1 baliba.h |
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 the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.symbianfoundation.org/legal/licencesv10.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 // Written by Brendan, Dec 1996 |
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15 // Library associated files for pluggable components |
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16 // |
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17 // |
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18 |
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19 #if !defined(__LIBASSOC_H__) |
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20 #define __LIBASSOC_H__ |
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21 #if !defined(__F32FILE_H__) |
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22 #include <f32file.h> |
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23 #endif |
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24 |
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25 |
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26 |
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27 |
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28 class TLibAssocBase |
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29 /** |
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30 @publishedAll |
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31 @released |
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32 |
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33 This is an implementation base class for TLibAssoc. |
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34 */ |
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35 { |
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36 protected: |
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37 inline TLibAssocBase(); |
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38 IMPORT_C TLibAssocBase(const RLibrary& aLib,TAny* aPtr); |
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39 IMPORT_C void Set(const RLibrary& aLib,TAny* aPtr); |
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40 IMPORT_C static void DoUnload(TAny* aThis); |
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41 public: |
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42 inline TBool IsNull() const; |
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43 private: |
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44 RLibrary iLibrary; |
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45 protected: |
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46 |
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47 /** |
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48 A Pointer to the class instance. |
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49 */ |
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50 TAny* iPtr; |
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51 }; |
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52 |
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53 |
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54 |
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55 |
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56 // class TLibAssoc inlines |
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57 inline TLibAssocBase::TLibAssocBase() |
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58 : iPtr(NULL) |
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59 /** |
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60 Default constructor. |
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61 |
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62 It sets the member TLibAssocBase::iPtr to NULL. |
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63 */ |
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64 {} |
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65 |
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66 |
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67 |
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68 |
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69 inline TBool TLibAssocBase::IsNull() const |
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70 /** |
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71 Tests whether the pointer to the class instance is NULL. |
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72 |
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73 @return ETrue, if the pointer is NULL; EFalse, otherwise. |
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74 */ |
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75 {return iPtr==NULL;} |
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76 |
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77 |
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78 // |
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79 // class TLibAssoc |
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80 // |
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81 template <class T> |
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82 class TLibAssoc : public TLibAssocBase |
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83 /** |
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84 @publishedAll |
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85 @released |
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86 |
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87 Associates a dynamically loadable DLL and an instance of a class that, |
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88 typically, will have been created using the ordinal 1 function of that DLL. |
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89 |
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90 An object of this type is useful when cleanup behaviour requires that |
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91 a class instance be deleted and the associated DLL be closed. |
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92 |
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93 The DLL is expected to be already open when the TLibAssoc object is created. |
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94 */ |
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95 { |
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96 public: |
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97 inline TLibAssoc(); |
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98 inline TLibAssoc(const RLibrary& aLib,T* aClass); |
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99 inline void Set(const RLibrary& aLib,T* aClass); |
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100 // |
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101 inline void Unload(); |
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102 // |
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103 inline operator TCleanupItem(); |
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104 operator TLibAssoc*(); // undefined, but here to prevent accidental delete(TLibAssoc) |
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105 // |
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106 inline T* Ptr(); |
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107 inline const T* PtrC() const; |
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108 // |
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109 inline operator T*(); |
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110 inline operator const T*() const; |
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111 // |
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112 inline T* operator->(); |
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113 inline const T* operator->() const; |
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114 private: |
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115 static void Cleanup(TAny* aThis); // for TCleanupOperation |
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116 }; |
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117 |
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118 |
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119 |
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120 |
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121 template <class T> |
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122 inline TLibAssoc<T>::TLibAssoc() |
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123 /** |
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124 Default constructor. |
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125 |
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126 An association between a DLL and a class instance can be made |
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127 after construction using the Set() function. |
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128 */ |
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129 {} |
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130 |
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131 |
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132 |
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133 template <class T> |
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134 inline TLibAssoc<T>::TLibAssoc(const RLibrary& aLib,T* aClass) |
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135 : TLibAssocBase(aLib,aClass) |
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136 /** |
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137 Constructs the object taking the specified DLL and an instance of |
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138 the specified class. |
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139 |
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140 @param aLib A reference to a DLL that has already been opened. |
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141 @param aClass A pointer to an object to be associated with the DLL. |
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142 Typically, this object will have been created using |
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143 the ordinal 1 function from that DLL. |
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144 */ |
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145 {} |
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146 |
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147 |
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148 |
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149 |
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150 template <class T> |
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151 inline void TLibAssoc<T>::Set(const RLibrary& aLib,T* aClass) |
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152 /** |
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153 Makes an association between the specified DLL and an instance of |
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154 the specified class. |
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155 |
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156 @param aLib A reference to a DLL that has already been opened. |
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157 @param aClass A pointer to an object to be associated with the DLL. |
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158 Typically, this object will have been created using |
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159 the ordinal 1 function from that DLL. |
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160 */ |
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161 {TLibAssocBase::Set(aLib,aClass);} |
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162 |
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163 |
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164 |
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165 |
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166 template <class T> |
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167 inline T* TLibAssoc<T>::Ptr() |
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168 /** |
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169 Gets a pointer to the class instance. |
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170 |
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171 @return A pointer to the class instance. |
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172 */ |
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173 {return (T*)iPtr;} |
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174 |
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175 |
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176 |
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177 |
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178 template <class T> |
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179 inline const T* TLibAssoc<T>::PtrC() const |
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180 /** |
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181 Gets a pointer to the const class instance. |
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182 |
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183 @return A pointer to the const class instance. |
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184 */ |
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185 {return (const T*)iPtr;} |
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186 |
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187 |
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188 |
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189 |
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190 template <class T> |
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191 inline TLibAssoc<T>::operator T*() |
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192 /** |
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193 Conversion operator. |
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194 |
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195 Invoked by the compiler when a TLibAssoc<T> type is passed to a function that |
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196 is prototyped to take a T* type. |
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197 */ |
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198 {return (T*)iPtr;} |
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199 |
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200 |
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201 |
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202 |
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203 template <class T> |
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204 inline TLibAssoc<T>::operator const T*() const |
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205 /** |
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206 Const conversion operator. |
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207 |
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208 Invoked by the compiler when a TLibAssoc<T> type is passed to a function that |
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209 is prototyped to take a const T* type. |
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210 */ |
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211 {return (const T*)iPtr;} |
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212 |
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213 |
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214 |
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215 |
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216 template <class T> |
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217 inline T* TLibAssoc<T>::operator->() |
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218 /** |
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219 Dereferencing operator. |
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220 |
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221 @return A pointer to the class instance. |
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222 */ |
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223 {return (T*)iPtr;} |
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224 |
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225 |
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226 |
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227 |
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228 template <class T> |
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229 inline const T* TLibAssoc<T>::operator->() const |
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230 /** |
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231 Const dereferencing operator. |
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232 |
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233 @return A pointer to the const class instance. |
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234 */ |
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235 {return (const T*)iPtr;} |
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236 |
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237 |
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238 |
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239 |
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240 template <class T> |
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241 inline TLibAssoc<T>::operator TCleanupItem() |
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242 /** |
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243 The TCleanupItem conversion operator. |
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244 |
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245 Invoked by the compiler when a TLibAssoc<T> type is passed to a function that |
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246 is prototyped to take a TCleanupItem type. |
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247 |
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248 The most common usage is to put a cleanup item onto the cleanup stack using |
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249 CleanupStack::PushL(). The cleanup operation is represented by the private |
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250 static function Cleanup(). |
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251 |
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252 For example, if we declare |
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253 |
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254 @code |
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255 TLibAssoc<A> a; |
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256 @endcode |
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257 |
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258 then we can simply put a cleanup item onto the cleanup stack |
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259 by calling |
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260 |
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261 @code |
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262 CleanupStack::PushL(a); |
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263 @endcode |
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264 |
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265 @see TCleanupItem |
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266 @see CleanupStack::PushL |
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267 */ |
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268 {return(TCleanupItem(Cleanup,this));} |
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269 |
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270 |
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271 |
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272 |
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273 template <class T> |
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274 inline void TLibAssoc<T>::Unload() |
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275 /** |
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276 Deletes the class instance and calls Close() on the associated DLL. |
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277 |
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278 @see RLibrary::Close |
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279 */ |
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280 {Cleanup(this);} |
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281 |
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282 |
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283 |
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284 |
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285 template <class T> |
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286 void TLibAssoc<T>::Cleanup(TAny* aThis) |
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287 /** |
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288 The cleanup operation. |
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289 |
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290 The implementation deletes the class instance and calls Close() on |
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291 the associated DLL. |
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292 |
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293 Note that this function is internal and is not intended for use; it is documented |
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294 for completeness. |
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295 */ |
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296 { |
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297 delete (T*)(((TLibAssoc<T>*)aThis)->iPtr); |
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298 TLibAssocBase::DoUnload(aThis); |
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299 } |
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300 |
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301 #endif |