Simple boolean CellEditor

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hello,

I am having trouble implementing a simple boolean celleditor:
- I am using subclasses of TableColumn for columns which also know about
  their data (the model's getValueAt method asks the appropriate column
  for a data object using getData(row)).
- for the column that should represent a yes/no descision using
  checkboxes, I implemented a CellRenderer that returns a new JCheckBox
  each time
- for the CellEditor, I am keeping an Array of JCheckBoxes which also
  capture the state

=> Problem: it doesn't work the way I implemented it: when I click on
another column, the cell that was selected last will be colored white
(empty). On my real application I have even more problems with this
implementation.

Minimal example is attached.

I know a boolean cell editor is easy/automatic, but I use a self-made
model (!= DefaultTableModel and such) so I went for the solution of
implementing a custom cell editor. Is there an easier way?

I guess DefaultCellEditor is difficult in this setup, because I'd like
to have other data in the cells too (and sort by these values).
If this is not possible, I'd be happy with a column that only contains
a JCheckBox too.

Thanks in advance!
--
Felix Natter

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Content-Type: text/x-java
Content-Disposition: inline; filename=TestJTableEditor.java

import javax.swing.*;
import javax.swing.table.*;
import javax.swing.text.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

abstract class TableColumnWithData extends TableColumn implements TableCellRenderer {
    public abstract Object getData(int row);
    public abstract Class getColumnClass();
}

class SeqNoColumn extends TableColumnWithData {

    public TableCellRenderer getCellRenderer() { return this; }
    public Object getHeaderValue() { return "Seqno."; }

    public Object getData(int row) {
        return new Integer(row + 1);
    }
    public Class getColumnClass() { return Integer.class; }

    // needed for TableCellRenderer
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
        return new JLabel(((Integer)value).toString());
    }

    public SeqNoColumn() {
    }
}

class CBColumn extends TableColumnWithData implements TableCellEditor, ActionListener {
    private JCheckBox[] cbs;
    private int cureditrow;
    private DataModel model;

    public TableCellRenderer getCellRenderer() { return this; }
    public TableCellEditor getCellEditor() { return this; }
    public Object getHeaderValue() { return "CB col"; }

    public Object getData(int row) {
        return row * 1.1;
    }
    public Class getColumnClass() { return Double.class; }

    public void actionPerformed(ActionEvent ae) {
        int row = Integer.parseInt(ae.getActionCommand());
        boolean sel = ((JCheckBox)ae.getSource()).isSelected();
        System.err.println("actionPerformed("+row+"="+sel+")");
    }

    public boolean isSelected(int row) {
        if (cbs[row] == null)
            return false;
        else
            return cbs[row].isSelected();
    }

    // needed for TableCellRenderer
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
        JCheckBox cb = new JCheckBox(String.format("value=%.1f", (Double)value), isSelected(row));
        cb.setHorizontalAlignment(JLabel.CENTER);
        return cb;
    }

    // needed for TableCellEditor
    public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {
        cureditrow = row;
        if (cbs[row] == null) {
            cbs[row] = new JCheckBox(String.format("value=%.1f", (Double)value), false);
            cbs[row].addActionListener(this);
            cbs[row].setActionCommand(Integer.toString(row));
            cbs[row].setRequestFocusEnabled(false);
            cbs[row].setHorizontalAlignment(JLabel.CENTER);
        }
        cbs[row].setVisible(true);
        return cbs[row];
    }

    public void addCellEditorListener(CellEditorListener l) { }
    public void removeCellEditorListener(CellEditorListener l) { }
    public void cancelCellEditing() {
        cbs[cureditrow].setVisible(false);
    }
    public Object getCellEditorValue() {
        return cbs[cureditrow].isSelected();
    }
    public boolean isCellEditable(EventObject anEvent) {
        return true;
    }
    public boolean shouldSelectCell(EventObject anEvent) {
        return false;
    }
    public boolean stopCellEditing() {
        cbs[cureditrow].setVisible(false);
        return true;
    }
    public CBColumn(DataModel model) {
        this.model = model;
        cbs = new JCheckBox[5];

        //setMaxWidth(getTableCellRendererComponent(null, getData(0), false, false, 0, 0).getPreferredSize().width);
    }
}

class DataModel extends AbstractTableModel {
    protected Vector<TableColumnWithData> cols;

    public void addCol(TableColumnWithData col) {
        col.setModelIndex(cols.size());
        cols.add(col);
    }

    @Override
        public Class<?> getColumnClass(int c) {
        return cols.get(c).getColumnClass();
    }

    public int getRowCount() { return 5; }
    public int getColumnCount() { return cols.size(); }
    public boolean isCellEditable(int r, int c) {
        if (c == 0)
            return false;
        else
            return true;
    }
    public Object getValueAt(int r, int c) {
        return cols.get(c).getData(r);
    }

    public DataModel() {
        cols = new Vector<TableColumnWithData>();
    }
}

class ColumnModel extends DefaultTableColumnModel {
    public ColumnModel() {
    }
}

public class TestJTableEditor extends JFrame {
    JTable dataTable;
    DataModel datamodel;
    ColumnModel colmodel;
    JPanel tablepnl;
    JScrollPane tblSP;

    public TestJTableEditor() {

        datamodel = new DataModel();
        colmodel = new ColumnModel();
    
        dataTable = new JTable(datamodel, colmodel);
        dataTable.setAutoCreateRowSorter(false);

        SeqNoColumn seqnocol = new SeqNoColumn();
        datamodel.addCol(seqnocol);
        dataTable.addColumn(seqnocol);

        CBColumn cbcol = new CBColumn(datamodel);
        datamodel.addCol(cbcol);
        dataTable.addColumn(cbcol);

        dataTable.setAutoCreateRowSorter(true);

        tblSP = new JScrollPane(dataTable);
        tblSP.setVisible(true);
        
        tablepnl = new JPanel();
        tablepnl.setLayout(new BoxLayout(tablepnl, BoxLayout.Y_AXIS));
        tablepnl.add(tblSP);
        add(tablepnl);
    }

    public static void main(String[] args) {
        TestJTableEditor frame = new TestJTableEditor();
        frame.addWindowListener( new WindowAdapter() {
                public void windowClosing( WindowEvent e ) {
                    System.exit(0);
                }
            });
        frame.pack();
        frame.setVisible(true);
    }
    
}
/*
  Local Variables:
  compile-command: "make run"
  End:
*/
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