), "$61.63" },
            { "Chateau La Tour de Mons, Margeaux", new Integer(1975), "$57.03" },
            { "Chateau Brane-Cantenac, Margeaux",  new Integer(1978), "$49.92" },
      };
 
      String columnheaders[] = { "Wine", "Vintage", "Price" };
 
      JTable table = new JTable(tabledata, columnheaders);
      table.setPreferredScrollableViewportSize(new Dimension(500, 70));
 
      // right align 2nd column
      TableColumnModel columnModel = table.getColumnModel();
      TableColumn column = columnModel.getColumn(1);  
      DefaultTableCellRenderer renderer = new DefaultTableCellRenderer();
      renderer.setHorizontalAlignment(JLabel.RIGHT);
      column.setCellRenderer(renderer);
 
      // right align 2nd column when editing
      JTextField tf = new JTextField();
      tf.setHorizontalAlignment(JTextField.RIGHT);
      column.setCellEditor(new DefaultCellEditor(tf));
 
      JScrollPane scrollPane = new JScrollPane(table);
      getContentPane().add(scrollPane);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(0);
         }
      });
 
      pack();
   }
 
   public static void main(String []args) {
      Main main = new Main();
      main.show();
   }
}