Re: The first & last visible rows in a JTable

From:
"Bart Cremers" <bcremers@gmail.com>
Newsgroups:
comp.lang.java.gui
Date:
5 Jul 2006 03:50:31 -0700
Message-ID:
<1152096631.075061.162090@b68g2000cwa.googlegroups.com>
Wes Harrison schreef:

Is there an elegant way to work out the first and last rows of a JTable that
are visible on the screen at a particular time? All I could come up with
was to go through each point on the screen and do a getRowAtPoint() and work
it out from that. Is there a better or simpler way?

Thanks,

Wes


I'm not really sure I understand what you really want, but following
code wil give you the first and last row in a table:

import javax.swing.*;
import javax.swing.event.ChangeListener;
import javax.swing.event.ChangeEvent;
import javax.swing.table.AbstractTableModel;
import java.awt.*;

public class TableTest extends JPanel {
    private TableTest() {
        setLayout(new BorderLayout());
        final JTable table = new JTable(new TestTableModel());

        JScrollPane scroller = new JScrollPane(table);
        add(scroller);

        scroller.getViewport().addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent e) {
                JViewport viewport = (JViewport) e.getSource();
                Rectangle viewRect = viewport.getViewRect();
                System.out.println("First = " + table.rowAtPoint(new
Point(0, viewRect.y)));
                System.out.println("Last = " + table.rowAtPoint(new
Point(0, viewRect.y + viewRect.height - 1)));
                System.out.println("=-=-=-=-=-=-=");
            }
        });
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JPanel panel = new TableTest();

                JFrame frame = new JFrame();
                frame.getContentPane().add(panel);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            }
        });
    }

    private static class TestTableModel extends AbstractTableModel {

        public int getColumnCount() {
            return 3;
        }

        public int getRowCount() {
            return 100;
        }

        public Object getValueAt(int rowIndex, int columnIndex) {
            return rowIndex + "-" + columnIndex;
        }
    }
}

Regards,

Bart

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