Having several JComboBoxes with different values in a JTable

Question

I want to create a JTable where in a specific column named "Tools" a JComboBox should be accommodated. the values of the JComboBox should differ for each row.

In the constructor I have the following piece of code:

public Table(List<Software> software_list) throws TransformerFactoryConfigurationError, TransformerException, Exception {

    //****** create an 2D array object containing the emulators list data to be sent to the table model ******
    software_list_to_array = new Object[software_list.size()][5];


    for(int x = 0; x < software_list_to_array.length; x++){

        software_list_to_array[x][0] = software_list.get(x).getNumber();

        software_list_to_array[x][1] = software_list.get(x).getAuthor();

        software_list_to_array[x][2] = software_list.get(x).getReleaseDate();

        software_list_to_array[x][3] = software_list.get(x).getName();


        app_str = new String[software_list.get(x).getApp().size()];
        System.out.println(app_str.length);

        for(int k = 0; k < app_str.length; k++){
            app_str[k] = software_list.get(x).getApp().get(k).getName()
            + " " + software_list.get(x).getApp().get(k).getVersion();

        }
        software_list_to_array[x][4] = app_str;

    }

    tableModel = new SftTableModel(software_list_to_array, software_list_to_array.length);

    this.setModel(tableModel);

    this.setSize(new Dimension(1000,500));

    this.setRenderingProperties(app_str);

}

I have created the following method:

public void setRenderingProperties(String[] str){

    this.setRowHeight(25);

    this.getTableHeader().setFont(new Font("Arial", Font.BOLD,12));
    this.getTableHeader().setAlignmentY(Component.RIGHT_ALIGNMENT);
    this.setAutoCreateRowSorter(true);
    this.setShowGrid(false);
    this.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);

    ...........

if(app_str.length > 1){

    this.getColumn("Tools").setCellRenderer(new ComboBoxRenderer());
    JComboBox comboBox = new JComboBox();
    for(int k=0;k<app_str.length;k++){
        comboBox.addItem(app_str[k]);
    }

    this.getColumn("Tools").setCellEditor(new DefaultCellEditor(comboBox));
}else{
    this.getColumn("Tools").setCellRenderer(new CellsRenderer());
}
    this.getColumn("Tools").setResizable(true);
    this.getColumn("Tools").setPreferredWidth(250);

}

The problem with this code is that in the Tools column all the comboboxes contain all the same value. Does anyone have suggestion for this issue?

Answer 1

You can override the getCellEditor(...) of the JTable to return a specific editor. Something like:

import java.awt.*;
import java.awt.event.*;
import java.util.List;
import java.util.ArrayList;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.table.*;

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

    public TableComboBoxByRow()
    {
        // Create the editors to be used for each row

        String[] items1 = { "Red", "Blue", "Green" };
        JComboBox comboBox1 = new JComboBox( items1 );
        DefaultCellEditor dce1 = new DefaultCellEditor( comboBox1 );
        editors.add( dce1 );

        String[] items2 = { "Circle", "Square", "Triangle" };
        JComboBox comboBox2 = new JComboBox( items2 );
        DefaultCellEditor dce2 = new DefaultCellEditor( comboBox2 );
        editors.add( dce2 );

        String[] items3 = { "Apple", "Orange", "Banana" };
        JComboBox comboBox3 = new JComboBox( items3 );
        DefaultCellEditor dce3 = new DefaultCellEditor( comboBox3 );
        editors.add( dce3 );

        //  Create the table with default data

        Object[][] data =
        {
            {"Color", "Red"},
            {"Shape", "Square"},
            {"Fruit", "Banana"},
            {"Plain", "Text"}
        };
        String[] columnNames = {"Type","Value"};
        DefaultTableModel model = new DefaultTableModel(data, columnNames);
        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 < 3)
                    return editors.get(row);
                else
                    return super.getCellEditor(row, column);
            }
        };

        JScrollPane scrollPane = new JScrollPane( table );
        getContentPane().add( scrollPane );
//      table.getColumnModel().getColumn(1).setCellRenderer(new ComboBoxRenderer() );
    }


/*
    class ComboBoxRenderer extends JComboBox implements TableCellRenderer
    {

        public ComboBoxRenderer()
        {
            setBorder(new EmptyBorder(0, 0, 0, 0));
        }

        public Component getTableCellRendererComponent(
            JTable table, Object value, boolean isSelected,
            boolean hasFocus, int row, int column)
        {
//          setFocusable(false);
            removeAllItems();
            addItem( value );
            return this;
        }
    }

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