qdbusabstractinterface.cpp

QT 开发环境里面一个很重要的文件

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#include "qdbusabstractinterface.h"

#include "qdbusabstractinterface_p.h"
#include "qdbusmetaobject_p.h"
#include "qdbusutil_p.h"

#include <QDebug>

QDBusAbstractInterfacePrivate::QDBusAbstractInterfacePrivate(const QString &serv,
                                                             const QString &p,
                                                             const QString &iface,
                                                             const QDBusConnection& con,
                                                             bool isDynamic)
    : connection(con), service(serv), path(p), interface(iface), isValid(true)
{
    if (isDynamic) {
        // QDBusInterface: service and object path can't be empty, but interface can
        Q_ASSERT_X(QDBusUtil::isValidBusName(service),
                   "QDBusInterface::QDBusInterface", "Invalid service name");
        Q_ASSERT_X(QDBusUtil::isValidObjectPath(path),
                   "QDBusInterface::QDBusInterface", "Invalid object path given");
        Q_ASSERT_X(interface.isEmpty() || QDBusUtil::isValidInterfaceName(interface),
                   "QDBusInterface::QDBusInterface", "Invalid interface name");
    } else {
        // all others: service and path can be empty here, but interface can't
        Q_ASSERT_X(service.isEmpty() || QDBusUtil::isValidBusName(service),
                   "QDBusAbstractInterface::QDBusAbstractInterface", "Invalid service name");
        Q_ASSERT_X(path.isEmpty() || QDBusUtil::isValidObjectPath(path),
                   "QDBusAbstractInterface::QDBusAbstractInterface", "Invalid object path given");
        Q_ASSERT_X(QDBusUtil::isValidInterfaceName(interface),
                   "QDBusAbstractInterface::QDBusAbstractInterface", "Invalid interface class!");
    }

    if (!connection.isConnected()) {
        lastError = QDBusError(QDBusError::Disconnected,
                               QLatin1String("Not connected to D-Bus server"));
        isValid = false;
    } else if (!service.isEmpty()) {
        // check if it's there first -- FIXME: add binding mode
        QString owner = connectionPrivate()->getNameOwner(service); // verify the name owner
        if (owner.isEmpty()) {
            isValid = false;
            lastError = connectionPrivate()->lastError;
        }
    }
}

QVariant QDBusAbstractInterfacePrivate::property(const QMetaProperty &mp) const
{
    if (!connection.isConnected())    // not connected
        return QVariant();

    // try to read this property
    QDBusMessage msg = QDBusMessage::createMethodCall(service, path,
                                                      QLatin1String(DBUS_INTERFACE_PROPERTIES),
                                                      QLatin1String("Get"));
    msg << interface << QString::fromUtf8(mp.name());
    QDBusMessage reply = connection.call(msg, QDBus::Block);

    if (reply.type() == QDBusMessage::ReplyMessage && reply.arguments().count() == 1 &&
        reply.signature() == QLatin1String("v")) {
        QVariant value = qvariant_cast<QDBusVariant>(reply.arguments().at(0)).variant();

        // make sure the type is right
        if (qstrcmp(mp.typeName(), value.typeName()) == 0) {
            if (mp.type() == QVariant::LastType)
                // QVariant is special in this context
                return qvariant_cast<QDBusVariant>(reply.arguments().at(0)).variant();

            return value;
        }
    }

    // there was an error...
    if (reply.type() == QDBusMessage::ErrorMessage)
        lastError = reply;
    else if (reply.signature() != QLatin1String("v")) {
        QString errmsg = QLatin1String("Invalid signature `%1' in return from call to "
                                       DBUS_INTERFACE_PROPERTIES);
        lastError = QDBusError(QDBusError::InvalidSignature, errmsg.arg(reply.signature()));
    } else {
        QString errmsg = QLatin1String("Unexpected type `%1' when retrieving property "
                                       "`%2 %3.%4'");
        lastError = QDBusError(QDBusError::InvalidSignature,
                               errmsg.arg(QLatin1String(reply.arguments().at(0).typeName()),
                                          QLatin1String(mp.typeName()),
                                          interface, QString::fromUtf8(mp.name())));
    }

    return QVariant();
}

void QDBusAbstractInterfacePrivate::setProperty(const QMetaProperty &mp, const QVariant &value)
{
    if (!connection.isConnected())    // not connected
        return;

    // send the value
    QDBusMessage msg = QDBusMessage::createMethodCall(service, path,
                                                QLatin1String(DBUS_INTERFACE_PROPERTIES),
                                                QLatin1String("Set"));
    msg << interface << QString::fromUtf8(mp.name()) << qVariantFromValue(QDBusVariant(value));
    QDBusMessage reply = connection.call(msg, QDBus::Block);

    if (reply.type() != QDBusMessage::ReplyMessage)
        lastError = reply;
}

void QDBusAbstractInterfacePrivate::_q_serviceOwnerChanged(const QString &name,
                                                           const QString &oldOwner,
                                                           const QString &newOwner)
{
    Q_UNUSED(oldOwner);
    //qDebug() << "QDBusAbstractInterfacePrivate serviceOwnerChanged" << name << oldOwner << newOwner;
    if (name == service)
        isValid = !newOwner.isEmpty();
}


/*!
    \class QDBusAbstractInterface
    \inmodule QtDBus
    \since 4.2

    \brief The QDBusAbstractInterface class is the base class for all D-Bus interfaces in the QtDBus binding, allowing access to remote interfaces

    Generated-code classes also derive from QDBusAbstractInterface, all methods described here are also
    valid for generated-code classes. In addition to those described here, generated-code classes
    provide member functions for the remote methods, which allow for compile-time checking of the
    correct parameters and return values, as well as property type-matching and signal
    parameter-matching.

    \sa {dbusxml2cpp.html}{The dbusxml2cpp compiler}, QDBusInterface
*/

/*!
    \internal
    This is the constructor called from QDBusInterface::QDBusInterface.
*/
QDBusAbstractInterface::QDBusAbstractInterface(QDBusAbstractInterfacePrivate &d, QObject *parent)
    : QObject(d, parent)
{
    // keep track of the service owner
    QObject::connect(d_func()->connectionPrivate(), SIGNAL(serviceOwnerChanged(QString,QString,QString)),
                     this, SLOT(_q_serviceOwnerChanged(QString,QString,QString)));
}

/*!
    \internal
    This is the constructor called from static classes derived from
    QDBusAbstractInterface (i.e., those generated by dbusxml2cpp).
*/
QDBusAbstractInterface::QDBusAbstractInterface(const QString &service, const QString &path,
                                               const char *interface, const QDBusConnection &con,
                                               QObject *parent)
    : QObject(*new QDBusAbstractInterfacePrivate(service, path, QString::fromLatin1(interface),
                                                 con, false), parent)
{
    // keep track of the service owner
    QObject::connect(d_func()->connectionPrivate(), SIGNAL(serviceOwnerChanged(QString,QString,QString)),
                     this, SLOT(_q_serviceOwnerChanged(QString,QString,QString)));
}

/*!
    Releases this object's resources.
*/
QDBusAbstractInterface::~QDBusAbstractInterface()
{
}

/*!
    Returns true if this is a valid reference to a remote object. It returns false if
    there was an error during the creation of this interface (for instance, if the remote
    application does not exist).

    Note: when dealing with remote objects, it is not always possible to determine if it
    exists when creating a QDBusInterface.
*/
bool QDBusAbstractInterface::isValid() const
{
    return d_func()->isValid;
}

/*!
    Returns the connection this interface is assocated with.
*/
QDBusConnection QDBusAbstractInterface::connection() const
{
    return d_func()->connection;
}

/*!
    Returns the name of the service this interface is associated with.
*/
QString QDBusAbstractInterface::service() const
{
    return d_func()->service;
}

/*!
    Returns the object path that this interface is associated with.
*/
QString QDBusAbstractInterface::path() const
{
    return d_func()->path;
}

/*!
    Returns the name of this interface.
*/
QString QDBusAbstractInterface::interface() const
{
    return d_func()->interface;
}

/*!
    Returns the error the last operation produced, or an invalid error if the last operation did not
    produce an error.
*/
QDBusError QDBusAbstractInterface::lastError() const
{
    return d_func()->lastError;
}

/*!
    Places a call to the remote method specified by \a method on this interface, using \a args as
    arguments. This function returns the message that was received as a reply, which can be a normal
    QDBusMessage::ReplyMessage (indicating success) or QDBusMessage::ErrorMessage (if the call
    failed). The \a mode parameter specifies how this call should be placed.

    If the call succeeds, lastError() will be cleared; otherwise, it will contain the error this
    call produced.

    Normally, you should place calls using call().