Implemented by widgets that support vertical scrolling.

abstract class HasVerticalScrolling {
 /**
  * Get the maximum position of vertical scrolling. This is usually the
  * <code>scrollHeight - clientHeight</code>.
  *
  * @return the maximum vertical scroll position
  */
 int getMaximumVerticalScrollPosition();

 /**
  * Get the minimum position of vertical scrolling.
  *
  * @return the minimum vertical scroll position
  */
 int getMinimumVerticalScrollPosition();

 /**
  * Gets the vertical scroll position.
  *
  * @return the vertical scroll position, in pixels
  */
 int getVerticalScrollPosition();

 /**
  * Sets the vertical scroll position.
  *
  * @param position the new vertical scroll position, in pixels
  */
 void setVerticalScrollPosition(int position);
}