protected MenuElement getNextValidItem(JPopupMenu popup, int start) {

		int n = popup.getComponentCount();
		for (int i = 0; i < n; i++) {

			// handle wrapping
			int updated = i + start;
			int index = (updated < n) ? updated : Math.abs(i - (n - start));

			Component c = popup.getComponent(index);
			if (isValidItem(c)) {
				return (MenuElement) c;
			}
		}
		return null;
	}
The work method of this handler.  This method will only be called when a menu or popup
menu is open.

@param manager the active menu selection manager
@param path the active menu path
Ghidra/Framework/Docking/src/main/java/docking/menu/keys/MenuKeyHandler.java