Spos_visible_in_window_p, 0, 3, 0,
"Return t if position POS is currently on the frame in WINDOW.\n\
Return nil if that position is scrolled vertically out of view.\n\
-If FULLY is non-nil, then only return t when POS is completely visible.\n\
+If a character is only partially visible, nil is returned, unless the\n\
+optional argument PARTIALLY is non-nil.\n\
POS defaults to point in WINDOW; WINDOW defaults to the selected window.")
- (pos, window, fully)
- Lisp_Object pos, window, fully;
+ (pos, window, partially)
+ Lisp_Object pos, window, partially;
{
register struct window *w;
register int posint;
that info. This doesn't work for POSINT == end pos, because
the window end pos is actually the position _after_ the last
char in the window. */
- if (!NILP (fully))
+ if (NILP (partially))
{
- pos_visible_p (w, posint, &fully_p, !NILP (fully));
+ pos_visible_p (w, posint, &fully_p, NILP (partially));
in_window = fully_p ? Qt : Qnil;
}
else
in_window = Qnil;
else
{
- if (pos_visible_p (w, posint, &fully_p, !NILP (fully)))
- in_window = NILP (fully) || fully_p ? Qt : Qnil;
+ if (pos_visible_p (w, posint, &fully_p, NILP (partially)))
+ in_window = !NILP (partially) || fully_p ? Qt : Qnil;
else
in_window = Qnil;
}
Lisp_Object tem;
int this_scroll_margin;
int preserve_y;
+ /* True if we fiddled the window vscroll field without really scrolling. */
+ int vscrolled = 0;
SET_TEXT_POS_FROM_MARKER (start, w->start);
if ((n > 0 && IT_CHARPOS (it) == ZV)
|| (n < 0 && IT_CHARPOS (it) == CHARPOS (start)))
{
- if (noerror)
- return;
- else if (IT_CHARPOS (it) == ZV)
- Fsignal (Qend_of_buffer, Qnil);
+ if (IT_CHARPOS (it) == ZV)
+ {
+ if (it.current_y + it.max_ascent + it.max_descent
+ > it.last_visible_y)
+ /* The last line was only partially visible, make it fully
+ visible. */
+ w->vscroll =
+ it.last_visible_y
+ - it.current_y + it.max_ascent + it.max_descent;
+ else if (noerror)
+ return;
+ else
+ Fsignal (Qend_of_buffer, Qnil);
+ }
else
- Fsignal (Qbeginning_of_buffer, Qnil);
+ {
+ if (w->vscroll != 0)
+ /* The first line was only partially visible, make it fully
+ visible. */
+ w->vscroll = 0;
+ else if (noerror)
+ return;
+ else
+ Fsignal (Qbeginning_of_buffer, Qnil);
+ }
+
+ /* If control gets here, then we vscrolled. */
+
+ XBUFFER (w->buffer)->prevent_redisplay_optimizations_p = 1;
+
+ /* Don't try to change the window start below. */
+ vscrolled = 1;
}
- /* Set the window start, and set up the window for redisplay. */
- set_marker_restricted (w->start, make_number (IT_CHARPOS (it)), w->buffer);
- w->start_at_line_beg = Fbolp ();
- w->update_mode_line = Qt;
- XSETFASTINT (w->last_modified, 0);
- XSETFASTINT (w->last_overlay_modified, 0);
- /* Set force_start so that redisplay_window will run the
- window-scroll-functions. */
- w->force_start = Qt;
+ if (! vscrolled)
+ {
+ /* Set the window start, and set up the window for redisplay. */
+ set_marker_restricted (w->start, make_number (IT_CHARPOS (it)),
+ w->buffer);
+ w->start_at_line_beg = Fbolp ();
+ w->update_mode_line = Qt;
+ XSETFASTINT (w->last_modified, 0);
+ XSETFASTINT (w->last_overlay_modified, 0);
+ /* Set force_start so that redisplay_window will run the
+ window-scroll-functions. */
+ w->force_start = Qt;
+ }
it.current_y = it.vpos = 0;
}
else if (n < 0)
{
+ int charpos, bytepos;
+
/* We moved the window start towards BEGV, so PT may be now
in the scroll margin at the bottom. */
move_it_to (&it, PT, -1,
it.last_visible_y - this_scroll_margin - 1, -1,
MOVE_TO_POS | MOVE_TO_Y);
+
+ /* Save our position, in case it's correct. */
+ charpos = IT_CHARPOS (it);
+ bytepos = IT_BYTEPOS (it);
- /* Don't put point on a partially visible line at the end. */
- if (it.current_y + it.max_ascent + it.max_descent
- > it.last_visible_y)
- move_it_by_lines (&it, -1, 0);
-
- SET_PT_BOTH (IT_CHARPOS (it), IT_BYTEPOS (it));
+ /* See if point is on a partially visible line at the end. */
+ move_it_by_lines (&it, 1, 1);
+ if (it.current_y > it.last_visible_y)
+ /* The last line was only partially visible, so back up two
+ lines to make sure we're on a fully visible line. */
+ {
+ move_it_by_lines (&it, -2, 0);
+ SET_PT_BOTH (IT_CHARPOS (it), IT_BYTEPOS (it));
+ }
+ else
+ /* No, the position we saved is OK, so use it. */
+ SET_PT_BOTH (charpos, bytepos);
}
}
}
int lines = (rest + CANON_Y_UNIT (f) - 1) / CANON_Y_UNIT (f);
it.vpos += lines;
}
+#if 0
else if (it.current_y < height && bottom_y > height)
/* Partially visible line at the bottom. */
++it.vpos;
+#endif
return it.vpos;
}