Java JTable Scroll tableCenterScroll(JPanel panel, JTable table, int row)

Description

Scrolls the given table such that the given row will be centered.

License

Open Source License

Declaration

public static void tableCenterScroll(JPanel panel, JTable table, int row) 

Method Source Code

//package com.java2s;
/********************************************************************************
 * The contents of this file are subject to the GNU General Public License      *
 * (GPL) Version 2 or later (the "License"); you may not use this file except   *
 * in compliance with the License. You may obtain a copy of the License at      *
 * http://www.gnu.org/copyleft/gpl.html                                         *
 *                                                                              *
 * Software distributed under the License is distributed on an "AS IS" basis,   *
 * without warranty of any kind, either expressed or implied. See the License   *
 * for the specific language governing rights and limitations under the         *
 * License.                                                                     *
 *                                                                              *
 * This file was originally developed as part of the software suite that        *
 * supports the book "The Elements of Computing Systems" by Nisan and Schocken, *
 * MIT Press 2005. If you modify the contents of this file, please document and *
 * mark your changes clearly, for the benefit of others.                        *
 ********************************************************************************/

import java.awt.*;
import javax.swing.*;

public class Main {
    /**/*from  ww  w. ja va2s  .  c o  m*/
     * Scrolls the given table such that the given row will be centered.
     * Also required are the containing panel and the number of visible rows in the table.
     */
    public static void tableCenterScroll(JPanel panel, JTable table, int row) {
        JScrollPane scrollPane = (JScrollPane) table.getParent().getParent();
        JScrollBar bar = scrollPane.getVerticalScrollBar();
        int beforeScrollValue = bar.getValue();
        Rectangle r = table.getCellRect(row, 0, true);
        table.scrollRectToVisible(r);
        panel.repaint();
        int afterScrollValue = bar.getValue();
        double visibleRowsCount = computeVisibleRowsCount(table);

        // The scroller moved down
        if (afterScrollValue > beforeScrollValue) {
            Rectangle newRectangle = table
                    .getCellRect((int) (Math.min(row + visibleRowsCount / 2, table.getRowCount() - 1)), 0, true);
            table.scrollRectToVisible(newRectangle);
            panel.repaint();
        }
        // The scroller moved up.
        else if (afterScrollValue < beforeScrollValue) {
            Rectangle newRectangle = table.getCellRect((int) (Math.max(row - visibleRowsCount / 2, 0)), 0, true);
            table.scrollRectToVisible(newRectangle);
            panel.repaint();
        }
    }

    /**
     * Returns the number of visible rows in the given table.
     */
    public static double computeVisibleRowsCount(JTable table) {
        return table.getParent().getBounds().getHeight() / table.getRowHeight();
    }
}

Related

1. selectAndScroll(JTable table, int rowIndex)
2. selectAndScrollToPosition(JTable table, int index0, int index1)
3. selectRow(int row, JTable table, JScrollPane pane)
4. selectRow(JTable table, int row, boolean bScroll)
5. showMessageDialogInScrollableUneditableTextArea( java.awt.Component owner, String text, String title, int messageType, final int maxPreferredWidth, final int maxPreferredHeight)
6. updateScrollMode(JScrollPane scroll, JTable table)