diff options
author | Thiago Macieira <thiago.macieira@intel.com> | 2013-01-11 11:25:28 -0800 |
---|---|---|
committer | The Qt Project <gerrit-noreply@qt-project.org> | 2013-01-14 13:03:50 +0100 |
commit | dc131e3a5378d84026941e6626db524688b988f4 (patch) | |
tree | d1a172da2b4b87f046b08508e7d333e070ccb1e9 /src/dbus | |
parent | 9110d4f1ed65f02d8bbcb81ed0634d5a38c2bf9f (diff) |
Make QDBusPendingReply behave like QDBusReply when dealing with errors
QDBusReply allows one to extract a QVariant and the type reply from an
error reply and getting a default-constructed value. This is useful when
a valid reply can never contain the default-constructed value (0, false,
empty strings, empty arrays, etc.), so it simplifies error checking.
More importantly, qdbusxml2cpp was changed a while ago from generating
QDBusReply to generating QDBusPendingReply, so we need to have the same
behavior.
Task-number: QTBUG-29046
Change-Id: Ia873b9fd4311c0d4e94f0ef623ba405c20bc0e8c
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Diffstat (limited to 'src/dbus')
-rw-r--r-- | src/dbus/qdbuspendingreply.cpp | 28 | ||||
-rw-r--r-- | src/dbus/qdbuspendingreply.h | 4 |
2 files changed, 23 insertions, 9 deletions
diff --git a/src/dbus/qdbuspendingreply.cpp b/src/dbus/qdbuspendingreply.cpp index 3d63c6a7fa..97d1b21a75 100644 --- a/src/dbus/qdbuspendingreply.cpp +++ b/src/dbus/qdbuspendingreply.cpp @@ -185,6 +185,11 @@ function's return value is undefined (will probably cause an assertion failure), so it is important to verify that the processing is finished and the reply is valid. + + If the reply does not contain an argument at position \a index or if the + reply was an error, this function returns an invalid QVariant. Since D-Bus + messages can never contain invalid QVariants, this return can be used to + detect an error condition. */ /*! @@ -197,6 +202,11 @@ Note that, if the reply hasn't arrived, this function causes the calling thread to block until the reply is processed. + + If the reply does not contain an argument at position \c Index or if the + reply was an error, this function returns a \c Type object that is default + constructed, which may be indistinguishable from a valid value. To reliably + determine whether the message was an error, use isError(). */ /*! @@ -211,6 +221,10 @@ Note that, if the reply hasn't arrived, this function causes the calling thread to block until the reply is processed. + + If the reply is an error reply, this function returns a default-constructed + \c T1 object, which may be indistinguishable from a valid value. To + reliably determine whether the message was an error, use isError(). */ /*! @@ -225,6 +239,10 @@ Note that, if the reply hasn't arrived, this function causes the calling thread to block until the reply is processed. + + If the reply is an error reply, this function returns a default-constructed + \c T1 object, which may be indistinguishable from a valid value. To + reliably determine whether the message was an error, use isError(). */ /*! @@ -260,14 +278,12 @@ void QDBusPendingReplyData::assign(const QDBusMessage &message) QVariant QDBusPendingReplyData::argumentAt(int index) const { - if (d) - d->waitForFinished(); // bypasses "const" + if (!d) + return QVariant(); - Q_ASSERT_X(d && index >= 0 && index < d->replyMessage.arguments().count(), - "QDBusPendingReply::argumentAt", - "Index out of bounds"); + d->waitForFinished(); // bypasses "const" - return d->replyMessage.arguments().at(index); + return d->replyMessage.arguments().value(index); } void QDBusPendingReplyData::setMetaTypes(int count, const int *types) diff --git a/src/dbus/qdbuspendingreply.h b/src/dbus/qdbuspendingreply.h index 47a82363db..6511d2df2c 100644 --- a/src/dbus/qdbuspendingreply.h +++ b/src/dbus/qdbuspendingreply.h @@ -168,9 +168,7 @@ public: template<int Index> inline const typename Select<Index>::Type argumentAt() const { - // static assert? - Q_ASSERT_X(Index < count() && Index >= 0, "QDBusPendingReply::argumentAt", - "Index out of bounds"); + Q_STATIC_ASSERT_X(Index >= 0 && Index < Count, "Index out of bounds"); typedef typename Select<Index>::Type ResultType; return qdbus_cast<ResultType>(argumentAt(Index), 0); } |