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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 QtDBus 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 "qdbuspendingcall.h" |
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43 #include "qdbuspendingcall_p.h" |
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44 |
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45 #include "qdbusconnection_p.h" |
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46 #include "qdbusmetatype_p.h" |
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47 #include "qcoreapplication.h" |
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48 #include "qcoreevent.h" |
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49 #include <private/qobject_p.h> |
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50 |
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51 QT_BEGIN_NAMESPACE |
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52 |
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53 /*! |
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54 \class QDBusPendingCall |
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55 \inmodule QtDBus |
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56 \since 4.5 |
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57 |
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58 \brief The QDBusPendingCall class refers to one pending asynchronous call |
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59 |
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60 A QDBusPendingCall object is a reference to a method call that was |
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61 sent over D-Bus without waiting for a reply. QDBusPendingCall is an |
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62 opaque type, meant to be used as a handle for a pending reply. |
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63 |
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64 In most programs, the QDBusPendingCall class will not be used |
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65 directly. It can be safely replaced with the template-based |
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66 QDBusPendingReply, in order to access the contents of the reply or |
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67 wait for it to be complete. |
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68 |
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69 The QDBusPendingCallWatcher class allows one to connect to a signal |
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70 that will indicate when the reply has arrived or if the call has |
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71 timed out. It also provides the |
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72 QDBusPendingCallWatcher::waitForFinished() method which will suspend |
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73 the execution of the program until the reply has arrived. |
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74 |
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75 \note If you create a copy of a QDBusPendingCall object, all |
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76 information will be shared among the many copies. Therefore, |
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77 QDBusPendingCall is an explicitly-shared object and does not |
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78 provide a method of detaching the copies (since they refer |
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79 to the same pending call) |
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80 |
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81 \sa QDBusPendingReply, QDBusPendingCallWatcher, |
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82 QDBusAbstractInterface::asyncCall() |
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83 */ |
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84 |
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85 /*! |
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86 \class QDBusPendingCallWatcher |
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87 \inmodule QtDBus |
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88 \since 4.5 |
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89 |
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90 \brief The QDBusPendingCallWatcher class provides a convenient way for |
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91 waiting for asynchronous replies |
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92 |
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93 The QDBusPendingCallWatcher provides the finished() signal that will be |
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94 emitted when a reply arrives. |
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95 |
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96 It is usually used like the following example: |
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97 |
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98 \snippet doc/src/snippets/code/src.qdbus.qdbuspendingcall.cpp 0 |
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99 |
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100 Note that it is not necessary to keep the original QDBusPendingCall |
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101 object around since QDBusPendingCallWatcher inherits from that class |
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102 too. |
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103 |
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104 The slot connected to by the above code could be something similar |
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105 to the following: |
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106 |
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107 \snippet doc/src/snippets/code/src.qdbus.qdbuspendingcall.cpp 1 |
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108 |
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109 Note the use of QDBusPendingReply to validate the argument types in |
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110 the reply. If the reply did not contain exactly two arguments |
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111 (one string and one QByteArray), QDBusPendingReply::isError() will |
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112 return true. |
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113 |
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114 \sa QDBusPendingReply, QDBusAbstractInterface::asyncCall() |
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115 */ |
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116 |
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117 /*! |
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118 \fn void QDBusPendingCallWatcher::finished(QDBusPendingCallWatcher *self) |
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119 |
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120 This signal is emitted when the pending call has finished and its |
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121 reply is available. The \a self parameter is a pointer to the |
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122 object itself, passed for convenience so that the slot can access |
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123 the properties and determine the contents of the reply. |
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124 */ |
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125 |
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126 void QDBusPendingCallWatcherHelper::add(QDBusPendingCallWatcher *watcher) |
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127 { |
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128 connect(this, SIGNAL(finished()), watcher, SLOT(_q_finished()), Qt::QueuedConnection); |
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129 } |
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130 |
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131 QDBusPendingCallPrivate::~QDBusPendingCallPrivate() |
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132 { |
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133 if (pending) { |
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134 q_dbus_pending_call_cancel(pending); |
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135 q_dbus_pending_call_unref(pending); |
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136 } |
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137 delete watcherHelper; |
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138 } |
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139 |
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140 bool QDBusPendingCallPrivate::setReplyCallback(QObject *target, const char *member) |
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141 { |
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142 receiver = target; |
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143 metaTypes.clear(); |
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144 methodIdx = -1; |
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145 if (!target) |
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146 return true;; // unsetting |
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147 |
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148 if (!member || !*member) { |
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149 // would not be able to deliver a reply |
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150 qWarning("QDBusPendingCall::setReplyCallback: error: cannot deliver a reply to %s::%s (%s)", |
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151 target ? target->metaObject()->className() : "(null)", |
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152 member ? member + 1 : "(null)", |
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153 target ? qPrintable(target->objectName()) : "no name"); |
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154 return false; |
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155 } |
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156 |
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157 methodIdx = QDBusConnectionPrivate::findSlot(target, member + 1, metaTypes); |
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158 if (methodIdx == -1) { |
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159 QByteArray normalizedName = QMetaObject::normalizedSignature(member + 1); |
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160 methodIdx = QDBusConnectionPrivate::findSlot(target, normalizedName, metaTypes); |
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161 } |
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162 if (methodIdx == -1) { |
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163 // would not be able to deliver a reply |
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164 qWarning("QDBusPendingCall::setReplyCallback: error: cannot deliver a reply to %s::%s (%s)", |
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165 target->metaObject()->className(), |
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166 member + 1, qPrintable(target->objectName())); |
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167 return false; |
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168 } |
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169 |
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170 // success |
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171 // construct the expected signature |
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172 int count = metaTypes.count() - 1; |
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173 if (count == 1 && metaTypes.at(1) == QDBusMetaTypeId::message) { |
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174 // wildcard slot, can receive anything, so don't set the signature |
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175 return true; |
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176 } |
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177 |
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178 if (metaTypes.at(count) == QDBusMetaTypeId::message) |
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179 --count; |
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180 |
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181 // QList<int> is actually a vector |
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182 // kids, don't try this at home |
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183 setMetaTypes(count, count ? &metaTypes.at(1) : 0); |
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184 return true; |
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185 } |
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186 |
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187 void QDBusPendingCallPrivate::setMetaTypes(int count, const int *types) |
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188 { |
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189 expectedReplyCount = count; |
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190 if (count == 0) { |
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191 expectedReplySignature = QLatin1String(""); // not null |
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192 return; |
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193 } |
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194 |
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195 QByteArray sig; |
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196 sig.reserve(count + count / 2); |
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197 for (int i = 0; i < count; ++i) { |
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198 const char *typeSig = QDBusMetaType::typeToSignature(types[i]); |
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199 if (!typeSig) { |
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200 qFatal("QDBusPendingReply: type %s is not registered with QtDBus", |
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201 QMetaType::typeName(types[i])); |
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202 } |
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203 sig += typeSig; |
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204 } |
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205 |
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206 expectedReplySignature = QString::fromLatin1(sig); |
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207 } |
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208 |
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209 void QDBusPendingCallPrivate::checkReceivedSignature() |
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210 { |
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211 if (replyMessage.type() == QDBusMessage::InvalidMessage) |
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212 return; // not yet finished - no message to |
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213 // validate against |
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214 if (replyMessage.type() == QDBusMessage::ErrorMessage) |
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215 return; // we don't have to check the signature of an error reply |
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216 |
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217 if (expectedReplySignature.isNull()) |
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218 return; // no signature to validate against |
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219 |
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220 // can't use startsWith here because a null string doesn't start or end with an empty string |
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221 if (!replyMessage.signature().indexOf(expectedReplySignature) == 0) { |
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222 QString errorMsg = QLatin1String("Unexpected reply signature: got \"%1\", " |
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223 "expected \"%2\""); |
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224 replyMessage = QDBusMessage::createError( |
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225 QDBusError::InvalidSignature, |
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226 errorMsg.arg(replyMessage.signature(), expectedReplySignature)); |
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227 |
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228 } |
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229 } |
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230 |
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231 void QDBusPendingCallPrivate::waitForFinished() |
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232 { |
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233 if (replyMessage.type() != QDBusMessage::InvalidMessage) |
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234 return; // already finished |
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235 |
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236 connection->waitForFinished(this); |
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237 } |
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238 |
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239 /*! |
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240 Creates a copy of the \a other pending asynchronous call. Note |
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241 that both objects will refer to the same pending call. |
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242 */ |
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243 QDBusPendingCall::QDBusPendingCall(const QDBusPendingCall &other) |
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244 : d(other.d) |
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245 { |
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246 } |
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247 |
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248 /*! |
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249 \internal |
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250 */ |
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251 QDBusPendingCall::QDBusPendingCall(QDBusPendingCallPrivate *dd) |
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252 : d(dd) |
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253 { |
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254 } |
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255 |
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256 /*! |
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257 Destroys this copy of the QDBusPendingCall object. If this copy is |
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258 also the last copy of a pending asynchronous call, the call will |
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259 be canceled and no further notifications will be received. There |
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260 will be no way of accessing the reply's contents when it arrives. |
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261 */ |
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262 QDBusPendingCall::~QDBusPendingCall() |
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263 { |
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264 // d deleted by QExplicitlySharedDataPointer |
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265 } |
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266 |
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267 |
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268 /*! |
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269 Creates a copy of the \a other pending asynchronous call and drops |
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270 the reference to the previously-referenced call. Note that both |
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271 objects will refer to the same pending call after this function. |
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272 |
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273 If this object contained the last reference of a pending |
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274 asynchronous call, the call will be canceled and no further |
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275 notifications will be received. There will be no way of accessing |
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276 the reply's contents when it arrives. |
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277 */ |
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278 QDBusPendingCall &QDBusPendingCall::operator=(const QDBusPendingCall &other) |
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279 { |
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280 d = other.d; |
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281 return *this; |
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282 } |
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283 |
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284 /*! |
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285 \fn bool QDBusPendingCallWatcher::isFinished() const |
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286 |
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287 Returns true if the pending call has finished processing and the |
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288 reply has been received. |
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289 |
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290 Note that this function only changes state if you call |
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291 waitForFinished() or if an external D-Bus event happens, which in |
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292 general only happens if you return to the event loop execution. |
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293 |
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294 \sa QDBusPendingReply::isFinished() |
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295 */ |
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296 /*! |
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297 \fn bool QDBusPendingReply::isFinished() const |
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298 |
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299 Returns true if the pending call has finished processing and the |
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300 reply has been received. If this function returns true, the |
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301 isError(), error() and reply() methods should return valid |
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302 information. |
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303 |
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304 Note that this function only changes state if you call |
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305 waitForFinished() or if an external D-Bus event happens, which in |
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306 general only happens if you return to the event loop execution. |
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307 |
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308 \sa QDBusPendingCallWatcher::isFinished() |
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309 */ |
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310 |
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311 bool QDBusPendingCall::isFinished() const |
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312 { |
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313 return d && (d->replyMessage.type() != QDBusMessage::InvalidMessage); |
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314 } |
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315 |
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316 void QDBusPendingCall::waitForFinished() |
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317 { |
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318 if (d) d->waitForFinished(); |
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319 } |
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320 |
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321 /*! |
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322 \fn bool QDBusPendingReply::isValid() const |
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323 |
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324 Returns true if the reply contains a normal reply message, false |
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325 if it contains anything else. |
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326 |
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327 If the pending call has not finished processing, this function |
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328 return false. |
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329 */ |
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330 bool QDBusPendingCall::isValid() const |
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331 { |
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332 return d ? d->replyMessage.type() == QDBusMessage::ReplyMessage : false; |
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333 } |
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334 |
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335 /*! |
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336 \fn bool QDBusPendingReply::isError() const |
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337 |
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338 Returns true if the reply contains an error message, false if it |
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339 contains a normal method reply. |
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340 |
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341 If the pending call has not finished processing, this function |
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342 also returns true. |
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343 */ |
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344 bool QDBusPendingCall::isError() const |
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345 { |
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346 return d ? d->replyMessage.type() == QDBusMessage::ErrorMessage : true; |
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347 } |
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348 |
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349 /*! |
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350 \fn QDBusError QDBusPendingReply::error() const |
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351 |
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352 Retrieves the error content of the reply message, if it has |
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353 finished processing. If the reply message has not finished |
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354 processing or if it contains a normal reply message (non-error), |
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355 this function returns an invalid QDBusError. |
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356 */ |
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357 QDBusError QDBusPendingCall::error() const |
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358 { |
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359 if (d) |
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360 return d->replyMessage; |
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361 |
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362 // not connected, return an error |
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363 QDBusError err = QDBusError(QDBusError::Disconnected, |
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364 QLatin1String("Not connected to D-Bus server")); |
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365 return err; |
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366 } |
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367 |
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368 /*! |
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369 \fn QDBusMessage QDBusPendingReply::reply() const |
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370 |
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371 Retrieves the reply message received for the asynchronous call |
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372 that was sent, if it has finished processing. If the pending call |
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373 is not finished, this function returns a QDBusMessage of type |
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374 QDBusMessage::InvalidMessage. |
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375 |
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376 After it has finished processing, the message type will either be |
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377 an error message or a normal method reply message. |
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378 */ |
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379 QDBusMessage QDBusPendingCall::reply() const |
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380 { |
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381 return d ? d->replyMessage : QDBusMessage::createError(error()); |
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382 } |
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383 |
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384 #if 0 |
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385 /*! |
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386 Sets the slot \a member in object \a target to be called when the |
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387 reply arrives. The slot's parameter list must match the reply |
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388 message's arguments for it to be called. |
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389 |
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390 It may, optionally, contain a QDBusMessage final parameter. If it |
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391 is present, the parameter will contain the reply message object. |
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392 |
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393 The callback will not be called if the reply is an error message. |
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394 |
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395 This function returns true if it could set the callback, false |
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396 otherwise. It is not a guarantee that the callback will be |
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397 called. |
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398 |
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399 \warning QDBusPendingCall only supports one callback per pending |
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400 asynchronous call, even if multiple QDBusPendingCall |
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401 objects are referencing the same pending call. |
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402 */ |
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403 bool QDBusPendingCall::setReplyCallback(QObject *target, const char *member) |
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404 { |
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405 if (!d) |
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406 return false; |
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407 |
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408 return d->setReplyCallback(target, member); |
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409 } |
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410 #endif |
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411 |
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412 /*! |
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413 \since 4.6 |
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414 Creates a QDBusPendingCall object based on the error condition |
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415 \a error. The resulting pending call object will be in the |
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416 "finished" state and QDBusPendingReply::isError() will return true. |
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417 |
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418 \sa fromCompletedCall() |
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419 */ |
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420 QDBusPendingCall QDBusPendingCall::fromError(const QDBusError &error) |
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421 { |
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422 return fromCompletedCall(QDBusMessage::createError(error)); |
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423 } |
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424 |
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425 /*! |
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426 \since 4.6 |
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427 Creates a QDBusPendingCall object based on the message \a msg. |
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428 The message must be of type QDBusMessage::ErrorMessage or |
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429 QDBusMessage::ReplyMessage (that is, a message that is typical |
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430 of a completed call). |
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431 |
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432 This function is useful for code that requires simulating a pending |
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433 call, but that has already finished. |
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434 |
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435 \sa fromError() |
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436 */ |
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437 QDBusPendingCall QDBusPendingCall::fromCompletedCall(const QDBusMessage &msg) |
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438 { |
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439 QDBusPendingCallPrivate *d = 0; |
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440 if (msg.type() == QDBusMessage::ErrorMessage || |
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441 msg.type() == QDBusMessage::ReplyMessage) { |
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442 d = new QDBusPendingCallPrivate; |
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443 d->replyMessage = msg; |
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444 d->connection = 0; |
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445 } |
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446 |
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447 return QDBusPendingCall(d); |
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448 } |
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449 |
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450 |
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451 class QDBusPendingCallWatcherPrivate: public QObjectPrivate |
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452 { |
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453 public: |
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454 void _q_finished(); |
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455 |
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456 Q_DECLARE_PUBLIC(QDBusPendingCallWatcher) |
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457 }; |
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458 |
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459 inline void QDBusPendingCallWatcherPrivate::_q_finished() |
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460 { |
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461 Q_Q(QDBusPendingCallWatcher); |
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462 emit q->finished(q); |
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463 } |
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464 |
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465 /*! |
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466 Creates a QDBusPendingCallWatcher object to watch for replies on the |
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467 asynchronous pending call \a call and sets this object's parent |
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468 to \a parent. |
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469 */ |
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470 QDBusPendingCallWatcher::QDBusPendingCallWatcher(const QDBusPendingCall &call, QObject *parent) |
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471 : QObject(*new QDBusPendingCallWatcherPrivate, parent), QDBusPendingCall(call) |
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472 { |
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473 if (d) { // QDBusPendingCall::d |
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474 if (!d->watcherHelper) { |
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475 d->watcherHelper = new QDBusPendingCallWatcherHelper; |
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476 if (isFinished()) { |
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477 // cause a signal emission anyways |
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478 QMetaObject::invokeMethod(d->watcherHelper, "finished", Qt::QueuedConnection); |
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479 } |
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480 } |
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481 d->watcherHelper->add(this); |
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482 } |
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483 } |
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484 |
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485 /*! |
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486 Destroys this object. If this QDBusPendingCallWatcher object was the |
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487 last reference to the unfinished pending call, the call will be |
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488 canceled. |
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489 */ |
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490 QDBusPendingCallWatcher::~QDBusPendingCallWatcher() |
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491 { |
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492 } |
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493 |
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494 /*! |
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495 \fn void QDBusPendingCallWatcher::waitForFinished() |
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496 |
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497 Suspends the execution of the calling thread until the reply is |
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498 received and processed. After this function returns, isFinished() |
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499 should return true, indicating the reply's contents are ready to |
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500 be processed. |
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501 |
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502 \sa QDBusPendingReply::waitForFinished() |
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503 */ |
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504 void QDBusPendingCallWatcher::waitForFinished() |
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505 { |
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506 if (d) { |
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507 d->waitForFinished(); |
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508 |
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509 // our signals were queued, so deliver them |
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510 QCoreApplication::sendPostedEvents(d->watcherHelper, QEvent::MetaCall); |
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511 QCoreApplication::sendPostedEvents(this, QEvent::MetaCall); |
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512 } |
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513 } |
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514 QT_END_NAMESPACE |
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515 |
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516 #include "moc_qdbuspendingcall.cpp" |