java.awt.event.ItemListener#itemStateChanged()源码实例Demo

private void fireSelectionChanged() {
    if ((selectionListeners == null) || selectionListeners.isEmpty()) {
        return;
    }

    final ItemEvent event = new ItemEvent(this,
                                          ItemEvent.ITEM_STATE_CHANGED,
                                          getSelectedRepository(),
                                          ItemEvent.SELECTED);
    for (ItemListener l : selectionListeners) {
        l.itemStateChanged(event);
    }
}
 

protected void fireItemEvent(ItemEvent event) {
    for (ItemListener listener : itemListeners) {
        listener.itemStateChanged(event);
    }
}
 

/**
 * Processes item events occurring on this check box menu item by
 * dispatching them to any registered {@code ItemListener} objects.
 * <p>
 * This method is not called unless item events are
 * enabled for this menu item. Item events are enabled
 * when one of the following occurs:
 * <ul>
 * <li>An {@code ItemListener} object is registered
 * via {@code addItemListener}.
 * <li>Item events are enabled via {@code enableEvents}.
 * </ul>
 * <p>Note that if the event parameter is {@code null}
 * the behavior is unspecified and may result in an
 * exception.
 *
 * @param       e the item event
 * @see         java.awt.event.ItemEvent
 * @see         java.awt.event.ItemListener
 * @see         #addItemListener
 * @see         java.awt.MenuItem#enableEvents
 * @since       1.1
 */
protected void processItemEvent(ItemEvent e) {
    ItemListener listener = itemListener;
    if (listener != null) {
        listener.itemStateChanged(e);
    }
}
 

/**
 * Processes item events occurring on this check box menu item by
 * dispatching them to any registered {@code ItemListener} objects.
 * <p>
 * This method is not called unless item events are
 * enabled for this menu item. Item events are enabled
 * when one of the following occurs:
 * <ul>
 * <li>An {@code ItemListener} object is registered
 * via {@code addItemListener}.
 * <li>Item events are enabled via {@code enableEvents}.
 * </ul>
 * <p>Note that if the event parameter is {@code null}
 * the behavior is unspecified and may result in an
 * exception.
 *
 * @param       e the item event
 * @see         java.awt.event.ItemEvent
 * @see         java.awt.event.ItemListener
 * @see         #addItemListener
 * @see         java.awt.MenuItem#enableEvents
 * @since       1.1
 */
protected void processItemEvent(ItemEvent e) {
    ItemListener listener = itemListener;
    if (listener != null) {
        listener.itemStateChanged(e);
    }
}