Moving table columns is very slow

Question

In my application moving table columns is very slow, with the rendering of table cells dragging behind the rendering of the table cell (using Java 1.5). I use a custom table cell renderer that subclasses a JPanel and contains a JTextField.
I checked I was overriding all the methods that DefaultTableCellRenderer does for performance reasons and found I wasnt overiding validate() and invalidate(), over-riding these the table column performance is now ok, but the cells are now not rendered correctly.
I also put a System.out.println into getTableRendererComponent() and found that even if I only move a column slightly the getTableRendererComponent() is called for every cell displayed rather than just the cells within the column moved/columns either side of it which is what i expect.
Any ideas what i should do. My own vague idea is to put some code into validate() and invalidate() to only call super implemntaions when really need to, but dont know how to work this out.

Answer 1

Hi, thanks for your help - ive created a full test case, code below. I have reworked the code so I dont need to do a removeAll() but the issues remaining are:
1. If I override validate() with an empty method nothing is displayed in the grid
2. The renderer is alot slower than the using default renderer even though ive removed stuff like borders.
The code below has validate without the empty method.
(My real renderer is a bit more complicated, and I do require to use a JPanel)
import com.jthink.jaikoz.settings.LAF;
import com.jthink.jaikoz.table.ID3Cell;
import javax.swing.*;
import javax.swing.table.*;
import java.util.Vector;
import java.awt.*;
public class SlowColumnMoveTest
    public static void main(String args[])
        new SlowColumnMoveTest();
    public SlowColumnMoveTest()
        Vector colNames = new Vector();
        colNames.add("col0");
        colNames.add("col1");
        colNames.add("col2");
        colNames.add("col3");
        colNames.add("col4");
        colNames.add("col5");
        colNames.add("col6");
        colNames.add("col7");
        colNames.add("col8");
        colNames.add("col9");
        Vector data = new Vector();
        for (int i = 0; i < 500; i++)
            Vector v = new Vector();
            v.add(i);
            for (int j = 1; j < 10; j++)
                v.add(String.valueOf((i + 1) * (j + 1)));
            data.add(v);
        JTable table = new JTable(new DefaultTableModel(data, colNames));
        table.getColumnModel().setColumnSelectionAllowed(true);
        table.setDefaultRenderer(Object.class, new SlowRenderer());
        JFrame frame = new JFrame("SlowColumnMoveTest");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        JScrollPane scrollPane = new JScrollPane(table);
        frame.add(scrollPane);
        frame.pack();
        frame.setVisible(true);
    static class SlowRenderer extends JPanel implements TableCellRenderer
        private static String PROPERTY_TABLE_BGCOLOUR = "Table.background";
        private static String PROPERTY_TABLE_FGCOLOUR = "Table.foreground";
        private static String PROPERTY_TABLE_SELECTION_BGCOLOUR = "Table.selectionBackground";
        private static String PROPERTY_TABLE_SELECTION_FGCOLOUR = "Table.selectionForeground";
        protected static Color tableBGColour = null;
        protected static Color tableFGColour = null;
        protected static Color selectionBGColour = null;
        protected static Color selectionFGColour = null;
        static
            tableBGColour = UIManager.getColor(PROPERTY_TABLE_BGCOLOUR);
            tableFGColour = UIManager.getColor(PROPERTY_TABLE_FGCOLOUR);
            selectionBGColour = UIManager.getColor(PROPERTY_TABLE_SELECTION_BGCOLOUR);
            selectionFGColour = UIManager.getColor(PROPERTY_TABLE_SELECTION_FGCOLOUR);
        protected JTextField text;
        public SlowRenderer()
            text = new JTextField();
            text.setBorder(null);
            text.setOpaque(false);
            text.setForeground(tableFGColour);
            setOpaque(true);
            this.setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
            this.add(text);
        public Component getTableCellRendererComponent(final JTable table,
                                                       final Object value,
                                                       final boolean isSelected,
                                                       final boolean hasFocus,
                                                       final int row,
                                                       final int column)
            //System.out.println("rendering:col:"+column+":row:"+row);
            text.setVisible(true);
            text.setText(value.toString());
            if (isSelected)
                text.setForeground(selectionFGColour);
                this.setBackground(selectionBGColour);
            else
                text.setForeground(tableFGColour);
                this.setBackground(tableBGColour);
            return this;
        @Override
        public final boolean isOpaque()
            return true;
        @Override
        public void invalidate()
            //System.out.println("invvalidate");
            //super.invalidate();
        @Override
        public void validate()
            //System.out.println("validate");
            super.validate();
        @Override
        public void revalidate()
        @Override
        public void repaint(long tm, int x, int y, int width, int height)
        @Override
        public void repaint(Rectangle r)
        @Override
        public void repaint()
        @Override
        protected final void firePropertyChange(final String propertyName, final Object oldValue, final Object newValue)
        @Override
        public final void firePropertyChange(final String propertyName, final boolean oldValue, final boolean newValue)
        private static final class UIResource
            extends DefaultTableCellRenderer
            implements javax.swing.plaf.UIResource
}