A method and system in a document viewer for scrolling a substantially
exact increment in a document, such as one page, regardless of whether
the zoom is such that some, all or one page is currently being viewed. In
one implementation, pressing a Page Down or Page Up keyboard key/button
allows a user to begin at any starting vertical location within a page,
and navigate to that same location on the next or previous page. For
example, if a user is viewing a page starting in a viewing area from the
middle of that page and ending at the bottom, a Page Down command will
cause the next page to be shown in the viewing area starting at the
middle of the next page and ending at the bottom of the next page.
Similar behavior occurs when there is more than one column of pages being
displayed in a row.