+ /**
+ * Responds to a mouse wheel movement by scrolling the alignment
+ * <ul>
+ * <li>left or right, if the shift key is down, else up or down</li>
+ * <li>right (or down) if the reported mouse movement is positive</li>
+ * <li>left (or up) if the reported mouse movement is negative</li>
+ * </ul>
+ * Note that this method may also be fired by scrolling with a gesture on a
+ * trackpad.
+ */