Cell rendering in JTable

Question

Can someone show me how to render the cells of a table column as a combo box and the cells of another table column as a check box.
thx.

Answer 1

Hi,
You can easily get the checkbox as the renderer by implementing the getColumnClass(int columnIndex). But the catch is that your checkbox-column should return Boolean as its class. Check for that. That can only be the problem. Otherwise, it should work fine.
public Class getColumnClass(int column) {
    switch(column) {
        case 1 :
            /* Assume that this is the column for which the checkbox
             * rendering has to take place.
            return Boolean.class;
            break;
        case 2 :
            //Return the datatype of this column, say it is a Number
            return Number.class;
            break;
        //Your other cases would go here
        default :
            return String.class;
            break;
}I hope that your problem is solved now. If not, there is another way by which you can explicitlt set the renderer of your column. In this case, there is no need to implement the getColumnClass() method. Here is the CheckBoxCellRender class...
class CheckBoxCellRenderer extends JCheckBox implements TableCellRenderer
    public CheckBoxCellRenderer() {
        setHorizontalAlignment(JLabel.CENTER);
    }//constructor
    public Component getTableCellRendererComponent(JTable table, Object value,
                           boolean isSelected, boolean hasFocus, int row, int column) {
    if (isSelected) {
        setForeground(table.getSelectionForeground());
        super.setBackground(table.getSelectionBackground());
    else {
        setForeground(table.getForeground());
        setBackground(table.getBackground());
        setSelected((value != null && ((Boolean)value).booleanValue()));
        return this;
    }//getTableCellRendererComponent
}Put this class as an inner class somewhere in your code, and then explicitly set this class as the column's default renderer. Here is how you can do it.
myTable.getColumn("myCheckboxColumn").setCellRenderer(new CheckBoxCellRenderer());