rockbox/apps/language.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 Daniel Stenberg
 *
 * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

#include <file.h>

#include "language.h"
#include "lang.h"
#include "debug.h"
#include "string.h"
#ifdef HAVE_LCD_BITMAP
#include "viewport.h"
#endif

/* The following header is generated by the build system and only defines
   MAX_LANGUAGE_SIZE to be the size of the largest currently available
   language! */
#include "max_language_size.h"

/* These defines must match the initial bytes in the binary lang file */
/* See tools/genlang (TODO: Use common include for both) */
#define LANGUAGE_COOKIE   0x1a
#define LANGUAGE_VERSION  0x06
#define LANGUAGE_FLAG_RTL 0x01

#define HEADER_SIZE 4
#define SUBHEADER_SIZE 6

static unsigned char language_buffer[MAX_LANGUAGE_SIZE];
static unsigned char lang_options = 0;

void lang_init(const unsigned char *builtin, unsigned char **dest, int count)
{
    while(count--) {
        *dest++ = (unsigned char *)builtin;
        /* advance pointer to next string */
        builtin += strlen((char *)builtin) + 1;
    }
}

int lang_load(const char *filename, const unsigned char *builtin, 
              unsigned char **dest, unsigned char *buffer, 
              unsigned int user_num, int max_lang_size,
              unsigned int max_id)
{
    int lang_size;
    int fd = open(filename, O_RDONLY);
    int retcode=0;
    unsigned char lang_header[HEADER_SIZE];
    unsigned char sub_header[SUBHEADER_SIZE];
    unsigned int id, num_strings, foffset;

    if(fd < 0)
        return 1;
    read(fd, lang_header, HEADER_SIZE);
    if((lang_header[0] == LANGUAGE_COOKIE) &&
       (lang_header[1] == LANGUAGE_VERSION) &&
       (lang_header[2] == TARGET_ID)) {
        /* jump to the proper entry in the table of subheaders */
        lseek(fd, user_num * SUBHEADER_SIZE, SEEK_CUR);
        read(fd, sub_header, SUBHEADER_SIZE);
        /* read in information about the requested lang */
        num_strings = (sub_header[0]<<8) | sub_header[1];
        lang_size = (sub_header[2]<<8) | sub_header[3];
        foffset = (sub_header[4]<<8) | sub_header[5];
        if(lang_size <= max_lang_size) {
            /* initialize with builtin */
            lang_init(builtin, dest, max_id);
            lseek(fd, foffset, SEEK_SET);
            read(fd, buffer, lang_size);

            while(lang_size>3) {
                id = ((buffer[0]<<8) | buffer[1]); /* get two-byte id */
                buffer += 2;                       /* pass the id */
                if(id < max_id) {
#if 0
                    DEBUGF("%2x New: %30s ", id, buffer);
                    DEBUGF("Replaces: %s\n", dest[id]);
#endif
                    dest[id] = buffer; /* point to this string */
                }
                while(*buffer) {               /* pass the string */
                    lang_size--;
                    buffer++;
                 }
                lang_size-=3; /* the id and the terminating zero */
                buffer++;     /* pass the terminating zero-byte */
            }
        }
        else {
            DEBUGF("Language %s too large: %d\n", filename, lang_size);
            retcode = 2;
        }
    }
    else {
        DEBUGF("Illegal language file\n");
        retcode = 3;
    }
    close(fd);
    lang_options = retcode ? 0 : lang_header[3];
    return retcode;
}

int lang_core_load(const char *filename)
{
    return lang_load(filename, core_language_builtin, language_strings,
                     language_buffer, 0, MAX_LANGUAGE_SIZE,
                     LANG_LAST_INDEX_IN_ARRAY);
}

int lang_english_to_id(const char *english)
{
    int i;
    unsigned char *ptr = (unsigned char *) core_language_builtin;
    
    for (i = 0; i < LANG_LAST_INDEX_IN_ARRAY; i++) {
        if (!strcmp(ptr, english))
            return i;
        ptr += strlen((char *)ptr) + 1; /* advance pointer to next string */
    }
    return -1;
}

int lang_is_rtl(void)
{
    return (lang_options & LANGUAGE_FLAG_RTL) != 0;
}