path
find_scrolled_box_path (box b, path sp, SI x, SI y, SI delta) {
if (is_nil (sp)) return b->find_box_path (x, y, delta, false);
else {
int m= sp->item;
SI xx= x - b->sx (m), yy= y - b->sy (m);
SI dd= delta + get_delta (xx, b[m]->x1, b[m]->x2);
return path (m, find_scrolled_box_path (b[m], sp->next, xx, yy, dd));
}
}
path
find_innermost_scroll (box b, path p) {
// Given a box b and a logical path p, this routine returns
// the longest box path sp such that b[sp] is a scroll node
path bp;
while (true) {
bool found= false;
bp= b->find_box_path (p, found);
if (found) break;
p= path_up (p);
if (is_nil (p)) return path ();
}
bp= path_up (bp);
path cp, sp;
while (!is_nil (bp)) {
if (b->get_type () == SCROLL_BOX) sp= reverse (cp);
b = b[bp->item];
cp= path (bp->item, cp);
bp= bp->next;
}
if (is_nil (sp)) return sp;
else return sp * 0;
}