Code
class DisableItemComboBox<E> extends JComboBox<E> {
private final Set<Integer> disableIndexSet = new HashSet<>();
private boolean isDisableIndex;
private final Action up = new AbstractAction() {
@Override public void actionPerformed(ActionEvent e) {
int si = getSelectedIndex();
for (int i = si - 1; i >= 0; i--) {
if (!disableIndexSet.contains(i)) {
setSelectedIndex(i);
break;
}
}
}
};
private final Action down = new AbstractAction() {
@Override public void actionPerformed(ActionEvent e) {
int si = getSelectedIndex();
for (int i = si + 1; i < getModel().getSize(); i++) {
if (!disableIndexSet.contains(i)) {
setSelectedIndex(i);
break;
}
}
}
};
public DisableItemComboBox() {
super();
}
public DisableItemComboBox(ComboBoxModel<E> aModel) {
super(aModel);
}
public DisableItemComboBox(E[] items) {
super(items);
}
@Override public void updateUI() {
super.updateUI();
setRenderer(new DefaultListCellRenderer() {
@Override public Component getListCellRendererComponent(
JList list, Object value, int index,
boolean isSelected, boolean cellHasFocus) {
Component c;
if (disableIndexSet.contains(index)) {
c = super.getListCellRendererComponent(
list, value, index, false, false);
c.setEnabled(false);
} else {
c = super.getListCellRendererComponent(
list, value, index, isSelected, cellHasFocus);
c.setEnabled(true);
}
return c;
}
});
ActionMap am = getActionMap();
am.put("selectPrevious3", up);
am.put("selectNext3", down);
InputMap im = getInputMap();
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0), "selectPrevious3");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_KP_UP, 0), "selectPrevious3");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0), "selectNext3");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_KP_DOWN, 0), "selectNext3");
}
public void setDisableIndex(Set<Integer> set) {
disableIndexSet.clear();
for (Integer i: set) {
disableIndexSet.add(i);
}
}
@Override public void setPopupVisible(boolean v) {
if (!v && isDisableIndex) {
isDisableIndex = false;
} else {
super.setPopupVisible(v);
}
}
@Override public void setSelectedIndex(int index) {
if (disableIndexSet.contains(index)) {
isDisableIndex = true;
} else {
// isDisableIndex = false;
super.setSelectedIndex(index);
}
}
}
References
