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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef nsIUnicodeDecoder_h___
#define nsIUnicodeDecoder_h___
#include "nscore.h"
#include "nsISupports.h"
// Interface ID for our Unicode Decoder interface
// {25359602-FC70-4d13-A9AB-8086D3827C0D}
//NS_DECLARE_ID(kIUnicodeDecoderIID,
// 0x25359602, 0xfc70, 0x4d13, 0xa9, 0xab, 0x80, 0x86, 0xd3, 0x82, 0x7c, 0xd);
#define NS_IUNICODEDECODER_IID \
{ 0x25359602, 0xfc70, 0x4d13, \
{ 0xa9, 0xab, 0x80, 0x86, 0xd3, 0x82, 0x7c, 0xd }}
#define NS_UNICODEDECODER_CONTRACTID_BASE "@mozilla.org/intl/unicode/decoder;1?charset="
/**
* Interface for a Converter from a Charset into Unicode.
*
* @created 23/Nov/1998
* @author Catalin Rotaru [CATA]
*/
class nsIUnicodeDecoder : public nsISupports
{
public:
NS_DECLARE_STATIC_IID_ACCESSOR(NS_IUNICODEDECODER_IID)
enum {
kOnError_Recover, // on an error, recover and continue
kOnError_Signal // on an error, stop and signal
};
/**
* Converts the data from one Charset to Unicode.
*
* About the byte ordering:
* - For input, if the converter cares (that depends of the charset, for
* example a singlebyte will ignore the byte ordering) it should assume
* network order. If necessary and requested, we can add a method
* SetInputByteOrder() so that the reverse order can be used, too. That
* method would have as default the assumed network order.
* - The output stream is Unicode, having the byte order which is internal
* for the machine on which the converter is running on.
*
* Unless there is not enough output space, this method must consume all the
* available input data! The eventual incomplete final character data will be
* stored internally in the converter and used when the method is called
* again for continuing the conversion. This way, the caller will not have to
* worry about managing incomplete input data by mergeing it with the next
* buffer.
*
* Error conditions:
* If the read value does not belong to this character set, one should
* replace it with the Unicode special 0xFFFD. When an actual input error is
* encountered, like a format error, the converter stop and return error.
* However, we should keep in mind that we need to be lax in decoding. When
* a decoding error is returned to the caller, it is the caller's
* responsibility to advance over the bad byte (unless aSrcLength is -1 in
* which case the caller should call the decoder with 0 offset again) and
* reset the decoder before trying to call the decoder again.
*
* Converter required behavior:
* In this order: when output space is full - return right away. When input
* data is wrong, return input pointer right after the wrong byte. When
* partial input, it will be consumed and cached. All the time input pointer
* will show how much was actually consumed and how much was actually
* written.
*
* @param aSrc [IN] the source data buffer
* @param aSrcLength [IN/OUT] the length of source data buffer; after
* conversion will contain the number of bytes read or
* -1 on error to indicate that the caller should re-push
* the same buffer after resetting the decoder
* @param aDest [OUT] the destination data buffer
* @param aDestLength [IN/OUT] the length of the destination data buffer;
* after conversion will contain the number of Unicode
* characters written
* @return NS_ERROR_UDEC_ILLEGALINPUT if an illegal input sequence
* was encountered and the behavior was set to "signal";
* the caller must skip over one byte, reset the decoder
* and retry.
* NS_OK_UDEC_MOREOUTPUT if only a partial conversion
* was done; more output space is needed to continue
* NS_OK_UDEC_MOREINPUT if the input ended in the middle
* of an input code unit sequence. If this is the last
* result the caller has at the end of the stream, the
* caller must append one U+FFFD to the output.
* NS_OK if the input ended after a complete input code
* unit sequence.
*/
NS_IMETHOD Convert(const char * aSrc, int32_t * aSrcLength,
char16_t * aDest, int32_t * aDestLength) = 0;
/**
* Returns a quick estimation of the size of the buffer needed to hold the
* converted data. Remember: this estimation is >= with the actual size of
* the buffer needed. It will be computed for the "worst case"
*
* @param aSrc [IN] the source data buffer
* @param aSrcLength [IN] the length of source data buffer
* @param aDestLength [OUT] the needed size of the destination buffer
* @return NS_EXACT_LENGTH if an exact length was computed
* NS_ERROR_OUT_OF_MEMORY if OOM
* NS_OK is all we have is an approximation
*/
MOZ_MUST_USE NS_IMETHOD GetMaxLength(const char* aSrc,
int32_t aSrcLength,
int32_t* aDestLength) = 0;
/**
* Resets the charset converter so it may be recycled for a completely
* different and urelated buffer of data.
*/
NS_IMETHOD Reset() = 0;
/**
* Specify what to do when a character cannot be mapped into unicode
*
* @param aBehavior [IN] the desired behavior
* @see kOnError_Recover
* @see kOnError_Signal
*/
virtual void SetInputErrorBehavior(int32_t aBehavior) = 0;
/**
* return the UNICODE character for unmapped character
*/
virtual char16_t GetCharacterForUnMapped() = 0;
};
NS_DEFINE_STATIC_IID_ACCESSOR(nsIUnicodeDecoder, NS_IUNICODEDECODER_IID)
#endif /* nsIUnicodeDecoder_h___ */
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