Added face parameter :extend.

This is an initial change to add a parameter :extend that will be used
in the display engine later.

2 files changed, 48 insertions, 8 deletions

diff --git a/src/dispextern.h b/src/dispextern.h
index 57400ae047a..519cc36345c 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -1677,11 +1677,9 @@ struct face
   /* Pixel value or color index of background color.  */
   unsigned long background;
 
-  /* Pixel value or color index of underline color.  */
+  /* Pixel value or color index of underline, overlined,
+     strike-through, or box color.  */
   unsigned long underline_color;
-
-  /* Pixel value or color index of overlined, strike-through, or box
-     color.  */
   unsigned long overline_color;
   unsigned long strike_through_color;
   unsigned long box_color;
@@ -1864,6 +1862,9 @@ struct face_cache
    ? FRAME_FACE_CACHE (F)->faces_by_id[ID]              \
    : NULL)
 
+#define FACE_EXTENSIBLE_P(F)                    \
+  (!NILP (F->lface[LFACE_EXTEND_INDEX]))
+
 /* True if FACE is suitable for displaying ASCII characters.  */
 INLINE bool
 FACE_SUITABLE_FOR_ASCII_CHAR_P (struct face *face)
@@ -2373,7 +2374,7 @@ struct it
   /* Face id of the iterator saved in case a glyph from dpvec contains
      a face.  The face is restored when all glyphs from dpvec have
      been delivered.  */
-  int saved_face_id;
+  int saved_face_id, saved_extend_face_id;
 
   /* Vector of glyphs for control character translation.  The pointer
      dpvec is set to ctl_chars when a control character is translated.
@@ -2435,7 +2436,7 @@ struct it
     ptrdiff_t prev_stop;
     ptrdiff_t base_level_stop;
     struct composition_it cmp_it;
-    int face_id;
+    int face_id, extend_face_id;
 
     /* Save values specific to a given method.  */
     union {
@@ -2493,6 +2494,9 @@ struct it
   /* Face to use.  */
   int face_id;
 
+  /* Face to extend at EOL/  */
+  int extend_face_id;
+
   /* Setting of buffer-local variable selective-display-ellipses.  */
   bool_bf selective_display_ellipsis_p : 1;
 
diff --git a/src/xfaces.c b/src/xfaces.c
index c7d6990f505..889bf83561c 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -1590,6 +1590,7 @@ the WIDTH times as wide as FACE on FRAME.  */)
 #define LFACE_FONT(LFACE)           AREF ((LFACE), LFACE_FONT_INDEX)
 #define LFACE_INHERIT(LFACE)        AREF ((LFACE), LFACE_INHERIT_INDEX)
 #define LFACE_FONTSET(LFACE)        AREF ((LFACE), LFACE_FONTSET_INDEX)
+#define LFACE_EXTEND(LFACE)         AREF ((LFACE), LFACE_EXTEND_INDEX)
 #define LFACE_DISTANT_FOREGROUND(LFACE) \
   AREF ((LFACE), LFACE_DISTANT_FOREGROUND_INDEX)
 
@@ -1633,6 +1634,10 @@ check_lface_attrs (Lisp_Object attrs[LFACE_VECTOR_SIZE])
            || SYMBOLP (attrs[LFACE_UNDERLINE_INDEX])
            || STRINGP (attrs[LFACE_UNDERLINE_INDEX])
            || CONSP (attrs[LFACE_UNDERLINE_INDEX]));
+  eassert (UNSPECIFIEDP (attrs[LFACE_EXTEND_INDEX])
+           || IGNORE_DEFFACE_P (attrs[LFACE_EXTEND_INDEX])
+           || SYMBOLP (attrs[LFACE_EXTEND_INDEX])
+           || STRINGP (attrs[LFACE_EXTEND_INDEX]));
   eassert (UNSPECIFIEDP (attrs[LFACE_OVERLINE_INDEX])
            || IGNORE_DEFFACE_P (attrs[LFACE_OVERLINE_INDEX])
            || SYMBOLP (attrs[LFACE_OVERLINE_INDEX])
@@ -2512,6 +2517,13 @@ merge_face_ref (struct window *w,
                                         err_msgs, named_merge_points))
                     err = true;
                 }
+              else if (EQ (keyword, QCextend))
+                {
+                  if (EQ (value, Qt) || NILP (value))
+                    to[LFACE_EXTEND_INDEX] = value;
+                  else
+                    err = true;
+                }
               else
                 err = true;
 
@@ -3030,6 +3042,17 @@ FRAME 0 means change the face on all frames, and change the default
       old_value = LFACE_INVERSE (lface);
       ASET (lface, LFACE_INVERSE_INDEX, value);
     }
+  else if (EQ (attr, QCextend))
+    {
+      if (!UNSPECIFIEDP (value) && !IGNORE_DEFFACE_P (value))
+        {
+          CHECK_SYMBOL (value);
+          if (!EQ (value, Qt) && !NILP (value))
+            signal_error ("Invalid extend face attribute value", value);
+        }
+      old_value = LFACE_EXTEND (lface);
+      ASET (lface, LFACE_EXTEND_INDEX, value);
+    }
   else if (EQ (attr, QCforeground))
     {
       /* Compatibility with 20.x.  */
@@ -3503,7 +3526,9 @@ DEFUN ("internal-set-lisp-face-attribute-from-resource",
     value = face_boolean_x_resource_value (value, true);
   else if (EQ (attr, QCweight) || EQ (attr, QCslant) || EQ (attr, QCwidth))
     value = intern (SSDATA (value));
-  else if (EQ (attr, QCreverse_video) || EQ (attr, QCinverse_video))
+  else if (EQ (attr, QCreverse_video)
+           || EQ (attr, QCinverse_video)
+           || EQ (attr, QCextend))
     value = face_boolean_x_resource_value (value, true);
   else if (EQ (attr, QCunderline)
            || EQ (attr, QCoverline)
@@ -3727,6 +3752,8 @@ frames).  If FRAME is omitted or nil, use the selected frame.  */)
     value = LFACE_SWIDTH (lface);
   else if (EQ (keyword, QCinherit))
     value = LFACE_INHERIT (lface);
+  else if (EQ (keyword, QCextend))
+    value = LFACE_EXTEND (lface);
   else if (EQ (keyword, QCfont))
     value = LFACE_FONT (lface);
   else if (EQ (keyword, QCfontset))
@@ -3754,7 +3781,9 @@ Value is nil if ATTR doesn't have a discrete set of valid values.  */)
 
   if (EQ (attr, QCunderline) || EQ (attr, QCoverline)
       || EQ (attr, QCstrike_through)
-      || EQ (attr, QCinverse_video) || EQ (attr, QCreverse_video))
+      || EQ (attr, QCinverse_video)
+      || EQ (attr, QCreverse_video)
+      || EQ (attr, QCextend))
     result = list2 (Qt, Qnil);
 
   return result;
@@ -4784,6 +4813,9 @@ gui_supports_face_attributes_p (struct frame *f,
       || (!UNSPECIFIEDP (attrs[LFACE_INVERSE_INDEX])
           && face_attr_equal_p (attrs[LFACE_INVERSE_INDEX],
                                 def_attrs[LFACE_INVERSE_INDEX]))
+      || (!UNSPECIFIEDP (attrs[LFACE_EXTEND_INDEX])
+          && face_attr_equal_p (attrs[LFACE_EXTEND_INDEX],
+                                def_attrs[LFACE_EXTEND_INDEX]))
       || (!UNSPECIFIEDP (attrs[LFACE_FOREGROUND_INDEX])
           && face_attr_equal_p (attrs[LFACE_FOREGROUND_INDEX],
                                 def_attrs[LFACE_FOREGROUND_INDEX]))
@@ -5362,6 +5394,9 @@ realize_default_face (struct frame *f)
         ASET (lface, LFACE_FONTSET_INDEX, Qnil);
     }
 
+  if (UNSPECIFIEDP (LFACE_EXTEND (lface)))
+    ASET (lface, LFACE_EXTEND_INDEX, Qnil);
+
   if (UNSPECIFIEDP (LFACE_UNDERLINE (lface)))
     ASET (lface, LFACE_UNDERLINE_INDEX, Qnil);
 
@@ -6539,6 +6574,7 @@ syms_of_xfaces (void)
   DEFSYM (QCstrike_through, ":strike-through");
   DEFSYM (QCbox, ":box");
   DEFSYM (QCinherit, ":inherit");
+  DEFSYM (QCextend, ":extend");
 
   /* Symbols used for Lisp face attribute values.  */
   DEFSYM (QCcolor, ":color");