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1 /* |
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2 * Copyright (c) 2005-2007 Nokia Corporation and/or its subsidiary(-ies). |
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3 * All rights reserved. |
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4 * This component and the accompanying materials are made available |
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5 * under the terms of "Eclipse Public License v1.0" |
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6 * which accompanies this distribution, and is available |
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7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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8 * |
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9 * Initial Contributors: |
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10 * Nokia Corporation - initial contribution. |
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11 * |
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12 * Contributors: |
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13 * |
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14 * Description: Fixed digit string handler class |
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15 * |
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16 */ |
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17 |
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18 |
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19 #ifndef VPBKENGUTILS_TFIXEDDIGITSTRING_H |
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20 #define VPBKENGUTILS_TFIXEDDIGITSTRING_H |
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21 |
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22 // INCLUDES |
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23 #include <e32std.h> |
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24 |
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25 namespace VPbkEngUtils { |
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26 |
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27 // FORWARD DECLARATIONS |
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28 |
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29 |
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30 // CLASS DECLARATIONS |
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31 |
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32 /** |
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33 * Fixed-length digit string. |
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34 * Phone number matching helper class: encodes decimal digit characters to BCD |
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35 * (Binary Coded Decimal) format for efficient matching. |
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36 */ |
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37 class TFixedDigitString |
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38 { |
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39 public: |
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40 /** |
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41 * Default constructor. Resets this digit string to empty. |
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42 */ |
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43 TFixedDigitString(); |
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44 |
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45 /** |
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46 * Returns the length of this digit string. |
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47 * @return the number of digits in this digit string, |
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48 */ |
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49 TInt Length() const; |
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50 |
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51 /** |
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52 * Returns true if this digit string is empty. |
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53 */ |
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54 TBool IsEmpty() const; |
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55 |
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56 /** |
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57 * Returns the maximum number of digits this object may contain. |
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58 */ |
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59 static TInt MaxLength(); |
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60 |
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61 /** |
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62 * Returns non-modifiable decimal digit at position aIndex. |
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63 * |
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64 * @pre aIndex >= 0 && aIndex < Length() |
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65 * @post result >= 0 && result <= 9 |
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66 */ |
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67 TInt operator[](TInt aIndex) const; |
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68 |
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69 /** |
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70 * Compares the digits in this string to another digit string. |
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71 * |
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72 * @param aOther the other digit string to compare this string with. |
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73 * @param aNumDigits the number of digits to compare. Zero means |
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74 * all digits are compared. |
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75 * @pre Result is undefined if aNumDigits < 0 || aNumDigits > MaxLength(). |
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76 * @return true if aNumDigits digits match |
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77 */ |
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78 TBool Compare(const TFixedDigitString& aOther, TInt aNumDigits) const; |
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79 |
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80 /** |
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81 * Resets this digit string to empty. |
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82 * @post Length() == 0 |
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83 */ |
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84 void Reset(); |
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85 |
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86 /** |
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87 * Encodes digit characters from text to this digit string. |
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88 * |
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89 * @param aDigitsText text to encode decimal digit characters from. |
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90 * Nondigit characters are skipped. The encoded |
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91 * and skipped characters are removed from the |
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92 * parameter. At maximum MaxLength() digits |
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93 * are encoded. |
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94 */ |
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95 void EncodeDigits(TPtrC& aDigitsText); |
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96 |
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97 private: // Implementation |
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98 enum |
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99 { |
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100 KBitsPerDigit = 4, |
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101 KMaxDigits = 8*sizeof(TUint) / KBitsPerDigit, |
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102 KMaxBits = KMaxDigits * KBitsPerDigit, |
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103 KNaNBCD = 0xf, |
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104 KNaN = -1 |
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105 }; |
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106 inline TBool DoCompare(const TFixedDigitString& aOther, TInt aNumDigits) const; |
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107 |
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108 private: // Data |
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109 /// Own. Bcd digits to be compared |
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110 TUint iBcdDigits; |
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111 }; |
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112 |
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113 |
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114 // INLINE FUNCTIONS |
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115 |
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116 inline TInt TFixedDigitString::MaxLength() |
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117 { |
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118 return KMaxDigits; |
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119 } |
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120 |
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121 /** |
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122 * Inline implementation of Compare. |
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123 */ |
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124 inline TBool TFixedDigitString::DoCompare |
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125 (const TFixedDigitString& aOther, TInt aNumDigits) const |
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126 { |
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127 const TUint mask = ~TUint(0) >> ((KBitsPerDigit*(KMaxDigits - aNumDigits)) % (KMaxBits)); |
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128 if ((iBcdDigits ^ aOther.iBcdDigits) & mask) |
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129 return EFalse; |
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130 else |
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131 return ETrue; |
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132 } |
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133 |
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134 #ifdef NDEBUG |
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135 // Inline version of TFixedDigitString::Compare for non-debug builds |
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136 inline TBool TFixedDigitString::Compare |
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137 (const TFixedDigitString& aOther, TInt aNumDigits) const |
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138 { |
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139 return DoCompare(aOther, aNumDigits); |
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140 } |
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141 #endif |
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142 |
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143 |
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144 } // namespace VPbkEngUtils |
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145 |
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146 #endif // VPBKENGUTILS_TFIXEDDIGITSTRING_H |
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147 |