These constants control the scrolling of an object or substring into a
window. Note, keep them synchronized with IA2ScrollType.
Scroll the top left of the object or substring to the top left of the
window (or as close as possible).
Scroll the bottom right of the object or substring to the bottom right of
the window (or as close as possible).
Scroll the top edge of the object or substring to the top edge of the
window (or as close as possible).
Scroll the bottom edge of the object or substring to the bottom edge of
the window (or as close as possible).
Scroll the left edge of the object or substring to the left edge of the
window (or as close as possible).
Scroll the right edge of the object or substring to the right edge of the
window (or as close as possible).
Scroll an object the minimum amount necessary in order for the entire
frame to be visible (if possible).