michael@0: /*
michael@0: **********************************************************************
michael@0: * Copyright (C) 2000-2004, International Business Machines
michael@0: * Corporation and others. All Rights Reserved.
michael@0: **********************************************************************
michael@0: * ucnv_cb.h:
michael@0: * External APIs for the ICU's codeset conversion library
michael@0: * Helena Shih
michael@0: *
michael@0: * Modification History:
michael@0: *
michael@0: * Date Name Description
michael@0: */
michael@0:
michael@0: /**
michael@0: * \file
michael@0: * \brief C UConverter functions to aid the writers of callbacks
michael@0: *
michael@0: * Callback API for UConverter
michael@0: *
michael@0: * These functions are provided here for the convenience of the callback
michael@0: * writer. If you are just looking for callback functions to use, please
michael@0: * see ucnv_err.h. DO NOT call these functions directly when you are
michael@0: * working with converters, unless your code has been called as a callback
michael@0: * via ucnv_setFromUCallback or ucnv_setToUCallback !!
michael@0: *
michael@0: * A note about error codes and overflow. Unlike other ICU functions,
michael@0: * these functions do not expect the error status to be U_ZERO_ERROR.
michael@0: * Callbacks must be much more careful about their error codes.
michael@0: * The error codes used here are in/out parameters, which should be passed
michael@0: * back in the callback's error parameter.
michael@0: *
michael@0: * For example, if you call ucnv_cbfromUWriteBytes to write data out
michael@0: * to the output codepage, it may return U_BUFFER_OVERFLOW_ERROR if
michael@0: * the data did not fit in the target. But this isn't a failing error,
michael@0: * in fact, ucnv_cbfromUWriteBytes may be called AGAIN with the error
michael@0: * status still U_BUFFER_OVERFLOW_ERROR to attempt to write further bytes,
michael@0: * which will also go into the internal overflow buffers.
michael@0: *
michael@0: * Concerning offsets, the 'offset' parameters here are relative to the start
michael@0: * of SOURCE. For example, Suppose the string "ABCD" was being converted
michael@0: * from Unicode into a codepage which doesn't have a mapping for 'B'.
michael@0: * 'A' will be written out correctly, but
michael@0: * The FromU Callback will be called on an unassigned character for 'B'.
michael@0: * At this point, this is the state of the world:
michael@0: * Target: A [..] [points after A]
michael@0: * Source: A B [C] D [points to C - B has been consumed]
michael@0: * 0 1 2 3
michael@0: * codePoint = "B" [the unassigned codepoint]
michael@0: *
michael@0: * Now, suppose a callback wants to write the substitution character '?' to
michael@0: * the target. It calls ucnv_cbFromUWriteBytes() to write the ?.
michael@0: * It should pass ZERO as the offset, because the offset as far as the
michael@0: * callback is concerned is relative to the SOURCE pointer [which points
michael@0: * before 'C'.] If the callback goes into the args and consumes 'C' also,
michael@0: * it would call FromUWriteBytes with an offset of 1 (and advance the source
michael@0: * pointer).
michael@0: *
michael@0: */
michael@0:
michael@0: #ifndef UCNV_CB_H
michael@0: #define UCNV_CB_H
michael@0:
michael@0: #include "unicode/utypes.h"
michael@0:
michael@0: #if !UCONFIG_NO_CONVERSION
michael@0:
michael@0: #include "unicode/ucnv.h"
michael@0: #include "unicode/ucnv_err.h"
michael@0:
michael@0: /**
michael@0: * ONLY used by FromU callback functions.
michael@0: * Writes out the specified byte output bytes to the target byte buffer or to converter internal buffers.
michael@0: *
michael@0: * @param args callback fromUnicode arguments
michael@0: * @param source source bytes to write
michael@0: * @param length length of bytes to write
michael@0: * @param offsetIndex the relative offset index from callback.
michael@0: * @param err error status. If U_BUFFER_OVERFLOW is returned, then U_BUFFER_OVERFLOW must
michael@0: * be returned to the user, because it means that not all data could be written into the target buffer, and some is
michael@0: * in the converter error buffer.
michael@0: * @see ucnv_cbFromUWriteSub
michael@0: * @stable ICU 2.0
michael@0: */
michael@0: U_STABLE void U_EXPORT2
michael@0: ucnv_cbFromUWriteBytes (UConverterFromUnicodeArgs *args,
michael@0: const char* source,
michael@0: int32_t length,
michael@0: int32_t offsetIndex,
michael@0: UErrorCode * err);
michael@0:
michael@0: /**
michael@0: * ONLY used by FromU callback functions.
michael@0: * This function will write out the correct substitution character sequence
michael@0: * to the target.
michael@0: *
michael@0: * @param args callback fromUnicode arguments
michael@0: * @param offsetIndex the relative offset index from the current source pointer to be used
michael@0: * @param err error status. If U_BUFFER_OVERFLOW is returned, then U_BUFFER_OVERFLOW must
michael@0: * be returned to the user, because it means that not all data could be written into the target buffer, and some is
michael@0: * in the converter error buffer.
michael@0: * @see ucnv_cbFromUWriteBytes
michael@0: * @stable ICU 2.0
michael@0: */
michael@0: U_STABLE void U_EXPORT2
michael@0: ucnv_cbFromUWriteSub (UConverterFromUnicodeArgs *args,
michael@0: int32_t offsetIndex,
michael@0: UErrorCode * err);
michael@0:
michael@0: /**
michael@0: * ONLY used by fromU callback functions.
michael@0: * This function will write out the error character(s) to the target UChar buffer.
michael@0: *
michael@0: * @param args callback fromUnicode arguments
michael@0: * @param source pointer to pointer to first UChar to write [on exit: 1 after last UChar processed]
michael@0: * @param sourceLimit pointer after last UChar to write
michael@0: * @param offsetIndex the relative offset index from callback which will be set
michael@0: * @param err error status U_BUFFER_OVERFLOW
michael@0: * @see ucnv_cbToUWriteSub
michael@0: * @stable ICU 2.0
michael@0: */
michael@0: U_STABLE void U_EXPORT2 ucnv_cbFromUWriteUChars(UConverterFromUnicodeArgs *args,
michael@0: const UChar** source,
michael@0: const UChar* sourceLimit,
michael@0: int32_t offsetIndex,
michael@0: UErrorCode * err);
michael@0:
michael@0: /**
michael@0: * ONLY used by ToU callback functions.
michael@0: * This function will write out the specified characters to the target
michael@0: * UChar buffer.
michael@0: *
michael@0: * @param args callback toUnicode arguments
michael@0: * @param source source string to write
michael@0: * @param length the length of source string
michael@0: * @param offsetIndex the relative offset index which will be written.
michael@0: * @param err error status U_BUFFER_OVERFLOW
michael@0: * @see ucnv_cbToUWriteSub
michael@0: * @stable ICU 2.0
michael@0: */
michael@0: U_STABLE void U_EXPORT2 ucnv_cbToUWriteUChars (UConverterToUnicodeArgs *args,
michael@0: const UChar* source,
michael@0: int32_t length,
michael@0: int32_t offsetIndex,
michael@0: UErrorCode * err);
michael@0:
michael@0: /**
michael@0: * ONLY used by ToU callback functions.
michael@0: * This function will write out the Unicode substitution character (U+FFFD).
michael@0: *
michael@0: * @param args callback fromUnicode arguments
michael@0: * @param offsetIndex the relative offset index from callback.
michael@0: * @param err error status U_BUFFER_OVERFLOW
michael@0: * @see ucnv_cbToUWriteUChars
michael@0: * @stable ICU 2.0
michael@0: */
michael@0: U_STABLE void U_EXPORT2 ucnv_cbToUWriteSub (UConverterToUnicodeArgs *args,
michael@0: int32_t offsetIndex,
michael@0: UErrorCode * err);
michael@0: #endif
michael@0:
michael@0: #endif