How to make JTable with multiple editor types in a row?

Question

I am rendering a JTable with certain cells being a normal text input or a ComboBox.

When I try it like this:

package sandbox.jtablegui;

import java.awt.*;
import java.awt.event.*;
import java.util.List;
import java.util.ArrayList;
import java.util.Hashtable;

import javax.swing.*;
import javax.swing.table.*;

public class App extends JFrame
{
    List<TableCellEditor> editors = new ArrayList<TableCellEditor>(3);

    public App()
    {
        String[] colNames = { "Name", "Value" };
        final String[] propertyNames = { "Val1", "Val2" };
        DefaultTableModel model = new DefaultTableModel(colNames, 2) {

            // set setting names
            public Object getValueAt(int row, int col) {
                if (col == 0)
                    return propertyNames[row];
                return super.getValueAt(row, col);
            }

            public boolean isCellEditable(int row, int col) {
                if (col == 0)
                    return false;
                return true;
            }
        };

        JComboBox<String> comboBox = new JComboBox<String>(new String[] { "Option1", "Option2" });
        final DefaultCellEditor comboBoxEditor = new DefaultCellEditor(comboBox)    {
            @Override
            public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {
                Object val = value;
                System.out.println(val);
                if (val == null) {
                    val = ((JComboBox<?>) getComponent()).getItemAt(0);
                    System.out.println(val);
                }
                return super.getTableCellEditorComponent(table, val, isSelected, row, column);
            }
        };

        JTable table = new JTable(model)
        {
            //  Determine editor to be used by row
            public TableCellEditor getCellEditor(int row, int column)
            {
                int modelColumn = convertColumnIndexToModel( column );

                if (modelColumn == 1 && row == 1)
                    return comboBoxEditor;
                else
                    return super.getCellEditor(row, column);
            }
        };
        RowEditorModel rowEditorModel = new RowEditorModel();



        JScrollPane scrollPane = new JScrollPane( table );
        getContentPane().add( scrollPane );
    }

    public static void main(String[] args)
    {
        App frame = new App();
        frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setVisible(true);
    }

    public class RowEditorModel {
        private Hashtable data;

        public RowEditorModel() {
            data = new Hashtable();
        }

        public void addEditorForRow(int row, TableCellEditor editor) {
            data.put(new Integer(row), editor);
        }

        public void removeEditorForRow(int row) {
            data.remove(new Integer(row));
        }

        public TableCellEditor getEditor(int row) {
            return (TableCellEditor) data.get(new Integer(row));
        }
    }
}

However, the default value is not shown in the JTable as you can see from the screenshot.

please whats problem is following officia Oracle tutorial, seems like as RowEditorModel isn't completed, there are bunch of better ways (to storing a value to the XxxTableModel) — mKorbel, Apr 29 '16 at 14:34
yes, discovering now that the tablemodel should manage the values e.g. http://stackoverflow.com/questions/11858286/how-to-use-custom-jtable-cell-editor-and-cell-renderer ? — poseid, May 02 '16 at 14:34

score 2 · Answer 1 · answered Apr 29 '16 at 09:39

2

Setting of selected index on combobox creation cannot help. You need to set it each time when it uses as editor. Something like this:

DefaultCellEditor comboBoxEditor = new DefaultCellEditor(comboBox) {
    @Override
    public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {
        Object val = value;
        if (val == null) {
            val = ((JComboBox<?>) getComponent()).getItemAt(0);
        }
        return super.getTableCellEditorComponent(table, val, isSelected, row, column);
    }

}

answered Apr 29 '16 at 09:39

Sergiy Medvynskyy

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thanks, hmm.. when is getTableCellEditorComponent called? I try to see the selected optoin with System.out.println(val); but there is no sign the function is called ... – poseid Apr 29 '16 at 10:04
This method is called by JTable each time when table prepares editor to show. If my solution has no effect, please provide a [SSCCE](http://sscce.org), so I can see what's wrong. – Sergiy Medvynskyy Apr 29 '16 at 10:14
1

@poseid editor is shown only when an editable cell of a table is clicked by the user. If you want to see it in table, you need to return it in `getValueAt()` method of your model. – Sergiy Medvynskyy Apr 29 '16 at 11:55
@poseid please also read about [editor/renderer concept in Swing](https://docs.oracle.com/javase/tutorial/uiswing/components/table.html#editrender) – Sergiy Medvynskyy Apr 29 '16 at 12:22
thanks, ok, I must set the default value via the JTable. I thought the JComboBox default value would be responsible for that. but it makes sense via getValueAt – poseid Apr 29 '16 at 14:15

How to make JTable with multiple editor types in a row?

1 Answers1