I've figured out how to get a JTable to be sorted properly, but I can't figure out how to get it to automatically update the sort order when a table cell is changed. Right now, I have this (admittedly long) code, mostly based on that in the Java Tutorial's How to Use Tables. I've highlighted the changes I've made with // ADDED. In this case, newly-added values sort properly, but when I go in to edit a value, it doesn't seem to resort, even though I call fireTableCellUpdated?
In short, how can I get a table to re-sort when a data value changes in the model?
/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved.
* See the standard BSD license.
*/
package components;
/*
* TableSortDemo.java requires no other files.
*/
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
public class TableSortDemo extends JPanel {
private boolean DEBUG = false;
public TableSortDemo() {
super();
setLayout(new BoxLayout(TableSortDemo.this, BoxLayout.PAGE_AXIS));
final MyTableModel m = new MyTableModel();
JTable table = new JTable(m);
table.setPreferredScrollableViewportSize(new Dimension(500, 70));
table.setFillsViewportHeight(true);
table.setAutoCreateRowSorter(true);
//Create the scroll pane and add the table to it.
JScrollPane scrollPane = new JScrollPane(table);
//Add the scroll pane to this panel.
add(scrollPane);
// ADDED: button to add a value
JButton addButton = new JButton("Add a new value");
addButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
m.addValue(
JOptionPane.showInputDialog(
TableSortDemo.this, "Value?"));
}
});
// ADDED button to change a value
JButton setButton = new JButton("Change a value");
setButton.addActionListener(new ActionListener() {
/* (non-Javadoc)
* @see java.awt.event.ActionListener#actionPerformed(java.awt.event.ActionEvent)
*/
public void actionPerformed(ActionEvent e) {
m.setValueAt(
JOptionPane.showInputDialog(
TableSortDemo.this, "Value?"),
Integer.parseInt(
JOptionPane.showInputDialog(
TableSortDemo.this, "Which?")), 0);
}
});
add(addButton);
add(setButton);
}
class MyTableModel extends AbstractTableModel {
private static final long serialVersionUID = -7053335255134714625L;
private String[] columnNames = {"Column"};
// ADDED data as mutable ArrayList
private ArrayList<String> data = new ArrayList<String>();
public MyTableModel() {
data.add("Anders");
data.add("Lars");
data.add("Betty");
data.add("Anna");
data.add("Jon");
data.add("Zach");
}
// ADDED
public void addValue(Object v) {
data.add(v.toString());
int row = data.size() - 1;
fireTableRowsInserted(row, row);
}
public int getColumnCount() {
return columnNames.length;
}
public int getRowCount() {
return data.size();
}
public String getColumnName(int col) {
return columnNames[col];
}
public Object getValueAt(int row, int col) {
return data.get(row) + " " + row;
}
/*
* JTable uses this method to determine the default renderer/
* editor for each cell. If we didn't implement this method,
* then the last column would contain text ("true"/"false"),
* rather than a check box.
*/
public Class<String> getColumnClass(int c) {
return String.class;
}
/*
* Don't need to implement this method unless your table's
* editable.
*/
public boolean isCellEditable(int row, int col) {
//Note that the data/cell address is constant,
//no matter where the cell appears onscreen.
if (col < 2) {
return false;
} else {
return true;
}
}
/*
* Don't need to implement this method unless your table's
* data can change.
*/
public void setValueAt(Object value, int row, int col) {
if (DEBUG) {
System.out.println("Setting value at " + row + "," + col
+ " to " + value
+ " (an instance of "
+ value.getClass() + ")");
}
data.set(row, value.toString());
// ADDED: uncommented this line, despite warnings to the contrary
fireTableCellUpdated(row, col);
if (DEBUG) {
System.out.println("New value of data:");
printDebugData();
}
}
private void printDebugData() {
int numRows = getRowCount();
int numCols = getColumnCount();
for (int i=0; i < numRows; i++) {
System.out.print(" row " + i + ":");
for (int j=0; j < numCols; j++) {
System.out.print(" " + data.get(i));
}
System.out.println();
}
System.out.println("--------------------------");
}
}
/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("TableSortDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
TableSortDemo newContentPane = new TableSortDemo();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}