X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/b35ac83e4679311c23e5827bd931096be3131f49..ff5dec5cd103f6a9b030d295b014f0ff81025def:/src/window.c

diff --git a/src/window.c b/src/window.c
index 2c178a65d2..882f76d975 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1,7 +1,7 @@
 /* Window creation, deletion and examination for GNU Emacs.
    Does not include redisplay.
    Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1996, 1997, 1998, 2000,
-                 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+                 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
                  Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
@@ -54,7 +54,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 Lisp_Object Qwindowp, Qwindow_live_p, Qwindow_configuration_p;
 Lisp_Object Qdisplay_buffer;
-Lisp_Object Qscroll_up, Qscroll_down;
+Lisp_Object Qscroll_up, Qscroll_down, Qscroll_command;
 Lisp_Object Qwindow_size_fixed;
 
 extern Lisp_Object Qleft_margin, Qright_margin;
@@ -4648,12 +4648,15 @@ grow_mini_window (w, delta)
   struct window *root;
 
   xassert (MINI_WINDOW_P (w));
-  xassert (delta >= 0);
+  /* Commenting out the following assertion goes against the stated interface
+     of the function, but it currently does not seem to do anything useful.
+     See discussion of this issue in the thread for bug#4534.
+     xassert (delta >= 0); */
 
   /* Compute how much we can enlarge the mini-window without deleting
      other windows.  */
   root = XWINDOW (FRAME_ROOT_WINDOW (f));
-  if (delta)
+  if (delta > 0)
     {
       int min_height = window_min_size (root, 0, 0, 0, 0);
       if (XFASTINT (root->total_lines) - delta < min_height)
@@ -4939,12 +4942,13 @@ window_scroll_pixel_based (window, n, whole, noerror)
   if (!NILP (Vscroll_preserve_screen_position))
     {
       /* We preserve the goal pixel coordinate across consecutive
-	 calls to scroll-up or scroll-down.  This avoids the
+	 calls to scroll-up, scroll-down and other commands that
+	 have the `scroll-command' property.  This avoids the
 	 possibility of point becoming "stuck" on a tall line when
 	 scrolling by one line.  */
       if (window_scroll_pixel_based_preserve_y < 0
-	  || (!EQ (current_kboard->Vlast_command, Qscroll_up)
-	      && !EQ (current_kboard->Vlast_command, Qscroll_down)))
+	  || !SYMBOLP (current_kboard->Vlast_command)
+	  || NILP (Fget (current_kboard->Vlast_command, Qscroll_command)))
 	{
 	  start_display (&it, w, start);
 	  move_it_to (&it, PT, -1, -1, -1, MOVE_TO_POS);
@@ -5204,8 +5208,8 @@ window_scroll_line_based (window, n, whole, noerror)
   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)))
+	  || !SYMBOLP (current_kboard->Vlast_command)
+	  || NILP (Fget (current_kboard->Vlast_command, Qscroll_command)))
 	{
 	  struct position posit
 	    = *compute_motion (startpos, 0, 0, 0,
@@ -7167,33 +7171,39 @@ init_window ()
 void
 syms_of_window ()
 {
-  Qscroll_up = intern ("scroll-up");
+  Qscroll_up = intern_c_string ("scroll-up");
   staticpro (&Qscroll_up);
 
-  Qscroll_down = intern ("scroll-down");
+  Qscroll_down = intern_c_string ("scroll-down");
   staticpro (&Qscroll_down);
 
-  Qwindow_size_fixed = intern ("window-size-fixed");
+  Qscroll_command = intern_c_string ("scroll-command");
+  staticpro (&Qscroll_command);
+
+  Fput (Qscroll_up, Qscroll_command, Qt);
+  Fput (Qscroll_down, Qscroll_command, Qt);
+
+  Qwindow_size_fixed = intern_c_string ("window-size-fixed");
   staticpro (&Qwindow_size_fixed);
   Fset (Qwindow_size_fixed, Qnil);
 
   staticpro (&Qwindow_configuration_change_hook);
   Qwindow_configuration_change_hook
-    = intern ("window-configuration-change-hook");
+    = intern_c_string ("window-configuration-change-hook");
 
-  Qwindowp = intern ("windowp");
+  Qwindowp = intern_c_string ("windowp");
   staticpro (&Qwindowp);
 
-  Qwindow_configuration_p = intern ("window-configuration-p");
+  Qwindow_configuration_p = intern_c_string ("window-configuration-p");
   staticpro (&Qwindow_configuration_p);
 
-  Qwindow_live_p = intern ("window-live-p");
+  Qwindow_live_p = intern_c_string ("window-live-p");
   staticpro (&Qwindow_live_p);
 
-  Qdisplay_buffer = intern ("display-buffer");
+  Qdisplay_buffer = intern_c_string ("display-buffer");
   staticpro (&Qdisplay_buffer);
 
-  Qtemp_buffer_show_hook = intern ("temp-buffer-show-hook");
+  Qtemp_buffer_show_hook = intern_c_string ("temp-buffer-show-hook");
   staticpro (&Qtemp_buffer_show_hook);
 
   staticpro (&Vwindow_list);
@@ -7262,7 +7272,9 @@ 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.  */);
+Any other value means point always keeps its screen position.
+Scroll commands should have the `scroll-command' property
+on their symbols to be controlled by this variable.  */);
   Vscroll_preserve_screen_position = Qnil;
 
   DEFVAR_LISP ("window-point-insertion-type", &Vwindow_point_insertion_type,
@@ -7374,12 +7386,9 @@ keys_of_window ()
   initial_define_key (control_x_map, '<', "scroll-left");
   initial_define_key (control_x_map, '>', "scroll-right");
 
-  initial_define_key (global_map, Ctl ('V'), "scroll-up");
+  initial_define_key (global_map, Ctl ('V'), "scroll-up-command");
   initial_define_key (meta_map, Ctl ('V'), "scroll-other-window");
-  initial_define_key (meta_map, 'v', "scroll-down");
-
-  initial_define_key (global_map, Ctl('L'), "recenter");
-  initial_define_key (meta_map, 'r', "move-to-window-line");
+  initial_define_key (meta_map, 'v', "scroll-down-command");
 }
 
 /* arch-tag: 90a9c576-0590-48f1-a5f1-6c96a0452d9f