Re: Coordinating multiple JTextField updates across panels

From:
"Jarrick Chagma" <jarrick@large.com>
Newsgroups:
comp.lang.java.gui
Date:
Tue, 16 Jun 2009 10:33:22 +1000
Message-ID:
<4a36e854$0$32391$5a62ac22@per-qv1-newsreader-01.iinet.net.au>
"markspace" <nospam@nowhere.biz> wrote in message
news:h16mug$3sg$1@news.eternal-september.org...

Jarrick Chagma wrote:

Is each field in a separate panel? Are there more than 50 panels on the
screen at once? Separate panels and their abundance are the keys.


I put 100 JTextFields each in it's own panel, plus some more panels and
containers for formatting, and I don't see any slowness. You might, and
maybe your needs are more sensitive than what I did, but this seems to
update fine for me.

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package fubar;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.LayoutManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;

/**
 *
 * @author Brenden
 */
public class UpdateTest {

    private static final int ROWS = 20;
    private static final int COLS = 5;

    private final List<JTextField> textFieldList =
            new ArrayList<JTextField>( ROWS * COLS );

    public static void main(String[] args) {

        SwingUtilities.invokeLater( new Runnable() {
            @Override
            public void run() {
                new UpdateTest().createAndShowGui();
            }
        } );
    }

    private void createAndShowGui() {
        JFrame jframe = new JFrame("Update Test");
        Box centralContent = new Box( BoxLayout.PAGE_AXIS );
        for( int rows = 0; rows < ROWS; rows++ ) {
            JPanel rowPanel = new JPanel();
            for( int cols = 0; cols < COLS; cols ++ ) {
                JTextField textField = new JTextField( 10 );
                textFieldList.add( textField );
                rowPanel.add( new JPanel().add( textField ) );
            }
            centralContent.add( rowPanel );
        }
        jframe.add( centralContent );
        JButton jbut = new JButton( "Update Now" );
        jbut.addActionListener( new UpdateListener() );
        JPanel bottom = new JPanel();
        LayoutManager layout = new FlowLayout( FlowLayout.CENTER );
        bottom.setLayout(layout);
        bottom.add( jbut );
        jframe.add( bottom, BorderLayout.SOUTH );
        jframe.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        jframe.pack();
        jframe.setLocationRelativeTo( null );
        jframe.setVisible( true );
    }

    private class UpdateListener implements ActionListener {
        private int count = 1;
        @Override
        public void actionPerformed(ActionEvent e) {
            String update = "Update" + count;
            for (JTextField t : textFieldList ) {
                t.setText( update );
            }
            count++;
        }
    }
}


I don't know, I am not doing anything particularly special but I see a
noticeable effect when multiple fields are updated simultaneously in
multiple panels. Perhaps it's my machine because I also notice a
considerable delay when restoring Swing applications that have been
minimised (as reported earlier) and nobody else seems to have that problem
either.

--
Regards,

Jarrick

------------------------------------
Jarrick.Chagma@your.mind.gmail.com
(Lose your mind before emailing me)

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