I have following method in my class which extends JTable:
protected void setTableCursor(Cursor cursor) {
// data gathering
cursor = (cursor != null) ? cursor : Cursor.getDefaultCursor();
JTableHeader header = getTableHeader();
// set
header.setCursor(cursor);
setCursor(cursor);
}
This method is called from time to time to show WAIT cursor when table is updated from DB.
The problem with it is that now when i try and resize columns I can't see default SPLIT cursor. How this can be fixed? So I need to add some code in order for mouse cursor always show split cursor when mouse is near column's edge.
Please also check example below. To reproduce issue just double-click on table header exactly on columns divider:
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;
import javax.swing.table.TableColumnModel;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.HashMap;
import java.util.Map;
abstract public class DemoTable extends JTable
{
protected DemoTable() {
super();
compose(false);
}
private void compose(boolean allowMultipleSelection) {
setModel(new DefaultTableModel(getColumnNames(), 0));
setColumnSelectionAllowed(false);
getSelectionModel().setSelectionMode(allowMultipleSelection ? ListSelectionModel.MULTIPLE_INTERVAL_SELECTION : ListSelectionModel.SINGLE_SELECTION);
getTableHeader().setReorderingAllowed(false);
getTableHeader().addMouseListener(new ColumnResizeListener(this));
}
protected void setTableCursor(Cursor cursor) {
// data gathering
cursor = (cursor != null) ? cursor : null;
JTableHeader header = getTableHeader();
// set
header.setCursor(cursor);
setCursor(cursor);
}
public void adjustColumnWidth(int column) {
setPreferredColumnWidth(column, getPreferredSizeForColumn(column));
}
private int getPreferredSizeForColumn(int columnIndex) {
// base setup
int preferredWidth = 0;
int rowCount = getRowCount();
TableColumnModel columnModel = getColumnModel();
TableColumn column = columnModel.getColumn(columnIndex);
TableCellRenderer renderer;
Component rendererComponent = null;
// header
renderer = column.getHeaderRenderer();
if (renderer != null) {
rendererComponent = renderer.getTableCellRendererComponent(this, column.getHeaderValue(), false, false, 0, 0);
if (rendererComponent != null) {
preferredWidth = rendererComponent.getPreferredSize().width;
}
}
// rendered values
Object value;
for (int row = 0; row < rowCount; row++) {
// base setup
value = getValueAt(row, columnIndex);
// renderer lookup
renderer = getCellRenderer(row, columnIndex);
if (renderer != null)
rendererComponent = renderer.getTableCellRendererComponent(this, value, false, false, row, columnIndex);
rendererComponent = (rendererComponent == null) ? new JLabel((value == null) ? "" : value.toString()) : rendererComponent;
// calculate the preferred size
preferredWidth = Math.max(preferredWidth, rendererComponent.getPreferredSize().width);
}
// exit
return (preferredWidth <= 0) ? 25 : (preferredWidth + 15);
}
public void adjustColumnWidths() {
Thread updateThread = new Thread()
{
public void run() {
try {
SwingUtilities.invokeAndWait(new Runnable()
{
public void run() {
int columns = getModel().getColumnCount();
Map<Integer, Integer> preferredWidths = new HashMap<Integer, Integer>();
for (int column = 0; column < columns; column++)
preferredWidths.put(column, getPreferredSizeForColumn(column));
// run the sets
for (Map.Entry<Integer, Integer> column : preferredWidths.entrySet())
setPreferredColumnWidth(column.getKey(), column.getValue());
}
});
// pause momentarily to let the cursor update take place
sleep(75);
}
catch (Exception e) {
// ignore
}
finally {
setTableCursor(null);
}
}
};
// execute the thread
updateThread.start();
if (updateThread.isAlive())
setTableCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
}
private void setPreferredColumnWidth(int column, int preferredWidth) {
getColumnModel().getColumn(column).setPreferredWidth(preferredWidth);
}
abstract protected String[] getColumnNames();
@Override
public boolean isCellEditable(int row, int column) {
return false;
}
private static class ColumnResizeListener extends MouseAdapter
{
DemoTable table;
public ColumnResizeListener(DemoTable table) {
super();
// attribute initialization
this.table = table;
}
@Override
public void mouseClicked(MouseEvent e) {
if (e.getSource() instanceof JTableHeader) {
// data gathering
int clicks = e.getClickCount();
// single click
if (clicks == 1) {
int column = table.getColumnModel().getColumnIndexAtX(e.getX());
table.adjustColumnWidth(column);
}
// double-click
else if (clicks == 2)
table.adjustColumnWidths();
}
}
}
public static void main(String args[]) {
final DemoTable table = new DemoTable() {
@Override
protected String[] getColumnNames() {
return new String[]{"one","two"};
}
};
JFrame frame = new JFrame("Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
((DefaultTableModel)table.getModel()).addRow(new String[]{"1", "2"});
((DefaultTableModel)table.getModel()).addRow(new String[]{"1","2"});
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.add(table.getTableHeader(), BorderLayout.NORTH);
panel.add(table, BorderLayout.CENTER);
frame.add(panel);
frame.pack();
panel.setSize(new Dimension(200, 100));
frame.setVisible(true);
}
}
