QDBusConnection¶

PyQt5.QtDBus.QDBusConnection

Description¶

The QDBusConnection class represents a connection to the D-Bus bus daemon.

This class is the initial point in a D-Bus session. Using it, you can get access to remote objects, interfaces; connect remote signals to your object’s slots; register objects, etc.

D-Bus connections are created using the connectToBus() function, which opens a connection to the server daemon and does the initial handshaking, associating that connection with a name. Further attempts to connect using the same name will return the same connection.

The connection is then torn down using the disconnectFromBus() function.

Once disconnected, calling connectToBus() will not reestablish a connection, you must create a new QDBusConnection instance.

As a convenience for the two most common connection types, the sessionBus() and systemBus() functions return open connections to the session server daemon and the system server daemon, respectively. Those connections are opened when first used and are closed when the QCoreApplication destructor is run.

D-Bus also supports peer-to-peer connections, without the need for a bus server daemon. Using this facility, two applications can talk to each other and exchange messages. This can be achieved by passing an address to connectToBus() function, which was opened by another D-Bus application using QDBusServer.

Classes¶

ConnectionCapabilities

RegisterOptions

Enums¶

BusType

Specifies the type of the bus connection. The valid bus types are:

On the Session Bus, one can find other applications by the same user that are sharing the same desktop session (hence the name). On the System Bus, however, processes shared for the whole system are usually found.

Member	Value	Description
ActivationBus	2	the activation bus, the “alias” for the bus that started the service
SessionBus	0	the session bus, associated with the running desktop session
SystemBus	1	the system bus, used to communicate with system-wide processes

ConnectionCapability

This enum describes the available capabilities for a D-Bus connection.

Methods¶

__init__(str)

Creates a QDBusConnection object attached to the connection with name name.

This does not open the connection. You have to call connectToBus() to open it.

__init__(QDBusConnection): Creates a copy of the other connection.

asyncCall(QDBusMessage, timeout: int = -1) → QDBusPendingCall

Sends the message over this connection and returns immediately. This function is suitable for method calls only. It returns an object of type QDBusPendingCall which can be used to track the status of the reply.

If no reply is received within timeout milliseconds, an automatic error will be delivered indicating the expiration of the call. The default timeout is -1, which will be replaced with an implementation-defined value that is suitable for inter-process communications (generally, 25 seconds). This timeout is also the upper limit for waiting in QDBusPendingCall::waitForFinished().

See the QDBusInterface::asyncCall() function for a more friendly way of placing calls.

baseService() → str

Returns the unique connection name for this connection, if this QDBusConnection object is connected, or an empty QString otherwise.

A Unique Connection Name is a string in the form “:x.xxx” (where x are decimal digits) that is assigned by the D-Bus server daemon upon connection. It uniquely identifies this client in the bus.

This function returns an empty QString for peer-to-peer connections.

call(QDBusMessage, mode: CallMode = Block, timeout: int = -1) → QDBusMessage

Sends the message over this connection and blocks, waiting for a reply, for at most timeout milliseconds. This function is suitable for method calls only. It returns the reply message as its return value, which will be either of type ReplyMessage or ErrorMessage.

If no reply is received within timeout milliseconds, an automatic error will be delivered indicating the expiration of the call. The default timeout is -1, which will be replaced with an implementation-defined value that is suitable for inter-process communications (generally, 25 seconds).

See the QDBusInterface::call() function for a more friendly way of placing calls.

Warning: If mode is BlockWithGui, this function will reenter the Qt event loop in order to wait for the reply. 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 .

callWithCallback(QDBusMessage, PYQT_SLOT, PYQT_SLOT, timeout: int = -1) → bool: TODO

connect(str, str, str, str, PYQT_SLOT) → bool: TODO

connect(str, str, str, str, str, PYQT_SLOT) → bool: TODO

connect(str, str, str, str, Iterable[str], str, PYQT_SLOT) → bool: TODO

connectionCapabilities() → ConnectionCapabilities: Returns the capabilities of this connection as negotiated with the bus server or peer. If this QDBusConnection is not connected, this function returns no capabilities.

@staticmethod connectToBus(BusType, str) → QDBusConnection: Opens a connection of type type to one of the known busses and associate with it the connection name name. Returns a QDBusConnection object associated with that connection.

@staticmethod connectToBus(str, str) → QDBusConnection: Opens a connection to a private bus on address address and associate with it the connection name name. Returns a QDBusConnection object associated with that connection.

@staticmethod connectToPeer(str, str) → QDBusConnection: Opens a peer-to-peer connection on address address and associate with it the connection name name. Returns a QDBusConnection object associated with that connection.

disconnect(str, str, str, str, PYQT_SLOT) → bool: TODO

disconnect(str, str, str, str, str, PYQT_SLOT) → bool: TODO

disconnect(str, str, str, str, Iterable[str], str, PYQT_SLOT) → bool: TODO

@staticmethod disconnectFromBus(str)

Closes the bus connection of name name.

Note that if there are still QDBusConnection objects associated with the same connection, the connection will not be closed until all references are dropped. However, no further references can be created using the QDBusConnection constructor.

@staticmethod disconnectFromPeer(str)

Closes the peer connection of name name.

Note that if there are still QDBusConnection objects associated with the same connection, the connection will not be closed until all references are dropped. However, no further references can be created using the QDBusConnection constructor.

interface() → QDBusConnectionInterface: Returns a QDBusConnectionInterface object that represents the D-Bus server interface on this connection.

isConnected() → bool: TODO

lastError() → QDBusError

Returns the last error that happened in this connection.

This function is provided for low-level code. If you’re using QDBusInterface::call(), error codes are reported by its return value.

Member	Value	Description
ExportAdaptors	TODO	TODO
ExportAllContents	TODO	TODO
ExportAllInvokables	TODO	TODO
ExportAllProperties	TODO	TODO
ExportAllSignal	TODO	TODO
ExportAllSignals	TODO	TODO
ExportAllSlots	TODO	TODO
ExportChildObjects	TODO	TODO
ExportNonScriptableContents	TODO	TODO
ExportNonScriptableInvokables	TODO	TODO
ExportNonScriptableProperties	TODO	TODO
ExportNonScriptableSignals	TODO	TODO
ExportNonScriptableSlots	TODO	TODO
ExportScriptableContents	TODO	TODO
ExportScriptableInvokables	TODO	TODO
ExportScriptableProperties	TODO	TODO
ExportScriptableSignals	TODO	TODO
ExportScriptableSlots	TODO	TODO