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1 // Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of "Eclipse Public License v1.0" |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // |
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15 |
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16 #include <apmrec.h> |
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17 #include <apmstd.h> |
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18 #include "RECTXT.H" |
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19 #include <ecom/implementationproxy.h> |
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20 |
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21 const TUid KUidMimeTxtRecognizer={0x100012FB}; |
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22 const TInt KMinBufferLength=42; // minimum amount of file needed to determine a text file IF it's not called .TXT |
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23 const TInt KMaxBufferLength=1024; // maximum amount of buffer space we will ever use |
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24 _LIT8(KDataTypeTextPlain,"text/plain"); |
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25 _LIT(KTextFileExt,".txt"); |
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26 |
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27 CApaTextRecognizer::CApaTextRecognizer() |
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28 :CApaDataRecognizerType(KUidMimeTxtRecognizer,CApaDataRecognizerType::ELow) |
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29 // Text files are low recognition - they don't have a clear signature |
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30 { |
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31 iCountDataTypes=1; |
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32 } |
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33 |
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34 TUint CApaTextRecognizer::PreferredBufSize() |
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35 { |
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36 return KMaxBufferLength; |
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37 } |
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38 |
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39 #if defined(_DEBUG) |
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40 TDataType CApaTextRecognizer::SupportedDataTypeL(TInt aIndex) const |
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41 #else |
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42 TDataType CApaTextRecognizer::SupportedDataTypeL(TInt /*aIndex*/) const |
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43 #endif |
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44 { |
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45 __ASSERT_DEBUG(aIndex==0,User::Invariant()); |
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46 return TDataType(KDataTypeTextPlain); |
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47 } |
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48 |
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49 void CApaTextRecognizer::DoRecognizeL(const TDesC& aName, const TDesC8& aBuffer) |
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50 { |
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51 TBool nameRecognized=EFalse; |
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52 |
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53 // check if the file has valid UIDs |
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54 if (aBuffer.Length() >= 16) |
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55 { |
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56 // if the first 3 bytes are valid UIDs,then this file is not a plain/text. |
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57 // Set iConfidence appropriately and exit. |
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58 const TCheckedUid checkUid(aBuffer.Left(16)); |
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59 if (checkUid.UidType().IsValid()) |
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60 { |
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61 iConfidence=ENotRecognized; |
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62 return; |
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63 } |
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64 } |
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65 |
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66 if (aName.Length()>4) |
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67 { |
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68 nameRecognized=(aName.Right(4).CompareF(KTextFileExt)==0); |
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69 } |
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70 const TInt length=Min(aBuffer.Length(), KMaxBufferLength); |
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71 if (length<KMinBufferLength && !nameRecognized) |
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72 return; |
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73 TInt ii; |
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74 for (ii=0; ii<length; ii++) |
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75 { |
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76 const TUint chr=aBuffer[ii]; |
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77 // these are guesses of what WON'T be in a text file |
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78 if (chr<9 || chr==11 || chr==12 || (chr>13 && chr<32)) |
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79 { |
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80 break; |
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81 } |
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82 if (chr>148) |
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83 { |
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84 break; |
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85 } |
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86 } |
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87 const TBool validChars=(ii==length); |
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88 |
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89 if (nameRecognized) |
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90 { |
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91 iConfidence=validChars? EProbable : EUnlikely; |
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92 } |
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93 else |
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94 { |
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95 if (!validChars) |
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96 { |
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97 return; |
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98 } |
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99 iConfidence=EPossible; |
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100 } |
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101 iDataType=TDataType(KDataTypeTextPlain); |
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102 } |
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103 |
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104 CApaDataRecognizerType* CApaTextRecognizer::CreateRecognizerL() |
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105 { |
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106 return new (ELeave) CApaTextRecognizer(); |
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107 } |
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108 |
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109 const TImplementationProxy ImplementationTable[] = |
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110 { |
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111 IMPLEMENTATION_PROXY_ENTRY(0x101F7DA0,CApaTextRecognizer::CreateRecognizerL) |
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112 }; |
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113 |
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114 EXPORT_C const TImplementationProxy* ImplementationGroupProxy(TInt& aTableCount) |
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115 { |
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116 aTableCount = sizeof(ImplementationTable) / sizeof(TImplementationProxy); |
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117 return ImplementationTable; |
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118 } |
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119 |
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120 |