Symaptic: os/textandloc/charconvfw/charconv_fw/src/charconv/unicodebig.cpp@bde4ae8d615e

     1 /*

     2 * Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:

    15 * Big-Endian converter

    16 *

    17 */

    20 #include <e32std.h>

    21 #include <convdata.h>

    22 #include "unicode.h"

    24 #define ARRAY_LENGTH(aArray) (sizeof(aArray)/sizeof((aArray)[0]))

    27 GLREF_D const SCnvConversionData unicodeConversionDataBig=

    28 	{

    29 	SCnvConversionData::EFixedBigEndian,

    30 		{

    31 		ARRAY_LENGTH(unicodeVariableByteDataRanges),

    32 		unicodeVariableByteDataRanges

    33 		},

    34 		{

    35 		ARRAY_LENGTH(unicodeTounicodeDataRanges),

    36 		unicodeTounicodeDataRanges

    37 		},

    38 		{

    39 		ARRAY_LENGTH(unicodeTounicodeDataRanges),

    40 		unicodeTounicodeDataRanges

    41 		},

    42 	NULL,

    43 	NULL

    44 	};

    46 GLREF_C void IsCharacterSetUnicodeBig(TInt& aConfidenceLevel, const TDesC8& aSample)

    47 	{

    49 	TInt sampleLength = aSample.Length();

    50 	aConfidenceLevel =70;

    51 	if (sampleLength < 2)

    52 		return;

    54 	if (aSample[0]==0xfe)

    55 		{

    56 		// The first byte is a possible ByteOrderMark

    57 		// Try matching the next character

    58 		if(aSample[1]==0xff)

    59 			{

    60 			// the byte order mark could be 0xFEFF or 0xFFFE depending on

    61 			// endianness of the sample text.

    62 			aConfidenceLevel=100;

    63 			}

    64 		}

    66 	for (TInt i = 0; i < sampleLength-1; ++i)

    67 		{

    68 		if (aSample[i] == 0x0d)

    69  			{

    70  			if (aSample[i+1] == 0x0a)

    71  				{

    72  				// Reduce the confidence level

    73  				aConfidenceLevel-= 25;

    74  				}

    75  			}

    76 		}

    78 	// if not 100% confident already, check if most even bytes are 0

    79 	#define MAX_SAMPLE_LENGTH 2048

    80 	if ( aConfidenceLevel < 100 )

    81 		{

    82 		TInt repeat=0;

    83 		// only check the first 2k if big sample

    84 		TInt length =( sampleLength > MAX_SAMPLE_LENGTH ? MAX_SAMPLE_LENGTH : sampleLength);

    86 		// start from 0 and check the even bytes

    87 		for (TInt i = 0; i < length-1; i+=2)

    88 			{

    89 			if (aSample[i] == 0x0)

    90 				repeat ++;

    91 			}

    93 		// if more than 80% even bytes zero then this IS big Endian

    94 		if ( (repeat * 100) /  (length * 5) >= 8)

    95 			aConfidenceLevel  = 100;

    96 		}

    98 	aConfidenceLevel =(aConfidenceLevel >0)? ((aConfidenceLevel > 100)? 100: aConfidenceLevel): 0;

    99 	}

author	sl@SLION-WIN7.fritz.box
	Fri, 15 Jun 2012 03:10:57 +0200
changeset 0	bde4ae8d615e
permissions	-rw-r--r--