Rubber stamp table cell renderers performance

Question

One never stops to learn...
http://java.sun.com/javase/6/docs/api/javax/swing/table/DefaultTableCellRenderer.html
+“...So this class overrides the validate, invalidate, revalidate, repaint, and firePropertyChange methods to be no-ops and override the isOpaque method solely to improve performance. If you write your own renderer, please keep this performance consideration in mind.”+
Hm. This was quite a revelation for me. However, I’m having troubles implementing it. I have rather complex cell renderers… To be exact: I have complex cell editors, for example one containing two textfields and two buttons (key & description textfields plus zoom & search buttons) inside a JPanel. The JPanel is the cell editor component. Because I want the buttons on exactly the same location in the renderer as in the editor, I have an editor-to-renderer wrapper.
I cannot disable the mentioned methods on the JPanel that is the renderer, then its contents isn’t painted anymore. Invalidate and validate must stay.
Now, I can easily build a simple text based renderer using DefaultTableCellRenderer aka JLabel. However, what if a table must show more than trivial stuff? Are there any good guides on how to build complex cell renderers?
Again: I often use the editor-as-renderer wrapper in order to not have to code stuff twice. At all works just fine, but appearantly is very slow (my tables are slow indeed)... Any way to do this correctly?

Answer 1

Ok, here you are with two SSCCE's! :-)
The first test only shows a regular complex renderer (2x textfield, 2x button). According to the specs the component must have certain methods disabled, so they are overridden in the jpanel that holds all these components. Run, and then try again with the two methods uncommented.
The second test is how I normally do it; I do not want to write separate editors and renderers, so I only write the editor and use an editor-to-renderer wrapper. In order to fulfill the requirement, I wrap the editor component in a second jpanel that overrides the required methods. Again, run and then try again with the two methods uncommented.
package test;
import java.awt.Component;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellRenderer;
* Test1: use a complex cell renderer and follow the specs in
* http://java.sun.com/javase/6/docs/api/javax/swing/table/DefaultTableCellRenderer.html
public class CellRendererTest
      * @param args
     public static void main(String[] args)
          SwingUtilities.invokeLater(new Runnable()
               @Override
               public void run()
                    JTable lJTable = new JTable(new DefaultTableModel(new String[][]{{"a1","b1"},{"a2","b2"}}, new String[]{"A","B"}));
                    lJTable.setDefaultRenderer(Object.class, new ComplexCellRenderer());
                    JFrame lJFrame = new JFrame();
                    lJFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    lJFrame.add(lJTable);
                    lJFrame.setSize(500,100);
                    lJFrame.setVisible(true);
     // =============================================================================
     static class ComplexCellRenderer implements TableCellRenderer
          JTextField iKey = new JTextField(5);
          JButton iSearch = new JButton("?");
          JButton iGoto = new JButton(">");
          JTextField iDescription = new JTextField(20);
          JPanel iJPanel = new JPanel()               
//               @Override public void validate() {}
//               @Override public void invalidate() {}
               @Override public void revalidate() {}
               @Override public void repaint() {}
               @Override public void firePropertyChange(String propertyName, Object oldValue, Object newValue) {}
               @Override public void firePropertyChange(String propertyName, boolean oldValue, boolean newValue) {}
               @Override public void firePropertyChange(String propertyName, int oldValue, int newValue) {}
          public ComplexCellRenderer()
               iKey.setBorder(null);
               iDescription.setBorder(null);
               iDescription.setEnabled(false);
               iJPanel.setLayout(new GridLayout());
               iJPanel.add(iKey);
               iJPanel.add(iSearch);
               iJPanel.add(iGoto);
               iJPanel.add(iDescription);
          @Override
          public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column)
               iKey.setText( value == null ? "" : value.toString() );
               iDescription.setText( value == null ? "" : value.toString() + "..." );
               return iJPanel;
}Test 2:
package test;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.GridLayout;
import javax.swing.AbstractCellEditor;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellEditor;
import javax.swing.table.TableCellRenderer;
* Test2: usually when have complex cell renderers, it actually means you have complex cell editors.
* You want the renderer to look 100% like the editor, so it is practical to implement a wrapper.
* Naturally the wrapped editor must adhere to the specs in: 
* http://java.sun.com/javase/6/docs/api/javax/swing/table/DefaultTableCellRenderer.html
* So the idea is the wrap it in a special panel, this is what the "useAsRenderer" method is for.
public class CellRendererTest2
      * @param args
     public static void main(String[] args)
          SwingUtilities.invokeLater(new Runnable()
               @Override
               public void run()
                    JTable lJTable = new JTable(new DefaultTableModel(new String[][]{{"a1","b1"},{"a2","b2"}}, new String[]{"A","B"}));
                    lJTable.setDefaultEditor(Object.class, new ComplexCellEditor());
                    lJTable.setDefaultRenderer(Object.class, new UseTableCellEditorAsTableCellRenderer(new ComplexCellEditor().useAsRenderer()));
                    JFrame lJFrame = new JFrame();
                    lJFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    lJFrame.add(lJTable);
                    lJFrame.setSize(500,100);
                    lJFrame.setVisible(true);
     // =============================================================================
     // The editor
     static class ComplexCellEditor extends AbstractCellEditor  implements TableCellEditor
          JTextField iKey = new JTextField(5);
          JButton iSearch = new JButton("?");
          JButton iGoto = new JButton(">");
          JTextField iDescription = new JTextField(20);
          JPanel iJPanel = new JPanel();
          public ComplexCellEditor()
               super();
               iKey.setBorder(null);
               iDescription.setBorder(null);
               iDescription.setEnabled(false);
               iJPanel.setLayout(new GridLayout());
               iJPanel.add(iKey);
               iJPanel.add(iSearch);
               iJPanel.add(iGoto);
               iJPanel.add(iDescription);
          @Override
          public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column)
               iKey.setText( value == null ? "" : value.toString() );
               iDescription.setText( value == null ? "" : value.toString() + "..." );
               return iJPanel;
          @Override
          public Object getCellEditorValue()
               return iKey.getText();
          public ComplexCellEditor useAsRenderer()
               JPanel lJPanel = new JPanel()
//                    @Override public void validate() {}
//                    @Override public void invalidate() {}
                    @Override public void revalidate() {}
                    @Override public void repaint() {}
                    @Override public void firePropertyChange(String propertyName, Object oldValue, Object newValue) {}
                    @Override public void firePropertyChange(String propertyName, boolean oldValue, boolean newValue) {}
                    @Override public void firePropertyChange(String propertyName, int oldValue, int newValue) {}
               lJPanel.setLayout(new BorderLayout());
               lJPanel.add(iJPanel);
               iJPanel = lJPanel;
               return this;
     // ==========================================================================================
     // Simplified version of the wrapper (normally this wrapper takes care of the special JPanel)
     static class UseTableCellEditorAsTableCellRenderer implements TableCellRenderer
          public UseTableCellEditorAsTableCellRenderer(TableCellEditor tableCellEditor)
               iTableCellEditor = tableCellEditor;
          private TableCellEditor iTableCellEditor = null;
          @Override
          public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column)
              // we use the editor as the renderer
              Component lEditor = iTableCellEditor.getTableCellEditorComponent(table, value, isSelected, row, column);
              return lEditor;
}