path: root/camel/camel-mime-filter-linewrap.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 *  Copyright (C) 2000 Helix Code, Inc.
 *
 *  Authors: Jeffrey Stedfast <fejj@helixcode.com>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library 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 Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <ctype.h>
#include "camel-mime-filter-linewrap.h"

static void filter (CamelMimeFilter *f, char *in, size_t len, size_t prespace,
            char **out, size_t *outlen, size_t *outprespace);
static void complete (CamelMimeFilter *f, char *in, size_t len,
              size_t prespace, char **out, size_t *outlen,
              size_t *outprespace);
static void reset (CamelMimeFilter *f);


static void
camel_mime_filter_linewrap_class_init (CamelMimeFilterLinewrapClass *klass)
{
    CamelMimeFilterClass *mime_filter_class =
        (CamelMimeFilterClass *) klass;
    
    mime_filter_class->filter = filter;
    mime_filter_class->complete = complete;
    mime_filter_class->reset = reset;
}

CamelType
camel_mime_filter_linewrap_get_type (void)
{
    static CamelType type = CAMEL_INVALID_TYPE;
    
    if (type == CAMEL_INVALID_TYPE) {
        type = camel_type_register (camel_mime_filter_get_type(), "CamelMimeFilterLinewrap",
                        sizeof (CamelMimeFilterLinewrap),
                        sizeof (CamelMimeFilterLinewrapClass),
                        (CamelObjectClassInitFunc) camel_mime_filter_linewrap_class_init,
                        NULL,
                        NULL,
                        NULL);
    }
    
    return type;
}

static void
filter (CamelMimeFilter *f, char *in, size_t len, size_t prespace,
    char **out, size_t *outlen, size_t *outprespace)
{
    CamelMimeFilterLinewrap *linewrap = (CamelMimeFilterLinewrap *)f;
    char *inend, *last, *p, *q;
    int nchars = linewrap->nchars;
    
    /* we'll be adding chars here so we need a bigger buffer */
    camel_mime_filter_set_size (f, 3 * len, FALSE);
    
    p = in;
    q = f->outbuf;
    inend = in + len;
    
    while (p < inend) {
        if (*p == '\n') {
            last = q;
            *q++ = *p++;
            nchars = 0;
        } else if (isspace (*p)) {
            last = q;
            
            if (nchars >= linewrap->wrap_len) {
                *q++ = '\n';
                p++;
                nchars = 0;
            } else {
                *q++ = *p++;
            }
        } else {
            *q++ = *p++;
            nchars++;
        }
        
        /* line is getting way too long, we must force a wrap here */
        if (nchars >= (linewrap->max_len - 1) && *p != '\n') {
            *q++ = '\n';
            *q++ = linewrap->indent;
            nchars = 0;
        }
    }
    
    linewrap->nchars = nchars;
    
    *out = f->outbuf;
    *outlen = q - f->outbuf;
    *outprespace = f->outpre;
}

static void 
complete (CamelMimeFilter *f, char *in, size_t len, size_t prespace,
      char **out, size_t *outlen, size_t *outprespace)
{
    if (len)
        filter (f, in, len, prespace, out, outlen, outprespace);
}

static void
reset (CamelMimeFilter *f)
{
    CamelMimeFilterLinewrap *linewrap = (CamelMimeFilterLinewrap *)f;
    
    linewrap->nchars = 0;
}

CamelMimeFilter *
camel_mime_filter_linewrap_new (guint preferred_len, guint max_len, char indent_char)
{
    CamelMimeFilterLinewrap *linewrap =
        CAMEL_MIME_FILTER_LINEWRAP (camel_object_new (CAMEL_MIME_FILTER_LINEWRAP_TYPE));
    
    linewrap->indent = indent_char;
    linewrap->wrap_len = preferred_len;
    linewrap->max_len = max_len;
    linewrap->nchars = 0;
    
    return (CamelMimeFilter *) linewrap;
}