setting up JCheckBox in JTable

[Alan Shiers]

Hi there,

I'm setting up a column in JTable that contains JCheckBoxes. I use the following renderer and editor to achieve this. It all works fine except when I click on a cell containing a JCheckBox, which initially appears centered in the cell, it suddenly moves to the left of the cell. I'd like it to stay where it is. Please advise.

Alan

import java.awt.Component;
import java.util.EventObject;
import javax.swing.AbstractCellEditor;
import javax.swing.JCheckBox;
import javax.swing.JTable;
import javax.swing.table.*;

public class CheckBoxEditor extends AbstractCellEditor implements TableCellEditor
{
    JCheckBox checkbox = null;
    
    public CheckBoxEditor()
    {
    	checkbox = new JCheckBox();
    }
    
	
	
	public Object getCellEditorValue() {
		return checkbox.isSelected();
	}

	
	public boolean isCellEditable(EventObject arg0) {
		return true;
	}

	
	public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int col)
	{
		if(value instanceof JCheckBox)
		{
			checkbox = (JCheckBox)value;
			checkbox.setSelected(isSelected);
		}
		return checkbox;
	}

}

//**************************************************

import javax.swing.*;
import javax.swing.table.*;
import java.awt.*;

public class CheckBoxRenderer extends JCheckBox implements TableCellRenderer { 
	 
    CheckBoxRenderer() { 
      setHorizontalAlignment(JLabel.CENTER); 
    } 

    public Component getTableCellRendererComponent(JTable table, Object value, 
        boolean isSelected, boolean hasFocus, int row, int column) { 
      if (isSelected) { 
        setForeground(table.getSelectionForeground()); 
        //super.setBackground(table.getSelectionBackground()); 
        setBackground(table.getSelectionBackground()); 
      } else { 
        setForeground(table.getForeground()); 
        setBackground(table.getBackground()); 
      } 
      setSelected((value != null && ((Boolean) value).booleanValue())); 
      return this; 
    } 
}

[Rob Camick]

There is no need to create a custom render and editor. JTable provides default implementations for this. Just override the getColumnClass(....) method to return Boolean for that column and the default renderer/editor will be used.