QScxmlStateMachine Class

Member Function Documentation

QStringList QScxmlStateMachine::activeStateNames(bool compress = true) const

Retrieves a list of state names of all active states.

When a state is active, all its parent states are active by definition. When compress is true (the default), the parent states will be filtered out and only the leaf states will be returned. When it is false, the full list of active states will be returned.

void QScxmlStateMachine::cancelDelayedEvent(const QString &sendId)

Cancels a delayed event with the specified sendId.

QMetaObject::Connection QScxmlStateMachine::connectToState(const QString &scxmlStateName, const QObject *receiver, const char *method, Qt::ConnectionType type = Qt::AutoConnection)

Creates a connection of the given type from the state identified by scxmlStateName to the method in the receiver object. The receiver's method may contain a boolean argument that indicates whether the state connected became active or inactive.

Returns a handle to the connection, which can be used later to disconnect.

BindingMethod QScxmlStateMachine::dataBinding() const

Returns the binding method used by the state machine.

QScxmlDataModel *QScxmlStateMachine::dataModel() const

Returns the data model used by the state machine.

Note: Getter function for property dataModel.

See also setDataModel().

[signal] void QScxmlStateMachine::eventOccurred(const QScxmlEvent &event)

This signal is emitted when the SCXML event event occurs. This signal is emitted for all events.

See also externalEventOccurred().

[signal] void QScxmlStateMachine::externalEventOccurred(const QScxmlEvent &event)

This signal is emitted for each <send> element in the SCXML file that contains the attribute type="qt:signal". The event that occurred is specified by event.

See also eventOccurred().

[signal] void QScxmlStateMachine::finished()

This signal is emitted when the state machine reaches a top-level final state.

See also running.

[static] QScxmlStateMachine *QScxmlStateMachine::fromData(QIODevice *data, const QString &fileName = QString())

Creates a state machine by reading from the QIODevice specified by data.

This method will always return a state machine. If errors occur while reading the SCXML file, fileName, the state machine cannot be started. The errors can be retrieved by calling the parseErrors() method.

See also parseErrors().

[static] QScxmlStateMachine *QScxmlStateMachine::fromFile(const QString &fileName)

Creates a state machine from the SCXML file specified by fileName.

This method will always return a state machine. If errors occur while reading the SCXML file, the state machine cannot be started. The errors can be retrieved by calling the parseErrors() method.

See also parseErrors().

[static] QString QScxmlStateMachine::generateSessionId(const QString &prefix)

Generates a unique ID by appending a unique number to the prefix.

The number is only unique within a single run of an application. This method is used when an invoked service does not have an ID set (the id attribute in <invoke>).

[slot] bool QScxmlStateMachine::init()

Initializes the state machine.

State machine initialization consists of calling QScxmlDataModel::setup(), setting the initial values for <data> elements, and executing any <script> tags of the <scxml> tag. The initial data values are taken from the initialValues property.

Returns false if parse errors occur or if any of the initialization steps fail. Returns true otherwise.

bool QScxmlStateMachine::isActive(const QString &scxmlStateName) const

Returns true if the state specified by scxmlStateName is active, false otherwise.

bool QScxmlStateMachine::isDispatchableTarget(const QString &target) const

Returns true if a message to target can be dispatched by this state machine.

Valid targets are:

• #_parent for the parent state machine if the current state machine is started by <invoke>
• #_internal for the current state machine
• #_scxml_sessionid, where sessionid is the session ID of the current state machine
• #_servicename, where servicename is the ID or name of a service started with <invoke> by this state machine

bool QScxmlStateMachine::isInvoked() const

Returns true when the state machine was started as a service with the <invoke> element, false otherwise.

bool QScxmlStateMachine::isRunning() const

Returns true if the state machine is running, false otherwise.

Note: Getter function for property running.

See also setRunning() and runningChanged().

[signal] void QScxmlStateMachine::log(const QString &label, const QString &msg)

This signal is emitted if a <log> tag is used in the SCXML. label is the value of the label attribute of the <log> tag. msg is the value of the evaluated expr attribute of the <log> tag. If there is no expr attribute, a null string will be returned.

QString QScxmlStateMachine::name() const

Returns the name of the state machine as set by the name attribute of the <scxml> tag.

QVector<QScxmlError> QScxmlStateMachine::parseErrors() const

Returns the list of parse errors that occurred while creating a state machine from an SCXML file.

[signal] void QScxmlStateMachine::reachedStableState()

This signal is emitted when the event queue is empty at the end of a macro step or when a final state is reached.

[signal] void QScxmlStateMachine::runningChanged(bool running)

This signal is emitted when the running property is changed with running as argument.

Note: Notifier signal for property running.

QScxmlEventFilter *QScxmlStateMachine::scxmlEventFilter() const

Returns the SCXML event filter if one is set, otherwise returns null.

See also setScxmlEventFilter().

QString QScxmlStateMachine::sessionId() const

Returns the session ID for the current state machine.

The session ID is used for message routing between parent and child state machines. If a state machine is started by an <invoke> element, any event it sends will have the invokeid field set to the session ID. The state machine will use the origin of an event (which is set by the target or targetexpr attribute in a <send> element) to dispatch messages to the correct child state machine.

See also setSessionId() and QScxmlEvent::invokeId().

void QScxmlStateMachine::setDataModel(QScxmlDataModel *model)

Sets the data model for this state machine to model. There is a 1:1 relation between state machines and models. After setting the model once you cannot change it anymore. Any further attempts to set the model using this method will be ignored.

Note: Setter function for property dataModel.

See also dataModel().

void QScxmlStateMachine::setRunning(bool running)

Starts the state machine if running is true, or stops it otherwise.

Note: Setter function for property running.

See also start(), stop(), isRunning(), and runningChanged().

void QScxmlStateMachine::setScxmlEventFilter(QScxmlEventFilter *newFilter)

Sets the newFilter as the SCXML event filter. Passing null will remove the current filter.

See also scxmlEventFilter().

void QScxmlStateMachine::setSessionId(const QString &id)

Sets the session ID for the current state machine to id.

See also sessionId().

[slot] void QScxmlStateMachine::start()

Starts this state machine. The machine will reset its configuration and transition to the initial state. When a final top-level state is entered, the machine will emit the finished() signal.

Note: A state machine will not run without a running event loop, such as the main application event loop started with QCoreApplication::exec() or QApplication::exec().

See also runningChanged(), setRunning(), stop(), and finished().

QStringList QScxmlStateMachine::stateNames(bool compress = true) const

Retrieves a list of state names of all states.

When compress is true (the default), the states that contain child states will be filtered out and only the leaf states will be returned. When it is false, the full list of all states will be returned.

The returned list does not contain the states of possible nested state machines.

[slot] void QScxmlStateMachine::stop()

Stops this state machine. The machine will not execute any further state transitions. Its running property is set to false.

See also runningChanged(), start(), and setRunning().

void QScxmlStateMachine::submitEvent(QScxmlEvent *event)

Submits the SCXML event event to the internal or external event queue depending on the priority of the event.

When a delay is set, the event will be queued for delivery after the timeout has passed.

void QScxmlStateMachine::submitEvent(const QString &eventName)

A utility method to create and submit an external event with the specified eventName as the name.

void QScxmlStateMachine::submitEvent(const QString &eventName, const QVariant &data)

A utility method to create and submit an external event with the specified eventName as the name and data as the payload data.