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1 /**************************************************************************** |
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2 ** |
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3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). |
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4 ** All rights reserved. |
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5 ** Contact: Nokia Corporation (qt-info@nokia.com) |
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6 ** |
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7 ** This file is part of the Qt3Support module of the Qt Toolkit. |
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8 ** |
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9 ** $QT_BEGIN_LICENSE:LGPL$ |
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10 ** No Commercial Usage |
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11 ** This file contains pre-release code and may not be distributed. |
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12 ** You may use this file in accordance with the terms and conditions |
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13 ** contained in the Technology Preview License Agreement accompanying |
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14 ** this package. |
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15 ** |
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16 ** GNU Lesser General Public License Usage |
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17 ** Alternatively, this file may be used under the terms of the GNU Lesser |
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18 ** General Public License version 2.1 as published by the Free Software |
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19 ** Foundation and appearing in the file LICENSE.LGPL included in the |
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20 ** packaging of this file. Please review the following information to |
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21 ** ensure the GNU Lesser General Public License version 2.1 requirements |
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22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. |
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23 ** |
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24 ** In addition, as a special exception, Nokia gives you certain additional |
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25 ** rights. These rights are described in the Nokia Qt LGPL Exception |
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26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. |
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28 ** If you have questions regarding the use of this file, please contact |
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29 ** Nokia at qt-info@nokia.com. |
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31 ** |
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32 ** |
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33 ** |
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34 ** |
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35 ** |
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36 ** |
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37 ** |
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38 ** $QT_END_LICENSE$ |
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39 ** |
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40 ****************************************************************************/ |
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41 |
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42 #include "q3ptrcollection.h" |
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43 |
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44 QT_BEGIN_NAMESPACE |
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45 |
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46 /*! |
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47 \class Q3PtrCollection |
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48 \reentrant |
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49 \brief The Q3PtrCollection class is the base class of most pointer-based Qt collections. |
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50 |
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51 \compat |
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52 |
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53 The Q3PtrCollection class is an abstract base class for the Qt |
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54 collection classes QDict, Q3PtrList, |
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55 etc. |
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56 |
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57 A Q3PtrCollection only knows about the number of objects in the |
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58 collection and the deletion strategy (see setAutoDelete()). |
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59 |
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60 A collection is implemented using the \c Item (generic collection |
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61 item) type, which is a \c void*. The template classes that create |
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62 the real collections cast the \c Item to the required type. |
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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 \typedef Q3PtrCollection::Item |
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68 |
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69 This type is the generic "item" in a Q3PtrCollection. |
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70 */ |
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71 |
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72 |
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73 /*! |
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74 \fn Q3PtrCollection::Q3PtrCollection() |
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75 |
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76 Constructs a collection. The constructor is protected because |
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77 Q3PtrCollection is an abstract class. |
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78 */ |
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79 |
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80 /*! |
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81 \fn Q3PtrCollection::Q3PtrCollection( const Q3PtrCollection & source ) |
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82 |
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83 Constructs a copy of \a source with autoDelete() set to false. The |
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84 constructor is protected because Q3PtrCollection is an abstract |
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85 class. |
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86 |
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87 Note that if \a source has autoDelete turned on, copying it will |
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88 risk memory leaks, reading freed memory, or both. |
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89 */ |
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90 |
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91 /*! |
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92 \fn Q3PtrCollection::~Q3PtrCollection() |
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93 |
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94 Destroys the collection. The destructor is protected because |
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95 Q3PtrCollection is an abstract class. |
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96 */ |
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97 |
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98 |
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99 /*! |
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100 \fn bool Q3PtrCollection::autoDelete() const |
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101 |
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102 Returns the setting of the auto-delete option. The default is false. |
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103 |
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104 \sa setAutoDelete() |
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105 */ |
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106 |
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107 /*! |
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108 \fn void Q3PtrCollection::setAutoDelete( bool enable ) |
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109 |
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110 Sets the collection to auto-delete its contents if \a enable is |
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111 true and to never delete them if \a enable is false. |
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112 |
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113 If auto-deleting is turned on, all the items in a collection are |
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114 deleted when the collection itself is deleted. This is convenient |
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115 if the collection has the only pointer to the items. |
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116 |
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117 The default setting is false, for safety. If you turn it on, be |
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118 careful about copying the collection - you might find yourself |
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119 with two collections deleting the same items. |
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120 |
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121 Note that the auto-delete setting may also affect other functions |
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122 in subclasses. For example, a subclass that has a remove() |
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123 function will remove the item from its data structure, and if |
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124 auto-delete is enabled, will also delete the item. |
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125 |
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126 \sa autoDelete() |
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127 */ |
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128 |
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129 |
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130 /*! |
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131 \fn virtual uint Q3PtrCollection::count() const |
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132 |
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133 Returns the number of objects in the collection. |
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134 */ |
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135 |
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136 /*! |
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137 \fn virtual void Q3PtrCollection::clear() |
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138 |
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139 Removes all objects from the collection. The objects will be |
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140 deleted if auto-delete has been enabled. |
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141 |
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142 \sa setAutoDelete() |
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143 */ |
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144 |
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145 /*! |
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146 \fn void Q3PtrCollection::deleteItem( Item d ) |
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147 |
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148 Reimplement this function if you want to be able to delete items. |
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149 |
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150 Deletes an item that is about to be removed from the collection. |
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151 |
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152 This function has to reimplemented in the collection template |
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153 classes, and should \e only delete item \a d if auto-delete has |
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154 been enabled. |
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155 |
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156 \warning If you reimplement this function you must also |
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157 reimplement the destructor and call the virtual function clear() |
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158 from your destructor. This is due to the way virtual functions and |
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159 destructors work in C++: Virtual functions in derived classes |
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160 cannot be called from a destructor. If you do not do this, your |
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161 deleteItem() function will not be called when the container is |
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162 destroyed. |
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163 |
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164 \sa newItem(), setAutoDelete() |
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165 */ |
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166 |
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167 /*! |
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168 Virtual function that creates a copy of an object that is about to |
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169 be inserted into the collection. |
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170 |
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171 The default implementation returns the \a d pointer, i.e. no copy |
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172 is made. |
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173 |
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174 This function is seldom reimplemented in the collection template |
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175 classes. It is not common practice to make a copy of something |
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176 that is being inserted. |
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177 |
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178 \sa deleteItem() |
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179 */ |
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180 |
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181 Q3PtrCollection::Item Q3PtrCollection::newItem(Item d) |
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182 { |
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183 return d; // just return reference |
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184 } |
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185 |
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186 QT_END_NAMESPACE |