Border together with GridBagLayout

[Emil Karlsson]

Hi,
Is there anyone who knows if there are any methods to set a border togehter with a GridBagLayout, in any other way than to add a JPanel to every cell?
What I would like to do is a Grid in a workspace, to guide the user in a DragDrop situation.
/Emil

[Nathan Pruett]

The code below paints directly on the container using GridBagLayout... the only problem I noticed was that there is no grid size until components start getting added to your layout. So, as components were added the grid would change...

Is this something like what you wanted?

import javax.swing.*;
import javax.swing.event.ChangeListener;
import javax.swing.event.ChangeEvent;
import java.awt.*;
 
/**
 * JPanel that has guide lines painted on it for GridBagLayout.
 * 
 * @author npruett
 */
public class GridBagGuidePanel extends JPanel {
    
    private boolean paintChildren = false;
    
    public GridBagGuidePanel() {
    }
    
    public void setChildPainting( boolean b ) {
        paintChildren = b;
        invalidate();
        validate();
        repaint();
    }
    
    public boolean isChildPainting() {
        return paintChildren;
    }
    
    public void paintChildren( Graphics g ) {
        if ( paintChildren ) {
            super.paintChildren( g );
        }
    }
    
    public void paintComponent( Graphics g ) {
        super.paintComponent( g );
        LayoutManager m = this.getLayout();
        if ( m instanceof GridBagLayout ) {
            GridBagLayout layout = (GridBagLayout)m;
            int[][] dim = layout.getLayoutDimensions();
            int[] col = dim[0];
            int[] row = dim[1];
            Point p = layout.getLayoutOrigin();
            int origX = new Double( p.getX() ).intValue();
            int origY = new Double( p.getY() ).intValue();
            Color f = getForeground();
            g.setColor( f );
            System.out.println( "origin - " + p.getX() + "," + p.getY() );
            System.out.println( "" );
            int x = origX;
            int y = origY;
            for ( int i = 0; i < col.length; i++ ) {
                for ( int j = 0; j < row.length; j++ ) {
                    g.drawRect( x, y, col[i], row[j] );
                    y += row[j];
                }
                x += col[i];
                y = origY;
            }
            for ( int i = 0; i < col.length; i++ ) {
                System.out.println( "col " + i + " - " + col[i] );
            }
            System.out.println( "" );
            for ( int i = 0; i < row.length; i++ ) {
                System.out.println( "row " + i + " - " + row[i] );
            }
        }
    }
    
    public static void main( String[] args ) {
        JFrame f = new JFrame( "GridBagGuidePanel Test" );
        final GridBagGuidePanel gbgp = new GridBagGuidePanel();
        GridBagLayout layout = new GridBagLayout();
        gbgp.setLayout( layout );
        GridBagConstraints constraints = new GridBagConstraints();
        JButton b = new JButton( "one" );
        layout.setConstraints( b, constraints );
        gbgp.add( b );
        JButton b2 = new JButton( "two" );
        layout.setConstraints( b2, constraints );
        gbgp.add( b2 );
        JButton b3 = new JButton( "three" );
        constraints.gridy = 6;
        layout.setConstraints( b3, constraints );
        gbgp.add( b3 );
        f.getContentPane().add( "Center", gbgp );
        JPanel p = new JPanel();
        final JCheckBox cb = new JCheckBox( "Paint Children?" );
        cb.addChangeListener( new ChangeListener() {
            public void stateChanged( ChangeEvent evt ) {
                gbgp.setChildPainting( cb.isSelected() );
            }
        } );
        cb.setSelected( false );
        p.add( cb );
        f.getContentPane().add( "North", p );
        f.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        f.setSize( 300, 300 );
        f.show();
    }
}

[ October 01, 2002: Message edited by: Nathan Pruett ]

[Emil Karlsson]

Thanks a lot Nathan!
For the moment it works just the way I like it.
/Emil