Scrolls text_view so that mark is on the screen in the position
indicated by xalign and yalign. An alignment of 0.0 indicates
left or top, 1.0 indicates right or bottom, 0.5 means center.
If use_align is FALSE, the text scrolls the minimal distance to
get the mark onscreen, possibly not scrolling at all. The effective
screen for purposes of this function is reduced by a margin of size
within_margin.
Scrolls text_view so that mark is on the screen in the position indicated by xalign and yalign. An alignment of 0.0 indicates left or top, 1.0 indicates right or bottom, 0.5 means center. If use_align is FALSE, the text scrolls the minimal distance to get the mark onscreen, possibly not scrolling at all. The effective screen for purposes of this function is reduced by a margin of size within_margin.