Cell won't update after an action is called in the cell editor

Question

I'm using a table with a cell renderer which allows me to place a button "x" in each cell with a value so that i can delete the value of the cell by pressing the button. The cell editor assigns the action listener to the button and the proper actions are called when the button is pressed.

Every column in the table model which is a DefaultTableModel is populated by an array list of values. I successfully manage to delete the right value from the array list by pressing the button and every other cell in the table refreshes after the change but the cell which's value was deleted remains unchanged. If i restart the application or add a value to the array list the table refreshes as expected and everything looks as it should.

Mo problem then is that is seems like the cell renderer won't forget the initial value of the cell and therefore still continues to print this value into the cell even though the table is redrawn. Does anyone have an idea of how i could properly refresh the table so the values are correctly shown?

Table class:

public class Table extends JTable {

public static DefaultTableModel model = new DefaultTableModel();
private Days d;
private JFrame frame;
private AddCellRenderer renderer;
private AddCellEditor editor;

public Table(Days d, JFrame frame) {
    // Assign the table model to the table
    super(model);
    this.d = d;
    this.frame = frame;

    // Define dimensions of table
    model.setRowCount(11);
    model.setColumnCount(5);

    // Block resizing and reordering of headers
    this.setColumnSelectionAllowed(false);
    this.setRowSelectionAllowed(false);
    this.setCellSelectionEnabled(true);
    this.setTableHeader(null);

    // Define first row height
    this.setRowHeight(38);
    // Define all other row's heights
    this.setRowHeight(0, 45);

    this.d.setTable(this);

    for (int i = 0; i < 5; i++) {
        editor = new AddCellEditor(new JCheckBox(), d.getVisibleDays().get(i), this);
        renderer = new AddCellRenderer(d.getVisibleDays().get(i), editor);
        this.getColumnModel().getColumn(i).setCellRenderer(renderer);
        this.getColumnModel().getColumn(i).setCellEditor(editor);
    }

    this.refresh();
}

public void refresh() {

    // Empty table
    for (int i = 0; i < 5; i++) {
        for (int j = 0; j < 11; j++) {
            this.getModel().setValueAt(null, j, i);
        }
    }

    // Populate table with entries for each day
    for (int i = 0; i < 5; i++) {

        Iterator<String> iterator = d.getVisibleDays().get(i).getEntryListIterator();

        int j = 0;

        while(iterator.hasNext()){
            String s = iterator.next();
            this.getModel().setValueAt(s, (j+1), i);
            j++;
        }

        this.getModel().setValueAt(d.getVisibleDays().get(i).getDayName(), 0, i);
    }
}

public void modelClearValueAt(int row, int column) {
    this.getModel().setValueAt(null, row, column);
}
}

Cell editor class:

public class AddCellEditor extends DefaultCellEditor {

private JPanel headerPanel;
private JPanel entryPanel;
private JLabel dayName;
private JLabel entryValue;
protected JButton addButton;
private JButton removeButton;
private String label;
private int row;
private int column;
private Day day;
private String date;
private Table table;
private AddCellRenderer renderer;

public AddCellEditor(JCheckBox checkBox, Day day, Table table) {
    super(checkBox);
    this.day = day;
    this.table = table;
    date = day.getDayDate();
    headerPanel = new JPanel();
    headerPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
    entryPanel = new JPanel();
    entryPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
    dayName = new JLabel();
    entryValue = new JLabel();
    addButton = new JButton();
    removeButton = new JButton();
    headerPanel.add(dayName);
    headerPanel.add(addButton);
    entryPanel.add(entryValue);
    entryPanel.add(removeButton);
    addButton.setOpaque(true);
    addButton.setPreferredSize(new Dimension(16, 16));
    removeButton.setOpaque(true);
    removeButton.setPreferredSize(new Dimension(16, 16));
    addButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            System.out.println("Add pressed");
            addItem();
            fireEditingStopped();
        }
    });
    removeButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            System.out.println("Remove pressed");
            removeItem();
            getTable().refresh();
            fireEditingStopped();
        }
    });

}

public void setRenderer(AddCellRenderer renderer) {
    this.renderer = renderer;
}

public Component getTableCellEditorComponent(JTable table, 
        Object value, boolean isSelected, int row, int column) {

    this.row = row;
    this.column = column;

    if (row == 0) {
         return this.headerPanel;
    }
    if (row != 0 && value != null) {
        return this.entryPanel;
    }
    return null;
}

public void addItem() {
    String input = JOptionPane.showInputDialog("Add entry for " + label + ":");

    if ((input != null) && (input.length() > 0)) {
        System.out.println("Added: " + input + "Item");
        day.addEntry(input, column);
    }
}

public void removeItem() {
    table.modelClearValueAt(row, column);
    day.removeEntry(row-1);
    System.out.println("Item removed");
}

public Table getTable() {
    return this.table;
}

public boolean stopCellEditing() {
    return super.stopCellEditing();
}

protected void fireEditingStopped() {
    super.fireEditingStopped();
}
}

Thanks in advance

Answer 1

If you're using a DefaultTableModel, then you would have to delete the value held by the model itself, not the value in the ArrayList that was used to build the model. You would do this by calling the setValueAt(...) method of the DefaultTableModel object.

You may wish to post an SSCCE for more specific help.

Answer 2

okay, couldn't resist (the alternative is to scrub the bathroom :-)

Below is a very raw outline (just enough to give you an idea) of how to solve your goal with well-behaved editor and custom tableModel.

• MyTableModel is a custom implementation basically backed by a List of arbitrary entries
• this tableModel supports removing/adding items. Privately for now, so you aren't tempted to call them from the editor :-) They are safe enough to expose with public scope, if needed, f.i. if other parts the program need to modify the entries as well
• the model can handle different value types in setValueAt: a Modify marker, a NewEntry or a plain value
• the custom editor is a panel with buttons to remove, add a row.
• the actions of the button set the editorValue as appropriate before calling editingStopped/canceled as needed

The model:

public static class MyTableModel extends AbstractTableModel {

    public enum Modify {
        ADD,
        REMOVE
    }

    public static class NewItem {
        public final Object entry;

        public NewItem(Object entry) {
            this.entry = entry;
        }
    }

    private List entries;

    public MyTableModel(List entries) {
        this.entries = entries;
    }

    @Override
    public int getRowCount() {
        return entries.size();
    }

    @Override
    public int getColumnCount() {
        return 1;
    }


    @Override
    public boolean isCellEditable(int rowIndex, int columnIndex) {
        return true;
    }

    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        return entries.get(rowIndex);
    }

    @Override
    public void setValueAt(Object aValue, int rowIndex, int columnIndex) {
        if (aValue instanceof NewItem) {
            addEntry(((NewItem) aValue).entry);
        } else if (Modify.REMOVE == aValue) {
            removeEntry(rowIndex);
        } else {
            entries.set(rowIndex, aValue);
        }    
    }

    private void removeEntry(int rowIndex) {
        entries.remove(rowIndex);
        fireTableRowsDeleted(rowIndex, rowIndex);
    }

    private void addEntry(Object aValue) {
        int last = getRowCount();
        entries.add(aValue);
        fireTableRowsInserted(last, last);
    }


}

The editor:

public static class MyCellEditor extends AbstractCellEditor implements TableCellEditor {

    private Object editorValue;
    private JLabel entryView;
    JComponent editor;

    public MyCellEditor() {
        editor = new JPanel();
        entryView = new JLabel();
        editor.add(entryView);
        Action add = createAddAction();
        editor.add(new JButton(add));
        Action remove = createRemoveAction();
        editor.add(new JButton(remove));
    }

    public Action createRemoveAction() {
        Action remove = new AbstractAction("Remove Entry") {

            @Override
            public void actionPerformed(ActionEvent e) {
                editorValue = MyTableModel.Modify.REMOVE;
                fireEditingStopped();
            }

        };
        return remove;
    }

    public Action createAddAction() {
        Action add = new AbstractAction("Add Entry") {

            @Override
            public void actionPerformed(ActionEvent e) {
                String input = JOptionPane.showInputDialog("Add entry: ");

                if ((input != null) && (input.length() > 0)) {
                    editorValue = new MyTableModel.NewItem(input);
                    fireEditingStopped();
                } else {
                    fireEditingCanceled();
                }

            }

        };
        return add;
    }

    @Override
    public Object getCellEditorValue() {
        return editorValue;
    }

    @Override
    public Component getTableCellEditorComponent(JTable table,
            Object value, boolean isSelected, int row, int column) {
        entryView.setText(value != null ? value.toString() : "");
        return editor;
    }


}

The usage:

    List entries = new ArrayList();
    for (int i = 0; i < 5; i++) {
        entries.add("entry " + i);
    }
    TableModel model = new MyTableModel(entries);
    JTable table = new JTable(model);
    table.getColumnModel().getColumn(0).setCellEditor(new MyCellEditor());
    table.getColumnModel().getColumn(0).setPreferredWidth(200);
    table.setRowHeight(50);