TableCellRenderer and how to refresh Cell backgrou

Question

• is possible to refresh background based on value from outside correctly, without to force for repaint table.repaint();

• Based, used and tested with great code made by kleopatra and Hovercraft Full Of Eels

• valid for Java6/7, because there weren't any changes in APIs

my SSCCE works correctly, repainted by JTable.repaint()

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.GridLayout;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;

public class MyTableAndRenderer {

    private JFrame frame = new JFrame();
    private JPanel panel = new JPanel();
    private String[] items = {"Item 1", "Item 2", "Item 3", "Item 4"};
    private DefaultComboBoxModel comboBoxModel = new DefaultComboBoxModel(items);
    private JComboBox combo = new JComboBox(comboBoxModel);
    private JPanel panel1 = new JPanel();
    private String[] columnNames = {"First Name", "Last Name", "Sport",
        "# of Years", "Vegetarian"};
    private Object[][] data = {
        {"Kathy", "Smith", "Item 1", new Integer(5), (false)},
        {"John", "Doe", "Item 1", new Integer(3), (true)},
        {"Sue", "Black", "Item 3", new Integer(2), (false)},
        {"Jane", "White", "Item 3", new Integer(20), (true)},
        {"Joe", "Brown", "Item 3", new Integer(10), (false)}
    };
    private DefaultTableModel model = new DefaultTableModel(data, columnNames) {
        private static final long serialVersionUID = 1L;

        @Override
        public Class getColumnClass(int column) {
            return getValueAt(0, column).getClass();
        }
    };
    private JTable table = new JTable(model);

    public MyTableAndRenderer() {
        panel.setBorder(new EmptyBorder(10, 0, 2, 0));
        panel.add(combo);
        //@HFOE
        /*table.setDefaultRenderer(Object.class, new DefaultTableCellRenderer() {
            @Override
            public Component getTableCellRendererComponent(JTable table,
                    Object value, boolean isSelected, boolean hasFocus,
                    int row, int column) {
                    super.getTableCellRendererComponent(table, value, isSelected,
                        hasFocus, row, column);
                String str = combo.getSelectedItem().toString();
                if (value.toString().equalsIgnoreCase(str)) {
                    setBackground(Color.RED);
                } else {
                    setBackground(null);
                }
                return this;
            }
        });*/
        //@kleopatra
        /*table.setDefaultRenderer(Object.class, new DefaultTableCellRenderer() {
            @Override
            public Component getTableCellRendererComponent(JTable table,
                    Object value, boolean isSelected, boolean hasFocus,
                    int row, int column) {
                String str = combo.getSelectedItem().toString();
                if (value.toString().equalsIgnoreCase(str)) {
                    setBackground(Color.RED);
                } else {
                    setBackground(null);
                }
                super.getTableCellRendererComponent(table, value, isSelected,
                        hasFocus, row, column);
                return this;
            }
        });*/
        table.setDefaultRenderer(Object.class, new DefaultTableCellRenderer() {
            @Override
            public Component getTableCellRendererComponent(JTable table,
                    Object value, boolean isSelected, boolean hasFocus,
                    int row, int column) {
                super.getTableCellRendererComponent(table, value, isSelected,
                        hasFocus, row, column);
                String str = combo.getSelectedItem().toString();
                if (value.toString().equalsIgnoreCase(str)) {
                    setBackground(Color.RED);
                    table.repaint();
                } else {
                    setBackground(null);
                    table.repaint();
                }
                return this;
            }
        });
        table.getTableHeader().setReorderingAllowed(false);
        table.setAutoCreateRowSorter(true);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        panel1.setLayout(new GridLayout(1, 1, 10, 10));
        panel1.add(new JScrollPane(table));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(panel, BorderLayout.NORTH);
        frame.add(panel1);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                MyTableAndRenderer fs = new MyTableAndRenderer();
            }
        });
    }
}

EDIT

@Devolus wrote Did you test what I posted? I took this snippet from my own working code, I just removed the stuff inbetween as it is not relevant for the answer. I'm using Java 6 here and this works for me.

public Component getTableCellRendererComponent(JTable table,
        Object value,
        boolean isSelected,
        boolean hasFocus, 
        int row, int column) 
{

    Component cell = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);

    ... determine the color value ...

    cell.setBackground(back);
    cell.setForeground(fore);
}

• caused

• doesn't matter Java6/7

from code (reason to post an SSCCE)

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.GridLayout;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;

public class MyTableAndRenderer {

    private JFrame frame = new JFrame();
    private JPanel panel = new JPanel();
    private String[] items = {"Item 1", "Item 2", "Item 3", "Item 4"};
    private DefaultComboBoxModel comboBoxModel = new DefaultComboBoxModel(items);
    private JComboBox combo = new JComboBox(comboBoxModel);
    private JPanel panel1 = new JPanel();
    private String[] columnNames = {"First Name", "Last Name", "Sport",
        "# of Years", "Vegetarian"};
    private Object[][] data = {
        {"Kathy", "Smith", "Item 1", new Integer(5), (false)},
        {"John", "Doe", "Item 1", new Integer(3), (true)},
        {"Sue", "Black", "Item 3", new Integer(2), (false)},
        {"Jane", "White", "Item 3", new Integer(20), (true)},
        {"Joe", "Brown", "Item 3", new Integer(10), (false)}
    };
    private DefaultTableModel model = new DefaultTableModel(data, columnNames) {
        private static final long serialVersionUID = 1L;

        @Override
        public Class getColumnClass(int column) {
            return getValueAt(0, column).getClass();
        }
    };
    private JTable table = new JTable(model);

    public MyTableAndRenderer() {
        panel.setBorder(new EmptyBorder(10, 0, 2, 0));
        panel.add(combo);
        table.setDefaultRenderer(Object.class, new DefaultTableCellRenderer() {
            @Override
            public Component getTableCellRendererComponent(JTable table,
                    Object value, boolean isSelected, boolean hasFocus,
                    int row, int column) {
                Component c = super.getTableCellRendererComponent(table, value, isSelected,
                        hasFocus, row, column);
                String str = combo.getSelectedItem().toString();
                if (value.toString().equalsIgnoreCase(str)) {
                    c.setBackground(Color.RED);
                } else {
                    c.setBackground(null);
                }
                return this;
            }
        });
        table.getTableHeader().setReorderingAllowed(false);
        table.setAutoCreateRowSorter(true);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        panel1.setLayout(new GridLayout(1, 1, 10, 10));
        panel1.add(new JScrollPane(table));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(panel, BorderLayout.NORTH);
        frame.add(panel1);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                MyTableAndRenderer fs = new MyTableAndRenderer();
            }
        });
    }
}

EDIT2

• from WinXp (for all Win OS don't to use Nimbus, Renderer is there very funny, never seen that, great!!! how is this possible)

EDIT3:

note I'm simplified code as is possible, tested before my question here, then casting Rendering Component to JComponent/JLabel doesn't works too (with JLabel.repaint()/setOpaque())

Answer 1

To fix your particular problem you can add the table.repaint() as shown.

However, to properly redraw the table, you should refresh it from the outside. In this example you should add an event listener on the combobox and then refresh it from there.

public Component getTableCellRendererComponent(JTable table,
        Object value,
        boolean isSelected,
        boolean hasFocus, 
        int row, int column) 
{
    Component cell = super.getTableCellRendererComponent(table, value, isSelected,
            hasFocus, row, column);
    String str = combo.getSelectedItem().toString();
    if (value.toString().equalsIgnoreCase(str))
    {
        cell.setBackground(Color.RED);
    }
    else
    {
        cell.setBackground(null);
    }

    return cell;
}

Answer 2

The issue occurs when you change the selected item. You have some implicit interaction between your combobox and you table (the selected item of the combo box influences the way the table is painted).

When the comboboxpopup is hidden, it automatically triggers a repaint of the hovered area (the RepaintManager will only repaint the hovered area, not the complete table). But in the meantime, you have changed the way the cells of the table are painted (the first cells are no longer painted in red because they don't match the selection anymore). However, the repaint manager forces to repaint only a small area of the table which does not cover completely the red cells, hence you see those visual glitches.

Here are 2 solutions I can come up with:

• Add an ActionListener to the combobox and invoke table.repaint() (easy to do)
• Change your table model and call fireTableCellUpdated(row, column) for the relevant cells.

SSCCE for the second solution:

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;

import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;

public class MyTableAndRenderer {

    private final class DefaultTableModelExtension extends DefaultTableModel {
        private static final long serialVersionUID = 1L;

        private String selected;

        private DefaultTableModelExtension(Object[][] data, Object[] columnNames) {
            super(data, columnNames);
        }

        @Override
        public Class getColumnClass(int column) {
            return getValueAt(0, column).getClass();
        }

        public String getSelected() {
            return selected;
        }

        public void setSelected(String selected) {
            if (this.selected == null && selected == null || this.selected != null && this.selected.equalsIgnoreCase(selected)) {
                return;
            }
            class Cell {
                public final int row;
                public final int column;

                public Cell(int row, int column) {
                    super();
                    this.row = row;
                    this.column = column;
                }
            }
            List<Cell> updatedCells = new ArrayList<Cell>();
            if (this.selected != null) {
                for (int i = 0; i < data.length; i++) {
                    Object[] o = data[i];
                    for (int j = 0; j < o.length; j++) {
                        Object object = o[j];
                        if (this.selected.toString().equalsIgnoreCase(object.toString())) {
                            updatedCells.add(new Cell(i, j));
                        }
                    }
                }
            }
            this.selected = selected;
            if (this.selected != null) {
                for (int i = 0; i < data.length; i++) {
                    Object[] o = data[i];
                    for (int j = 0; j < o.length; j++) {
                        Object object = o[j];
                        if (this.selected.toString().equalsIgnoreCase(object.toString())) {
                            updatedCells.add(new Cell(i, j));
                        }
                    }
                }
            }
            for (Cell pair : updatedCells) {
                fireTableCellUpdated(pair.row, pair.column);
            }
        }
    }

    private JFrame frame = new JFrame();
    private JPanel panel = new JPanel();
    private String[] items = { "Item 1", "Item 2", "Item 3", "Item 4" };
    private DefaultComboBoxModel comboBoxModel = new DefaultComboBoxModel(items);
    private JComboBox combo = new JComboBox(comboBoxModel);
    private JPanel panel1 = new JPanel();
    private String[] columnNames = { "First Name", "Last Name", "Sport", "# of Years", "Vegetarian" };
    private Object[][] data = { { "Kathy", "Smith", "Item 1", new Integer(5), false }, { "John", "Doe", "Item 1", new Integer(3), true },
            { "Sue", "Black", "Item 3", new Integer(2), false }, { "Jane", "White", "Item 3", new Integer(20), true },
            { "Joe", "Brown", "Item 3", new Integer(10), false } };
    private DefaultTableModelExtension model = new DefaultTableModelExtension(data, columnNames);
    private JTable table = new JTable(model);

    public MyTableAndRenderer() {
        panel.setBorder(new EmptyBorder(10, 0, 2, 0));
        panel.add(combo);
        combo.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                updateSelected();
            }

        });
        // Need first synch
        updateSelected();
        table.setDefaultRenderer(Object.class, new DefaultTableCellRenderer() {
            @Override
            public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row,
                    int column) {
                Component c = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
                String str = combo.getSelectedItem().toString();
                if (value.toString().equalsIgnoreCase(str)) {
                    c.setBackground(Color.RED);
                } else {
                    c.setBackground(null);
                }
                return this;
            }
        });
        table.getTableHeader().setReorderingAllowed(false);
        table.setAutoCreateRowSorter(true);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        panel1.setLayout(new GridLayout(1, 1, 10, 10));
        panel1.add(new JScrollPane(table));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(panel, BorderLayout.NORTH);
        frame.add(panel1);
        frame.pack();
        frame.setVisible(true);
    }

    private void updateSelected() {
        model.setSelected((String) combo.getSelectedItem());
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                MyTableAndRenderer fs = new MyTableAndRenderer();
            }
        });
    }
}