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

 // All rights reserved.

 // This component and the accompanying materials are made available

 // under the terms of "Eclipse Public License v1.0"

 // which accompanies this distribution, and is available

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

 //

 // Initial Contributors:

 // Nokia Corporation - initial contribution.

 //

 // Contributors:

 //

 // Description:

 //

 #include <apmrec.h>

 #include <apmstd.h>

 #include "RECTXT.H"

 #include <ecom/implementationproxy.h>

 const TUid KUidMimeTxtRecognizer={0x100012FB};

 const TInt KMinBufferLength=42;  // minimum amount of file needed to determine a text file IF it's not called .TXT

 const TInt KMaxBufferLength=1024; // maximum amount of buffer space we will ever use

 _LIT8(KDataTypeTextPlain,"text/plain");

 _LIT(KTextFileExt,".txt");

 CApaTextRecognizer::CApaTextRecognizer()

 	:CApaDataRecognizerType(KUidMimeTxtRecognizer,CApaDataRecognizerType::ELow)

 	// Text files are low recognition - they don't have a clear signature

 	{

 	iCountDataTypes=1;

 	}

 TUint CApaTextRecognizer::PreferredBufSize()

 	{

 	return KMaxBufferLength;

 	}

 #if defined(_DEBUG)

 TDataType CApaTextRecognizer::SupportedDataTypeL(TInt aIndex) const

 #else

 TDataType CApaTextRecognizer::SupportedDataTypeL(TInt /*aIndex*/) const

 #endif

 	{

 	__ASSERT_DEBUG(aIndex==0,User::Invariant());

 	return TDataType(KDataTypeTextPlain);

 	}

 void CApaTextRecognizer::DoRecognizeL(const TDesC& aName, const TDesC8& aBuffer)

 	{

 	TBool nameRecognized=EFalse;

 	// check if the file has valid UIDs 

 	if (aBuffer.Length() >= 16)

 		{

 		// if the first 3 bytes are valid UIDs,then this file is not a plain/text. 

 		// Set iConfidence appropriately and exit.

 		const TCheckedUid checkUid(aBuffer.Left(16));    

 		if (checkUid.UidType().IsValid())

 			{

 			iConfidence=ENotRecognized;

 			return;

 			}

 		}

 	if (aName.Length()>4)

 		{

 		nameRecognized=(aName.Right(4).CompareF(KTextFileExt)==0);

 		}

 	const TInt length=Min(aBuffer.Length(), KMaxBufferLength);

 	if (length<KMinBufferLength && !nameRecognized)

 		return;

 	TInt ii;

 	for (ii=0; ii<length; ii++)

 		{

 		const TUint chr=aBuffer[ii];

 		// these are guesses of what WON'T be in a text file

 		if (chr<9 || chr==11 || chr==12 || (chr>13 && chr<32))

 			{

 			break;

 			}

 		if (chr>148)

 			{

 			break;

 			}

 		}

 	const TBool validChars=(ii==length);

 	if (nameRecognized)

 		{

 		iConfidence=validChars? EProbable : EUnlikely;

 		}

 	else

 		{

 		if (!validChars)

 			{

 			return;

 			}

 		iConfidence=EPossible;

 		}

 	iDataType=TDataType(KDataTypeTextPlain);

 	}

 CApaDataRecognizerType* CApaTextRecognizer::CreateRecognizerL()

 	{

 	return new (ELeave) CApaTextRecognizer();

 	}

 const TImplementationProxy ImplementationTable[] = 

     {

 	IMPLEMENTATION_PROXY_ENTRY(0x101F7DA0,CApaTextRecognizer::CreateRecognizerL)

 	};

 EXPORT_C const TImplementationProxy* ImplementationGroupProxy(TInt& aTableCount)

     {

     aTableCount = sizeof(ImplementationTable) / sizeof(TImplementationProxy);

     return ImplementationTable;

     }