Background Pattern for a Cell in JTable

[Pomchi Bedi]

Hi,
I need to set some kind of background pattern (like dots,cross) for cells that are inactive.I was using lightGray color to do the same......but I want to color those cells and wish to have a different background to show that these are disabled.
Any suggestions are welcome.
Thanks
Pomchi

[Rob Ross]

You'll need to create a custom TableCellRenderer and install on your table columns so that you can override the cell component's paint() method to do your custom background pattern drawing.
Rob

[Pomchi Bedi]

Hi Rob,
I know that this is how I can put an icon in the cell.But I want my pattern to occupy the entire cell space.It should increase or decrease with the cell width.
Any example related to this would help.
Thanks
Pomchi
[ January 09, 2002: Message edited by: Pomchi Bedi ]

[Nathan Pruett]

Pomchi,

Here's a quick example to do what you want... look especially at the PatternRenderer class... that defines the behaivior you want...

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.*;
 
public class PatternTable extends JFrame {
 
    public static void main( String[] arg ) {
        new PatternTable();
    }
 
    public PatternTable() {
        super( "Table With Pattern Image Cells" );
        PatternTableModel ptModel = new PatternTableModel();
        JTable table = new JTable( ptModel );
        table.setDefaultRenderer( new Pattern( "Orange Fur" ).getClass(),
                new PatternRenderer() );
        JScrollPane sp = new JScrollPane( table );
        getContentPane().add( sp );
        setSize( 300, 300 );
        addWindowListener( new ExitHandler() );
        setVisible( true );
    }
 
    private class PatternTableModel extends DefaultTableModel {
 
        private Object[][] data = {
                { "Thomas", "Cat",     new Pattern( "Orange Fur" ) },
                { "Devil",  "Cat",     new Pattern( "White Fur" ) },
                { "Alley",  "Dog",     new Pattern( "Brown Fur" ) },
                { "Gub Gub", "Iguana", new Pattern( "Green Scales" ) } };
        private Object[] colNames = { "Name", "Type", "Color" };
 
        public PatternTableModel() {
            setDataVector( data, colNames );
        }
 
        public boolean isCellEditable( int row, int column ) {
            return( false );
        }
 
        public Class getColumnClass( int columnIndex ) {
            Class returnedClass = null;
            switch( columnIndex ) {
                case( 0 ) : returnedClass =  new String().getClass();
                            break;
                case( 1 ) : returnedClass =  new String().getClass();
                            break;
                case( 2 ) : returnedClass =  new Pattern( "Orange Fur" ).getClass();
                            break;
            }
 
            return( returnedClass );
        }
    }
 
    private class PatternRenderer extends JPanel implements TableCellRenderer {
        private Icon thePattern;
 
        public PatternRenderer() {
            super();
            thePattern = new ImageIcon( "orangefur.gif" );
            setOpaque( true );
        }
 
        public void paintComponent( Graphics g ) {
            Dimension size = getSize();
            int iconW = thePattern.getIconWidth();
            int iconH = thePattern.getIconHeight();
 
            for ( int i = 0; i < size.width; i += iconW ) {
                for( int j = 0; j < size.height; j += iconH ) {
                    thePattern.paintIcon( this, g, i, j );
                }
            }
        }
 
        public Component getTableCellRendererComponent( JTable table, Object value,
                                                        boolean isSelected,
                                                        boolean hasFocus,
                                                        int row, int column )
        {
            System.out.println( value );
            if( value instanceof Pattern ) {
                Pattern p = ( Pattern )value;
                thePattern = p.getPattern();
            }
            return( this );
        }
    }
 
    private class ExitHandler extends WindowAdapter {
        public void windowClosing( WindowEvent e ) {
            System.exit( 0 );
        }
    }
}
 
class Pattern {
    private Icon thisPattern;
    private String name;
    public static final Icon ORANGE_FUR = new ImageIcon( "orangefur.gif" );
    public static final Icon WHITE_FUR  = new ImageIcon( "whitefur.gif" );
    public static final Icon BROWN_FUR  = new ImageIcon( "brownfur.gif" );
    public static final Icon GREEN_SCALES = new ImageIcon( "greenscales.gif" );
 
    public Pattern( String s ) {
        name = s;
        if ( s.equals( "Orange Fur" ) ) {
            thisPattern = ORANGE_FUR;
        }
        else if ( s.equals( "White Fur" ) ) {
            thisPattern = WHITE_FUR;
        }
        else if ( s.equals( "Brown Fur" ) ) {
            thisPattern = BROWN_FUR;
        }
        else if ( s.equals( "Green Scales" ) ) {
            thisPattern = GREEN_SCALES;
        }
        else {
            thisPattern = new ImageIcon();
        }
    }
 
    public Icon getPattern() {
        return( thisPattern );
    }
 
    public String toString() {
        return( name );
    }
}

-Nate

[Pomchi Bedi]

Hi Nate,
Thanks so much for your help.
But I have one more problem.All my rows have different background colors and in each row there are a few cells that are inactive/disabled.I want the background color of those inactive cells to be the same as the other ones in the row but along with the background color I want the background pattern to appear for the diasbled cells.
That means I want to change the background of the imageIcon I am rendering.Is it possible??
Thanks & Regards
Pomchi

[Nathan Pruett]

If you use images for your ImageIcons that support transparency (like Gifs) then yes, you can... you'll also need to call super.paintComponent( g ) in the first line of your PatternRenderer paintComponent() method. If you don't want to make image files, you can always just extend Icon and draw the image you need in it's paintIcon() method...

-Nate

[Pomchi Bedi]

Thanks a lot Nate!!
It worked!
-Pomchi