[Emacs-diffs] Changes to emacs/src/window.c,v

[Stefan Monnier]

CVSROOT:        /sources/emacs
Module name:    emacs
Changes by:     Stefan Monnier <monnier>        08/06/05 03:57:10

Index: src/window.c
===================================================================
RCS file: /sources/emacs/emacs/src/window.c,v
retrieving revision 1.613
retrieving revision 1.614
diff -u -b -r1.613 -r1.614
--- src/window.c        5 Jun 2008 03:22:48 -0000       1.613
+++ src/window.c        5 Jun 2008 03:57:09 -0000       1.614
@@ -224,8 +224,14 @@
 
 /* Used by the function window_scroll_pixel_based */
 
+static int window_scroll_pixel_based_preserve_x;
 static int window_scroll_pixel_based_preserve_y;
 
+/* Same for window_scroll_line_based.  */
+
+static int window_scroll_preserve_hpos;
+static int window_scroll_preserve_vpos;
+
 #if 0 /* This isn't used anywhere.  */
 /* Nonzero means we can split a frame even if it is "unsplittable".  */
 static int inhibit_frame_unsplittable;
@@ -5216,10 +5222,12 @@
          start_display (&it, w, start);
          move_it_to (&it, PT, -1, -1, -1, MOVE_TO_POS);
          window_scroll_pixel_based_preserve_y = it.current_y;
+         window_scroll_pixel_based_preserve_x = it.current_x;
        }
     }
   else
-    window_scroll_pixel_based_preserve_y = -1;
+    window_scroll_pixel_based_preserve_y
+      = window_scroll_pixel_based_preserve_x = -1;
 
   /* Move iterator it from start the specified distance forward or
      backward.  The result is the new window start.  */
@@ -5355,10 +5363,11 @@
        {
          /* If we have a header line, take account of it.
             This is necessary because we set it.current_y to 0, above.  */
-         move_it_to (&it, -1, -1,
+         move_it_to (&it, -1,
+                     window_scroll_pixel_based_preserve_x,
                      window_scroll_pixel_based_preserve_y
                      - (WINDOW_WANTS_HEADER_LINE_P (w) ? 1 : 0 ),
-                     -1, MOVE_TO_Y);
+                     -1, MOVE_TO_Y | MOVE_TO_X);
          SET_PT_BOTH (IT_CHARPOS (it), IT_BYTEPOS (it));
        }
       else
@@ -5416,8 +5425,9 @@
          /* It would be wrong to subtract CURRENT_HEADER_LINE_HEIGHT
             here because we called start_display again and did not
             alter it.current_y this time.  */
-         move_it_to (&it, -1, -1, window_scroll_pixel_based_preserve_y, -1,
-                     MOVE_TO_Y);
+         move_it_to (&it, -1, window_scroll_pixel_based_preserve_x,
+                     window_scroll_pixel_based_preserve_y, -1,
+                     MOVE_TO_Y | MOVE_TO_X);
          SET_PT_BOTH (IT_CHARPOS (it), IT_BYTEPOS (it));
        }
       else
@@ -5455,8 +5465,7 @@
   int lose;
   Lisp_Object bolp;
   int startpos;
-  struct position posit;
-  int original_vpos;
+  Lisp_Object original_pos = Qnil;
 
   /* If scrolling screen-fulls, compute the number of lines to
      scroll from the window's height.  */
@@ -5465,11 +5474,24 @@
 
   startpos = marker_position (w->start);
 
-  posit = *compute_motion (startpos, 0, 0, 0,
+  if (!NILP (Vscroll_preserve_screen_position))
+    {
+      if (window_scroll_preserve_vpos <= 0
+         || (!EQ (current_kboard->Vlast_command, Qscroll_up)
+             && !EQ (current_kboard->Vlast_command, Qscroll_down)))
+       {
+         struct position posit
+           = *compute_motion (startpos, 0, 0, 0,
                           PT, ht, 0,
                           -1, XINT (w->hscroll),
                           0, w);
-  original_vpos = posit.vpos;
+         window_scroll_preserve_vpos = posit.vpos;
+         window_scroll_preserve_hpos = posit.hpos + XINT (w->hscroll);
+       }
+
+      original_pos = Fcons (make_number (window_scroll_preserve_hpos),
+                           make_number (window_scroll_preserve_vpos));
+    }
 
   XSETFASTINT (tem, PT);
   tem = Fpos_visible_in_window_p (tem, window, Qnil);
@@ -5520,7 +5542,7 @@
          && (whole || !EQ (Vscroll_preserve_screen_position, Qt)))
        {
          SET_PT_BOTH (pos, pos_byte);
-         Fvertical_motion (make_number (original_vpos), window);
+         Fvertical_motion (original_pos, window);
        }
       /* If we scrolled forward, put point enough lines down
         that it is outside the scroll margin.  */
@@ -5542,7 +5564,7 @@
          else if (!NILP (Vscroll_preserve_screen_position))
            {
              SET_PT_BOTH (pos, pos_byte);
-             Fvertical_motion (make_number (original_vpos), window);
+             Fvertical_motion (original_pos, window);
            }
          else
            SET_PT (top_margin);
@@ -5567,7 +5589,7 @@
              if (!NILP (Vscroll_preserve_screen_position))
                {
                  SET_PT_BOTH (pos, pos_byte);
-                 Fvertical_motion (make_number (original_vpos), window);
+                 Fvertical_motion (original_pos, window);
                }
              else
                Fvertical_motion (make_number (-1), window);
@@ -7439,7 +7461,10 @@
   minibuf_selected_window = Qnil;
   staticpro (&minibuf_selected_window);
 
+  window_scroll_pixel_based_preserve_x = -1;
   window_scroll_pixel_based_preserve_y = -1;
+  window_scroll_preserve_hpos = -1;
+  window_scroll_preserve_vpos = -1;
 
   DEFVAR_LISP ("temp-buffer-show-function", &Vtemp_buffer_show_function,
               doc: /* Non-nil means call as function to display a help buffer.
@@ -7640,7 +7665,7 @@
 
   DEFVAR_LISP ("scroll-preserve-screen-position",
               &Vscroll_preserve_screen_position,
-              doc: /* *Controls if scroll commands move point to keep its 
screen line unchanged.
+              doc: /* *Controls if scroll commands move point to keep its 
screen position 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