Undo: fix problem with col widths after paste undo.

[gnumeric.git] / plugins / html / latex.c

/* vim: set sw=8: -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 * latex.c
 *
 * Copyright (C) 1999, 2000 Rasca, Berlin
 * EMail: thron@gmx.de
 *
 * Copyright (C) 2001 Adrian Custer, Berkeley
 * email: acuster@nature.berkeley.edu
 *
 * Copyright (C) 2001-2014 Andreas J. Guelzow, Edmonton
 * email: aguelzow@pyrshep.ca
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, see <https://www.gnu.org/licenses/>.
 */


/*
 * This file contains the LaTeX2e plugin functions.
 *
 *
 * The LaTeX2e functions are named:
 *              latex_file_save()
 *              latex_table_visible_file_save()
 *              latex_table_file_save
 *
 */


#include <gnumeric-config.h>
#include <gnumeric.h>
#include <gnumeric-conf.h>
#include "latex.h"
#include <goffice/goffice.h>
#include <workbook-view.h>
#include <workbook.h>
#include <sheet.h>
#include <sheet-merge.h>
#include <style.h>
#include <style-color.h>
#include <font.h>
#include <cell.h>
#include <gnm-format.h>
#include <style-border.h>
#include <sheet-style.h>
#include <parse-util.h>
#include <rendered-value.h>
#include <cellspan.h>
#include <print-info.h>

#include <locale.h>
#include <gsf/gsf-output.h>
#include <string.h>

typedef enum {
        LATEX_NO_BORDER = 0,
        LATEX_SINGLE_BORDER = 1,
        LATEX_DOUBLE_BORDER = 2,
        LATEX_MAX_BORDER
} latex_border_t;

typedef struct {
        latex_border_t latex;
        char const     *vertical;
        char const     *horizontal;
} latex_border_translator_t;

/* the index into the following array is GnmStyleBorderType */
static latex_border_translator_t const border_styles[] = {
        {LATEX_NO_BORDER,     "",  "~"},
        {LATEX_SINGLE_BORDER, "|", "-"},
        {LATEX_SINGLE_BORDER, "|", "-"},
        {LATEX_SINGLE_BORDER, "|", "-"},
        {LATEX_SINGLE_BORDER, "|", "-"},
        {LATEX_DOUBLE_BORDER, "||","="},
        {LATEX_DOUBLE_BORDER, "||","="},
        {LATEX_SINGLE_BORDER, "|", "-"},
        {LATEX_SINGLE_BORDER, "|", "-"},
        {LATEX_SINGLE_BORDER, "|", "-"},
        {LATEX_SINGLE_BORDER, "|", "-"},
        {LATEX_SINGLE_BORDER, "|", "-"},
        {LATEX_SINGLE_BORDER, "|", "-"},
        {LATEX_NO_BORDER,     "",  ""}
};

typedef struct {
        char const     *p_1;
        char const     *p_2;
} latex_border_connectors_t;


static latex_border_connectors_t const conn_styles[LATEX_MAX_BORDER]
[LATEX_MAX_BORDER][LATEX_MAX_BORDER][LATEX_MAX_BORDER] = {
        /*  FIXME: once we are sure that none of the numbered */
        /*entries are in fact needed we should removed the digits */
        {{{{"",""}, { "",""}, { "",""}},
          {{"",""}, { "|",""}, { "32",""}},
          {{"",""}, { "11",""}, { "","|t:"}}},
         {{{"",""}, { "",""}, { "",""}},
          {{"","|"}, { "|",""}, { "33",""}},
          {{"1",""}, { "13",""}, { "34",""}}},
         {{{"",""}, { "",""}, { "|","|"}},
          {{"","|b|"}, { "14",""}, { "|","|"}},
          {{"","|b:"}, { "|b:",""}, { "|",":"}}}},
        {{{{"",""}, { "",""}, { "",""}},
          {{"",""}, { "|",""}, { "35",""}},
          {{"","|"}, { "17",""}, { "36",""}}},
         {{{"","|"}, { "|",""}, { "37",""}},
          {{"|",""}, { "",""}, { "38",""}},
          {{"4",""}, { "19",""}, { "39",""}}},
         {{{"","|b|"}, { "20",""}, { "|","|"}},
          {{"5",""}, { "21",""}, { "|","|"}},
          {{"|b:",""}, { "22",""}, { "40",""}}}},
        {{{{"",""}, { "23",""}, { ":t|",""}},
          {{"|",""}, { "24",""}, { ":t|",""}},
          {{"",""}, { "",""}, { ":t:",""}}},
         {{{"7",""}, { "26",""}, { ":t|",""}},
          {{"8",""}, { "27",""}, { "43",""}},
          {{"",""}, { "",""}, { ":t:",""}}},
         {{{":b|",""}, { "29",""}, { ":","|"}},
          {{":b|",""}, { "30",""}, { ":|",""}},
          {{":b:",""}, { ":b:",""}, { ":",":"}}}}
};

/**
 * latex_raw_str :
 * @p:      a pointer to a char, start of the string to be processed
 * @output: output stream where the processed characters are written.
 * @utf8:   is this a utf8 string?
 *
 * @return:
 * If @p is in form of \L{foo}, return the char pointer pointing to '}' of \L{foo}
 * else return @p untouched;
 *
 * Check if @p is in form of \L{foo}.
 * If it is, the exact "foo" will be put into @output, without any esacaping.
 *
 */
static char const *
latex_raw_str(char const *p, GsfOutput *output, gboolean utf8)
{
        char const *p_begin, *p_orig = p;
        int depth = 1;
        if(strncasecmp(p, "\\L{", 3) == 0){
                p += 3;
                p_begin = p;
                /* find the matching close bracket */
                for(; *p; p = utf8 ? g_utf8_next_char(p) : p + 1){
                        switch(*p){ /* FIXME: how to put in unmatched brackets? */
                                case '{':
                                        depth ++;
                                        break;
                                case '}':
                                        depth--;
                                        if(depth == 0){
                                                /* put the string beginning from p_begin to p to output */
                                                gsf_output_write(output, p - p_begin, p_begin);
                                                return p;
                                        }
                        }
                }
        }
        return p_orig;
}


/**
 * latex_fputs_utf :
 *
 * @p:      a pointer to a char, start of the string to be processed.
 * @output: output stream where the processed characters are written.
 *
 * This escapes any special LaTeX characters from the LaTeX engine,
 * except the ones enclosed in "\L{" and "}".
 * Re-ordered from Rasca's code to have most common first.
 */
static void
latex_fputs_utf (char const *p, GsfOutput *output)
{
        char const *rlt;
        for (; *p; p = g_utf8_next_char (p)) {
                switch (g_utf8_get_char (p)) {

                        /* These are the classic TeX symbols $ & % # _ { } (see Lamport, p.15) */
                case '$': case '&': case '%': case '#':
                case '_': case '{': case '}':
                        gsf_output_printf (output, "\\%c", *p);
                        break;
                        /* These are the other special characters ~ ^ \ (see Lamport, p.15) */
                case '^': case '~':
                        gsf_output_printf (output, "\\%c{ }", *p);
                        break;
                case '\\':
                        rlt = latex_raw_str(p, output, TRUE);
                        if(rlt == p)
                            gsf_output_puts (output, "$\\backslash$");
                        else
                            p = rlt;
                        break;
                        /* Are these available only in LaTeX through mathmode? */
                case '>': case '<':
                        gsf_output_printf (output, "$%c$", *p);
                        break;

                default:
                        gsf_output_write (output,
                                          (g_utf8_next_char (p)) - p, p);
                        break;
                }
        }
}

/**
 * latex_math_fputs_utf :
 *
 * @p:     a pointer to a char, start of the string to be processed.
 * @output: output stream where the processed characters are written.
 *
 * This escapes any special LaTeX characters from the LaTeX engine,
 * except the ones enclosed in "\L{" and "}".
 *
 * We assume that htis will be set in Mathematics mode.
 */
static void
latex_math_fputs_utf (char const *p, GsfOutput *output)
{
        char const *rlt;
        for (; *p; p = g_utf8_next_char (p)) {
                switch (g_utf8_get_char (p)) {

                        /* These are the classic TeX symbols $ & % # (see Lamport, p.15) */
                        case '$': case '&': case '%': case '#':
                                gsf_output_printf (output, "\\%c", *p);
                                break;
                        /* These are the other special characters ~ (see Lamport, p.15) */
                        case '~':
                                gsf_output_printf (output, "\\%c{ }", *p);
                                break;
                        case '\\':
                                rlt = latex_raw_str(p, output, TRUE);
                                if(rlt == p)
                                    gsf_output_puts (output, "$\\backslash$");
                                else
                                    p = rlt;
                                break;
                        default:
                                gsf_output_write (output,
                                                  (g_utf8_next_char (p)) - p, p);
                                break;
                }
        }
}

/**
 * latex_convert_latin_to_utf
 *
 * @text: string to convert
 *
 * return value needs to be freed with g_free
 *
 * call g_convert_with_fallback and also handle utf minus.
 *
 */
static char *
latex_convert_latin_to_utf (char const *text)
{
        char * encoded_text = NULL;

        gsize bytes_read;
        gsize bytes_written;

        if (g_utf8_strchr (text,-1, 0x2212) == NULL) {
                encoded_text = g_convert_with_fallback
                        (text, strlen (text),
                         "ISO-8859-1", "UTF-8", (gchar *)"?",
                         &bytes_read, &bytes_written, NULL);
        } else {
                gunichar* ucs_string = NULL;
                gunichar* this_unichar;
                char *new_text;
                glong items_read;
                glong items_written;

                ucs_string = g_utf8_to_ucs4_fast (text, -1, &items_written);
                for (this_unichar = ucs_string; *this_unichar != '\0'; this_unichar++) {
                        if (*this_unichar == 0x2212)
                                *this_unichar = 0x002d;
                }
                new_text = g_ucs4_to_utf8 (ucs_string, -1, &items_read, &items_written, NULL);
                g_free (ucs_string);
                encoded_text = g_convert_with_fallback
                        (new_text, strlen (new_text),
                         "ISO-8859-1", "UTF-8", (gchar *)"?",
                         &bytes_read, &bytes_written, NULL);
                g_free (new_text);
        }

        return encoded_text;
}

/**
 * latex_fputs_latin :
 *
 * @p:      a pointer to a char, start of the string to be processed.
 * @output: output stream where the processed characters are written.
 *
 * This escapes any special LaTeX characters from the LaTeX engine,
 * except the ones enclosed in "\L{" and "}".
 * Re-ordered from Rasca's code to have most common first.
 */
static void
latex_fputs_latin (char const *text, GsfOutput *output)
{
        char * encoded_text = NULL;
        char const *p;
        char const *rlt;

        encoded_text = latex_convert_latin_to_utf (text);

        for (p = encoded_text; *p; p++) {
                switch (*p) {

                        /* These are the classic TeX symbols $ & % # _ { } (see Lamport, p.15) */
                case '$': case '&': case '%': case '#':
                case '_': case '{': case '}':
                        gsf_output_printf (output, "\\%c", *p);
                        break;
                        /* These are the other special characters ~ ^ \ (see Lamport, p.15) */
                case '^': case '~':
                        gsf_output_printf (output, "\\%c{ }", *p);
                        break;
                case '\\':
                        rlt = latex_raw_str(p, output, FALSE);
                        if(rlt == p)
                            gsf_output_puts (output, "$\\backslash$");
                        else
                            p = rlt;
                        break;
                        /* Are these available only in LaTeX through mathmode? */
                case '>': case '<': case 'µ':
                        gsf_output_printf (output, "$%c$", *p);
                        break;

                default:
                        gsf_output_write (output, 1, p);
                        break;
                }
        }
        g_free (encoded_text);
}

/**
 * latex_math_fputs_latin :
 *
 * @p:     a pointer to a char, start of the string to be processed.
 * @output: output stream where the processed characters are written.
 *
 * This escapes any special LaTeX characters from the LaTeX engine,
 * except the ones enclosed in "\L{" and "}".
 *
 * We assume that htis will be set in Mathematics mode.
 */
static void
latex_math_fputs_latin (char const *text, GsfOutput *output)
{
        char * encoded_text = NULL;
        char const *p;
        char const *rlt;

        encoded_text = latex_convert_latin_to_utf (text);

        for (p = encoded_text; *p; p++) {
                switch (*p) {

                        /* These are the classic TeX symbols $ & % # (see Lamport, p.15) */
                        case '$': case '&': case '%': case '#':
                                gsf_output_printf (output, "\\%c", *p);
                                break;
                        /* These are the other special characters ~ (see Lamport, p.15) */
                        case '~':
                                gsf_output_printf (output, "\\%c{ }", *p);
                                break;
                        case '\\':
                                rlt = latex_raw_str(p, output, FALSE);
                                if(rlt == p)
                                    gsf_output_puts (output, "$\\backslash$");
                                else
                                    p = rlt;
                                break;

                        default:
                                gsf_output_write (output, 1, p);
                                break;
                }
        }
        g_free (encoded_text);
}

static void
latex_fputs (char const *text, GsfOutput *output)
{
        if (gnm_conf_get_plugin_latex_use_utf8 ())
                latex_fputs_utf (text, output);
        else
                latex_fputs_latin (text, output);
}

static void
latex_math_fputs (char const *text, GsfOutput *output)
{
        if (gnm_conf_get_plugin_latex_use_utf8 ())
                latex_math_fputs_utf (text, output);
        else
                latex_math_fputs_latin (text, output);
}

static GnmValue *
cb_find_font_encodings (GnmCellIter const *iter, gboolean *fonts)
{
        GnmCell *cell = iter->cell;
        if (cell) {
                char const *rs =
                        gnm_rendered_value_get_text
                        (gnm_cell_fetch_rendered_value (cell, TRUE));
                while (*rs) {
                        gunichar ch = g_utf8_get_char (rs);
                        GUnicodeScript script = g_unichar_get_script (ch);
                        if (script > 0 && script <= G_UNICODE_SCRIPT_MANDAIC)
                                fonts [script] = 1;
                        rs = g_utf8_next_char (rs);
                }
        }
        return NULL;
}

/**
 * latex2e_write_font_encodings writes
 * \usepackage[T2A]{fontenc}
 * in the presence of cyrillic text
 */

static void
latex2e_write_font_encodings (GsfOutput *output, Sheet *sheet, GnmRange const *range)
{
        gboolean *fonts = g_new0 (gboolean, G_UNICODE_SCRIPT_MANDAIC + 1);

        sheet_foreach_cell_in_range
                (sheet, CELL_ITER_IGNORE_BLANK | CELL_ITER_IGNORE_HIDDEN, range,
                 (CellIterFunc)&cb_find_font_encodings, fonts);

        if (fonts[G_UNICODE_SCRIPT_CYRILLIC])
                gsf_output_puts (output,
"       \\usepackage[T2A]{fontenc}\n"
                                 );
}

/**
 * latex2e_write_file_header:
 *
 * @output: Output stream where the cell contents will be written.
 *
 * This ouputs the LaTeX header. Kept separate for esthetics.
 */

static void
latex2e_write_file_header(GsfOutput *output, Sheet *sheet, GnmRange const *range)
{
        gboolean is_landscape = FALSE, use_utf8;
        GtkPageOrientation orient = print_info_get_paper_orientation (sheet->print_info);

        is_landscape = (orient == GTK_PAGE_ORIENTATION_LANDSCAPE ||
                        orient == GTK_PAGE_ORIENTATION_REVERSE_LANDSCAPE);
        use_utf8 = gnm_conf_get_plugin_latex_use_utf8 ();

        gsf_output_puts (output,
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
"%%                                                                  %%\n"
"%%  This is the header of a LaTeX2e file exported from Gnumeric.    %%\n"
"%%                                                                  %%\n"
"%%  This file can be compiled as it stands or included in another   %%\n"
"%%  LaTeX document. The table is based on the longtable package so  %%\n"
"%%  the longtable options (headers, footers...) can be set in the   %%\n"
"%%  preamble section below (see PRAMBLE).                           %%\n"
"%%                                                                  %%\n"
"%%  To include the file in another, the following two lines must be %%\n"
"%%  in the including file:                                          %%\n"
"%%        \\def\\inputGnumericTable{}                                 %%\n"
"%%  at the beginning of the file and:                               %%\n"
"%%        \\input{name-of-this-file.tex}                             %%\n"
"%%  where the table is to be placed. Note also that the including   %%\n"
"%%  file must use the following packages for the table to be        %%\n"
"%%  rendered correctly:                                             %%\n"
);

        if (use_utf8)
                gsf_output_puts (output,
"%%    \\usepackage{ucs}                                              %%\n"
"%%    \\usepackage[utf8x]{inputenc}                                  %%\n"
"%%    \\usepackage[T2A]{fontenc}    % if cyrillic is used            %%\n"
                        );
        else
                gsf_output_puts (output,
"%%    \\usepackage[latin1]{inputenc}                                 %%\n"
                        );

        gsf_output_puts (output,
"%%    \\usepackage{color}                                            %%\n"
"%%    \\usepackage{array}                                            %%\n"
"%%    \\usepackage{longtable}                                        %%\n"
"%%    \\usepackage{calc}                                             %%\n"
"%%    \\usepackage{multirow}                                         %%\n"
"%%    \\usepackage{hhline}                                           %%\n"
"%%    \\usepackage{ifthen}                                           %%\n"
"%%  optionally (for landscape tables embedded in another document): %%\n"
"%%    \\usepackage{lscape}                                           %%\n"
"%%                                                                  %%\n"
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
"\n"
"\n"
"\n"
"%%  This section checks if we are begin input into another file or  %%\n"
"%%  the file will be compiled alone. First use a macro taken from   %%\n"
"%%  the TeXbook ex 7.7 (suggestion of Han-Wen Nienhuys).            %%\n"
"\\def\\ifundefined#1{\\expandafter\\ifx\\csname#1\\endcsname\\relax}\n"
"\n"
"\n"
"%%  Check for the \\def token for inputed files. If it is not        %%\n"
"%%  defined, the file will be processed as a standalone and the     %%\n"
"%%  preamble will be used.                                          %%\n"
"\\ifundefined{inputGnumericTable}\n"
"\n"
"%%  We must be able to close or not the document at the end.        %%\n"
"       \\def\\gnumericTableEnd{\\end{document}}\n"
"\n"
"\n"
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
"%%                                                                  %%\n"
"%%  This is the PREAMBLE. Change these values to get the right      %%\n"
"%%  paper size and other niceties.                                  %%\n"
"%%                                                                  %%\n"
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
"\n"
                );
        if (is_landscape)
                gsf_output_puts (output,
"       \\documentclass[12pt%\n"
"                         ,landscape%\n"
"                    ]{report}\n"
                                 );
        else
                gsf_output_puts (output,
"       \\documentclass[12pt%\n"
"                         %,landscape%\n"
"                    ]{report}\n"
                                 );



        if (gnm_conf_get_plugin_latex_use_utf8 ()) {
                gsf_output_puts (output,
"       \\usepackage{ucs}\n"
"       \\usepackage[utf8x]{inputenc}\n"
                        );
                latex2e_write_font_encodings (output, sheet, range);
        } else
                gsf_output_puts (output,
"       \\usepackage[latin1]{inputenc}\n"
                        );

        gsf_output_puts (output,
"       \\usepackage{fullpage}\n"
"       \\usepackage{color}\n"
"       \\usepackage{array}\n"
"       \\usepackage{longtable}\n"
"       \\usepackage{calc}\n"
"       \\usepackage{multirow}\n"
"       \\usepackage{hhline}\n"
"       \\usepackage{ifthen}\n"
"\n"
"       \\begin{document}\n"
"\n"
"\n"
"%%  End of the preamble for the standalone. The next section is for %%\n"
"%%  documents which are included into other LaTeX2e files.          %%\n"
"\\else\n"
"\n"
"%%  We are not a stand alone document. For a regular table, we will %%\n"
"%%  have no preamble and only define the closing to mean nothing.   %%\n"
"    \\def\\gnumericTableEnd{}\n"
"\n"
"%%  If we want landscape mode in an embedded document, comment out  %%\n"
"%%  the line above and uncomment the two below. The table will      %%\n"
"%%  begin on a new page and run in landscape mode.                  %%\n"
"%       \\def\\gnumericTableEnd{\\end{landscape}}\n"
"%       \\begin{landscape}\n"
"\n"
"\n"
"%%  End of the else clause for this file being \\input.              %%\n"
"\\fi\n"
"\n"
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
"%%                                                                  %%\n"
"%%  The rest is the gnumeric table, except for the closing          %%\n"
"%%  statement. Changes below will alter the table\'s appearance.     %%\n"
"%%                                                                  %%\n"
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
"\n"
"\\providecommand{\\gnumericmathit}[1]{#1} \n"
"%%  Uncomment the next line if you would like your numbers to be in %%\n"
"%%  italics if they are italizised in the gnumeric table.           %%\n"
"%\\renewcommand{\\gnumericmathit}[1]{\\mathit{#1}}\n"
"\\providecommand{\\gnumericPB}[1]%\n"
"{\\let\\gnumericTemp=\\\\#1\\let\\\\=\\gnumericTemp\\hspace{0pt}}\n"
" \\ifundefined{gnumericTableWidthDefined}\n"
"        \\newlength{\\gnumericTableWidth}\n"
"        \\newlength{\\gnumericTableWidthComplete}\n"
"        \\newlength{\\gnumericMultiRowLength}\n"
"        \\global\\def\\gnumericTableWidthDefined{}\n"
" \\fi\n"
"%% The following setting protects this code from babel shorthands.  %%\n"
" \\ifthenelse{\\isundefined{\\languageshorthands}}{}{\\languageshorthands{english}}"
"\n"
"%%  The default table format retains the relative column widths of  %%\n"
"%%  gnumeric. They can easily be changed to c, r or l. In that case %%\n"
"%%  you may want to comment out the next line and uncomment the one %%\n"
"%%  thereafter                                                      %%\n"
"\\providecommand\\gnumbox{\\makebox[0pt]}\n"
"%%\\providecommand\\gnumbox[1][]{\\makebox}\n"
"\n"
"%% to adjust positions in multirow situations                       %%\n"
"\\setlength{\\bigstrutjot}{\\jot}\n"
"\\setlength{\\extrarowheight}{\\doublerulesep}\n"
"\n"
"%%  The \\setlongtables command keeps column widths the same across  %%\n"
"%%  pages. Simply comment out next line for varying column widths.  %%\n"
"\\setlongtables\n"
"\n"
);
}


/**
 * latex2e_write_table_header:
 *
 * @output:   Output stream where the cell contents will be written.
 * @num_cols: The number of columns in the table
 *
 * A convenience function that also helps make nicer code.
 */
static void
latex2e_write_table_header(GsfOutput *output, int num_cols)
{
        int col;


        gsf_output_puts (output,
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
"%%  The longtable options. (Caption, headers... see Goosens, p.124) %%\n"
"%\t\\caption{The Table Caption.}             \\\\      %\n"
"% \\hline      % Across the top of the table.\n"
"%%  The rest of these options are table rows which are placed on    %%\n"
"%%  the first, last or every page. Use \\multicolumn if you want.    %%\n"
"\n"
"%%  Header for the first page.                                      %%\n"
);

        gsf_output_printf (output, "%%\t\\multicolumn{%d}{c}{The First Header} \\\\ \\hline \n", num_cols);
        gsf_output_printf (output, "%%\t\\multicolumn{1}{c}{colTag}\t%%Column 1\n");
        for (col = 2 ; col < num_cols; col++)
                gsf_output_printf (output, "%%\t&\\multicolumn{1}{c}{colTag}\t%%Column %d\n",col);
        gsf_output_printf (output, "%%\t&\\multicolumn{1}{c}{colTag}\t\\\\ \\hline %%Last column\n");
        gsf_output_printf (output, "%%\t\\endfirsthead\n\n");

        gsf_output_printf (output, "%%%%  The running header definition.                                  %%%%\n");
        gsf_output_printf (output, "%%\t\\hline\n");
        gsf_output_printf (output, "%%\t\\multicolumn{%d}{l}{\\ldots\\small\\slshape continued} \\\\ \\hline\n", num_cols);
        gsf_output_printf (output, "%%\t\\multicolumn{1}{c}{colTag}\t%%Column 1\n");
        for (col = 2 ; col < num_cols; col++)
                                gsf_output_printf (output, "%%\t&\\multicolumn{1}{c}{colTag}\t%%Column %d\n",col);
        gsf_output_printf (output, "%%\t&\\multicolumn{1}{c}{colTag}\t\\\\ \\hline %%Last column\n");
        gsf_output_printf (output, "%%\t\\endhead\n\n");

        gsf_output_printf (output, "%%%%  The running footer definition.                                  %%%%\n");
        gsf_output_printf (output, "%%\t\\hline\n");
        gsf_output_printf (output, "%%\t\\multicolumn{%d}{r}{\\small\\slshape continued\\ldots}", num_cols);
        gsf_output_printf (output, " \\\\\n");
        gsf_output_printf (output, "%%\t\\endfoot\n\n");

        gsf_output_printf (output, "%%%%  The ending footer definition.                                   %%%%\n");
        gsf_output_printf (output, "%%\t\\multicolumn{%d}{c}{That's all folks} \\\\ \\hline \n", num_cols);
        gsf_output_printf (output, "%%\t\\endlastfoot\n");
        gsf_output_puts (output, "%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n\n");

}

/**
 * latex2e_find_vline:
 *
 * @col:
 * @row:
 * @sheet:
 * @which_border: GnmStyleElement (MSTYLE_BORDER_LEFT or MSTYLE_BORDER_RIGHT)
  *
 * Determine the border style
 *
 */
static GnmStyleBorderType
latex2e_find_this_vline (int col, int row, Sheet *sheet, GnmStyleElement which_border)
{
        GnmBorder const *border;
        GnmStyle const  *style;

        if (col < 0 || row < 0)
                return GNM_STYLE_BORDER_NONE;

        style = sheet_style_get (sheet, col, row);
        border = gnm_style_get_border (style, which_border);

        if (!gnm_style_border_is_blank (border))
                return border->line_type;

        if (which_border == MSTYLE_BORDER_LEFT) {
                if (col <= 0)
                        return GNM_STYLE_BORDER_NONE;
                style = sheet_style_get (sheet, col - 1, row);
                border = gnm_style_get_border (style, MSTYLE_BORDER_RIGHT);
                return ((border == NULL) ? GNM_STYLE_BORDER_NONE : border->line_type);
        } else {
                if ((col+1) >= colrow_max (TRUE, sheet))
                    return GNM_STYLE_BORDER_NONE;
                style = sheet_style_get (sheet, col + 1, row);
                border = gnm_style_get_border (style, MSTYLE_BORDER_LEFT);
                return ((border == NULL) ? GNM_STYLE_BORDER_NONE : border->line_type);
        }

        return GNM_STYLE_BORDER_NONE;
}

static GnmStyleBorderType
latex2e_find_vline (int col, int row, Sheet *sheet, GnmStyleElement which_border)
{
        /* We are checking for NONE boreders first since there should only be a few merged ranges */
        GnmStyleBorderType result = latex2e_find_this_vline (col, row, sheet, which_border);
        GnmCellPos pos;
        GnmRange const * range;

        if (result == GNM_STYLE_BORDER_NONE)
                return GNM_STYLE_BORDER_NONE;

        pos.col = col;
        pos.row = row;
        range = gnm_sheet_merge_contains_pos (sheet, &pos);

        if (range) {
                if ((which_border == MSTYLE_BORDER_LEFT && col == range->start.col)
                    || (which_border == MSTYLE_BORDER_RIGHT&& col == range->end.col))
                        return result;
                else
                        return GNM_STYLE_BORDER_NONE;
        }
        return result;
}

/**
 * latex2e_print_vert_border:
 *
 * @output: Output stream where the cell contents will be written.
 * @clines:  GnmStyleBorderType indicating the type of border
 *
 */
static void
latex2e_print_vert_border (GsfOutput *output, GnmStyleBorderType style)
{
        g_return_if_fail (/* style >= 0 && */ style < G_N_ELEMENTS (border_styles));

        gsf_output_printf (output, "%s", border_styles[style].vertical);
}

/**
 * latex2e_write_blank_multicolumn_cell:
 *
 * @output: output stream where the cell contents will be written.
 * @star_col:
 * @start_row:
 * @num_merged_cols: an integer value of the number of columns to merge.
 * @num_merged_rows: an integer value of the number of rows to merge.
 * @sheet:  the current sheet.
 *
 * This function creates all the LaTeX code for the cell of a table (i.e. all
 * the code that might fall between two ampersands (&)), assuming that
 * the cell is in fact NULL. We therefore have only to worry about a few
 * formatting issues.
 *
 */
static void
latex2e_write_blank_multicolumn_cell (GsfOutput *output, int start_col,
                                      G_GNUC_UNUSED int start_row,
                                      int num_merged_cols, int num_merged_rows,
                                      gint index,
                                      GnmStyleBorderType *borders, Sheet *sheet)
{
        int merge_width = 0;
        GnmStyleBorderType left_border = GNM_STYLE_BORDER_NONE;
        GnmStyleBorderType right_border = GNM_STYLE_BORDER_NONE;

        if (num_merged_cols > 1 || num_merged_rows > 1) {
                ColRowInfo const * ci;
                int i;

                for (i = 0; i < num_merged_cols; i++) {
                        ci = sheet_col_get_info (sheet, start_col + i);
                        merge_width += ci->size_pixels;
                }
        }

        if (index == 0) {
                left_border = *borders;
        }
        right_border = borders[index + num_merged_cols];

        /* We only set up a multicolumn command if necessary */
        if (num_merged_cols > 1) {
                int i;

                /* Open the multicolumn statement. */
                gsf_output_printf (output, "\\multicolumn{%d}{", num_merged_cols);

                if (left_border != GNM_STYLE_BORDER_NONE)
                        latex2e_print_vert_border (output, left_border);

                if (num_merged_rows > 1) {
                        gsf_output_printf (output, "c");
                } else {
                        gsf_output_printf (output, "p{");
                        for (i = 0; i < num_merged_cols; i++) {
                                gsf_output_printf (output, "\t\\gnumericCol%s+%%\n",
                                         col_name (start_col + i));
                        }
                        gsf_output_printf (output, "\t\\tabcolsep*2*%i}", num_merged_cols - 1);
                }

                if (right_border != GNM_STYLE_BORDER_NONE)
                        latex2e_print_vert_border (output, right_border);

                /*Close the right delimiter, as above. Also open the text delimiter.*/
                gsf_output_printf (output,"}%%\n\t{");
        } else if (left_border != GNM_STYLE_BORDER_NONE || right_border != GNM_STYLE_BORDER_NONE) {

                /* Open the multicolumn statement. */
                gsf_output_printf (output, "\\multicolumn{1}{");

                if (left_border != GNM_STYLE_BORDER_NONE)
                        latex2e_print_vert_border (output, left_border);

                /* Drop in the left hand format delimiter. */
                gsf_output_printf (output, "p{\\gnumericCol%s}", col_name(start_col));

                if (right_border != GNM_STYLE_BORDER_NONE)
                        latex2e_print_vert_border (output, right_border);

                /*Close the right delimiter, as above. Also open the text delimiter.*/
                gsf_output_printf (output,"}%%\n\t{");

        }

        if (num_merged_rows > 1) {
                int i;
                /* Open the multirow statement. */
                gsf_output_printf (output, "\\setlength{\\gnumericMultiRowLength}{0pt}%%\n");
                for (i = 0; i < num_merged_cols; i++) {
                        gsf_output_printf (output, "\t \\addtolength{\\gnumericMultiRowLength}{\\gnumericCol%s}%%\n", col_name (start_col + i));
                        if (i>0)
                                gsf_output_printf (output, "\t \\addtolength{\\gnumericMultiRowLength}{\\tabcolsep}%%\n");
                }
                gsf_output_printf (output, "\t \\multirow{%i}[%i]{\\gnumericMultiRowLength}{%%\n\t ", num_merged_rows, num_merged_rows/2);

                /* Close the multirowtext. */
                gsf_output_printf (output, "}");
        }

        /* Close the multicolumn text bracket. */
        if (num_merged_cols > 1 || left_border != GNM_STYLE_BORDER_NONE
            || right_border != GNM_STYLE_BORDER_NONE)
                gsf_output_printf (output, "}");

        /* And we are done. */
        gsf_output_printf (output, "\n");

}


/**
 * latex2e_write_multicolumn_cell:
 *
 * @output: output stream where the cell contents will be written.
 * @cell:   the cell whose contents are to be written.
 * @star_col:
 * @num_merged_cols: an integer value of the number of columns to merge.
 * @num_merged_rows: an integer value of the number of rows to merge.
 * @sheet:  the current sheet.
 *
 * This function creates all the LaTeX code for the cell of a table (i.e. all
 * the code that might fall between two ampersands (&)).
 *
 * Note: we are _not_ putting single cell into \multicolumns since this
 * makes it much more difficult to change column widths later on.
 */
static void
latex2e_write_multicolumn_cell (GsfOutput *output, GnmCell *cell, int start_col,
                                int num_merged_cols, int num_merged_rows,
                                gint index,
                                GnmStyleBorderType *borders, Sheet *sheet)
{
        char * rendered_string;
        gushort r,g,b;
        gboolean wrap = FALSE;
        GOFormatFamily cell_format_family;
        int merge_width = 0;
        GnmStyleBorderType left_border = GNM_STYLE_BORDER_NONE;
        GnmStyleBorderType right_border = GNM_STYLE_BORDER_NONE;

        /* Print the cell according to its style. */
        GnmStyle const *style = gnm_cell_get_style (cell);
        gboolean hidden = gnm_style_get_contents_hidden (style);

        g_return_if_fail (style != NULL);

        if (num_merged_cols > 1 || num_merged_rows > 1) {
                ColRowInfo const * ci;
                int i;

                for (i = 0; i < num_merged_cols; i++) {
                        ci = sheet_col_get_info (sheet, start_col + i);
                        merge_width += ci->size_pixels;
                }
        }

        if (index == 0) {
                left_border = *borders;
        }
        right_border = borders[index + num_merged_cols];

        /* We only set up a multicolumn command if necessary */
        if (num_merged_cols > 1) {
                int i;

                /* Open the multicolumn statement. */
                gsf_output_printf (output, "\\multicolumn{%d}{", num_merged_cols);

                if (left_border != GNM_STYLE_BORDER_NONE)
                        latex2e_print_vert_border (output, left_border);

                if (num_merged_rows > 1) {
                        gsf_output_printf (output, "c");
                } else {
                        gsf_output_printf (output, "p{");
                        for (i = 0; i < num_merged_cols; i++) {
                                gsf_output_printf (output, "\t\\gnumericCol%s+%%\n",
                                         col_name (start_col + i));
                        }
                        gsf_output_printf (output, "\t\\tabcolsep*2*%i}", num_merged_cols - 1);
                }

                if (right_border != GNM_STYLE_BORDER_NONE)
                        latex2e_print_vert_border (output, right_border);

                /*Close the right delimiter, as above. Also open the text delimiter.*/
                gsf_output_printf (output,"}%%\n\t{");
        } else if (left_border != GNM_STYLE_BORDER_NONE || right_border != GNM_STYLE_BORDER_NONE) {

                /* Open the multicolumn statement. */
                gsf_output_printf (output, "\\multicolumn{1}{");

                if (left_border != GNM_STYLE_BORDER_NONE)
                        latex2e_print_vert_border (output, left_border);

                /* Drop in the left hand format delimiter. */
                gsf_output_printf (output, "p{\\gnumericCol%s}", col_name(start_col));

                if (right_border != GNM_STYLE_BORDER_NONE)
                        latex2e_print_vert_border (output, right_border);

                /*Close the right delimiter, as above. Also open the text delimiter.*/
                gsf_output_printf (output,"}%%\n\t{");

        }

        if (num_merged_rows > 1) {
                int i;
                /* Open the multirow statement. */
                gsf_output_printf (output, "\\setlength{\\gnumericMultiRowLength}{0pt}%%\n");
                for (i = 0; i < num_merged_cols; i++) {
                        gsf_output_printf (output, "\t \\addtolength{\\gnumericMultiRowLength}{\\gnumericCol%s}%%\n", col_name (start_col + i));
                        if (i>0)
                                gsf_output_printf (output, "\t \\addtolength{\\gnumericMultiRowLength}{\\tabcolsep}%%\n");
                }
                gsf_output_printf (output,
                                   "\t \\multirow{%i}[%i]{\\gnumericMultiRowLength}"
                                   "{\\parbox{\\gnumericMultiRowLength}{%%\n\t ",
                                   num_merged_rows, num_merged_rows/2);
        }


        /* Send the alignment of the cell through a routine to deal with
         * GNM_HALIGN_GENERAL and then deal with the three cases. */
        switch (gnm_style_default_halign (style, cell)) {
        case GNM_HALIGN_RIGHT:
                gsf_output_printf (output, "\\gnumericPB{\\raggedleft}");
                break;
        case GNM_HALIGN_DISTRIBUTED:
        case GNM_HALIGN_CENTER:
        case GNM_HALIGN_CENTER_ACROSS_SELECTION:
                gsf_output_printf (output, "\\gnumericPB{\\centering}");
                break;
        case GNM_HALIGN_LEFT:
                gsf_output_printf (output, "\\gnumericPB{\\raggedright}");
                break;
        case GNM_HALIGN_JUSTIFY:
                break;
        default:
                break;
        }

        /* Check whether we should do word wrapping */
        wrap = gnm_style_get_wrap_text (style);

        /* if we don't wrap put it into an mbox, adjusted to width 0 to avoid moving */
        /* it to the second line of the parbox */
        if (!wrap)
                switch (gnm_style_default_halign (style, cell)) {
                case GNM_HALIGN_RIGHT:
                        gsf_output_printf (output, "\\gnumbox[r]{");
                        break;
                case GNM_HALIGN_DISTRIBUTED:
                case GNM_HALIGN_CENTER:
                case GNM_HALIGN_CENTER_ACROSS_SELECTION:
                        gsf_output_printf (output, "\\gnumbox{");
                        break;
                case GNM_HALIGN_LEFT:
                        gsf_output_printf (output, "\\gnumbox[l]{");
                        break;
                case GNM_HALIGN_JUSTIFY:
                        gsf_output_printf (output, "\\gnumbox[s]{");
                        break;
                default:
                        gsf_output_printf (output, "\\makebox{");
                        break;
                }

        if (!gnm_cell_is_empty (cell)) {
                /* Check the foreground (text) colour. */
                GOColor fore = gnm_cell_get_render_color (cell);
                if (fore == 0)
                        r = g = b = 0;
                else {
                        r = GO_COLOR_UINT_R (fore);
                        g = GO_COLOR_UINT_G (fore);
                        b = GO_COLOR_UINT_B (fore);
                }
                if (r != 0 || g != 0 || b != 0) {
                        gchar buffer[7] = {0};
                        gsf_output_printf (output, "{\\color[rgb]{");
                        g_ascii_formatd (buffer, 7, "%.2f",r/255.0);
                        gsf_output_printf (output, "%s,", buffer);
                        g_ascii_formatd (buffer, 7, "%.2f",g/255.0);
                        gsf_output_printf (output, "%s,", buffer);
                        g_ascii_formatd (buffer, 7, "%.2f",b/255.0);
                        gsf_output_printf (output, "%s", buffer);
                        gsf_output_printf (output, "} ");
                }

                /* Establish the font's style for the styles that can be addressed by LaTeX.
                 * More complicated efforts (like changing fonts) are left to the user.
                 */

                if (hidden)
                        gsf_output_printf (output, "\\phantom{");

                if (font_is_monospaced (style))
                        gsf_output_printf (output, "\\texttt{");
                else if (font_is_sansserif (style))
                        gsf_output_printf (output, "\\textsf{");
                if (gnm_style_get_font_bold (style))
                        gsf_output_printf (output, "\\textbf{");
                if (gnm_style_get_font_italic (style))
                        gsf_output_printf (output, "\\textit{");


                cell_format_family = go_format_get_family (gnm_cell_get_format (cell));
                if (cell_format_family == GO_FORMAT_NUMBER ||
                    cell_format_family == GO_FORMAT_CURRENCY ||
                    cell_format_family == GO_FORMAT_PERCENTAGE ||
                    cell_format_family == GO_FORMAT_FRACTION ||
                    cell_format_family == GO_FORMAT_SCIENTIFIC){
                        gsf_output_printf (output, "$");
                        if (gnm_style_get_font_italic(style))
                            gsf_output_printf (output, "\\gnumericmathit{");

                        /* Print the cell contents. */
                        rendered_string = gnm_cell_get_rendered_text (cell);
                        latex_math_fputs (rendered_string, output);
                        g_free (rendered_string);

                        if (gnm_style_get_font_italic(style))
                            gsf_output_printf (output, "}");
                        gsf_output_printf (output, "$");
                } else {
                        /* Print the cell contents. */
                        rendered_string = gnm_cell_get_rendered_text (cell);
                        latex_fputs (rendered_string, output);
                        g_free (rendered_string);
                }

                /* Close the styles for the cell. */
                if (gnm_style_get_font_italic (style))
                        gsf_output_printf (output, "}");
                if (gnm_style_get_font_bold (style))
                        gsf_output_printf (output, "}");
                if (font_is_monospaced (style))
                        gsf_output_printf (output, "}");
                else if (font_is_sansserif (style))
                        gsf_output_printf (output, "}");
                if (hidden)
                        gsf_output_printf (output, "}");
                if (r != 0 || g != 0 || b != 0)
                        gsf_output_printf (output, "}");
        }

        /* if we don't wrap close the mbox */
        if (!wrap)
                gsf_output_printf (output, "}");

        /* Close the multirowtext. */
        if (num_merged_rows > 1)
                gsf_output_printf (output, "}}");

        /* Close the multicolumn text bracket. */
        if (num_merged_cols > 1 || left_border != GNM_STYLE_BORDER_NONE
            || right_border != GNM_STYLE_BORDER_NONE)
                gsf_output_printf (output, "}");

        /* And we are done. */
        gsf_output_printf (output, "\n");

}

/**
 * latex2e_find_hhlines :
 *
 * @clines:  array of GnmStyleBorderType* indicating the type of border
 * @length:  (remaining) positions in clines
 * @col:
 * @row:
 * @sheet:
 *
 * Determine the border style
 *
 */

static gboolean
latex2e_find_hhlines (GnmStyleBorderType *clines, G_GNUC_UNUSED int length, int col, int row,
                      Sheet *sheet, GnmStyleElement type)
{
        GnmStyle const  *style;
        GnmBorder const *border;
        GnmRange const  *range;
        GnmCellPos pos;

        style = sheet_style_get (sheet, col, row);
        border = gnm_style_get_border (style, type);
        if (gnm_style_border_is_blank (border))
                return FALSE;
        clines[0] = border->line_type;

        pos.col = col;
        pos.row = row;
        range = gnm_sheet_merge_contains_pos (sheet, &pos);
        if (range) {
                if ((type == MSTYLE_BORDER_TOP && row > range->start.row)
                    || (type == MSTYLE_BORDER_BOTTOM&& row < range->end.row)) {
                        clines[0] = GNM_STYLE_BORDER_NONE;
                        return FALSE;
                }
        }

        return TRUE;
}


/**
 * latex2e_print_hhline :
 *
 * @output: output stream where the cell contents will be written.
 * @clines:  an array of GnmStyleBorderType* indicating the type of border
 * @n: the number of elements in clines
 *
 * This procedure prints an hhline command according to the content
 * of clines.
 *
 */
static void
latex2e_print_hhline (GsfOutput *output, GnmStyleBorderType *clines, int n, GnmStyleBorderType *prev_vert,
                      GnmStyleBorderType *next_vert)
{
        int col;
        gsf_output_printf (output, "\\hhline{");
        gsf_output_printf (output, "%s", conn_styles[LATEX_NO_BORDER]
                 [prev_vert ? border_styles[prev_vert[0]].latex : LATEX_NO_BORDER]
                 [border_styles[clines[0]].latex]
                 [next_vert ? border_styles[next_vert[0]].latex : LATEX_NO_BORDER].p_1);
        gsf_output_printf (output, "%s", conn_styles[LATEX_NO_BORDER]
                 [prev_vert ? border_styles[prev_vert[0]].latex : LATEX_NO_BORDER]
                 [border_styles[clines[0]].latex]
                 [next_vert ? border_styles[next_vert[0]].latex : LATEX_NO_BORDER].p_2);
        for (col = 0; col < n - 1; col++) {
                gsf_output_printf (output, "%s", border_styles[clines[col]].horizontal);
                gsf_output_printf (output, "%s", conn_styles[border_styles[clines[col]].latex]
                         [prev_vert ? border_styles[prev_vert[col + 1]].latex :
                          LATEX_NO_BORDER]
                         [border_styles[clines[col+1]].latex]
                         [next_vert ? border_styles[next_vert[col + 1]].latex :
                          LATEX_NO_BORDER].p_1);
                gsf_output_printf (output, "%s", conn_styles[border_styles[clines[col]].latex]
                         [prev_vert ? border_styles[prev_vert[col + 1]].latex :
                          LATEX_NO_BORDER]
                         [border_styles[clines[col+1]].latex]
                         [next_vert ? border_styles[next_vert[col + 1]].latex :
                          LATEX_NO_BORDER].p_2);
        }
        gsf_output_printf (output, "%s", border_styles[clines[n - 1]].horizontal);
        gsf_output_printf (output, "%s", conn_styles[border_styles[clines[n - 1]].latex]
                 [prev_vert ? border_styles[prev_vert[n]].latex : LATEX_NO_BORDER]
                 [LATEX_NO_BORDER]
                 [next_vert ? border_styles[next_vert[n]].latex :
                  LATEX_NO_BORDER].p_1);
        gsf_output_printf (output, "%s", conn_styles[border_styles[clines[n - 1]].latex]
                 [prev_vert ? border_styles[prev_vert[n]].latex : LATEX_NO_BORDER]
                 [LATEX_NO_BORDER]
                 [next_vert ? border_styles[next_vert[n]].latex :
                  LATEX_NO_BORDER].p_2);

        gsf_output_printf (output, "}\n");
}

static GnmRange
file_saver_sheet_get_extent (Sheet *sheet)
{
        GnmRangeRef *range
                = g_object_get_data (G_OBJECT (sheet->workbook),
                                     "ssconvert-range");
        if (range) {
                Sheet *start_sheet, *end_sheet;
                GnmEvalPos ep;
                GnmRange r;

                gnm_rangeref_normalize (range,
                                        eval_pos_init_sheet (&ep, sheet),
                                        &start_sheet, &end_sheet,
                                        &r);
                if (start_sheet == sheet)
                        return r;
        }
        return sheet_get_extent (sheet, TRUE, TRUE);
}

/**
 * latex_file_save :  The LaTeX2e exporter plugin function.
 *
 * @FileSaver:        New structure for file plugins. I don't understand.
 * @IOcontext:        currently not used but reserved for the future.
 * @WorkbookView:     this provides the way to access the sheet being exported.
 * @filename:         where we'll write.
 *
 * This writes the top sheet of a Gnumeric workbook to a LaTeX2e longtable. We
 * check for merges here, then call the function latex2e_write_multicolum_cell()
 * to render the format and contents of the cell.
 */
void
latex_file_save (G_GNUC_UNUSED GOFileSaver const *fs, G_GNUC_UNUSED GOIOContext *io_context,
                 WorkbookView const *wb_view, GsfOutput *output)
{
        GnmCell *cell;
        Sheet *current_sheet;
        GnmRange total_range;
        GnmRange const *merge_range;
        int row, col, num_cols, length;
        int num_merged_cols, num_merged_rows;
        GnmStyleBorderType *clines, *this_clines;
        GnmStyleBorderType *prev_vert = NULL, *next_vert = NULL, *this_vert;
        gboolean needs_hline;

        /* Get the topmost sheet and its range from the plugin function argument. */
        current_sheet = wb_view_cur_sheet(wb_view);
        total_range = file_saver_sheet_get_extent (current_sheet);

        /* This is the preamble of the LaTeX2e file. */
        latex2e_write_file_header(output, current_sheet, &total_range);

        num_cols = total_range.end.col - total_range.start.col + 1;

        gsf_output_printf (output, "\\setlength\\gnumericTableWidth{%%\n");
        for (col = total_range.start.col; col <=  total_range.end.col; col++) {
                ColRowInfo const * ci;
                ci = sheet_col_get_info (current_sheet, col);
                gsf_output_printf (output, "\t%ipt+%%\n", ci->size_pixels * 10 / 12);
        }
        gsf_output_printf (output, "0pt}\n\\def\\gumericNumCols{%i}\n", num_cols);

        gsf_output_puts (output, ""
"\\setlength\\gnumericTableWidthComplete{\\gnumericTableWidth+%\n"
"         \\tabcolsep*\\gumericNumCols*2+\\arrayrulewidth*\\gumericNumCols}\n"
"\\ifthenelse{\\lengthtest{\\gnumericTableWidthComplete > \\linewidth}}%\n"
"         {\\def\\gnumericScale{\\ratio{\\linewidth-%\n"
"                        \\tabcolsep*\\gumericNumCols*2-%\n"
"                        \\arrayrulewidth*\\gumericNumCols}%\n"
"{\\gnumericTableWidth}}}%\n"
"{\\def\\gnumericScale{1}}\n"
"\n"
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
"%%                                                                  %%\n"
"%% The following are the widths of the various columns. We are      %%\n"
"%% defining them here because then they are easier to change.       %%\n"
"%% Depending on the cell formats we may use them more than once.    %%\n"
"%%                                                                  %%\n"
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
"\n"
);

        for (col = total_range.start.col; col <=  total_range.end.col; col++) {
                ColRowInfo const * ci;
                char const *colname = col_name (col);

                ci = sheet_col_get_info (current_sheet, col);
                gsf_output_printf (output, "\\ifthenelse{\\isundefined{\\gnumericCol%s}}"
                                   "{\\newlength{\\gnumericCol%s}}{}\\settowidth{\\gnumericCol%s}"
                                   "{\\begin{tabular}{@{}p{%ipt*\\gnumericScale}@{}}x\\end{tabular}}\n",
                                   colname, colname, colname, ci->size_pixels * 10 / 12);
        }

        /* Start outputting the table. */
        gsf_output_printf (output, "\n\\begin{longtable}[c]{%%\n");
        for (col = total_range.start.col; col <=  total_range.end.col; col++) {
                gsf_output_printf (output, "\tb{\\gnumericCol%s}%%\n", col_name (col));
        }
        gsf_output_printf (output, "\t}\n\n");

        /* Output the table header. */
        latex2e_write_table_header (output, num_cols);


        /* Step through the sheet, writing cells as appropriate. */
        for (row = total_range.start.row; row <= total_range.end.row; row++) {
                ColRowInfo const * ri;
                ri = sheet_row_get_info (current_sheet, row);
                if (ri->needs_respan)
                        row_calc_spans ((ColRowInfo *) ri, row, current_sheet);

                /* We need to check for horizontal borders at the top of this row */
                length = num_cols;
                clines = g_new0 (GnmStyleBorderType, length);
                needs_hline = FALSE;
                this_clines = clines;
                for (col = total_range.start.col; col <= total_range.end.col; col++) {
                        needs_hline = latex2e_find_hhlines (this_clines, length,  col, row,
                                                            current_sheet, MSTYLE_BORDER_TOP)
                                || needs_hline;
                        this_clines ++;
                        length--;
                }
                /* or at the bottom of the previous */
                if (row > total_range.start.row) {
                        length = num_cols;
                        this_clines = clines;
                        for (col = total_range.start.col; col <= total_range.end.col; col++) {
                                needs_hline = latex2e_find_hhlines (this_clines, length,  col,
                                                                    row - 1, current_sheet,
                                                                    MSTYLE_BORDER_BOTTOM)
                                        || needs_hline;
                                this_clines ++;
                                length--;
                        }
                }
                /* We also need to know vertical borders */
                /* We do this here rather than as we output the cells since */
                /* we need to know the right connectors! */
                prev_vert = next_vert;
                next_vert = g_new0 (GnmStyleBorderType, num_cols + 1);
                this_vert = next_vert;
                *this_vert = latex2e_find_vline (total_range.start.col, row,
                                                current_sheet, MSTYLE_BORDER_LEFT);
                this_vert++;
                for (col = total_range.start.col; col <= total_range.end.col; col++) {
                        *this_vert = latex2e_find_vline (col, row, current_sheet,
                                                        MSTYLE_BORDER_RIGHT);
                        this_vert ++;
                }

                if (needs_hline)
                        latex2e_print_hhline (output, clines, num_cols, prev_vert, next_vert);
                g_free (clines);

                for (col = total_range.start.col; col <= total_range.end.col; col++) {
                        GnmCellPos pos;

                        pos.col = col;
                        pos.row = row;

                        /* Get the cell. */
                        cell = sheet_cell_get (current_sheet, col, row);

                        /* Check if we are not the first cell in the row.*/
                        if (col != total_range.start.col)
                                gsf_output_printf (output, "\t&");
                        else
                                gsf_output_printf (output, "\t ");

                        /* Check a merge. */
                        merge_range = gnm_sheet_merge_is_corner (current_sheet, &pos);
                        if (merge_range == NULL) {
                                if (gnm_cell_is_empty(cell))
                                        latex2e_write_blank_multicolumn_cell(output, col, row,
                                                                             1, 1,
                                                               col - total_range.start.col,
                                                               next_vert, current_sheet);
                                else
                                        latex2e_write_multicolumn_cell(output, cell, col,
                                                                       1, 1,
                                                               col - total_range.start.col,
                                                               next_vert, current_sheet);
                                continue;
                        }

                        /* Get the extent of the merge. */
                        num_merged_cols = merge_range->end.col - merge_range->start.col + 1;
                        num_merged_rows = merge_range->end.row - merge_range->start.row + 1;

                        if (gnm_cell_is_empty(cell))
                                latex2e_write_blank_multicolumn_cell(output, col, row,
                                                                     num_merged_cols,
                                                                     num_merged_rows,
                                                                     col - total_range.start.col,
                                                                     next_vert, current_sheet);
                        else
                                latex2e_write_multicolumn_cell(output, cell, col, num_merged_cols,
                                                               num_merged_rows,
                                                               col - total_range.start.col,
                                                               next_vert, current_sheet);
                        col += (num_merged_cols - 1);
                        continue;
                }
                gsf_output_printf (output, "\\\\\n");
                g_free (prev_vert);
        }

        /* We need to check for horizontal borders at the bottom  of  the last  row */
        clines = g_new0 (GnmStyleBorderType, total_range.end.col - total_range.start.col + 1);
        needs_hline = FALSE;
        /* In case that we are at the very bottom of the sheet we can not */
        /* check on the next line! */
        if (row < colrow_max (FALSE, current_sheet)) {
                length = num_cols;
                this_clines = clines;
                for (col = total_range.start.col; col <= total_range.end.col; col++) {
                        needs_hline = latex2e_find_hhlines (this_clines, length,  col, row,
                                                            current_sheet, MSTYLE_BORDER_TOP)
                                || needs_hline;
                        this_clines ++;
                        length--;
                }
        }
        length = num_cols;
        this_clines = clines;
        for (col = total_range.start.col; col <= total_range.end.col; col++) {
                needs_hline = latex2e_find_hhlines (this_clines, length,  col,
                                                    row - 1, current_sheet,
                                                    MSTYLE_BORDER_BOTTOM)
                        || needs_hline;
                this_clines ++;
                length--;
        }
        if (needs_hline)
                latex2e_print_hhline (output, clines, num_cols, next_vert, NULL);
        g_free (clines);

        g_free (next_vert);

        gsf_output_puts (output, "\\end{longtable}\n\n"
                         "\\ifthenelse{\\isundefined{\\languageshorthands}}"
                         "{}{\\languageshorthands{\\languagename}}\n"
                         "\\gnumericTableEnd\n");
}


/**
 * latex2e_table_cell:
 *
 * @output: output stream where the cell contents will be written.
 * @cell:   the cell whose contents are to be written.
 *
 * This function creates all the LaTeX code for the cell of a table (i.e. all
 * the code that might fall between two ampersands (&)).
 *
 */
static void
latex2e_table_write_cell (GsfOutput *output, GnmCell *cell)
{
        GnmStyle const *style = gnm_cell_get_style (cell);

        if (gnm_style_get_contents_hidden (style))
                return;

        if (!gnm_cell_is_empty (cell)) {
                char * rendered_string;

                rendered_string = gnm_cell_get_rendered_text (cell);
                latex_fputs (rendered_string, output);
                g_free (rendered_string);
        }
}


/**
 * latex2e_table_write_file_header:
 *
 * @output: Output stream where the cell contents will be written.
 *
 * This ouputs the LaTeX header. Kept separate for esthetics.
 */

static void
latex2e_table_write_file_header(GsfOutput *output)
{
        gsf_output_puts (output,
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
"%%                                                                  %%\n"
"%%  This is a LaTeX2e table fragment exported from Gnumeric.        %%\n"
"%%                                                                  %%\n"
"%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n"
        );
}

/**
 * latex_table_file_save :  The LaTeX2e exporter plugin function.
 *
 * @WorkbookView:     this provides the way to access the sheet being exported.
 * @outpu:            where we'll write.
 * @all:              Whether to write all rows or just the visible ones.
 *
 * This writes the top sheet of a Gnumeric workbook as the content of a latex table environment.
 * We try to avoid all formatting.
 */
static void
latex_table_file_save_impl (WorkbookView const *wb_view, GsfOutput *output, gboolean all)
{
        GnmCell *cell;
        Sheet *current_sheet;
        GnmRange total_range;
        int row, col;

        /* This is the preamble of the LaTeX2e file. */
        latex2e_table_write_file_header(output);

        /* Get the topmost sheet and its range from the plugin function argument. */
        current_sheet = wb_view_cur_sheet(wb_view);
        total_range = file_saver_sheet_get_extent (current_sheet);

        /* Step through the sheet, writing cells as appropriate. */
        for (row = total_range.start.row; row <= total_range.end.row; row++) {
                ColRowInfo const * ri;
                ri = sheet_row_get_info (current_sheet, row);
                if (all || ri->visible) {
                        if (ri->needs_respan)
                                row_calc_spans ((ColRowInfo *) ri, row, current_sheet);

                        for (col = total_range.start.col; col <= total_range.end.col; col++) {
                                /* Get the cell. */
                                cell = sheet_cell_get (current_sheet, col, row);

                                /* Check if we are not the first cell in the row.*/
                                if (col != total_range.start.col)
                                        gsf_output_printf (output, "\t&");

                                if (gnm_cell_is_empty (cell))
                                        continue;

                                latex2e_table_write_cell(output, cell);
                        }
                        gsf_output_printf (output, "\\\\\n");
                }
        }
}

/**
 * latex_table_file_save :  The LaTeX2e exporter plugin function.
 *
 * @FileSaver:        New structure for file plugins. I don't understand.
 * @IOcontext:        currently not used but reserved for the future.
 * @WorkbookView:     this provides the way to access the sheet being exported.
 * @output:           where we'll write.
 *
 * This writes the top sheet of a Gnumeric workbook as the content of a latex table environment.
 * We try to avoid all formatting.
 */
void
latex_table_file_save (G_GNUC_UNUSED GOFileSaver const *fs,
                       G_GNUC_UNUSED GOIOContext *io_context,
                       WorkbookView const *wb_view, GsfOutput *output)
{
        latex_table_file_save_impl (wb_view, output, TRUE);
}

/**
 * latex_table_visible_file_save :  The LaTeX2e exporter plugin function.
 *
 * @FileSaver:        New structure for file plugins. I don't understand.
 * @IOcontext:        currently not used but reserved for the future.
 * @WorkbookView:     this provides the way to access the sheet being exported.
 * @output:           where we'll write.
 *
 * This writes the top sheet of a Gnumeric workbook as the content of a latex table environment.
 * We try to avoid all formatting.
 */
void
latex_table_visible_file_save (G_GNUC_UNUSED GOFileSaver const *fs,
                       G_GNUC_UNUSED GOIOContext *io_context,
                       WorkbookView const *wb_view, GsfOutput *output)
{
        latex_table_file_save_impl (wb_view, output, FALSE);
}