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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 QtCore 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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27 ** |
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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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30 ** |
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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 "qobjectcleanuphandler.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 QObjectCleanupHandler |
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48 \brief The QObjectCleanupHandler class watches the lifetime of multiple QObjects. |
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49 |
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50 \ingroup objectmodel |
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51 |
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52 A QObjectCleanupHandler is useful whenever you need to know when a |
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53 number of \l{QObject}s that are owned by someone else have been |
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54 deleted. This is important, for example, when referencing memory |
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55 in an application that has been allocated in a shared library. |
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56 |
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57 To keep track of some \l{QObject}s, create a |
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58 QObjectCleanupHandler, and add() the objects you are interested |
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59 in. If you are no longer interested in tracking a particular |
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60 object, use remove() to remove it from the cleanup handler. If an |
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61 object being tracked by the cleanup handler gets deleted by |
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62 someone else it will automatically be removed from the cleanup |
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63 handler. You can delete all the objects in the cleanup handler |
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64 with clear(), or by destroying the cleanup handler. isEmpty() |
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65 returns true if the QObjectCleanupHandler has no objects to keep |
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66 track of. |
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67 |
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68 \sa QPointer |
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69 */ |
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70 |
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71 /*! |
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72 Constructs an empty QObjectCleanupHandler. |
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73 */ |
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74 QObjectCleanupHandler::QObjectCleanupHandler() |
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75 { |
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76 } |
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77 |
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78 /*! |
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79 Destroys the cleanup handler. All objects in this cleanup handler |
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80 will be deleted. |
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81 |
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82 \sa clear() |
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83 */ |
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84 QObjectCleanupHandler::~QObjectCleanupHandler() |
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85 { |
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86 clear(); |
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87 } |
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88 |
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89 /*! |
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90 Adds \a object to this cleanup handler and returns the pointer to |
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91 the object. |
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92 |
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93 \sa remove() |
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94 */ |
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95 QObject *QObjectCleanupHandler::add(QObject* object) |
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96 { |
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97 if (!object) |
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98 return 0; |
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99 |
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100 connect(object, SIGNAL(destroyed(QObject*)), this, SLOT(objectDestroyed(QObject*))); |
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101 cleanupObjects.insert(0, object); |
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102 return object; |
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103 } |
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104 |
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105 /*! |
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106 Removes the \a object from this cleanup handler. The object will |
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107 not be destroyed. |
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108 |
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109 \sa add() |
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110 */ |
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111 void QObjectCleanupHandler::remove(QObject *object) |
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112 { |
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113 int index; |
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114 if ((index = cleanupObjects.indexOf(object)) != -1) { |
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115 cleanupObjects.removeAt(index); |
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116 disconnect(object, SIGNAL(destroyed(QObject*)), this, SLOT(objectDestroyed(QObject*))); |
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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 Returns true if this cleanup handler is empty or if all objects in |
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122 this cleanup handler have been destroyed; otherwise return false. |
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123 |
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124 \sa add() remove() clear() |
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125 */ |
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126 bool QObjectCleanupHandler::isEmpty() const |
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127 { |
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128 return cleanupObjects.isEmpty(); |
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129 } |
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130 |
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131 /*! |
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132 Deletes all objects in this cleanup handler. The cleanup handler |
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133 becomes empty. |
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134 |
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135 \sa isEmpty() |
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136 */ |
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137 void QObjectCleanupHandler::clear() |
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138 { |
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139 while (!cleanupObjects.isEmpty()) |
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140 delete cleanupObjects.takeFirst(); |
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141 } |
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142 |
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143 void QObjectCleanupHandler::objectDestroyed(QObject *object) |
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144 { |
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145 remove(object); |
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146 } |
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147 |
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148 QT_END_NAMESPACE |