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

[Chong Yidong]

CVSROOT:        /sources/emacs
Module name:    emacs
Changes by:     Chong Yidong <cyd>      08/07/05 05:31:13

Index: xdisp.c
===================================================================
RCS file: /sources/emacs/emacs/src/xdisp.c,v
retrieving revision 1.1227
retrieving revision 1.1228
diff -u -b -r1.1227 -r1.1228
--- xdisp.c     2 Jul 2008 15:20:33 -0000       1.1227
+++ xdisp.c     5 Jul 2008 05:31:12 -0000       1.1228
@@ -346,10 +346,17 @@
   (!NILP (Voverflow_newline_into_fringe)       \
    && FRAME_WINDOW_P (it->f)                   \
    && WINDOW_RIGHT_FRINGE_WIDTH (it->w) > 0    \
-   && it->current_x == it->last_visible_x)
+   && it->current_x == it->last_visible_x      \
+   && it->line_wrap != WORD_WRAP)
 
 #endif /* HAVE_WINDOW_SYSTEM */
 
+/* Test if the display element loaded in IT is a space or tab
+   character.  This is used to determine word wrapping.  */
+
+#define IT_DISPLAYING_WHITESPACE(it)                           \
+  (it->what == IT_CHARACTER && (it->c == ' ' || it->c == '\t'))
+
 /* Non-nil means show the text cursor in void text areas
    i.e. in blank areas after eol and eob.  This used to be
    the default in 21.3.  */
@@ -6664,7 +6671,7 @@
 {
   enum move_it_result result = MOVE_UNDEFINED;
   struct glyph_row *saved_glyph_row;
-  struct it wrap_it, atpos_it;
+  struct it wrap_it, atpos_it, atx_it;
   int may_wrap = 0;
 
   /* Don't produce glyphs in produce_glyphs.  */
@@ -6672,11 +6679,13 @@
   it->glyph_row = NULL;
 
   /* Use wrap_it to save a copy of IT wherever a word wrap could
-     occur.  Use atpos_it to save a copy of IT at the desired
+     occur.  Use atpos_it to save a copy of IT at the desired buffer
      position, if found, so that we can scan ahead and check if the
-     word later overshoots the window edge.  */
+     word later overshoots the window edge.  Use atx_it similarly, for
+     pixel positions.  */
   wrap_it.sp = -1;
   atpos_it.sp = -1;
+  atx_it.sp = -1;
 
 #define BUFFER_POS_REACHED_P()                                 \
   ((op & MOVE_TO_POS) != 0                                     \
@@ -6689,39 +6698,35 @@
   /* If there's a line-/wrap-prefix, handle it.  */
   if (it->hpos == 0 && it->method == GET_FROM_BUFFER
       && it->current_y < it->last_visible_y)
-    {
       handle_line_prefix (it);
-    }
 
   while (1)
     {
       int x, i, ascent = 0, descent = 0;
 
-      /* Stop if we move beyond TO_CHARPOS (after an image or stretch glyph).  
*/
+/* Utility macro to reset an iterator with x, ascent, and descent.  */
+#define IT_RESET_X_ASCENT_DESCENT(IT)                  \
+  ((IT)->current_x = x, (IT)->max_ascent = ascent,     \
+   (IT)->max_descent = descent)
+
+      /* Stop if we move beyond TO_CHARPOS (after an image or stretch
+        glyph).  */
       if ((op & MOVE_TO_POS) != 0
          && BUFFERP (it->object)
          && it->method == GET_FROM_BUFFER
          && IT_CHARPOS (*it) > to_charpos)
        {
-         if (it->line_wrap == WORD_WRAP)
-           {
-             /* If wrap_it is valid, the current position might be in
-                a word that is wrapped to the next line, so continue
-                to see if that happens.  */
-             if (wrap_it.sp < 0)
+         if (it->line_wrap != WORD_WRAP || wrap_it.sp < 0)
                {
                  result = MOVE_POS_MATCH_OR_ZV;
                  break;
                }
-             if (atpos_it.sp < 0)
+         else if (it->line_wrap == WORD_WRAP && atpos_it.sp < 0)
+           /* If wrap_it is valid, the current position might be in a
+              word that is wrapped.  So, save the iterator in
+              atpos_it and continue to see if wrapping happens.  */
                atpos_it = *it;
            }
-         else
-           {
-             result = MOVE_POS_MATCH_OR_ZV;
-             break;
-           }
-       }
 
       /* Stop when ZV reached.
          We used to stop here when TO_CHARPOS reached as well, but that is
@@ -6743,31 +6748,39 @@
        }
       else
        {
-         /* Remember the line height so far in case the next element
-            doesn't fit on the line.  */
-         ascent = it->max_ascent;
-         descent = it->max_descent;
-
          if (it->line_wrap == WORD_WRAP)
            {
-             if (it->what == IT_CHARACTER
-                 && (it->c == ' ' || it->c == '\t'))
+             if (IT_DISPLAYING_WHITESPACE (it))
                may_wrap = 1;
              else if (may_wrap)
                {
-                 /* We are done if the position is already found.  */
+                 /* We have reached a glyph that follows one or more
+                    whitespace characters.  If the position is
+                    already found, we are done.  */
                  if (atpos_it.sp >= 0)
                    {
                      *it = atpos_it;
-                     atpos_it.sp = -1;
-                     goto buffer_pos_reached;
+                     result = MOVE_POS_MATCH_OR_ZV;
+                     goto done;
+                   }
+                 if (atx_it.sp >= 0)
+                   {
+                     *it = atx_it;
+                     result = MOVE_X_REACHED;
+                     goto done;
                    }
+                 /* Otherwise, we can wrap here.  */
                  wrap_it = *it;
                  may_wrap = 0;
                }
            }
        }
 
+      /* Remember the line height for the current line, in case
+        the next element doesn't fit on the line.  */
+      ascent = it->max_ascent;
+      descent = it->max_descent;
+
       /* The call to produce_glyphs will get the metrics of the
         display element IT is loaded with.  Record the x-position
         before this display element, in case it doesn't fit on the
@@ -6818,20 +6831,29 @@
                {
                  if (BUFFER_POS_REACHED_P ())
                    {
-                     if (it->line_wrap == WORD_WRAP)
-                       {
-                         if (wrap_it.sp < 0)
+                     if (it->line_wrap != WORD_WRAP || wrap_it.sp < 0)
                            goto buffer_pos_reached;
                          if (atpos_it.sp < 0)
+                       {
                            atpos_it = *it;
+                         IT_RESET_X_ASCENT_DESCENT (&atpos_it);
                        }
-                     else
-                       goto buffer_pos_reached;
                    }
+                 else
+                   {
+                     if (it->line_wrap != WORD_WRAP || wrap_it.sp < 0)
+                       {
                  it->current_x = x;
                  result = MOVE_X_REACHED;
                  break;
                }
+                     if (atx_it.sp < 0)
+                       {
+                         atx_it = *it;
+                         IT_RESET_X_ASCENT_DESCENT (&atx_it);
+                       }
+                   }
+               }
 
              if (/* Lines are continued.  */
                  it->line_wrap != TRUNCATE
@@ -6860,11 +6882,22 @@
                             now that we know it fits in this row.  */
                          if (BUFFER_POS_REACHED_P ())
                            {
+                             if (it->line_wrap != WORD_WRAP
+                                 || wrap_it.sp < 0)
+                               {
                              it->hpos = hpos_before_this_char;
                              it->current_x = x_before_this_char;
                              result = MOVE_POS_MATCH_OR_ZV;
                              break;
                            }
+                             if (it->line_wrap == WORD_WRAP
+                                 && atpos_it.sp < 0)
+                               {
+                                 atpos_it = *it;
+                                 atpos_it.current_x = x_before_this_char;
+                                 atpos_it.hpos = hpos_before_this_char;
+                               }
+                           }
 
                          set_iterator_to_next (it, 1);
 #ifdef HAVE_WINDOW_SYSTEM
@@ -6893,16 +6926,13 @@
                        }
                    }
                  else
-                   {
-                     it->current_x = x;
-                     it->max_ascent = ascent;
-                     it->max_descent = descent;
-                   }
+                   IT_RESET_X_ASCENT_DESCENT (it);
 
                  if (wrap_it.sp >= 0)
                    {
                      *it = wrap_it;
                      atpos_it.sp = -1;
+                     atx_it.sp = -1;
                    }
 
                  TRACE_MOVE ((stderr, "move_it_in: continued at %d\n",
@@ -6913,15 +6943,13 @@
 
              if (BUFFER_POS_REACHED_P ())
                {
-                 if (it->line_wrap == WORD_WRAP)
-                   {
-                     if (wrap_it.sp < 0)
+                 if (it->line_wrap != WORD_WRAP || wrap_it.sp < 0)
                        goto buffer_pos_reached;
-                     if (atpos_it.sp < 0)
+                 if (it->line_wrap == WORD_WRAP && atpos_it.sp < 0)
+                   {
                        atpos_it = *it;
+                     IT_RESET_X_ASCENT_DESCENT (&atpos_it);
                    }
-                 else
-                   goto buffer_pos_reached;
                }
 
              if (new_x > it->first_visible_x)
@@ -6938,9 +6966,7 @@
       else if (BUFFER_POS_REACHED_P ())
        {
        buffer_pos_reached:
-         it->current_x = x;
-         it->max_ascent = ascent;
-         it->max_descent = descent;
+         IT_RESET_X_ASCENT_DESCENT (it);
          result = MOVE_POS_MATCH_OR_ZV;
          break;
        }
@@ -6990,14 +7016,19 @@
          result = MOVE_LINE_TRUNCATED;
          break;
        }
+#undef IT_RESET_X_ASCENT_DESCENT
     }
 
 #undef BUFFER_POS_REACHED_P
 
   /* If we scanned beyond to_pos and didn't find a point to wrap at,
-     return iterator at to_pos.  */
+     restore the saved iterator.  */
   if (atpos_it.sp >= 0)
     *it = atpos_it;
+  else if (atx_it.sp >= 0)
+    *it = atx_it;
+
+ done:
 
   /* Restore the iterator settings altered at the beginning of this
      function.  */
@@ -16506,8 +16537,7 @@
 
          if (it->line_wrap == WORD_WRAP && it->area == TEXT_AREA)
            {
-             if (it->what == IT_CHARACTER
-                 && (it->c == ' ' || it->c == '\t'))
+             if (IT_DISPLAYING_WHITESPACE (it))
                may_wrap = 1;
              else if (may_wrap)
                {
@@ -16604,6 +16634,18 @@
                      ++it->hpos;
                      if (i == nglyphs - 1)
                        {
+                         /* If line-wrap is on, check if a previous
+                            wrap point was found.  */
+                         if (wrap_row_used > 0
+                             /* Even if there is a previous wrap
+                                point, continue the line here as
+                                usual, if (i) the previous character
+                                was a space or tab AND (ii) the
+                                current character is not.  */
+                             && (!may_wrap
+                                 || IT_DISPLAYING_WHITESPACE (it)))
+                           goto back_to_wrap;
+
                          set_iterator_to_next (it, 1);
 #ifdef HAVE_WINDOW_SYSTEM
                          if (IT_OVERFLOW_NEWLINE_INTO_FRINGE (it))
@@ -16622,8 +16664,6 @@
                                }
                            }
 #endif /* HAVE_WINDOW_SYSTEM */
-                         if (wrap_row_used > 0)
-                           goto back_to_wrap;
                        }
                    }
                  else if (CHAR_GLYPH_PADDING_P (*glyph)