<Swing Dev> Review rquest for 7055065, NPE from JTable when quit editing with empty value in number culumns

[Pavel Porvatov]

Hi Jonathan,

The fix looks good. Could you please write an automatic test, put it 
into an appropriate place of repository and make a webrev with fix and test?

Regards, Pavel
> Hello swing-dev,
>
> I've got a patch for bug 7055065, can anybody please help to take a look?
> http://cr.openjdk.java.net/~luchsh/7055065/
>
> And also a simple test case for this issue here.
>
> /*
>  * Copyright (c) 2012 Oracle and/or its affiliates. All rights reserved.
>  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
>  *
>  * This code is free software; you can redistribute it and/or modify it
>  * under the terms of the GNU General Public License version 2 only, as
>  * published by the Free Software Foundation.
>  *
>  * This code is distributed in the hope that it will be useful, but 
> WITHOUT
>  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
>  * version 2 for more details (a copy is included in the LICENSE file 
> that
>  * accompanied this code).
>  *
>  * You should have received a copy of the GNU General Public License 
> version
>  * 2 along with this work; if not, write to the Free Software Foundation,
>  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
>  *
>  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 
> USA
>  * or visit www.oracle.com if you need additional information or have any
>  * questions.
>  */
>
> /*
>  * Portions Copyright (c) 2012 IBM Corporation
>  */
>
> import javax.swing.JFrame;
> import javax.swing.JPanel;
> import javax.swing.JScrollPane;
> import javax.swing.JTable;
> import javax.swing.table.AbstractTableModel;
> import javax.swing.table.TableModel;
> import javax.swing.table.TableRowSorter;
> import java.awt.Dimension;
> import java.awt.GridLayout;
>
> public class TableDemo extends JPanel {
>
>     public TableDemo() {
>         super(new GridLayout(1, 0));
>
>         final String[] columnNames = { "String", "Number" };
>         final Object[][] data = { { "aaaa", new Integer(5) },
>                 { "bbbb", new Integer(3) }, { "cccc", new Integer(2) },
>                 { "dddd", new Integer(20) }, { "eeee", new Integer(10) 
> } };
>         final JTable table = new JTable(data, columnNames);
>
>         table.setPreferredScrollableViewportSize(new Dimension(500, 
> 400));
>         table.setFillsViewportHeight(true);
>         TableModel dataModel = new AbstractTableModel() {
>
>             public int getColumnCount() {
>                 return columnNames.length;
>             }
>             public int getRowCount() {
>                 return data.length;
>             }
>             public Object getValueAt(int row, int col) {
>                 return data[row][col];
>             }
>             public String getColumnName(int column) {
>                 return columnNames[column];
>             }
>             public Class<?> getColumnClass(int c) {
>                 return getValueAt(0, c).getClass();
>             }
>             public boolean isCellEditable(int row, int col) {
>                 return col != 5;
>             }
>             public void setValueAt(Object aValue, int row, int column) {
>                 data[row][column] = aValue;
>             }
>         };
>         table.setModel(dataModel);
>         TableRowSorter<TableModel> sorter = new 
> TableRowSorter<TableModel>(
>                 dataModel);
>         table.setRowSorter(sorter);
>
>         JScrollPane scrollPane = new JScrollPane(table);
>         add(scrollPane);
>     }
>
>     public static void main(String[] args) throws Exception {
>         javax.swing.SwingUtilities.invokeAndWait(new Runnable() {
>             public void run() {
>                 JFrame frame = new JFrame("SimpleTableDemo");
>                 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
>
>                 TableDemo newContentPane = new TableDemo();
>                 newContentPane.setOpaque(true);
>                 frame.setContentPane(newContentPane);
>
>                 frame.pack();
>                 frame.setVisible(true);
>             }
>         });
>     }
> }
>
> To reproduce the problem,
> please click on one cell from the "Number" column, delete all the 
> content but do not press enter to quit editing status, then click the 
> column title of "Number" column to sort, NPE will be thrown.
>
> The cause of this problem is when trying to quit editing with empty 
> content of a cell  and also try to accept the partially edited value 
> using stopCellEditing(), following two actions will be taken.
> 1, the cellEditor of current table will be set to null.
> 2, the value type of this column does not have a constructor to accept 
> "Object[]" parameter, false will be returned.
> Then swing will try to cancel edition without accepting the partially 
> edited value using cancelCellEditing() which will get null for the 
> value of cellEditor thus lead to this NPE.
>
> The patch is trying to return earlier before the type compatibility 
> check of partially edited values when empty cell values encountered.
>
> Cheers!
> - Jonathan
>