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39
40#include "qdbusmessage.h"
41#include "qdbusconnection.h"
42#include "qdbusabstractadaptor.h"
43
44#include "qdbuscontext.h"
45#include "qdbuscontext_p.h"
46
47#ifndef QT_NO_DBUS
48
49QT_BEGIN_NAMESPACE
50
51QDBusContextPrivate *QDBusContextPrivate::set(QObject *obj, QDBusContextPrivate *newContext)
52{
53 // determine if this is an adaptor or not
54 if (qobject_cast<QDBusAbstractAdaptor *>(obj))
55 obj = obj->parent();
56
57 Q_ASSERT(obj);
58
59 void *ptr = obj->qt_metacast("QDBusContext");
60 QDBusContext *q_ptr = reinterpret_cast<QDBusContext *>(ptr);
61 if (q_ptr) {
62 QDBusContextPrivate *old = q_ptr->d_ptr;
63 q_ptr->d_ptr = newContext;
64 return old;
65 }
66
67 return 0;
68}
69
70/*!
71 \since 4.3
72 \class QDBusContext
73 \inmodule QtDBus
74
75 \brief The QDBusContext class allows slots to determine the D-Bus context of the calls.
76
77 When a slot is called in an object due to a signal delivery or due
78 to a remote method call, it is sometimes necessary to know the
79 context in which that happened. In particular, if the slot
80 determines that it wants to send the reply at a later opportunity
81 or if it wants to reply with an error, the context is needed.
82
83 The QDBusContext class is an alternative to accessing the context
84 that doesn't involve modifying the code generated by the \l
85 {Qt D-Bus XML compiler (qdbusxml2cpp)}.
86
87 QDBusContext is used by subclassing it from the objects being
88 exported using QDBusConnection::registerObject(). The following
89 example illustrates the usage:
90
91 \snippet code/src_qdbus_qdbuscontext.cpp 0
92
93 The example illustrates the two typical uses, that of sending
94 error replies and that of delayed replies.
95
96 Note: do not subclass QDBusContext and QDBusAbstractAdaptor at the
97 same time. QDBusContext should appear in the real object, not the
98 adaptor. If it's necessary from the adaptor code to determine the
99 context, use a public inheritance and access the functions via
100 QObject::parent().
101*/
102
103/*!
104 Constructs an empty QDBusContext.
105 */
106QDBusContext::QDBusContext()
107 : d_ptr(0)
108{
109}
110
111/*!
112 An empty destructor.
113 */
114QDBusContext::~QDBusContext()
115{
116}
117
118/*!
119 Returns \c true if we are processing a D-Bus call. If this function
120 returns \c true, the rest of the functions in this class are
121 available.
122
123 Accessing those functions when this function returns \c false is
124 undefined and may lead to crashes.
125*/
126bool QDBusContext::calledFromDBus() const
127{
128 return d_ptr;
129}
130
131/*!
132 Returns the connection from which this call was received.
133*/
134QDBusConnection QDBusContext::connection() const
135{
136 return d_ptr->connection;
137}
138
139/*!
140 Returns the message that generated this call.
141*/
142const QDBusMessage &QDBusContext::message() const
143{
144 return d_ptr->message;
145}
146
147/*!
148 Returns \c true if this call will have a delayed reply.
149
150 \sa setDelayedReply()
151*/
152bool QDBusContext::isDelayedReply() const
153{
154 return message().isDelayedReply();
155}
156
157/*!
158 Sets whether this call will have a delayed reply or not.
159
160 If \a enable is false, Qt D-Bus will automatically generate a reply
161 back to the caller, if needed, as soon as the called slot returns.
162
163 If \a enable is true, Qt D-Bus will not generate automatic
164 replies. It will also ignore the return value from the slot and
165 any output parameters. Instead, the called object is responsible
166 for storing the incoming message and send a reply or error at a
167 later time.
168
169 Failing to send a reply will result in an automatic timeout error
170 being generated by D-Bus.
171*/
172void QDBusContext::setDelayedReply(bool enable) const
173{
174 message().setDelayedReply(enable);
175}
176
177/*!
178 Sends an error \a name as a reply to the caller. The optional \a
179 msg parameter is a human-readable text explaining the failure.
180
181 If an error is sent, the return value and any output parameters
182 from the called slot will be ignored by Qt D-Bus.
183*/
184void QDBusContext::sendErrorReply(const QString &name, const QString &msg) const
185{
186 setDelayedReply(true);
187 connection().send(message().createErrorReply(name, msg));
188}
189
190/*!
191 \overload
192 Sends an error \a type as a reply to the caller. The optional \a
193 msg parameter is a human-readable text explaining the failure.
194
195 If an error is sent, the return value and any output parameters
196 from the called slot will be ignored by Qt D-Bus.
197*/
198void QDBusContext::sendErrorReply(QDBusError::ErrorType type, const QString &msg) const
199{
200 setDelayedReply(true);
201 connection().send(message().createErrorReply(type, msg));
202}
203
204QT_END_NAMESPACE
205
206#endif // QT_NO_DBUS
207