JTable frozen column alignment issue (Java 1.6)

Question

I have implemented JTable frozen columns as below.When scrolling on a large dataset using vertical scrollbar, the columns in the frozen table are not aligned with the main table.Please help

enter image description here

JTable      table,fixedTable
JScrollPane     _scrl_table;

table = new JTable();
table.setName("MAIN_TABLE");
table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
table.setVisibleRowCount(8);


fixedTable = new JTable();
fixedTable.setName("FIXED_TABLE");
fixedTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
fixedTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);

 _scrl_table = new JScrollPane(table,JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,
            JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);

fixedTable.setPreferredScrollableViewportSize(fixedTable.getPreferredSize());
    _scrl_table.setRowHeaderView( fixedTable );
    _scrl_table.setCorner(JScrollPane.UPPER_LEFT_CORNER,         fixedTable.getTableHeader());

I think I figured out the issue. when the value of the first column on the main table has empty spaces, the row height of the main table is slightly off from the fixed table which causes the alignment issue. To verify, I changed the first column of main table to be same as the last column of the fixed table and i didn't notice the issue. Is there a way to make the row height of the main table to be same as row height of the fixed table? — udk, Aug 02 '12 at 17:00
I've resolved the issue by adding the last column from the fixed table to the main table as first and set the min,preferred and max width to 1. — udk, Aug 02 '12 at 19:52

score 2 · Answer 1 · edited May 23 '17 at 12:19

maybe there no reason to use two JTables
use proper RowNumberTable by camickr or RowHeader
you can to share AdjustmentListener, with or without BoundedRangeModel

example scrolling horizontal directions, have to change to the vertical

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


public class FixedRowExample extends JFrame {

    private static final long serialVersionUID = 1L;
    private Object[][] data;
    private Object[] column;
    private JTable fixedTable, table;
    private int FIXED_NUM = 2;

    public FixedRowExample() {
        super("Fixed Row Example");
        data = new Object[][]{
                    {"a", "", "", "", "", ""},
                    {"", "b", "", "", "", ""},
                    {"", "", "c", "", "", ""},
                    {"", "", "", "d", "", ""},
                    {"", "", "", "", "e", ""},
                    {"", "", "", "", "", "f"},
                    {"fixed1", "", "", "", "", "", "", ""},
                    {"fixed2", "", "", "", "", "", "", ""}};
        column = new Object[]{"A", "B", "C", "D", "E", "F"};
        AbstractTableModel model = new AbstractTableModel() {

            private static final long serialVersionUID = 1L;

            @Override
            public int getColumnCount() {
                return column.length;
            }

            @Override
            public int getRowCount() {
                return data.length - FIXED_NUM;
            }

            @Override
            public String getColumnName(int col) {
                return (String) column[col];
            }

            @Override
            public Object getValueAt(int row, int col) {
                return data[row][col];
            }

            @Override
            public void setValueAt(Object obj, int row, int col) {
                data[row][col] = obj;
            }

            public boolean CellEditable(int row, int col) {
                return true;
            }
        };

        AbstractTableModel fixedModel = new AbstractTableModel() {

            private static final long serialVersionUID = 1L;

            @Override
            public int getColumnCount() {
                return column.length;
            }

            @Override
            public int getRowCount() {
                return FIXED_NUM;
            }

            @Override
            public Object getValueAt(int row, int col) {
                return data[row + (data.length - FIXED_NUM)][col];
            }
        };
        table = new JTable(model);
        table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
        table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        fixedTable = new JTable(fixedModel);
        fixedTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
        fixedTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        JScrollPane scroll = new JScrollPane(table);
        scroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
        JScrollPane fixedScroll = new JScrollPane(fixedTable) {

            private static final long serialVersionUID = 1L;

            @Override
            public void setColumnHeaderView(Component view) {
            } // work around
        }; // fixedScroll.setColumnHeader(null);  
        fixedScroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
        JScrollBar bar = fixedScroll.getVerticalScrollBar();
        JScrollBar dummyBar = new JScrollBar() {

            private static final long serialVersionUID = 1L;

            @Override
            public void paint(Graphics g) {
            }
        };
        dummyBar.setPreferredSize(bar.getPreferredSize());
        fixedScroll.setVerticalScrollBar(dummyBar);

        final JScrollBar bar1 = scroll.getHorizontalScrollBar();
        JScrollBar bar2 = fixedScroll.getHorizontalScrollBar();
        bar2.addAdjustmentListener(new AdjustmentListener() {

            @Override
            public void adjustmentValueChanged(AdjustmentEvent e) {
                bar1.setValue(e.getValue());
            }
        });
        scroll.setPreferredSize(new Dimension(400, 100));
        fixedScroll.setPreferredSize(new Dimension(400, 52)); 
        getContentPane().add(scroll, BorderLayout.CENTER);
        getContentPane().add(fixedScroll, BorderLayout.SOUTH);
    }

    public static void main(String[] args) {
        FixedRowExample frame = new FixedRowExample();
        frame.addWindowListener(new WindowAdapter() {

            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        frame.pack();
        frame.setVisible(true);
    }
}

maybe there no reason to use two JTables -- How do i implement it without having two jtables? — udk, Aug 02 '12 at 16:31
Please note that horizontal alignment is progressively off as i scroll down deep (200 rows+) — udk, Aug 02 '12 at 16:34
JTable.setRowMargin(int); and JTable.setRowHeight(int); could be rigth way — mKorbel, Aug 02 '12 at 17:00

JTable frozen column alignment issue (Java 1.6)

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