Qt 4.3: QDBusAbstractInterface Class Reference

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# QDBusAbstractInterface Class Reference
[QtDBus module]

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

     #include <QDBusAbstractInterface>

Inherits QObject.

Inherited by QDBusConnectionInterface and QDBusInterface.

This class was introduced in Qt 4.2.

- List of all members, including inherited members

### Public Functions

- virtual ~QDBusAbstractInterface ()
- QDBusMessage call ( const QString & method, const QVariant & arg1 = QVariant(), const QVariant & arg2 = QVariant(), const QVariant & arg3 = QVariant(), const QVariant & arg4 = QVariant(), const QVariant & arg5 = QVariant(), const QVariant & arg6 = QVariant(), const QVariant & arg7 = QVariant(), const QVariant & arg8 = QVariant() )
- QDBusMessage call ( QDBus::CallMode mode, const QString & method, const QVariant & arg1 = QVariant(), const QVariant & arg2 = QVariant(), const QVariant & arg3 = QVariant(), const QVariant & arg4 = QVariant(), const QVariant & arg5 = QVariant(), const QVariant & arg6 = QVariant(), const QVariant & arg7 = QVariant(), const QVariant & arg8 = QVariant() )
- QDBusMessage callWithArgumentList ( QDBus::CallMode mode, const QString & method, const QList<QVariant> & args )
- bool callWithCallback ( const QString & method, const QList<QVariant> & args, QObject * receiver, const char * returnMethod, const char * errorMethod )
- bool callWithCallback ( const QString & method, const QList<QVariant> & args, QObject * receiver, const char * slot )
- QDBusConnection connection () const
- QString interface () const
- bool isValid () const
- QDBusError lastError () const
- QString path () const
- QString service () const

- 29 public functions inherited from QObject

### Additional Inherited Members

- 1 property inherited from QObject
- 1 public slot inherited from QObject
- 1 signal inherited from QObject
- 5 static public members inherited from QObject
- 7 protected functions inherited from QObject

## Detailed Description

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.

See also The QDBus compiler and QDBusInterface.

## Member Function Documentation

### QDBusAbstractInterface::~QDBusAbstractInterface () `[virtual]`

Releases this object's resources.

### QDBusMessage QDBusAbstractInterface::call ( const QString & method, const QVariant & arg1 = QVariant(), const QVariant & arg2 = QVariant(), const QVariant & arg3 = QVariant(), const QVariant & arg4 = QVariant(), const QVariant & arg5 = QVariant(), const QVariant & arg6 = QVariant(), const QVariant & arg7 = QVariant(), const QVariant & arg8 = QVariant() )

Calls the method method on this interface and passes the parameters to this function to the method.

The parameters to `call` are passed on to the remote function via D-Bus as input arguments. Output arguments are returned in the QDBusMessage reply. If the reply is an error reply, lastError() will also be set to the contents of the error message.

This function can be used with up to 8 parameters, passed in arguments arg1, arg2, arg3, arg4, arg5, arg6, arg7 and arg8. If you need more than 8 parameters or if you have a variable number of parameters to be passed, use callWithArgumentList().

It can be used the following way:

     QString value = retrieveValue();
     QDBusMessage reply;

     QDBusReply<int> api = interface->call(QLatin1String("GetAPIVersion"));
     if (api >= 14)
       reply = interface->call(QLatin1String("ProcessWorkUnicode"), value);
     else
       reply = interface->call(QLatin1String("ProcessWork"), QLatin1String("UTF-8"), value.toUtf8());

This example illustrates function calling with 0, 1 and 2 parameters and illustrates different parameter types passed in each (the first call to `"ProcessWorkUnicode"` will contain one Unicode string, the second call to `"ProcessWork"` will contain one string and one byte array).

### QDBusMessage QDBusAbstractInterface::call ( QDBus::CallMode mode, const QString & method, const QVariant & arg1 = QVariant(), const QVariant & arg2 = QVariant(), const QVariant & arg3 = QVariant(), const QVariant & arg4 = QVariant(), const QVariant & arg5 = QVariant(), const QVariant & arg6 = QVariant(), const QVariant & arg7 = QVariant(), const QVariant & arg8 = QVariant() )

This is an overloaded member function, provided for convenience.

Calls the method method on this interface and passes the parameters to this function to the method. If mode is `NoWaitForReply`, then this function will return immediately after placing the call, without waiting for a reply from the remote method. Otherwise, mode indicates whether this function should activate the Qt Event Loop while waiting for the reply to arrive.

This function can be used with up to 8 parameters, passed in arguments arg1, arg2, arg3, arg4, arg5, arg6, arg7 and arg8. If you need more than 8 parameters or if you have a variable number of parameters to be passed, use callWithArgumentList().

If this function reenters the Qt event loop in order to wait for the reply, it will exclude user input. During the wait, it may deliver signals and other method calls to your application. Therefore, it must be prepared to handle a reentrancy whenever a call is placed with call().

### QDBusMessage QDBusAbstractInterface::callWithArgumentList ( QDBus::CallMode mode, const QString & method, const QList<QVariant> & args )

Places a call to the remote method specified by method on this interface, using 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 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().

Warning: If you use `UseEventLoop`, your code must be prepared to deal with any reentrancy: other method calls and signals may be delivered before this function returns, as well as other Qt queued signals and events.

Note: This function is thread-safe.

### bool QDBusAbstractInterface::callWithCallback ( const QString & method, const QList<QVariant> & args, QObject * receiver, const char * returnMethod, const char * errorMethod )

Places a call to the remote method specified by method on this interface, using args as arguments. This function returns immediately after queueing the call. The reply from the remote function is delivered to the returnMethod on object receiver. If an error occurs, the errorMethod on object receiver is called instead.

This function returns true if the queueing succeeds. It does not indicate that the executed call succeeded. If it fails, the errorMethod is called.

The returnMethod must have as its parameters the types returned by the function call. Optionally, it may have a QDBusMessage parameter as its last or only parameter. The errorMethod must have a QDBusError as its only parameter.

This function was introduced in Qt 4.3.

See also QDBusError and QDBusMessage.

### bool QDBusAbstractInterface::callWithCallback ( const QString & method, const QList<QVariant> & args, QObject * receiver, const char * slot )

This is an overloaded member function, provided for convenience.

This function is deprecated. Please use the overloaded version.

Places a call to the remote method specified by method on this interface, using args as arguments. This function returns immediately after queueing the call. The reply from the remote function or any errors emitted by it are delivered to the slot slot on object receiver.

This function returns true if the queueing succeeded: it does not indicate that the call succeeded. If it failed, the slot will be called with an error message. lastError() will not be set under those circumstances.

See also QDBusError and QDBusMessage.

### QDBusConnection QDBusAbstractInterface::connection () const

Returns the connection this interface is assocated with.

### QString QDBusAbstractInterface::interface () const

Returns the name of this interface.

### bool QDBusAbstractInterface::isValid () const

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.

### QDBusError QDBusAbstractInterface::lastError () const

Returns the error the last operation produced, or an invalid error if the last operation did not produce an error.

### QString QDBusAbstractInterface::path () const

Returns the object path that this interface is associated with.

### QString QDBusAbstractInterface::service () const

Returns the name of the service this interface is associated with.