Previewing textfiles in a JFileChooser

Use the setAccessory method!

Main.java:

import javax.swing.filechooser.*;
import java.awt.event.*;
import javax.swing.*;
import java.beans.*;
import java.awt.*;
import java.io.*;
  
public class Main extends JFrame {
   public static void main(String[] args) {
      JFileChooser fc = new JFileChooser();
 
      // show only directories and .txt files       
      fc.addChoosableFileFilter(new TextfileFilter());
 
      // set the accessory JComponent to our panel that previews textfiles
      fc.setAccessory(new TextfilePreview(fc));
 
      int returnVal = fc.showDialog(new JFrame(), "Open");
 
      if (returnVal == JFileChooser.APPROVE_OPTION) {
         File file = fc.getSelectedFile();
      }
 
      System.exit(0);
   }
}
 
class TextfileFilter extends javax.swing.filechooser.FileFilter
{
   public boolean accept(File f) {
      if (f.isDirectory()) return true;
 
      return f.getName().toLowerCase().endsWith(".txt");
   }
 
   public String getDescription() {
      return "TextFiles (*.txt)";
   }
}
 
class TextfilePreview extends JPanel
                      implements PropertyChangeListener {
   File textfile;
   JTextArea ta;
 
   public TextfilePreview(JFileChooser fc) {
      fc.addPropertyChangeListener(this);
      ta = new JTextArea();
      JScrollPane sp = new JScrollPane(ta);
      setLayout(new BorderLayout());
      add(BorderLayout.CENTER, sp);
      setPreferredSize(new Dimension(150, 200));
   }
 
   public void loadTextfile() {
      if (textfile == null) return;
 
      try {
         ta.setText("");
         BufferedReader br = new BufferedReader(new FileReader(textfile));
         String line;
         while ((line = br.readLine()) != null) {
            ta.append(line + "n");
         }
         br.close();
      }
      catch(IOException e) {
      }
   } 
 
   public void propertyChange(PropertyChangeEvent e) {
      String prop = e.getPropertyName();
      if (prop.equals(JFileChooser.SELECTED_FILE_CHANGED_PROPERTY)) {
         textfile = (File) e.getNewValue();
         if (isShowing()) {
            loadTextfile();
            repaint();
         }
      }
   }
}

Creating a JTable with hideable columns

Courtesy of Nobuo Tamemasa (http://www2.gol.com/users/tame/swing/examples/JTableExamples8.html)



HideColumnTableExample.java:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
 
/**
 * @version 1.0 05/31/99
 */
public class HideColumnTableExample extends JFrame {

  public HideColumnTableExample(){
    super( "HideColumnTable Example" );
    
    JTable table = new JTable(5, 7);
    ColumnButtonScrollPane pane = new ColumnButtonScrollPane(table);
    getContentPane().add(pane);
  }

  public static void main(String[] args) {
    HideColumnTableExample frame = new HideColumnTableExample();
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
    frame.setSize( 400, 100 );
    frame.setVisible(true);
  }
}

ColumnButtonScrollPane.java:

import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.table.*;
import javax.swing.event.*;
import jp.gr.java_conf.tame.swing.layout.*;
import jp.gr.java_conf.tame.swing.border.*;
import jp.gr.java_conf.tame.swing.icon.*;
 
/**
 * @version 1.0 05/31/99
 */
public class ColumnButtonScrollPane extends JScrollPane {
  Component columnButton;

  public ColumnButtonScrollPane(JTable table) {
    super(table);
    TableColumnModel cm = table.getColumnModel();
    LimitedTableHeader header = new LimitedTableHeader(cm);
    table.setTableHeader(header);
    columnButton = createUpperCorner(header);
    setCorner(UPPER_RIGHT_CORNER, columnButton);
    setVerticalScrollBarPolicy(VERTICAL_SCROLLBAR_ALWAYS);
    ColumnButtonScrollPaneLayout layout = new ColumnButtonScrollPaneLayout();
    setLayout(layout);
    layout.syncWithScrollPane(this);
  }
  
  protected Component createUpperCorner(JTableHeader header) {
    ColumnButton corner = new ColumnButton(header);
    return corner;
  }

  
  public class LimitedTableHeader extends JTableHeader {
    public LimitedTableHeader(TableColumnModel cm) {
      super(cm);
    }
       
    // actually, this is a not complete way. but easy one.
    // you can see last column painted wider, short time :) 
    // If you don't like this kind cheap fake,
    // you have to overwrite the paint method in UI class.
    public void paintComponent(Graphics g) {
      super.paintComponent(g);
      columnButton.repaint();
    }    
  }

  
  public class ColumnButton extends JPanel {    
    JTable table;
    TableColumnModel cm;
    JButton revealButton; 
    JButton hideButton;
    Stack stack;  
    
    public ColumnButton(JTableHeader header) {
      setLayout(new GridLayout(1,2));
      setBorder(new LinesBorder(SystemColor.controlShadow, new Insets(0,1,0,0)));
      
      stack = new Stack();
      table = header.getTable();
      cm    = table.getColumnModel();
      
      revealButton = createButton(header, SwingConstants.WEST);
      hideButton   = createButton(header, SwingConstants.EAST);
      add(revealButton);
      add(hideButton);   
         
      revealButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {      
          TableColumn column = (TableColumn)stack.pop();
          cm.addColumn(column);
          if (stack.empty()) {
            revealButton.setEnabled(false);
          }
          hideButton.setEnabled(true);
          table.sizeColumnsToFit(-1);
        }
      });
      hideButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {      
          int n = cm.getColumnCount();
          TableColumn column = cm.getColumn(n -1);
          stack.push(column);
          cm.removeColumn(column);
          if (n < 3) {
            hideButton.setEnabled(false);
          }
          revealButton.setEnabled(true);
          table.sizeColumnsToFit(-1);
        }
      });
      
      if (1 < cm.getColumnCount()) {
        hideButton.setEnabled(true);
      } else {
        hideButton.setEnabled(false);
      }
      revealButton.setEnabled(false);
    }
    
    protected JButton createButton(JTableHeader header,
                                   int direction) {
      //int iconHeight = header.getPreferredSize().height - 6;
      int iconHeight = 8;
      JButton button = new JButton();
      button.setIcon(new ArrowIcon(iconHeight, direction, true));
      button.setDisabledIcon(new ArrowIcon(iconHeight, direction, false));
      button.setRequestFocusEnabled(false);
      button.setForeground(header.getForeground());
      button.setBackground(header.getBackground());
      button.setBorder(UIManager.getBorder("TableHeader.cellBorder"));
      return button;
    }    
  }
}

ColumnButtonScrollPaneLayout.java:

import java.awt.*;
import javax.swing.*;


/**
 * @version 1.0 05/29/99
 */
public class ColumnButtonScrollPaneLayout extends  ScrollPaneLayout {

  public ColumnButtonScrollPaneLayout() {
    super.setVerticalScrollBarPolicy(VERTICAL_SCROLLBAR_ALWAYS);
  }

  public void setVerticalScrollBarPolicy(int x) {
    // VERTICAL_SCROLLBAR_ALWAYS
    super.setVerticalScrollBarPolicy(VERTICAL_SCROLLBAR_ALWAYS);
  }
  
  public void layoutContainer(Container parent) {
    super.layoutContainer(parent);
    
    if ((colHead == null) || (! colHead.isVisible()) ||
        (upperRight == null) || (vsb == null)) {
      return;
    }
    
    Rectangle vsbR = new Rectangle(0, 0, 0, 0);
    vsbR = vsb.getBounds(vsbR);
    
    Rectangle colHeadR = new Rectangle(0, 0, 0, 0);
    colHeadR = colHead.getBounds(colHeadR);
    colHeadR.width -= vsbR.width;
    colHead.getBounds(colHeadR);
    
    Rectangle upperRightR = upperRight.getBounds();
    upperRightR.x     -= vsbR.width;
    upperRightR.width += vsbR.width + 1;
    upperRight.setBounds(upperRightR);
  }  
}

LinesBorder.java:

import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
 
/**
 * @version 1.0 03/09/99
 */
public class LinesBorder extends AbstractBorder implements SwingConstants { 
  protected int northThickness;
  protected int southThickness;
  protected int eastThickness;
  protected int westThickness;  
  protected Color northColor;
  protected Color southColor;
  protected Color eastColor;
  protected Color westColor;
  
  public LinesBorder(Color color) {
    this(color, 1);
  }

  public LinesBorder(Color color, int thickness)  {
    setColor(color);
    setThickness(thickness);
  }

  public LinesBorder(Color color, Insets insets)  {
    setColor(color);
    setThickness(insets);
  }

  public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
    Color oldColor = g.getColor();
    
    g.setColor(northColor);
    for (int i = 0; i < northThickness; i++)  {
      g.drawLine(x, y+i, x+width-1, y+i);
    }
    g.setColor(southColor);
    for (int i = 0; i < southThickness; i++)  {
      g.drawLine(x, y+height-i-1, x+width-1, y+height-i-1);
    }
    g.setColor(eastColor);
    for (int i = 0; i < westThickness; i++)  {
      g.drawLine(x+i, y, x+i, y+height-1);
    }
    g.setColor(westColor);
    for (int i = 0; i < eastThickness; i++)  {
      g.drawLine(x+width-i-1, y, x+width-i-1, y+height-1);
    }

    g.setColor(oldColor);
  }

  public Insets getBorderInsets(Component c)       {
    return new Insets(northThickness, westThickness, southThickness, eastThickness);
  }

  public Insets getBorderInsets(Component c, Insets insets) {
    return new Insets(northThickness, westThickness, southThickness, eastThickness);    
  }


  public boolean isBorderOpaque() { return true; }
    
  public void setColor(Color c) {
    northColor = c;
    southColor = c;
    eastColor  = c;
    westColor  = c;
  }
  
  public void setColor(Color c, int direction) {
    switch (direction) {
      case NORTH: northColor = c; break;
      case SOUTH: southColor = c; break;
      case EAST:  eastColor  = c; break;
      case WEST:  westColor  = c; break;
      default: 
    }
  }
    
  public void setThickness(int n) {
    northThickness = n;
    southThickness = n;
    eastThickness  = n;
    westThickness  = n;
  }
    
  public void setThickness(Insets insets) {
    northThickness = insets.top;
    southThickness = insets.bottom;
    eastThickness  = insets.right;
    westThickness  = insets.left;
  }
  
  public void setThickness(int n, int direction) {
    switch (direction) {
      case NORTH: northThickness = n; break;
      case SOUTH: southThickness = n; break;
      case EAST:  eastThickness  = n; break;
      case WEST:  westThickness  = n; break;
      default: 
    }
  }

  public void append(LinesBorder b, boolean isReplace) {
    if (isReplace) {
      northThickness = b.northThickness;
      southThickness = b.southThickness;
      eastThickness  = b.eastThickness;
      westThickness  = b.westThickness;
    } else {
      northThickness = Math.max(northThickness ,b.northThickness);
      southThickness = Math.max(southThickness ,b.southThickness);
      eastThickness  = Math.max(eastThickness  ,b.eastThickness);
      westThickness  = Math.max(westThickness  ,b.westThickness);
    }
  }

  public void append(Insets insets, boolean isReplace) {
    if (isReplace) {
      northThickness = insets.top;
      southThickness = insets.bottom;
      eastThickness  = insets.right;
      westThickness  = insets.left;
    } else {
      northThickness = Math.max(northThickness ,insets.top);
      southThickness = Math.max(southThickness ,insets.bottom);
      eastThickness  = Math.max(eastThickness  ,insets.right);
      westThickness  = Math.max(westThickness  ,insets.left);
    }
  }
}

ArrowIcon.java:

import java.awt.*;
import javax.swing.*;
import javax.swing.plaf.basic.*;
  
/**
 * @version 1.0 02/26/99
 */
public class ArrowIcon implements Icon, SwingConstants {
  private static final int DEFAULT_SIZE = 11;
  //private static final int DEFAULT_SIZE = 5;

  private int size;
  private int iconSize;
  private int direction;
  private boolean isEnabled;
  private BasicArrowButton iconRenderer;

  public ArrowIcon(int direction, boolean isPressedView) {
    this(DEFAULT_SIZE, direction, isPressedView);
  }

  public ArrowIcon(int iconSize, int direction, boolean isEnabled) {
    this.size = iconSize / 2;
    this.iconSize = iconSize;
    this.direction = direction;
    this.isEnabled = isEnabled;
    iconRenderer = new BasicArrowButton(direction);
  }

  public void paintIcon(Component c, Graphics g, int x, int y) {
    iconRenderer.paintTriangle(g, x, y, size, direction, isEnabled);
  }

  public int getIconWidth() {
    //int retCode;
    switch (direction) {
      case NORTH:
      case SOUTH: return iconSize;
      case EAST:
      case WEST:  return size;
    }
    return iconSize;
  }

  public int getIconHeight() {
    switch (direction) {
      case NORTH:
      case SOUTH: return size;
      case EAST:
      case WEST:  return iconSize;
    }
    return size;
  }
}

Having a JRadioButton cell in a JTable

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



JRadioButtonTableExample.java:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.event.*;
 
class RadioButtonRenderer implements TableCellRenderer {
  public Component getTableCellRendererComponent(JTable table, Object value,
                   boolean isSelected, boolean hasFocus, int row, int column) {
    if (value==null) return null;
    return (Component)value;
  }
}
 
class RadioButtonEditor extends    DefaultCellEditor
                        implements ItemListener {
  private JRadioButton button;
 
  public RadioButtonEditor(JCheckBox checkBox) {
    super(checkBox);
  }
 
  public Component getTableCellEditorComponent(JTable table, Object value,
                   boolean isSelected, int row, int column) {
    if (value==null) return null;
    button = (JRadioButton)value;
    button.addItemListener(this);
    return (Component)value;
  }
 
  public Object getCellEditorValue() {
    button.removeItemListener(this);
    return button;
  }
 
  public void itemStateChanged(ItemEvent e) {
    super.fireEditingStopped();
  }
}
 
public class JRadioButtonTableExample extends JFrame {
 
  public JRadioButtonTableExample(){
    super( "JRadioButtonTable Example" );
    UIDefaults ui = UIManager.getLookAndFeel().getDefaults();    
    UIManager.put("RadioButton.focus", ui.getColor("control"));
 
    DefaultTableModel dm = new DefaultTableModel();
    dm.setDataVector(
      new Object[][]{
        {"Group 1",new JRadioButton("A")},
        {"Group 1",new JRadioButton("B")},
        {"Group 1",new JRadioButton("C")},
        {"Group 2",new JRadioButton("a")},
        {"Group 2",new JRadioButton("b")}},
      new Object[]{"String","JRadioButton"});
                      
    JTable table = new JTable(dm) {
      public void tableChanged(TableModelEvent e) {
        super.tableChanged(e);
        repaint();
      }
    };
    ButtonGroup group1 = new ButtonGroup();
    group1.add((JRadioButton)dm.getValueAt(0,1));
    group1.add((JRadioButton)dm.getValueAt(1,1));
    group1.add((JRadioButton)dm.getValueAt(2,1));
    ButtonGroup group2 = new ButtonGroup();
    group2.add((JRadioButton)dm.getValueAt(3,1));
    group2.add((JRadioButton)dm.getValueAt(4,1));
    table.getColumn("JRadioButton").setCellRenderer(new RadioButtonRenderer());
    table.getColumn("JRadioButton").setCellEditor(new RadioButtonEditor(new JCheckBox()));
    JScrollPane scroll = new JScrollPane(table);
    getContentPane().add( scroll );
    setSize( 200, 140 );
    setVisible(true);
  }
 
  public static void main(String[] args) {
    JRadioButtonTableExample frame = new JRadioButtonTableExample();
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
  }
}



JRadioButtonTableExample2.java:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.event.*;

/**
 * @version 1.2 08/13/99
 */
public class JRadioButtonTableExample2 extends JFrame {
 
  public JRadioButtonTableExample2(){
    super( "JRadioButtonTable Example" );
 
    DefaultTableModel dm = new DefaultTableModel();
    dm.setDataVector(
      new Object[][]{
        {"1",new Integer(-1)},
        {"2",new Integer(-1)},
        {"3",new Integer(0)},
        {"4",new Integer(1)},
        {"5",new Integer(2)}},
      new Object[]{"Question","Answer"});
                      
    JTable table = new JTable(dm);
    String[] answer = {"A","B","C"};
     
    table.getColumn("Answer").setCellRenderer(
      new RadioButtonRenderer(answer)
    );
    table.getColumn("Answer").setCellEditor(
      new RadioButtonEditor(new JCheckBox(), 
                            new RadioButtonPanel(answer))
    );
    JScrollPane scroll = new JScrollPane(table);
    getContentPane().add( scroll );
  }
   
  // Cell base
  class RadioButtonPanel extends JPanel {
    JRadioButton[] buttons;
     
    RadioButtonPanel(String[] str) {
      setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
      buttons = new JRadioButton[str.length];
      for (int i=0; i<buttons.length; i++) {
        buttons[i] = new JRadioButton(str[i]);
        buttons[i].setFocusPainted(false);
        add(buttons[i]);
      }      
    }
     
    public void setSelectedIndex(int index) {
      for (int i=0;i<buttons.length;i++) {
        buttons[i].setSelected(i == index);
      }
    }
     
    public int getSelectedIndex() {
      for (int i=0; i<buttons.length; i++) {
        if (buttons[i].isSelected()) {
          return i;
        }
      }      
      return -1;      
    }
     
    public JRadioButton[] getButtons() {
      return buttons;
    }
  }
 
 
   
  class RadioButtonRenderer extends    RadioButtonPanel
                            implements TableCellRenderer {    
    RadioButtonRenderer(String[] strs) {
      super(strs);
    }
     
    public Component getTableCellRendererComponent(JTable table, Object value,
                   boolean isSelected, boolean hasFocus, int row, int column) {
      if (value instanceof Integer) {
        setSelectedIndex(((Integer)value).intValue());
      }      
      return this;
    }
  }
 
 
 
  class RadioButtonEditor extends    DefaultCellEditor
                          implements ItemListener {
    RadioButtonPanel panel;
 
    public RadioButtonEditor(JCheckBox checkBox,RadioButtonPanel panel) {
      super(checkBox);
      this.panel = panel;
      ButtonGroup buttonGroup = new ButtonGroup();
      JRadioButton[] buttons  = panel.getButtons();
      for (int i=0; i<buttons.length; i++) {
        buttonGroup.add(buttons[i]);
        buttons[i].addItemListener(this);
      }                  
    }
 
    public Component getTableCellEditorComponent(JTable table, Object value,
                   boolean isSelected, int row, int column) {
      if (value instanceof Integer) {
        panel.setSelectedIndex(((Integer)value).intValue());
      }      
      return panel;
    }
 
    public Object getCellEditorValue() {
      return new Integer(panel.getSelectedIndex());
    }
 
    public void itemStateChanged(ItemEvent e) {
      super.fireEditingStopped();
    }
  }
 
  public static void main(String[] args) {
    JRadioButtonTableExample2 frame = new JRadioButtonTableExample2();
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
    frame.setSize( 230, 140 );
    frame.setVisible(true);
  }
}

Change the row height of a JTable that resides in a JFrame automatically when that frame is resized

Maybe this code gives you some ideas.

Main.java:

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" },
            { "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" };
 
      final JTable table = new JTable(tabledata, columnheaders);
      table.setPreferredScrollableViewportSize(new Dimension(500, 70));
      JScrollPane scrollPane = new JScrollPane(table);
 
      // initial height
      table.setRowHeight(20);
 
      getContentPane().setLayout(new BorderLayout());
      getContentPane().add(scrollPane);
 
      addComponentListener(new ComponentAdapter() {
         int oldHeight;
 
         public void componentResized(ComponentEvent e) {
            if (oldHeight > 0) {
               int newRowHeight = ( table.getRowHeight() * getHeight() ) / oldHeight;
               table.setRowHeight(newRowHeight);
            }
  
            oldHeight = getHeight();
         }
      });
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(0);
         }
      });
 
      pack();
   }
 
   public static void main(String []args) {
      Main main = new Main();
      main.show();
   }
}

Adding a background image to a JTree that does not scroll

(1.3+)

Main.java:

import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import java.awt.*;
import java.net.*;
import java.awt.event.*;
 
public class Main extends JFrame
{
   public Main() {
      DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
      for (int i=0; i<100; i++) {
         DefaultMutableTreeNode child = new DefaultMutableTreeNode("Child " + (i+1));
         root.add(child);
      }
      JTree tree = new JTree(root);
 
      tree.setOpaque( false );
  
 
      DefaultTreeCellRenderer cr = new DefaultTreeCellRenderer();
      cr.setOpaque(false);
      cr.setBackground(new Color(0, 0, 0, 0));  
      cr.setBackgroundNonSelectionColor(null);
      tree.setCellRenderer(cr);
 
      ImageJScrollPane scrollpane = new ImageJScrollPane(tree);
      scrollpane.setBackgroundImage(new ImageIcon("mong.jpg"));
 
      getContentPane().add(scrollpane);
 
      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);
   }
}
 
class ImageJScrollPane extends JScrollPane
{
   private ImageIcon image = null;
 
   public ImageJScrollPane() {
      this(null, VERTICAL_SCROLLBAR_AS_NEEDED, HORIZONTAL_SCROLLBAR_AS_NEEDED);
   }
 
   public ImageJScrollPane(Component view) {
      this(view, VERTICAL_SCROLLBAR_AS_NEEDED, HORIZONTAL_SCROLLBAR_AS_NEEDED);
   }
 
   public ImageJScrollPane(Component view, int vsbPolicy, int hsbPolicy) {
      super(view, vsbPolicy, hsbPolicy);
      if (view instanceof JComponent) {
         ((JComponent) view).setOpaque(false);
      }
      setOpaque(false);
      getViewport().setOpaque(false);
      getViewport().setScrollMode(JViewport.BLIT_SCROLL_MODE);
   }
 
   public ImageJScrollPane(int vsbPolicy, int hsbPolicy) {
      this(null, vsbPolicy, hsbPolicy);
   }
 
   public void setBackgroundImage(ImageIcon image) {
      this.image = image;
   }
 
   public void paint(Graphics g) {
      if (image != null) {
         Rectangle rect = getViewport().getViewRect();
         for (int x=0; x<rect.width; x+=image.getIconWidth()) {
            for (int y=0; y<rect.height; y+=image.getIconHeight()) {
               g.drawImage(image.getImage(), x, y, null, null);
            }
         }
         super.paint(g);
      }
 
   }
}

Image used:

Example of TreeTable

The example program about TreeTable discussed in Sun’s article Creating TreeTables: Part 2 adds unnecessary complexity. The following is a much simpler one and will get you started much quicker.

Prerequisite: Download src.zip from the above url and compile the with both programs presented here.

Main.java:

import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.*;
import javax.swing.table.*;
import javax.swing.tree.*;
import java.awt.*;
import java.awt.event.*;
import java.text.NumberFormat;
 
public class Main extends JFrame {
   protected MyTreeTableModel  model;
   protected JTreeTable        treeTable;
 
   public Main() {
      super("Main");
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(0);
         }
      });
 
      model     = new MyTreeTableModel();
      treeTable = new JTreeTable(model);
 
      getContentPane().add(new JScrollPane(treeTable));
 
      try {
         UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
         SwingUtilities.updateComponentTreeUI(this);
      }
      catch(Exception e) {
         e.printStackTrace();
      }
 
      pack();
      show();
   }
 
   public static void main(String[] args) {
      new Main();
   }
}

MyTreeTableModel.java:

import java.io.IOException;
import java.io.File;
import java.util.Date;
import java.util.Stack;
import javax.swing.SwingUtilities;
import javax.swing.tree.TreePath;
import java.util.*;
 
public class MyTreeTableModel extends AbstractTreeTableModel {
 
   // Names of the columns.
   static protected String[] cNames = {"Column 1", "Column 2", 
                                       "Column 3", "Column 4"};
   // Types of the columns.
   static protected Class[]  cTypes = { TreeTableModel.class, String.class, 
                                        String.class, String.class };
   static Entry rootEntry;  
 
   /******** Entry class represents the parent and leaf nodes **********/
   static class Entry {
      private String name; 
      private boolean isLeaf;
      private Vector children = new Vector();
 
      public Entry(String name, boolean isLeaf) {
         this.name = name;
         this.isLeaf = isLeaf;
      }
 
      public Vector getChildren() {
         return children;
      }
 
      public boolean isLeaf() {
         return isLeaf;
      }
 
      public String getName() {
         return name;
      }
 
      public String toString() {
         return name;
      }
   }
 
   static {
      rootEntry = new Entry("rootentry", false);
      rootEntry.getChildren().addElement(new Entry("test1", true));
      rootEntry.getChildren().addElement(new Entry("test2", true));

      Entry subEntry1 = new Entry("subentry1", false);
      subEntry1.getChildren().addElement(new Entry("test3", true));
      subEntry1.getChildren().addElement(new Entry("test4", true));
      Entry subEntry2 = new Entry("subentry2", false);
      subEntry2.getChildren().addElement(new Entry("test5", true));
      subEntry2.getChildren().addElement(new Entry("test6", true));
      rootEntry.getChildren().addElement(subEntry1);
      rootEntry.getChildren().addElement(subEntry2); 
   }
   /*************************************/
 
   public MyTreeTableModel() { 
      super(rootEntry);
   }
 
   public int getChildCount(Object node) { 
      if (!((Entry) node).isLeaf()) {
         return ((Entry) node).getChildren().size();
      }
      return 0;
   }
 
   public Object getChild(Object node, int i) { 
      return ((Entry) node).getChildren().elementAt(i);
   }
 
   public boolean isLeaf(Object node) {
      return ((Entry) node).isLeaf();
   }
 
   public int getColumnCount() {
      return cNames.length;
   }
 
   public String getColumnName(int column) {
      return cNames[column];
   } 
 
   public Class getColumnClass(int column) {
      return cTypes[column];
   }
 
   public Object getValueAt(Object node, int column) {
      switch(column) {
         case 0:
            return node;
         case 1:
            return "value1";
         case 2:
            return "value2";
         case 3:
            return "value3";
      }
   
      return null; 
   }
}

Showing the trademark symbol in a JLabel

Main.java:

import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
   
public class Main extends JFrame {
   public Main() {
      getContentPane().setLayout(new FlowLayout());
 
      final JLabel label = new JLabel("Javau2122");
      getContentPane().add(label);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent event) {
            System.exit(0);   
         }      
      });
 
      pack();
   }
 
   public static void main(String[] args) {
      (new Main()).show();
   }
}

Embedding a JTextArea and ImageIcon in a JTable cell

JTextAreaTableExample.java:

import javax.swing.border.*;
import javax.swing.event.*;
import javax.swing.table.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.awt.*;
  
public class JTextAreaTableExample extends JFrame {
 
  public JTextAreaTableExample() {
    super( "JTextAreaTableExample Example" );
  
    DefaultTableModel dtm = new DefaultTableModel() {
       // make first cell uneditable
       public boolean isCellEditable(int row, int column)
       {
          return !(column == 0);
       }
    };
 
    dtm.setDataVector(new Object[][]{{ "JTextArea1", "This is a testnon long linesn" },
                                     { "JTextArea2", "Hello, world!" }},
                      new Object[]{ "String","JTextArea"});
                     
    JTable table = new JTable(dtm);
    table.getColumn("JTextArea").setCellRenderer(new TextAreaRenderer());
    table.getColumn("JTextArea").setCellEditor(new TextAreaEditor());
 
    table.setRowHeight(80);
    JScrollPane scroll = new JScrollPane(table);
    getContentPane().add(scroll);
 
    setSize( 400, 250 );
    setVisible(true);
  }
 
  public static void main(String[] args) {
    JTextAreaTableExample frame = new JTextAreaTableExample();
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
  }
}
  
class TextAreaRenderer extends JScrollPane implements TableCellRenderer
{
   JTextArea textarea;
 
   public TextAreaRenderer() {
      textarea = new JTextArea();
      textarea.setLineWrap(true);
      textarea.setWrapStyleWord(true);
      textarea.setBorder(new TitledBorder("This is a JTextArea"));
      JPanel panel = new JPanel();
      panel.setLayout(new BorderLayout());
      panel.add(BorderLayout.WEST, new JLabel(new ImageIcon("TrafficRed.gif")));
      panel.add(BorderLayout.CENTER, textarea);
      getViewport().add(panel);
   }
 
   public Component getTableCellRendererComponent(JTable table, Object value,
                                  boolean isSelected, boolean hasFocus,
                                  int row, int column)
   {
      if (isSelected) {
         setForeground(table.getSelectionForeground());
         setBackground(table.getSelectionBackground());
         textarea.setForeground(table.getSelectionForeground());
         textarea.setBackground(table.getSelectionBackground());
      } else {
         setForeground(table.getForeground());
         setBackground(table.getBackground());
         textarea.setForeground(table.getForeground());
         textarea.setBackground(table.getBackground());
      }
 
      textarea.setText((String) value); 
      textarea.setCaretPosition(0);
      return this;
   }
}
 
class TextAreaEditor extends DefaultCellEditor {
   protected JScrollPane scrollpane;
   protected JTextArea textarea; 
 
   public TextAreaEditor() {
      super(new JCheckBox());
      scrollpane = new JScrollPane();
      textarea = new JTextArea();  
      textarea.setLineWrap(true);
      textarea.setWrapStyleWord(true);
      textarea.setBorder(new TitledBorder("This is a JTextArea"));
      JPanel panel = new JPanel();
      panel.setLayout(new BorderLayout());
      panel.add(BorderLayout.WEST, new JLabel(new ImageIcon("TrafficRed.gif")));
      panel.add(BorderLayout.CENTER, textarea);
      scrollpane.getViewport().add(panel);
   }
 
   public Component getTableCellEditorComponent(JTable table, Object value,
                                   boolean isSelected, int row, int column) {
      textarea.setText((String) value);
 
      return scrollpane;
   }
 
   public Object getCellEditorValue() {
      return textarea.getText();
   }
}

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Listing the available fonts on your system

You could use the Toolkit method getFontList:

      String fontnames[] = Toolkit.getDefaultToolkit().getFontList();

However, this method is deprecated. Here’s a newer version:

import java.awt.*;
 
public class Main
{
   public static void main(String[] args) {
 
     GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
     String[] fontnames = env.getAvailableFontFamilyNames();
 
     System.out.println("Available fonts:n");
     for(int i=0; i<fontnames.length; i++)
        System.out.println(fontnames[i]);
     }
}

outputs:

Available fonts:

Andale Mono IPA
Arial
Arial Black
Arial Narrow
Book Antiqua
Bookman Old Style
Century Gothic
Comic Sans MS
Courier New
Curlz MT
Default
Dialog
dialog.bold
dialog.bolditalic
dialog.italic
DialogInput
dialoginput.bold
dialoginput.bolditalic
dialoginput.italic
Edwardian Script ITC
eelfont001
eelfont002
Engravers MT
Franklin Gothic Book
Franklin Gothic Demi Cond
Franklin Gothic Heavy
Franklin Gothic Medium Cond
Garamond
Georgia Ref
Haettenschweiler
Impact
Jokerman
Juice ITC
Lucida Bright
Lucida Console
Lucida Sans
Lucida Sans Typewriter
Lucida Sans Unicode
Marlett
Mediascape OSD Icon
Mistral
Monospaced
monospaced.bold
monospaced.bolditalic
monospaced.italic
MS Reference 1
MS Reference 2
MS Reference Sans Serif
MS Reference Serif
MS Reference Specialty
OCR A Extended
RefSpecialty
Rockwell
SansSerif
sansserif.bold
sansserif.bolditalic
sansserif.italic
Serif
serif.bold
serif.bolditalic
serif.italic
Symbol
Tahoma
Tera Special
Times New Roman
Trebuchet MS
Verdana
Verdana Ref
Webdings
Wingdings
Wingdings 2

Drawing a filled arc in Swing

Main.java:

import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
 
public class Main extends JFrame {
   public Main() {
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(1);
         }
      });
   }
 
   public void paint(Graphics g) {
      Graphics2D g2d = (Graphics2D) g;
 
      g2d.setColor(Color.green); 
      g2d.fillArc(10, 50, getSize().width-20, getSize().height-50, 90, 45);
   }
 
   public static void main(String []args) {
      Main main = new Main();
      main.setSize(100, 100);
      main.setVisible(true);
   }
}