printer.cpp   [plain text]

// -*- C++ -*-

// <groff_src_dir>/src/libs/libdriver/printer.cpp

/* Copyright (C) 1989, 1990, 1991, 1992, 2001, 2002, 2003, 2004, 2005
   Free Software Foundation, Inc.
   Written by James Clark (jjc@jclark.com)

   Last update: 02 Mar 2005

   This file is part of groff.

   groff is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   groff is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with groff; see the file COPYING.  If not, write to the Free
   Software Foundation, 51 Franklin St - Fifth Floor, Boston, MA
   02110-1301, USA.
*/

#include "driver.h"

/* If we are sending output to an onscreen pager (as is the normal case
   when reading man pages), then we may get an error state on the output
   stream, if the user does not read all the way to the end.

   We normally expect to catch this, and clean up the error context, when
   the pager exits, because we should get, and handle, a SIGPIPE.

   However ...
*/

#if (defined(_MSC_VER) || defined(_WIN32)) \
    && !defined(__CYGWIN__) && !defined(_UWIN)

  /* Native MS-Windows doesn't know about SIGPIPE, so we cannot detect the
     early exit from the pager, and therefore, cannot clean up the error
     context; thus we use the following static function to identify this
     particular error context, and so suppress unwanted diagnostics.
  */

  static int
  check_for_output_error (FILE* stream)
  {
    /* First, clean up any prior error context on the output stream */
    if (ferror (stream))
      clearerr (stream);
    /* Clear errno, in case clearerr() and fflush() don't */
    errno = 0;
    /* Flush the output stream, so we can capture any error context, other
       than the specific case we wish to suppress.
       
       Microsoft doesn't document it, but the error code for the specific
       context we are trying to suppress seems to be EINVAL -- a strange
       choice, since it is not normally associated with fflush(); of course,
       it *should* be EPIPE, but this *definitely* is not used, and *is* so
       documented.
    */
    return ((fflush(stream) < 0) && (errno != EINVAL));
  }

#else

  /* For other systems, we simply assume that *any* output error context
     is to be reported.
  */
# define check_for_output_error(stream) ferror(stream) || fflush(stream) < 0

#endif


font_pointer_list::font_pointer_list(font *f, font_pointer_list *fp)
: p(f), next(fp)
{
}

printer::printer()
: font_list(0), font_table(0), nfonts(0)
{
}

printer::~printer()
{
  a_delete font_table;
  while (font_list) {
    font_pointer_list *tem = font_list;
    font_list = font_list->next;
    delete tem->p;
    delete tem;
  }
  if (check_for_output_error(stdout))
    fatal("output error");
}

void printer::load_font(int n, const char *nm)
{
  assert(n >= 0);
  if (n >= nfonts) {
    if (nfonts == 0) {
      nfonts = 10;
      if (nfonts <= n)
	nfonts = n + 1;
      font_table = new font *[nfonts];
      for (int i = 0; i < nfonts; i++)
	font_table[i] = 0;
    }
    else {
      font **old_font_table = font_table;
      int old_nfonts = nfonts;
      nfonts *= 2;
      if (n >= nfonts)
	nfonts = n + 1;
      font_table = new font *[nfonts];
      int i;
      for (i = 0; i < old_nfonts; i++)
	font_table[i] = old_font_table[i];
      for (i = old_nfonts; i < nfonts; i++)
	font_table[i] = 0;
      a_delete old_font_table;
    }
  }
  font *f = find_font(nm);
  font_table[n] = f;
}

font *printer::find_font(const char *nm)
{
  for (font_pointer_list *p = font_list; p; p = p->next)
    if (strcmp(p->p->get_name(), nm) == 0)
      return p->p;
  font *f = make_font(nm);
  if (!f)
    fatal("sorry, I can't continue");
  font_list = new font_pointer_list(f, font_list);
  return f;
}

font *printer::make_font(const char *nm)
{
  return font::load_font(nm);
}

void printer::end_of_line()
{
}

void printer::special(char *, const environment *, char)
{
}

void printer::devtag(char *, const environment *, char)
{
}

void printer::draw(int, int *, int, const environment *)
{
}

void printer::change_color(const environment * const)
{
}

void printer::change_fill_color(const environment * const)
{
}

void printer::set_ascii_char(unsigned char c, const environment *env, 
			     int *widthp)
{
  char  buf[2];
  int   w;
  font *f;

  buf[0] = c;
  buf[1] = '\0';

  int i = set_char_and_width(buf, env, &w, &f);
  set_char(i, f, env, w, 0);
  if (widthp) {
    *widthp = w;
  }
}

void printer::set_special_char(const char *nm, const environment *env,
			       int *widthp)
{
  font *f;
  int w;
  int i = set_char_and_width(nm, env, &w, &f);
  if (i != -1) {
    set_char(i, f, env, w, nm);
    if (widthp)
      *widthp = w;
  }
}

int printer::set_char_and_width(const char *nm, const environment *env,
				int *widthp, font **f)
{
  int i = font::name_to_index(nm);
  int fn = env->fontno;
  if (fn < 0 || fn >= nfonts) {
    error("bad font position `%1'", fn);
    return(-1);
  }
  *f = font_table[fn];
  if (*f == 0) {
    error("no font mounted at `%1'", fn);
    return(-1);
  }
  if (!(*f)->contains(i)) {
    if (nm[0] != '\0' && nm[1] == '\0')
      error("font `%1' does not contain ascii character `%2'",
	    (*f)->get_name(),
	    nm[0]);
    else
      error("font `%1' does not contain special character `%2'",
	    (*f)->get_name(),
	    nm);
    return(-1);
  }
  int w = (*f)->get_width(i, env->size);
  if (widthp)
    *widthp = w;
  return( i );
}

void printer::set_numbered_char(int num, const environment *env, int *widthp)
{
  int i = font::number_to_index(num);
  int fn = env->fontno;
  if (fn < 0 || fn >= nfonts) {
    error("bad font position `%1'", fn);
    return;
  }
  font *f = font_table[fn];
  if (f == 0) {
    error("no font mounted at `%1'", fn);
    return;
  }
  if (!f->contains(i)) {
    error("font `%1' does not contain numbered character %2",
	  f->get_name(),
	  num);
    return;
  }
  int w = f->get_width(i, env->size);
  if (widthp)
    *widthp = w;
  set_char(i, f, env, w, 0);
}

font *printer::get_font_from_index(int fontno)
{
  if ((fontno >= 0) && (fontno < nfonts))
    return(font_table[fontno]);
  else
    return(0);
}