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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 "qdbusmessage.h" |
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43 #include "qdbusconnection.h" |
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44 #include "qdbusabstractadaptor.h" |
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45 |
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46 #include "qdbuscontext.h" |
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47 #include "qdbuscontext_p.h" |
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48 |
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49 QT_BEGIN_NAMESPACE |
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50 |
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51 QDBusContextPrivate *QDBusContextPrivate::set(QObject *obj, QDBusContextPrivate *newContext) |
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52 { |
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53 // determine if this is an adaptor or not |
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54 if (qobject_cast<QDBusAbstractAdaptor *>(obj)) |
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55 obj = obj->parent(); |
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56 |
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57 Q_ASSERT(obj); |
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58 |
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59 void *ptr = obj->qt_metacast("QDBusContext"); |
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60 QDBusContext *q_ptr = reinterpret_cast<QDBusContext *>(ptr); |
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61 if (q_ptr) { |
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62 QDBusContextPrivate *old = q_ptr->d_ptr; |
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63 q_ptr->d_ptr = newContext; |
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64 return old; |
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65 } |
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66 |
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67 return 0; |
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68 } |
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69 |
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70 /*! |
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71 \since 4.3 |
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72 \class QDBusContext |
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73 \inmodule QtDBus |
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74 |
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75 \brief The QDBusContext class allows slots to determine the D-Bus context of the calls. |
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76 |
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77 When a slot is called in an object due to a signal delivery or due |
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78 to a remote method call, it is sometimes necessary to know the |
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79 context in which that happened. In particular, if the slot |
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80 determines that it wants to send the reply at a later opportunity |
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81 or if it wants to reply with an error, the context is needed. |
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82 |
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83 The QDBusContext class is an alternative to accessing the context |
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84 that doesn't involve modifying the code generated by the \l |
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85 {QtDBus XML Compiler (qdbusxml2cpp)}. |
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86 |
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87 QDBusContext is used by subclassing it from the objects being |
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88 exported using QDBusConnection::registerObject(). The following |
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89 example illustrates the usage: |
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90 |
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91 \snippet doc/src/snippets/code/src_qdbus_qdbuscontext.cpp 0 |
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92 |
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93 The example illustrates the two typical uses, that of sending |
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94 error replies and that of delayed replies. |
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95 |
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96 Note: do not subclass QDBusContext and QDBusAbstractAdaptor at the |
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97 same time. QDBusContext should appear in the real object, not the |
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98 adaptor. If it's necessary from the adaptor code to determine the |
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99 context, use a public inheritance and access the functions via |
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100 QObject::parent(). |
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101 */ |
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102 |
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103 /*! |
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104 Constructs an empty QDBusContext. |
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105 */ |
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106 QDBusContext::QDBusContext() |
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107 : d_ptr(0) |
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108 { |
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109 } |
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110 |
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111 /*! |
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112 An empty destructor. |
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113 */ |
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114 QDBusContext::~QDBusContext() |
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115 { |
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116 } |
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117 |
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118 /*! |
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119 Returns true if we are processing a D-Bus call. If this function |
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120 returns true, the rest of the functions in this class are |
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121 available. |
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122 |
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123 Accessing those functions when this function returns false is |
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124 undefined and may lead to crashes. |
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125 */ |
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126 bool QDBusContext::calledFromDBus() const |
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127 { |
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128 return d_ptr; |
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129 } |
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130 |
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131 /*! |
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132 Returns the connection from which this call was received. |
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133 */ |
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134 QDBusConnection QDBusContext::connection() const |
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135 { |
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136 return d_ptr->connection; |
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137 } |
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138 |
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139 /*! |
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140 Returns the message that generated this call. |
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141 */ |
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142 const QDBusMessage &QDBusContext::message() const |
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143 { |
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144 return d_ptr->message; |
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145 } |
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146 |
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147 /*! |
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148 Returns true if this call will have a delayed reply. |
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149 |
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150 \sa setDelayedReply() |
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151 */ |
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152 bool QDBusContext::isDelayedReply() const |
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153 { |
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154 return message().isDelayedReply(); |
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155 } |
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156 |
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157 /*! |
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158 Sets whether this call will have a delayed reply or not. |
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159 |
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160 If \a enable is false, QtDBus will automatically generate a reply |
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161 back to the caller, if needed, as soon as the called slot returns. |
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162 |
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163 If \a enable is true, QtDBus will not generate automatic |
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164 replies. It will also ignore the return value from the slot and |
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165 any output parameters. Instead, the called object is responsible |
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166 for storing the incoming message and send a reply or error at a |
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167 later time. |
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168 |
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169 Failing to send a reply will result in an automatic timeout error |
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170 being generated by D-Bus. |
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171 */ |
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172 void QDBusContext::setDelayedReply(bool enable) const |
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173 { |
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174 message().setDelayedReply(enable); |
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175 } |
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176 |
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177 /*! |
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178 Sends an error \a name as a reply to the caller. The optional \a |
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179 msg parameter is a human-readable text explaining the failure. |
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180 |
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181 If an error is sent, the return value and any output parameters |
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182 from the called slot will be ignored by QtDBus. |
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183 */ |
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184 void QDBusContext::sendErrorReply(const QString &name, const QString &msg) const |
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185 { |
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186 setDelayedReply(true); |
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187 connection().send(message().createErrorReply(name, msg)); |
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188 } |
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189 |
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190 /*! |
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191 \overload |
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192 Sends an error \a type as a reply to the caller. The optional \a |
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193 msg parameter is a human-readable text explaining the failure. |
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194 |
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195 If an error is sent, the return value and any output parameters |
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196 from the called slot will be ignored by QtDBus. |
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197 */ |
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198 void QDBusContext::sendErrorReply(QDBusError::ErrorType type, const QString &msg) const |
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199 { |
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200 setDelayedReply(true); |
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201 connection().send(message().createErrorReply(type, msg)); |
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202 } |
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203 |
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204 QT_END_NAMESPACE |