private void refreshMenu() { if (menuItems != null && menuItems.length > 0) { firstIndex = Math.max(topFixedCount, firstIndex); firstIndex = Math.min(menuItems.length - bottomFixedCount - scrollCount, firstIndex); upItem.setEnabled(firstIndex > topFixedCount); downItem.setEnabled(firstIndex + scrollCount < menuItems.length - bottomFixedCount); menu.removeAll(); for (int i = 0; i < topFixedCount; i++) { menu.add(menuItems[i]); } if (topFixedCount > 0) { menu.add(new JSeparator()); } menu.add(upItem); for (int i = firstIndex; i < scrollCount + firstIndex; i++) { menu.add(menuItems[i]); } menu.add(downItem); if (bottomFixedCount > 0) { menu.add(new JSeparator()); } for (int i = menuItems.length - bottomFixedCount; i < menuItems.length; i++) { menu.add(menuItems[i]); } JComponent parent = (JComponent) upItem.getParent(); parent.revalidate(); parent.repaint(); } }
/** * Sets the scroll interval in milliseconds * * @param interval the scroll interval in milliseconds * @throws IllegalArgumentException if interval is 0 or negative */ public void setInterval(int interval) { if (interval <= 0) { throw new IllegalArgumentException("interval must be greater than 0"); } upItem.setInterval(interval); downItem.setInterval(interval); this.interval = interval; }
upItem = new MenuScrollItem(MenuIcon.UP, -1); downItem = new MenuScrollItem(MenuIcon.DOWN, +1); setScrollCount(scrollCount); setInterval(interval);
public MenuScrollItem(MenuIcon icon, int increment) { setIcon(icon); setDisabledIcon(icon); timer = new MenuScrollTimer(increment, interval); addChangeListener(this); }