We would like to know how to add JCheckBox components to JComboBox.
import java.awt.Color; import java.awt.Component; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; /* w w w .j ava2s.c o m*/ import javax.swing.JCheckBox; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JPanel; import javax.swing.ListCellRenderer; public class Main { public static void main(String[] args) { JFrame f = new JFrame(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.getContentPane().add(new CheckCombo().getContent()); f.setSize(300, 160); f.setLocation(200, 200); f.setVisible(true); } } class CheckCombo implements ActionListener { public void actionPerformed(ActionEvent e) { JComboBox cb = (JComboBox) e.getSource(); CheckComboStore store = (CheckComboStore) cb.getSelectedItem(); CheckComboRenderer ccr = (CheckComboRenderer) cb.getRenderer(); ccr.checkBox.setSelected((store.state = !store.state)); } public JPanel getContent() { String[] ids = { "north", "west", "south", "east" }; Boolean[] values = { Boolean.TRUE, Boolean.FALSE, Boolean.FALSE, Boolean.FALSE }; CheckComboStore[] stores = new CheckComboStore[ids.length]; for (int j = 0; j < ids.length; j++) stores[j] = new CheckComboStore(ids[j], values[j]); JComboBox combo = new JComboBox(stores); combo.setRenderer(new CheckComboRenderer()); combo.addActionListener(this); JPanel panel = new JPanel(); panel.add(combo); return panel; } } class CheckComboRenderer implements ListCellRenderer { JCheckBox checkBox; public CheckComboRenderer() { checkBox = new JCheckBox(); } public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) { CheckComboStore store = (CheckComboStore) value; checkBox.setText(store.id); checkBox.setSelected(((Boolean) store.state).booleanValue()); checkBox.setBackground(isSelected ? Color.red : Color.white); checkBox.setForeground(isSelected ? Color.white : Color.black); return checkBox; } } class CheckComboStore { String id; Boolean state; public CheckComboStore(String id, Boolean state) { this.id = id; this.state = state; } }