diff options
Diffstat (limited to 'src/window.c')
| -rw-r--r-- | src/window.c | 91 |
1 files changed, 73 insertions, 18 deletions
diff --git a/src/window.c b/src/window.c index fd40cf593ee..941c0a00133 100644 --- a/src/window.c +++ b/src/window.c @@ -17,8 +17,8 @@ GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Emacs; see the file COPYING. If not, write to -the Free Software Foundation, Inc., 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. */ +the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, +Boston, MA 02110-1301, USA. */ #include <config.h> #include "lisp.h" @@ -4783,7 +4783,9 @@ window_scroll_pixel_based (window, n, whole, noerror) /* We moved the window start towards ZV, so PT may be now in the scroll margin at the top. */ move_it_to (&it, PT, -1, -1, -1, MOVE_TO_POS); - if (IT_CHARPOS (it) == PT && it.current_y >= this_scroll_margin) + if (IT_CHARPOS (it) == PT && it.current_y >= this_scroll_margin + && (NILP (Vscroll_preserve_screen_position) + || EQ (Vscroll_preserve_screen_position, Qt))) /* We found PT at a legitimate height. Leave it alone. */ ; else if (preserve_y >= 0) @@ -4820,7 +4822,9 @@ window_scroll_pixel_based (window, n, whole, noerror) /* 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, + (it.last_visible_y - CURRENT_HEADER_LINE_HEIGHT (w) + - this_scroll_margin - 1), + -1, MOVE_TO_POS | MOVE_TO_Y); /* Save our position, in case it's correct. */ @@ -4836,7 +4840,9 @@ window_scroll_pixel_based (window, n, whole, noerror) partial_p = it.current_y > it.last_visible_y; } - if (charpos == PT && !partial_p) + if (charpos == PT && !partial_p + && (NILP (Vscroll_preserve_screen_position) + || EQ (Vscroll_preserve_screen_position, Qt))) /* We found PT before we found the display margin, so PT is ok. */ ; else if (preserve_y >= 0) @@ -4951,7 +4957,8 @@ window_scroll_line_based (window, n, whole, noerror) the window-scroll-functions. */ w->force_start = Qt; - if (whole && !NILP (Vscroll_preserve_screen_position)) + if (!NILP (Vscroll_preserve_screen_position) + && (whole || !EQ (Vscroll_preserve_screen_position, Qt))) { SET_PT_BOTH (pos, pos_byte); Fvertical_motion (make_number (original_vpos), window); @@ -5326,6 +5333,8 @@ and redisplay normally--don't erase and redraw the frame. */) struct buffer *obuf = current_buffer; int center_p = 0; int charpos, bytepos; + int iarg; + int this_scroll_margin; /* If redisplay is suppressed due to an error, try again. */ obuf->display_error_modiff = 0; @@ -5352,6 +5361,12 @@ and redisplay normally--don't erase and redraw the frame. */) set_buffer_internal (buf); + /* Do this after making BUF current + in case scroll_margin is buffer-local. */ + this_scroll_margin = max (0, scroll_margin); + this_scroll_margin = min (this_scroll_margin, + XFASTINT (w->total_lines) / 4); + /* Handle centering on a graphical frame specially. Such frames can have variable-height lines and centering point on the basis of line counts would lead to strange effects. */ @@ -5368,14 +5383,17 @@ and redisplay normally--don't erase and redraw the frame. */) charpos = IT_CHARPOS (it); bytepos = IT_BYTEPOS (it); } - else if (XINT (arg) < 0) + else if (iarg < 0) { struct it it; struct text_pos pt; - int nlines = - XINT (arg); + int nlines = -iarg; int extra_line_spacing; int h = window_box_height (w); + iarg = XINT (arg); + iarg = - max (-iarg, this_scroll_margin); + SET_TEXT_POS (pt, PT, PT_BYTE); start_display (&it, w, pt); @@ -5434,7 +5452,11 @@ and redisplay normally--don't erase and redraw the frame. */) else { struct position pos; - pos = *vmotion (PT, - XINT (arg), w); + + iarg = XINT (arg); + iarg = max (iarg, this_scroll_margin); + + pos = *vmotion (PT, -iarg, w); charpos = pos.bufpos; bytepos = pos.bytepos; } @@ -5445,11 +5467,17 @@ and redisplay normally--don't erase and redraw the frame. */) int ht = window_internal_height (w); if (center_p) - arg = make_number (ht / 2); + iarg = make_number (ht / 2); else if (XINT (arg) < 0) - arg = make_number (XINT (arg) + ht); + iarg = XINT (arg) + ht; + else + iarg = XINT (arg); + + /* Don't let it get into the margin at either top or bottom. */ + iarg = max (iarg, this_scroll_margin); + iarg = min (iarg, ht - this_scroll_margin - 1); - pos = *vmotion (PT, - XINT (arg), w); + pos = *vmotion (PT, - iarg, w); charpos = pos.bufpos; bytepos = pos.bytepos; } @@ -5498,6 +5526,9 @@ zero means top of window, negative means relative to bottom of window. */) struct window *w = XWINDOW (selected_window); int lines, start; Lisp_Object window; +#if 0 + int this_scroll_margin; +#endif window = selected_window; start = marker_position (w->start); @@ -5513,13 +5544,33 @@ zero means top of window, negative means relative to bottom of window. */) Fgoto_char (w->start); lines = displayed_window_lines (w); + +#if 0 + this_scroll_margin = max (0, scroll_margin); + this_scroll_margin = min (this_scroll_margin, lines / 4); +#endif + if (NILP (arg)) XSETFASTINT (arg, lines / 2); else { - arg = Fprefix_numeric_value (arg); - if (XINT (arg) < 0) - XSETINT (arg, XINT (arg) + lines); + int iarg = XINT (Fprefix_numeric_value (arg)); + + if (iarg < 0) + iarg = iarg + lines; + +#if 0 /* This code would prevent move-to-window-line from moving point + to a place inside the scroll margins (which would cause the + next redisplay to scroll). I wrote this code, but then concluded + it is probably better not to install it. However, it is here + inside #if 0 so as not to lose it. -- rms. */ + + /* Don't let it get into the margin at either top or bottom. */ + iarg = max (iarg, this_scroll_margin); + iarg = min (iarg, lines - this_scroll_margin - 1); +#endif + + arg = make_number (iarg); } /* Skip past a partially visible first line. */ @@ -6914,9 +6965,13 @@ If there is only one window, it is split regardless of this value. */); DEFVAR_LISP ("scroll-preserve-screen-position", &Vscroll_preserve_screen_position, - doc: /* *Non-nil means scroll commands move point to keep its screen line unchanged. -This is only when it is impossible to keep point fixed and still -scroll as specified. */); + doc: /* *Controls if scroll commands move point to keep its screen line unchanged. +A value of nil means point does not keep its screen position except +at the scroll margin or window boundary respectively. +A value of t means point keeps its screen position if the scroll +command moved it vertically out of the window, e.g. when scrolling +by full screens. +Any other value means point always keeps its screen position. */); Vscroll_preserve_screen_position = Qnil; DEFVAR_LISP ("window-configuration-change-hook", |