display.c

在非GUI环境下

    col_temp = _rl_col_width (new, nfd - new, ne - new);
  else
    col_temp = temp;

  if (col_lendiff > 0)	/* XXX - was lendiff */
    {
      /* Non-zero if we're increasing the number of lines. */
      int gl = current_line >= _rl_vis_botlin && inv_botlin > _rl_vis_botlin;
      /* Sometimes it is cheaper to print the characters rather than
	 use the terminal's capabilities.  If we're growing the number
	 of lines, make sure we actually cause the new line to wrap
	 around on auto-wrapping terminals. */
      if (_rl_terminal_can_insert && ((2 * col_temp) >= col_lendiff || _rl_term_IC) && (!_rl_term_autowrap || !gl))
	{
	  /* If lendiff > prompt_visible_length and _rl_last_c_pos == 0 and
	     _rl_horizontal_scroll_mode == 1, inserting the characters with
	     _rl_term_IC or _rl_term_ic will screw up the screen because of the
	     invisible characters.  We need to just draw them. */
	  if (*ols && (!_rl_horizontal_scroll_mode || _rl_last_c_pos > 0 ||
			lendiff <= prompt_visible_length || !current_invis_chars))
	    {
	      insert_some_chars (nfd, lendiff, col_lendiff);
	      _rl_last_c_pos += col_lendiff;
	    }
	  else if (*ols == 0 && lendiff > 0)
	    {
	      /* At the end of a line the characters do not have to
		 be "inserted".  They can just be placed on the screen. */
	      /* However, this screws up the rest of this block, which
		 assumes you've done the insert because you can. */
	      _rl_output_some_chars (nfd, lendiff);
	      _rl_last_c_pos += col_lendiff;
	    }
	  else
	    {
	      /* We have horizontal scrolling and we are not inserting at
		 the end.  We have invisible characters in this line.  This
		 is a dumb update. */
	      _rl_output_some_chars (nfd, temp);
	      _rl_last_c_pos += col_temp;
	      return;
	    }
	  /* Copy (new) chars to screen from first diff to last match. */
	  temp = nls - nfd;
	  if ((temp - lendiff) > 0)
	    {
	      _rl_output_some_chars (nfd + lendiff, temp - lendiff);
#if 1
	     /* XXX -- this bears closer inspection.  Fixes a redisplay bug
		reported against bash-3.0-alpha by Andreas Schwab involving
		multibyte characters and prompt strings with invisible
		characters, but was previously disabled. */
	      _rl_last_c_pos += _rl_col_width (nfd+lendiff, 0, temp-col_lendiff);
#else
	      _rl_last_c_pos += _rl_col_width (nfd+lendiff, 0, temp-lendiff);
#endif
	    }
	}
      else
	{
	  /* cannot insert chars, write to EOL */
	  _rl_output_some_chars (nfd, temp);
	  _rl_last_c_pos += col_temp;
	}
    }
  else				/* Delete characters from line. */
    {
      /* If possible and inexpensive to use terminal deletion, then do so. */
      if (_rl_term_dc && (2 * col_temp) >= -col_lendiff)
	{
	  /* If all we're doing is erasing the invisible characters in the
	     prompt string, don't bother.  It screws up the assumptions
	     about what's on the screen. */
	  if (_rl_horizontal_scroll_mode && _rl_last_c_pos == 0 &&
	      -lendiff == visible_wrap_offset)
	    col_lendiff = 0;

	  if (col_lendiff)
	    delete_chars (-col_lendiff); /* delete (diff) characters */

	  /* Copy (new) chars to screen from first diff to last match */
	  temp = nls - nfd;
	  if (temp > 0)
	    {
	      _rl_output_some_chars (nfd, temp);
	      _rl_last_c_pos += _rl_col_width (nfd, 0, temp);;
	    }
	}
      /* Otherwise, print over the existing material. */
      else
	{
	  if (temp > 0)
	    {
	      _rl_output_some_chars (nfd, temp);
	      _rl_last_c_pos += col_temp;
	    }
	  lendiff = (oe - old) - (ne - new);
	  if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
	    col_lendiff = _rl_col_width (old, 0, oe - old) - _rl_col_width (new, 0, ne - new);
	  else
	    col_lendiff = lendiff;

	  if (col_lendiff)
	    {	  
	      if (_rl_term_autowrap && current_line < inv_botlin)
		space_to_eol (col_lendiff);
	      else
		_rl_clear_to_eol (col_lendiff);
	    }
	}
    }
}

/* Tell the update routines that we have moved onto a new (empty) line. */
int
rl_on_new_line ()
{
  if (visible_line)
    visible_line[0] = '\0';

  _rl_last_c_pos = _rl_last_v_pos = 0;
  _rl_vis_botlin = last_lmargin = 0;
  if (vis_lbreaks)
    vis_lbreaks[0] = vis_lbreaks[1] = 0;
  visible_wrap_offset = 0;
  return 0;
}

/* Tell the update routines that we have moved onto a new line with the
   prompt already displayed.  Code originally from the version of readline
   distributed with CLISP.  rl_expand_prompt must have already been called
   (explicitly or implicitly).  This still doesn't work exactly right. */
int
rl_on_new_line_with_prompt ()
{
  int prompt_size, i, l, real_screenwidth, newlines;
  char *prompt_last_line, *lprompt;

  /* Initialize visible_line and invisible_line to ensure that they can hold
     the already-displayed prompt. */
  prompt_size = strlen (rl_prompt) + 1;
  init_line_structures (prompt_size);

  /* Make sure the line structures hold the already-displayed prompt for
     redisplay. */
  lprompt = local_prompt ? local_prompt : rl_prompt;
  strcpy (visible_line, lprompt);
  strcpy (invisible_line, lprompt);

  /* If the prompt contains newlines, take the last tail. */
  prompt_last_line = strrchr (rl_prompt, '\n');
  if (!prompt_last_line)
    prompt_last_line = rl_prompt;

  l = strlen (prompt_last_line);
  if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
    _rl_last_c_pos = _rl_col_width (prompt_last_line, 0, l);
  else
    _rl_last_c_pos = l;

  /* Dissect prompt_last_line into screen lines. Note that here we have
     to use the real screenwidth. Readline's notion of screenwidth might be
     one less, see terminal.c. */
  real_screenwidth = _rl_screenwidth + (_rl_term_autowrap ? 0 : 1);
  _rl_last_v_pos = l / real_screenwidth;
  /* If the prompt length is a multiple of real_screenwidth, we don't know
     whether the cursor is at the end of the last line, or already at the
     beginning of the next line. Output a newline just to be safe. */
  if (l > 0 && (l % real_screenwidth) == 0)
    _rl_output_some_chars ("\n", 1);
  last_lmargin = 0;

  newlines = 0; i = 0;
  while (i <= l)
    {
      _rl_vis_botlin = newlines;
      vis_lbreaks[newlines++] = i;
      i += real_screenwidth;
    }
  vis_lbreaks[newlines] = l;
  visible_wrap_offset = 0;

  rl_display_prompt = rl_prompt;	/* XXX - make sure it's set */

  return 0;
}

/* Actually update the display, period. */
int
rl_forced_update_display ()
{
  if (visible_line)
    {
      register char *temp = visible_line;

      while (*temp)
	*temp++ = '\0';
    }
  rl_on_new_line ();
  forced_display++;
  (*rl_redisplay_function) ();
  return 0;
}

/* Move the cursor from _rl_last_c_pos to NEW, which are buffer indices.
   DATA is the contents of the screen line of interest; i.e., where
   the movement is being done. */
void
_rl_move_cursor_relative (new, data)
     int new;
     const char *data;
{
  register int i;

  /* If we don't have to do anything, then return. */
#if defined (HANDLE_MULTIBYTE)
  /* If we have multibyte characters, NEW is indexed by the buffer point in
     a multibyte string, but _rl_last_c_pos is the display position.  In
     this case, NEW's display position is not obvious and must be
     calculated. */
  if (MB_CUR_MAX == 1 || rl_byte_oriented)
    {
      if (_rl_last_c_pos == new)
	return;
    }
  else if (_rl_last_c_pos == _rl_col_width (data, 0, new))
    return;
#else
  if (_rl_last_c_pos == new) return;
#endif

  /* It may be faster to output a CR, and then move forwards instead
     of moving backwards. */
  /* i == current physical cursor position. */
  i = _rl_last_c_pos - W_OFFSET(_rl_last_v_pos, visible_wrap_offset);
  if (new == 0 || CR_FASTER (new, _rl_last_c_pos) ||
      (_rl_term_autowrap && i == _rl_screenwidth))
    {
#if defined (__MSDOS__)
      putc ('\r', rl_outstream);
#else
      tputs (_rl_term_cr, 1, _rl_output_character_function);
#endif /* !__MSDOS__ */
      _rl_last_c_pos = 0;
    }

  if (_rl_last_c_pos < new)
    {
      /* Move the cursor forward.  We do it by printing the command
	 to move the cursor forward if there is one, else print that
	 portion of the output buffer again.  Which is cheaper? */

      /* The above comment is left here for posterity.  It is faster
	 to print one character (non-control) than to print a control
	 sequence telling the terminal to move forward one character.
	 That kind of control is for people who don't know what the
	 data is underneath the cursor. */
#if defined (HACK_TERMCAP_MOTION)
      if (_rl_term_forward_char)
	{
	  if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
	    {
	      int width;
	      width = _rl_col_width (data, _rl_last_c_pos, new);
	      for (i = 0; i < width; i++)
		tputs (_rl_term_forward_char, 1, _rl_output_character_function);
	    }
	  else
	    {
	      for (i = _rl_last_c_pos; i < new; i++)
		tputs (_rl_term_forward_char, 1, _rl_output_character_function);
	    }
	}
      else if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
	{
	  tputs (_rl_term_cr, 1, _rl_output_character_function);
	  for (i = 0; i < new; i++)
	    putc (data[i], rl_outstream);
	}
      else
	for (i = _rl_last_c_pos; i < new; i++)
	  putc (data[i], rl_outstream);

#else /* !HACK_TERMCAP_MOTION */

      if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
	{
	  tputs (_rl_term_cr, 1, _rl_output_character_function);
	  for (i = 0; i < new; i++)
	    putc (data[i], rl_outstream);
	}
      else
	for (i = _rl_last_c_pos; i < new; i++)
	  putc (data[i], rl_outstream);

#endif /* !HACK_TERMCAP_MOTION */

    }
#if defined (HANDLE_MULTIBYTE)
  /* NEW points to the buffer point, but _rl_last_c_pos is the display point.
     The byte length of the string is probably bigger than the column width
     of the string, which means that if NEW == _rl_last_c_pos, then NEW's
     display point is less than _rl_last_c_pos. */
  else if (_rl_last_c_pos >= new)
#else
  else if (_rl_last_c_pos > new)
#endif
    {
      if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
	_rl_backspace (_rl_last_c_pos - _rl_col_width (data, 0, new));
      else
	_rl_backspace (_rl_last_c_pos - new);
    }

  if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
    _rl_last_c_pos =  _rl_col_width (data, 0, new);
  else
    _rl_last_c_pos = new;
}

/* PWP: move the cursor up or down. */
void
_rl_move_vert (to)
     int to;
{
  register int delta, i;

  if (_rl_last_v_pos == to || to > _rl_screenheight)
    return;

  if ((delta = to - _rl_last_v_pos) > 0)
    {
      for (i = 0; i < delta; i++)
	putc ('\n', rl_outstream);
#if defined (__MSDOS__)
      putc ('\r', rl_outstream);
#else
      tputs (_rl_term_cr, 1, _rl_output_character_function);
#endif
      _rl_last_c_pos = 0;
    }
  else
    {			/* delta < 0 */
      if (_rl_term_up && *_rl_term_up)
	for (i = 0; i < -delta; i++)
	  tputs (_rl_term_up, 1, _rl_output_character_function);
    }

  _rl_last_v_pos = to;		/* Now TO is here */
}

/* Physically print C on rl_outstream.  This is for functions which know
   how to optimize the display.  Return the number of characters output. */
int
rl_show_char (c)
     int c;
{
  int n = 1;
  if (META_CHAR (c) && (_rl_output_meta_chars == 0))
    {
      fprintf (rl_outstream, "M-");
      n += 2;
      c = UNMETA (c);
    }

#if defined (DISPLAY_TABS)
  if ((CTRL_CHAR (c) && c != '\t') || c == RUBOUT)
#else
  if (CTRL_CHAR (c) || c == RUBOUT)
#endif /* !DISPLAY_TABS */
    {
      fprintf (rl_outstream, "C-");
      n += 2;
      c = CTRL_CHAR (c) ? UNCTRL (c) : '?';
    }

  putc (c, rl_outstream);
  fflush (rl_outstream);
  return n;
}

int
rl_character_len (c, pos)
     register int c, pos;
{
  unsigned char uc;

  uc = (unsigned char)c;

  if (META_CHAR (uc))
    return ((_rl_output_meta_chars == 0) ? 4 : 1);

  if (uc == '\t')
    {
#if defined (DISPLAY_TABS)
      return (((pos | 7) + 1) - pos);
#else
      return (2);
#endif /* !DISPLAY_TABS */
    }

  if (CTRL_CHAR (c) || c == RUBOUT)
    return (2);

  return ((ISPRINT (uc)) ? 1 : 2);
}

/* How to print things in the "echo-area".  The prompt is treated as a
   mini-modeline. */

#if defined (USE_VARARGS)
int
#if defined (PREFER_STDARG)
rl_message (const char *format, ...)
#else
rl_message (va_alist)
     va_dcl
#endif
{
  va_list args;
#if defined (PREFER_VARARGS)
  char *format;
#endif

#if defined (PREFER_STDARG)
  va_start (args, format);
#else
  va_start (args);
  format = va_arg (args, char *);
#endif

#if defined (HAVE_VSNPRINTF)
  vsnprintf (msg_buf, sizeof (msg_buf) - 1, format, args);
#else
  vsprintf (msg_buf, format, args);
  msg_buf[sizeof(msg_buf) - 1] = '\0';	/* overflow? */
#endif
  va_end (args);

  rl_display_prompt = msg_buf;
  (*rl_redisplay_function) ();
  return 0;
}
#else /* !USE_VARARGS */
int
rl_message (format, arg1, arg2)
     char *format;
{
  sprintf (msg_buf, format, arg1, arg2);
  msg_buf[sizeof(msg_buf) - 1] = '\0';	/* overflow? */
  rl_display_prompt = msg_buf;
  (*rl_redisplay_function) ();
  return 0;
}
#endif /* !USE_VARARGS */