Display-fill-column-indicator NEWS info.

*etc/NEWS: Added information about the fill-column-indicator mode.
*lisp/faces.el: Added a face for the display fill column indicator.

1 files changed, 46 insertions, 17 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index f1609664277..c6f8133a838 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -20164,17 +20164,26 @@ append_space_for_newline (struct it *it, bool default_face_p)
              same place than the line */
           if (!NILP (Vdisplay_fill_column_indicator)
               && (it->w->pseudo_window_p == 0)
-              && FIXNATP (Vdisplay_fill_column_indicator_column)
+              && (!NILP (Vdisplay_fill_column_indicator_column))
               && FIXNATP (Vdisplay_fill_column_indicator_character))
             {
+               int fill_column_indicator_column = -1;
+
+               if (EQ (Vdisplay_fill_column_indicator_column, Qt)
+                   && FIXNATP (BVAR (current_buffer, fill_column)))
+                 fill_column_indicator_column =
+                   XFIXNAT (BVAR (current_buffer, fill_column));
+               else if (FIXNATP (Vdisplay_fill_column_indicator_column))
+                 fill_column_indicator_column =
+                   XFIXNAT (Vdisplay_fill_column_indicator_column);
+
                struct font *font =
                  default_face->font ? default_face->font : FRAME_FONT (it->f);
                const int char_width =
                  font->average_width ? font->average_width : font->space_width;
-               const int fill_column =
-                 XFIXNAT (Vdisplay_fill_column_indicator_column);
+
                const int column_x =
-                 char_width * fill_column + it->lnum_pixel_width;
+                 char_width * fill_column_indicator_column + it->lnum_pixel_width;
 
                if (it->current_x == column_x)
                  {
@@ -20416,18 +20425,26 @@ extend_face_to_end_of_line (struct it *it)
              active */
           if (!NILP (Vdisplay_fill_column_indicator)
               && (it->w->pseudo_window_p == 0)
-              && FIXNATP (Vdisplay_fill_column_indicator_column)
+              && (!NILP (Vdisplay_fill_column_indicator_column))
               && FIXNATP (Vdisplay_fill_column_indicator_character))
             {
+               int fill_column_indicator_column = -1;
+
+               if (EQ (Vdisplay_fill_column_indicator_column, Qt)
+                   && FIXNATP (BVAR (current_buffer, fill_column)))
+                 fill_column_indicator_column =
+                   XFIXNAT (BVAR (current_buffer, fill_column));
+               else if (FIXNATP (Vdisplay_fill_column_indicator_column))
+                 fill_column_indicator_column =
+                   XFIXNAT (Vdisplay_fill_column_indicator_column);
+
               struct font *font =
                 default_face->font ? default_face->font : FRAME_FONT (f);
               const int char_width =
                 font->average_width ? font->average_width : font->space_width;
 
-              const int fill_column =
-                XFIXNAT (Vdisplay_fill_column_indicator_column);
-
-              const int column_x = char_width * fill_column + it->lnum_pixel_width;
+              const int column_x = char_width * fill_column_indicator_column +
+                it->lnum_pixel_width;
 
               if ((it->current_x <= column_x)
                   && (column_x <= it->last_visible_x))
@@ -20606,14 +20623,23 @@ extend_face_to_end_of_line (struct it *it)
         it->face_id = face->id;
 
       /* Display fill-column-line if mode is active */
-      if (!NILP (Vdisplay_fill_column_indicator))
+      if (!NILP (Vdisplay_fill_column_indicator)
+          && (!NILP (Vdisplay_fill_column_indicator_column))
+          && FIXNATP (Vdisplay_fill_column_indicator_character))
         {
-          const int fill_column_indicator_line =
-            XFIXNAT (Vdisplay_fill_column_indicator_column)
-              + it->lnum_pixel_width;
+          int fill_column_indicator_column = -1;
+
+          if (EQ (Vdisplay_fill_column_indicator_column, Qt)
+              && FIXNATP (BVAR (current_buffer, fill_column)))
+            fill_column_indicator_column =
+              XFIXNAT (BVAR (current_buffer, fill_column));
+          else if (FIXNATP (Vdisplay_fill_column_indicator_column))
+            fill_column_indicator_column =
+              XFIXNAT (Vdisplay_fill_column_indicator_column);
+
           do
             {
-              if (it->current_x == fill_column_indicator_line)
+              if (it->current_x == fill_column_indicator_column)
                 {
                   const int saved_face = it->face_id;
                   it->face_id =
@@ -33382,9 +33408,12 @@ either `relative' or `visual'.  */);
   Fmake_variable_buffer_local (Qdisplay_fill_column_indicator);
 
   DEFVAR_LISP ("display-fill-column-indicator-column", Vdisplay_fill_column_indicator_column,
-    doc: /* Column to draw the indicator when `display-fill-column-indicator' is non-nil.
-The default value is the variable `fill-column' if not other value is given. */);
-  Vdisplay_fill_column_indicator_column = Qnil;
+    doc: /* Column to draw the fill column indicator when
+`display-fill-column-indicator' is non-nil.  The default value is t
+which means that the indicator will use the `fill-column' variable. If
+a numeric value is set, the indicator will be drawn in that column
+independently of the `fill-column' value.  */);
+  Vdisplay_fill_column_indicator_column = Qt;
   DEFSYM (Qdisplay_fill_column_indicator_column, "display-fill-column-indicator-column");
   Fmake_variable_buffer_local (Qdisplay_fill_column_indicator_column);