在Mac OS X上使用JTable进行拖放

Question

i have a problem with DnD and JTable on macs. If you start the following program and click (fast) around in the table, sometimes selecting something, sometimes do DnD after a while the application crashes or at least DnD will not be possible anymore. I tested it on 2 Macs.

Java version: 1.6.0_35 Mac OS X: 10.6.8

Does anyone can confirm this? Any workaround?

package tablednd;

import javax.swing.JFrame;
import javax.swing.JTable;
import javax.swing.SwingUtilities;

public class TableDnD {
public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            Object[][] data = {
                {"Mary", "Campione", "Snowboarding", new Integer(5), new Boolean(false)},
                {"Alison", "Huml", "Rowing", new Integer(3), new Boolean(true)},
                {"Kathy", "Walrath", "Chasing toddlers", new Integer(2), new Boolean(false)},
                {"Mark", "Andrews", "Speed reading", new Integer(20), new Boolean(true)},
                {"Angela", "Lih", "Teaching high school", new Integer(4), new Boolean(false)}
            };

            String[] columnNames = {"First Name", "Last Name", "Sport", "# of Years", "Vegetarian"};

            final JTable table = new JTable(data, columnNames);
            JFrame frame = new JFrame();
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            table.setDragEnabled(true);
            frame.add(table);
            frame.pack();
            frame.setLocationRelativeTo(null);
            frame.setVisible(true);
        }
    });
}
}

Answer 1

When dropping a dragged row anywhere else on the table, I (sometimes) get the errors shown below back as far as Mac OS X 10.5.8. The target selection rectangle remains on the screen, and no further drag operations are possible. I'm not sure why, but I suppose a cell is not recognized as a suitable destination for a row.

2012-10-14 14:14:23.912 java[44061:10b] *** -[NSWindowViewAWT draggingEnded:]:
    unrecognized selector sent to instance 0x1001e7140
2012-10-14 14:14:23.913 java[44061:10b] *** -[NSWindowViewAWT draggingEnded:]:
    unrecognized selector sent to instance 0x1001e7140

Dropping the dragged row on another application works as expected.

As an aside, auto-boxing can simplify the initialization code:

Object[][] data = {
    {"Mary", "Campione", "Snowboarding", 5, false},
    {"Alison", "Huml", "Rowing", 3, true},
    {"Kathy", "Walrath", "Chasing toddlers", 2, false},
    {"Mark", "Andrews", "Speed reading", 20, true},
    {"Angela", "Lih", "Teaching high school", 4, false}
};

Addendum: This image shows the drag in progress; after triggering the anomaly, the gray rectangle remains immobile when the frame is dragged.

As a workaround, there is a solution to disable the grey rectangle altogether .