Problem with focus border and ListCellRenderer in custom listbox

Question

I have a bug in some code that I adapted from another posting on this board -- basically what I've done is I have a class that implements a custom "key/value" mapping listbox in which each list item/cell is actually a JPanel consisting of 3 JLabels: the first label is the "key", the second is a fixed "==>" mapping string, and the 3rd is the value to which "key" is mapped.
The code works fine as long as the list cell doesn't have the focus. When it does, it draws a border rectangle to indicate focus, but if the listbox needs to scroll horizontally to display all the text, part of the text gets cut off (i.e. "sometex..." where "sometext" should be displayed).
The ListCellRenderer creates a Gridlayout to lay out the 3 labels in the cell's JPanel.
What can I do to remedy this situation? I'm not sure what I'd need to do in terms of setting the size of the panel so that all the text gets displayed OK within the listbox. Or if there's something else I can do to fix this. The code and a main() to run the code are provided below. To reproduce the problem, click the Add Left and Add Right buttons to add a "mapping" -- when it doesn't have focus, everything displays fine, but when you give it focus, note the text on the right label gets cut off.
//======================================================================
// Begin Source Listing
//======================================================================
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.Collection;
import java.util.Iterator;
import java.util.Vector;
import java.util.Enumeration;
public class TwoColumnListbox extends JPanel
private JList m_list;
private JScrollPane m_Pane;
public TwoColumnListbox(Collection c)
     DataMapListModel model = new DataMapListModel();
     if (c != null)
     Iterator it = c.iterator();
     while (it.hasNext())
     model.addElement(it.next());
     m_list = new JList(model);
     ListBoxRenderer renderer= new ListBoxRenderer();
          m_list.setCellRenderer(renderer);
          setLayout(new BorderLayout());
          m_list.setVisibleRowCount(4);
          m_Pane = new JScrollPane(m_list);
          add(m_Pane, BorderLayout.NORTH);
public JList getList()
return m_list;
public JScrollPane getScrollPane()
return m_Pane;
public static void main(String s[])
          JFrame frame = new JFrame("TwoColumnListbox");
          frame.addWindowListener(new WindowAdapter() {
          public void windowClosing(WindowEvent e) {System.exit(0);}
final DataMappings dm = new DataMappings();
final TwoColumnListbox lb = new TwoColumnListbox(dm.getMappings());
          final DataMap map = new DataMap();
          JButton leftAddBtn = new JButton("Add Left");
          leftAddBtn.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e)
          map.setSource("JButton1");
          DefaultListModel model = new DefaultListModel();
          model.addElement(map);
          lb.getList().setModel(model);
          JButton leftRemoveBtn = new JButton("Remove Left");
          leftRemoveBtn.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e)
          map.setSource("");
          DefaultListModel model = new DefaultListModel();
          model.addElement(map);
          lb.getList().setModel(model);
          JButton rightAddBtn = new JButton("Add Right");
rightAddBtn.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e)
          map.setDestination("/getQuote/symbol[]");
          DefaultListModel model = new DefaultListModel();
          model.addElement(map);
          lb.getList().setModel(model);
          JButton rightRemoveBtn = new JButton("Remove Right");
rightRemoveBtn.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e)
          map.setDestination("");
          DefaultListModel model = new DefaultListModel();
          model.addElement(map);
          lb.getList().setModel(model);
          JPanel leftPanel = new JPanel(new BorderLayout());
          leftPanel.add(leftAddBtn, BorderLayout.NORTH);
          leftPanel.add(leftRemoveBtn, BorderLayout.SOUTH);
JPanel rightPanel = new JPanel(new BorderLayout());
          rightPanel.add(rightAddBtn, BorderLayout.NORTH);
          rightPanel.add(rightRemoveBtn, BorderLayout.SOUTH);
frame.getContentPane().add(leftPanel, BorderLayout.WEST);
          frame.getContentPane().add(lb,BorderLayout.CENTER);
frame.getContentPane().add(rightPanel, BorderLayout.EAST);
          frame.pack();
          frame.setVisible(true);
     class ListBoxRenderer extends JPanel implements ListCellRenderer
          private JLabel left;
          private JLabel arrow;
          private JLabel right;
          private Color clrForeground = UIManager.getColor("List.foreground");
private Color clrBackground = UIManager.getColor("List.background");
private Color clrSelectionForeground = UIManager.getColor("List.selectionForeground");
private Color clrSelectionBackground = UIManager.getColor("List.selection.Background");
          public ListBoxRenderer()
               setLayout(new GridLayout(1, 2, 10, 0));
               //setBorder(BorderFactory.createEmptyBorder(4, 4, 4, 4));
               left = new JLabel("");
               left.setForeground(clrForeground);               
               arrow = new JLabel("");
               arrow.setHorizontalAlignment(SwingConstants.CENTER);
               arrow.setForeground(clrForeground);
               right = new JLabel("");
               right.setHorizontalAlignment(SwingConstants.RIGHT);
               right.setForeground(clrForeground);
               add(left);
               add(arrow);
               add(right);
          public Component getListCellRendererComponent(JList list, Object value,
                    int index, boolean isSelected, boolean cellHasFocus)
               if (isSelected)
                    setBackground(list.getSelectionBackground());
                    setForeground(list.getSelectionForeground());
                    left.setForeground(clrSelectionForeground);
                    arrow.setForeground(clrSelectionForeground);
                    right.setForeground(clrSelectionForeground);
               else
                    setBackground(list.getBackground());
                    setForeground(list.getForeground());
               left.setForeground(clrForeground);
                    arrow.setForeground(clrForeground);
                    right.setForeground(clrForeground);               
               // draw focus rectangle if control has focus. Problem with focus
// and cut off text!!
               if (cellHasFocus)
               // FIXME: for Windows LAF I'm not getting the correct thing here for some reason.
               // Looks OK on Metal though.
               setBorder(BorderFactory.createLineBorder(UIManager.getColor("focusCellHighlightBorder")));
               else
               setBorder(BorderFactory.createEmptyBorder());               
DataMap map = (DataMap) value;
               String displaySource = map.getSource();
               String displayDest = map.getDestination();
               left.setText(displaySource);
               arrow.setText("=>to<=");
               right.setText(displayDest);
               return this;
/** Interface for macro editor UI
* @version 1.0
class DataMappings
private Collection mappings;
public DataMappings()
setMappings(new Vector(0));
public DataMappings(Collection maps)
setMappings(maps);
/** gets mapping value of a specified source object
* @param src -- the "key" or source object, what is mapped.
* @return what the source object is mapped to
* @version 1.0
public Object getValue(String src)
if (src != null)
Iterator it = mappings.iterator();
while (it.hasNext());
DataMap thisMap = (DataMap) it.next();
if (thisMap.getSource().equals(src))
return thisMap.getDestination();
return null;
/** sets mapping value of a specified source object
* @param src -- the "key" or source object, what is mapped.
* @param what the source object is to be mapped to
* @version 1.0
public void setValue(String src, String dest)
if (src != null)
// see if the value is in there first.
Iterator it = mappings.iterator();
while (it.hasNext())
DataMap thisMap = (DataMap) it.next();
if (thisMap.getSource().equals(src))
thisMap.setDestination(dest);
return;
// not in the collection, add it
mappings.add(new DataMap(src, dest));
/** gets collection of mappings
* @return a collection of all mappings in this object.
* @version 1.0
public Collection getMappings()
return mappings;
/** sets collection of mappings
* @param maps a collection of src to destination mappings.
* @version 1.0
public void setMappings(Collection maps)
mappings = maps;
/** adds a DataMap
* @param map a DataMap to add to the mappings
* @version 1.0
public void add(DataMap map)
if (map != null)
mappings.add(map);
class DataMap
public DataMap() {}
public DataMap(String source, String destination)
m_source = source;
m_destination = destination;
public String getSource()
return m_source;
public void setSource(String s)
m_source = s;
public String getDestination()
return m_destination;
public void setDestination(String s)
m_destination = s;
protected String m_source = null;
protected String m_destination = null;
/** list model for datamaps that provides ways
* to determine whether a source is already mapped or
* a destination is already mapped.
class DataMapListModel extends DefaultListModel
public DataMapListModel()
super();          
/** determines whether a source is already mapped
* @param src -- the source property of a datamapping
* @return true if the source is in the list, false if not
public boolean containsSource(Object src)
Enumeration enum = elements();
while (enum.hasMoreElements())
DataMap dm = (DataMap) enum.nextElement();
if (dm.getSource().equals(src))
return true;
return false;
/** determines whether a destination is already mapped
* @param dest -- the destination property of a datamapping
* @return true if the destination is in the list, false if not
public boolean containsDest(Object dest)
Enumeration enum = elements();
while (enum.hasMoreElements())
DataMap dm = (DataMap) enum.nextElement();
if (dm.getDestination().equals(dest))
return true;
return false;
public DataMappings getDataMaps()
DataMappings maps = new DataMappings();
// add all the datamaps in the model
Enumeration enum = elements();
while (enum.hasMoreElements())
DataMap dm = (DataMap) enum.nextElement();
maps.add(dm);
return maps;
//======================================================================
// End of Source Listing
//======================================================================

Answer 1

I did not read the program, but the chopping looks like a layout problem.
I think it's heavy to use a panel + 3 components in a gridlayout for each cell. look at this sample where i draw the Cell myself,
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;
public class Jlist3 extends JFrame 
     Vector      v  = new Vector();
     JList       jc = new JList(v);
     JScrollPane js = new JScrollPane(jc);
public Jlist3()
     addWindowListener(new WindowAdapter()
    {     public void windowClosing(WindowEvent ev)
          {     dispose();
               System.exit(0);}});
     for (int j=0; j < 70; j++)     v.add(""+j*1000+"a  d"+j);
       setBounds(1,1,400,310);
     getContentPane().add(js);
     js.setPreferredSize(new Dimension(230,259));
     jc.setSelectedIndex(1);
     jc.setCellRenderer(new MyCellRenderer());
     getContentPane().setLayout(new FlowLayout());
     setVisible(true);
public class MyCellRenderer extends JLabel implements ListCellRenderer
     String  txt;
     int     idx;
     boolean sel;
public Component getListCellRendererComponent(JList list,
                         Object  value,           // value to display
                         int     index,           // cell index
                         boolean isSelected,      // is the cell selected
                         boolean cellHasFocus)    // the list and the cell have the focus
     idx = index;
     txt = value.toString();
     sel = isSelected;
     setText(txt);
     return(this);
public void paintComponent(Graphics g)
     if (idx%2 == 1) g.setColor(Color.white);
          else        g.setColor(Color.lightGray);
     if (sel)        g.setColor(Color.blue);
     g.fillRect(0,0,getWidth(),getHeight());
     StringTokenizer st = new StringTokenizer(txt.trim()," ");
     g.setColor(Color.black);
     if (st.hasMoreTokens())     g.drawString(st.nextToken(),1,14);
     g.setColor(Color.red);
     g.drawString("===>",70,14);
     g.setColor(Color.black);
     if (st.hasMoreTokens())     g.drawString(st.nextToken(),110,14);
public static void main (String[] args) 
     new Jlist3();
Noah
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;
public class Jlist3 extends JFrame
     Vector v = new Vector();
     JList jc = new JList(v);
     JScrollPane js = new JScrollPane(jc);
public Jlist3()
     addWindowListener(new WindowAdapter()
{     public void windowClosing(WindowEvent ev)
          {     dispose();
               System.exit(0);}});
     for (int j=0; j < 70; j++)     v.add(""+j*1000+"a d"+j);
     setBounds(1,1,400,310);
     getContentPane().add(js);
     js.setPreferredSize(new Dimension(230,259));
     jc.setSelectedIndex(1);
     jc.setCellRenderer(new MyCellRenderer());
     getContentPane().setLayout(new FlowLayout());
     setVisible(true);
public class MyCellRenderer extends JLabel implements ListCellRenderer
     String txt;
     int idx;
     boolean sel;
public Component getListCellRendererComponent(JList list,
                         Object value, // value to display
                         int index, // cell index
                         boolean isSelected, // is the cell selected
                         boolean cellHasFocus) // the list and the cell have the focus
     idx = index;
     txt = value.toString();
     sel = isSelected;
     setText(txt);
     return(this);
public void paintComponent(Graphics g)
     if (idx%2 == 1) g.setColor(Color.white);
          else g.setColor(Color.lightGray);
     if (sel) g.setColor(Color.blue);
     g.fillRect(0,0,getWidth(),getHeight());
     StringTokenizer st = new StringTokenizer(txt.trim()," ");
     g.setColor(Color.black);
     if (st.hasMoreTokens())     g.drawString(st.nextToken(),1,14);
     g.setColor(Color.red);
     g.drawString("===>",70,14);
     g.setColor(Color.black);
     if (st.hasMoreTokens())     g.drawString(st.nextToken(),110,14);
public static void main (String[] args)
     new Jlist3();
}