nmrtf.c

Linux下的多协议即时通讯程序源代码

							return status;
					} else {               /* parsing a hex encoded character */
						if (ctx->ris != NMRTF_STATE_HEX)
							return NMRTF_ASSERTION;

						hex_byte = hex_byte << 4;
						if (isdigit(ch))
							hex_byte += (char) ch - '0';
						else {
							if (islower(ch)) {
								if (ch < 'a' || ch > 'f')
									return NMRTF_INVALID_HEX;
								hex_byte += (char) ch - 'a' + 10;
							} else {
								if (ch < 'A' || ch > 'F')
									return NMRTF_INVALID_HEX;
								hex_byte += (char) ch - 'A' + 10;
							}
						}
						hex_count--;
						if (hex_count == 0) {
							if ((status = rtf_dispatch_char(ctx, hex_byte)) != NMRTF_OK)
								return status;
							hex_count = 2;
							hex_byte = 0;
							ctx->ris = NMRTF_STATE_NORMAL;
						}
					}
					break;
            }
        }
    }
    if (ctx->depth < 0)
        return NMRTF_STACK_OVERFLOW;
    if (ctx->depth > 0)
        return NMRTF_UNMATCHED_BRACE;
    return NMRTF_OK;
}

/*
 * Push the current state onto stack
 */
static int
rtf_push_state(NMRtfContext *ctx)
{
    NMRtfStateSave *save = g_new0(NMRtfStateSave, 1);
    save->chp = ctx->chp;
    save->rds = ctx->rds;
    save->ris = ctx->ris;
	ctx->saved = g_slist_prepend(ctx->saved, save);
    ctx->ris = NMRTF_STATE_NORMAL;
    (ctx->depth)++;
    return NMRTF_OK;
}

/*
 * Restore the state at the top of the stack
 */
static int
rtf_pop_state(NMRtfContext *ctx)
{
    NMRtfStateSave *save_old;
	GSList *link_old;

    if (ctx->saved == NULL)
        return NMRTF_STACK_UNDERFLOW;

	save_old = ctx->saved->data;
    ctx->chp = save_old->chp;
    ctx->rds = save_old->rds;
    ctx->ris = save_old->ris;
    (ctx->depth)--;

    g_free(save_old);
	link_old = ctx->saved;
	ctx->saved = g_slist_remove_link(ctx->saved, link_old);
	g_slist_free_1(link_old);
    return NMRTF_OK;
}

/*
 * Step 2:
 * Get a control word (and its associated value) and
 * dispatch the control.
 */
static int
rtf_parse_keyword(NMRtfContext *ctx)
{
	int status = NMRTF_OK;
    guchar ch;
    gboolean param_set = FALSE;
    gboolean is_neg = FALSE;
    int param = 0;
    char keyword[30];
    char parameter[20];
	int i;

    keyword[0] = '\0';
    parameter[0] = '\0';
    if ((status = rtf_get_char(ctx, &ch)) != NMRTF_OK)
        return status;

    if (!isalpha(ch)) {
		/* a control symbol; no delimiter. */
        keyword[0] = (char) ch;
        keyword[1] = '\0';
        return rtf_dispatch_control(ctx, keyword, 0, param_set);
    }

	/* parse keyword */
	for (i = 0; isalpha(ch) && (i < sizeof(keyword) - 1); rtf_get_char(ctx, &ch)) {
		keyword[i] = (char) ch;
		i++;
	}
	keyword[i] = '\0';

	/* check for '-' indicated a negative parameter value  */
    if (ch == '-') {
        is_neg = TRUE;
        if ((status = rtf_get_char(ctx, &ch)) != NMRTF_OK)
            return status;
    }

	/* check for numerical param */
    if (isdigit(ch)) {

        param_set = TRUE;
		for (i = 0; isdigit(ch) && (i < sizeof(parameter) - 1); rtf_get_char(ctx, &ch)) {
			parameter[i] = (char) ch;
			i++;
		}
		parameter[i] = '\0';

        ctx->param = param = atoi(parameter);
        if (is_neg)
            ctx->param = param = -param;
    }

	/* space after control is optional, put character back if it is not a space */
    if (ch != ' ')
        rtf_unget_char(ctx, ch);

    return rtf_dispatch_control(ctx, keyword, param, param_set);
}

/*
 * Route the character to the appropriate destination
 */
static int
rtf_dispatch_char(NMRtfContext *ctx, guchar ch)
{
    if (ctx->ris == NMRTF_STATE_BIN && --(ctx->bytes_to_skip) <= 0)
        ctx->ris = NMRTF_STATE_NORMAL;

    switch (ctx->rds) {
		case NMRTF_STATE_SKIP:
			return NMRTF_OK;
		case NMRTF_STATE_NORMAL:
			return rtf_print_char(ctx, ch);
        case NMRTF_STATE_FONTTABLE:
            if (ch == ';')  {
				rtf_add_font_entry(ctx, ctx->chp.font_idx,
								   ctx->ansi->str, ctx->chp.font_charset);
				g_string_truncate(ctx->ansi, 0);
            }
            else {
                return rtf_print_char(ctx, ch);
            }
            return NMRTF_OK;
		default:
			return NMRTF_OK;
    }
}

/* Handle a unicode character */
static int
rtf_dispatch_unicode_char(NMRtfContext *ctx, gunichar ch)
{
    switch (ctx->rds) {
		case NMRTF_STATE_SKIP:
			return NMRTF_OK;
		case NMRTF_STATE_NORMAL:
        case NMRTF_STATE_FONTTABLE:
			return rtf_print_unicode_char(ctx, ch);
		default:
			return NMRTF_OK;
    }
}

/*
 * Output a character
 */
static int
rtf_print_char(NMRtfContext *ctx, guchar ch)
{

	ctx->ansi = g_string_append_c(ctx->ansi, ch);

    return NMRTF_OK;
}

/*
 * Output a unicode character
 */
static int
rtf_print_unicode_char(NMRtfContext *ctx, gunichar ch)
{
	char buf[7];
	int num;

	/* convert and flush the ansi buffer to the utf8 buffer */
	rtf_flush_data(ctx);

	/* convert the unicode character to utf8 and add directly to the output buffer */
	num = g_unichar_to_utf8((gunichar) ch, buf);
	buf[num] = 0;
	purple_debug_info("novell", "converted unichar 0x%X to utf8 char %s\n", ch, buf);

	ctx->output = g_string_append(ctx->output, buf);
	return NMRTF_OK;
}

/*
 * Flush the output text
 */
static int
rtf_flush_data(NMRtfContext *ctx)
{
    int status = NMRTF_OK;
	char *conv_data = NULL;
	const char *enc = NULL;
	GError *gerror = NULL;

    if (ctx->rds == NMRTF_STATE_NORMAL && ctx->ansi->len > 0) {
		enc = get_current_encoding(ctx);
		conv_data = g_convert(ctx->ansi->str, ctx->ansi->len, "UTF-8", enc,
							  NULL, NULL, &gerror);
		if (conv_data) {
			ctx->output = g_string_append(ctx->output, conv_data);
			g_free(conv_data);
			ctx->ansi = g_string_truncate(ctx->ansi, 0);
		} else {
			status = NMRTF_CONVERT_ERROR;
			purple_debug_info("novell", "failed to convert data! error code = %d msg = %s\n",
							gerror->code, gerror->message);
			g_free(gerror);
		}
	}

    return status;
}

/*
 * Handle a property change
 */
static int
rtf_apply_property(NMRtfContext *ctx, NMRtfProperty prop, int val)
{
    if (ctx->rds == NMRTF_STATE_SKIP)  /* If we're skipping text, */
        return NMRTF_OK;          /* don't do anything. */

	/* Need to flush any temporary data before a property change*/
	rtf_flush_data(ctx);

    switch (prop) {
		case NMRTF_PROP_FONT_IDX:
			ctx->chp.font_idx = val;
			break;
		case NMRTF_PROP_FONT_CHARSET:
			ctx->chp.font_charset = val;
			break;
		default:
			return NMRTF_BAD_TABLE;
    }

    return NMRTF_OK;
}

/*
 * Step 3.
 * Search the table for keyword and evaluate it appropriately.
 *
 * Inputs:
 * keyword:   The RTF control to evaluate.
 * param:     The parameter of the RTF control.
 * param_set: TRUE if the control had a parameter; (that is, if param is valid)
 *            FALSE if it did not.
 */
static int
rtf_dispatch_control(NMRtfContext *ctx, char *keyword, int param, gboolean param_set)
{
    int idx;

    for (idx = 0; idx < table_size; idx++) {
        if (strcmp(keyword, rtf_symbols[idx].keyword) == 0)
            break;
	}

    if (idx == table_size)  {
        if (ctx->skip_unknown)
            ctx->rds = NMRTF_STATE_SKIP;
        ctx->skip_unknown = FALSE;
        return NMRTF_OK;
    }

    /* found it! use kwd_type and action to determine what to do with it. */
    ctx->skip_unknown = FALSE;
    switch (rtf_symbols[idx].kwd_type) {
		case NMRTF_KWD_PROP:
			if (rtf_symbols[idx].pass_default || !param_set)
				param = rtf_symbols[idx].default_val;
			return rtf_apply_property(ctx, rtf_symbols[idx].action, param);
		case NMRTF_KWD_CHAR:
			return rtf_dispatch_char(ctx, rtf_symbols[idx].action);
		case NMRTF_KWD_DEST:
			return rtf_change_destination(ctx, rtf_symbols[idx].action);
		case NMRTF_KWD_SPEC:
			return rtf_dispatch_special(ctx, rtf_symbols[idx].action);
		default:
			return NMRTF_BAD_TABLE;
    }
    return NMRTF_BAD_TABLE;
}

/*
 * Change to the destination specified.
 */
static int
rtf_change_destination(NMRtfContext *ctx, NMRtfDestinationType type)
{
	/* if we're skipping text, don't do anything */
    if (ctx->rds == NMRTF_STATE_SKIP)
        return NMRTF_OK;

    switch (type) {
		case NMRTF_DEST_FONTTABLE:
            ctx->rds = NMRTF_STATE_FONTTABLE;
			g_string_truncate(ctx->ansi, 0);
            break;
		default:
			ctx->rds = NMRTF_STATE_SKIP;       /* when in doubt, skip it... */
			break;
    }
    return NMRTF_OK;
}

/*
 * Dispatch an RTF control that needs special processing
 */
static int
rtf_dispatch_special(NMRtfContext *ctx, NMRtfSpecialKwd type)
{
	int status = NMRTF_OK;
	guchar ch;

    if (ctx->rds == NMRTF_STATE_SKIP && type != NMRTF_SPECIAL_BIN)  /* if we're skipping, and it's not */
        return NMRTF_OK;                        /* the \bin keyword, ignore it. */

    switch (type) {
		case NMRTF_SPECIAL_BIN:
			ctx->ris = NMRTF_STATE_BIN;
			ctx->bytes_to_skip = ctx->param;
			break;
		case NMRTF_SPECIAL_SKIP:
			ctx->skip_unknown = TRUE;
			break;
		case NMRTF_SPECIAL_HEX:
			ctx->ris = NMRTF_STATE_HEX;
			break;
		case NMRTF_SPECIAL_UNICODE:
			purple_debug_info("novell", "parsing unichar\n");
			status = rtf_dispatch_unicode_char(ctx, ctx->param);
 			/* Skip next char */
			if (status == NMRTF_OK)
				status = rtf_get_char(ctx, &ch);
			break;
		default:
			status = NMRTF_BAD_TABLE;
			break;
    }

    return status;
}

/*
 * Get the next character from the input stream
 */
static int
rtf_get_char(NMRtfContext *ctx, guchar *ch)
{
    if (ctx->nextch >= 0) {
        *ch = ctx->nextch;
        ctx->nextch = -1;
    }
    else {
		*ch = *(ctx->input);
		ctx->input++;
    }

	if (*ch)
		return NMRTF_OK;
	else
		return NMRTF_EOF;
}

/*
 * Move a character back into the input stream
 */
static int
rtf_unget_char(NMRtfContext *ctx, guchar ch)
{
    ctx->nextch = ch;
    return NMRTF_OK;
}