QScxmlStateMachine¶

The QScxmlStateMachine class provides an interface to the state machines created from SCXML files. More…

Synopsis¶

Functions¶

def activeStateNames ([compress=true])
def cancelDelayedEvent (sendId)
def connectToEvent (scxmlEventSpec, receiver, method[, type=Qt.AutoConnection])
def connectToState (scxmlStateName, receiver, method[, type=Qt.AutoConnection])
def dataModel ()
def initialValues ()
def invokedServices ()
def isActive (scxmlStateName)
def isActive (stateIndex)
def isDispatchableTarget (target)
def isInitialized ()
def isInvoked ()
def isRunning ()
def loader ()
def name ()
def parseErrors ()
def sessionId ()
def setDataModel (model)
def setInitialValues (initialValues)
def setLoader (loader)
def setRunning (running)
def setTableData (tableData)
def stateNames ([compress=true])
def submitEvent (event)
def submitEvent (eventName)
def submitEvent (eventName, data)
def tableData ()

Slots¶

def init ()
def start ()
def stop ()

Signals¶

def dataModelChanged (model)
def finished ()
def initialValuesChanged (initialValues)
def initializedChanged (initialized)
def invokedServicesChanged (invokedServices)
def loaderChanged (loader)
def log (label, msg)
def reachedStableState ()
def runningChanged (running)
def tableDataChanged (tableData)

Static functions¶

def fromData (data[, fileName=””])
def fromFile (fileName)

Detailed Description¶

QScxmlStateMachine is an implementation of the State Chart XML (SCXML) .

All states that are defined in the SCXML file are accessible as properties of QScxmlStateMachine . These properties are boolean values and indicate whether the state is active or inactive.

Note

The QScxmlStateMachine needs a QEventLoop to work correctly. The event loop is used to implement the delay attribute for events and to schedule the processing of a state machine when events are received from nested (or parent) state machines.

class PySide6.QtScxml.QScxmlStateMachine(metaObject[, parent=None])¶

Parameters

metaObject – PySide6.QtCore.QMetaObject
parent – PySide6.QtCore.QObject

PySide6.QtScxml.QScxmlStateMachine.activeStateNames([compress=true])¶

Parameters: compress – bool
Return type: list of strings

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.

PySide6.QtScxml.QScxmlStateMachine.cancelDelayedEvent(sendId)¶

Parameters: sendId – str

Cancels a delayed event with the specified sendId.

PySide6.QtScxml.QScxmlStateMachine.connectToEvent(scxmlEventSpec, receiver, method[, type=Qt.AutoConnection])¶

Parameters

scxmlEventSpec – str
receiver – PySide6.QtCore.QObject
method – str
type – ConnectionType

Return type

PySide6.QtCore.QMetaObject.Connection

Creates a connection of the specified type from the event specified by scxmlEventSpec to the method in the receiver object. The receiver’s method may take a QScxmlEvent as a parameter. For example:

void mySlot(const QScxmlEvent &event);

In contrast to event specifications in SCXML documents, spaces are not allowed in the scxmlEventSpec here. In order to connect to multiple events with different prefixes, has to be called multiple times.

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

PySide6.QtScxml.QScxmlStateMachine.connectToState(scxmlStateName, receiver, method[, type=Qt.AutoConnection])¶

Parameters

scxmlStateName – str
receiver – PySide6.QtCore.QObject
method – str
type – ConnectionType

Return type

PySide6.QtCore.QMetaObject.Connection

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 take a boolean argument that indicates whether the state connected became active or inactive. For example:

void mySlot(bool active);

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

PySide6.QtScxml.QScxmlStateMachine.dataModel()¶

Return type: PySide6.QtScxml.QScxmlDataModel

This property holds The data model to be used for this state machine..

SCXML data models are described in SCXML Specification - 5 Data Model and Data Manipulation . For more information about supported data models, see SCXML Compliance .

Changing the data model when the state machine has been initialized is not specified in the SCXML standard and leads to undefined behavior.

See also

QScxmlDataModel QScxmlNullDataModel QScxmlCppDataModel

PySide6.QtScxml.QScxmlStateMachine.dataModelChanged(model)¶

Parameters: model – PySide6.QtScxml.QScxmlDataModel

PySide6.QtScxml.QScxmlStateMachine.finished()¶

static PySide6.QtScxml.QScxmlStateMachine.fromData(data[, fileName=""])¶

Parameters

data – PySide6.QtCore.QIODevice
fileName – str

Return type

PySide6.QtScxml.QScxmlStateMachine

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 PySide6.QtScxml.QScxmlStateMachine.fromFile(fileName)¶

Parameters: fileName – str
Return type: PySide6.QtScxml.QScxmlStateMachine

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()

PySide6.QtScxml.QScxmlStateMachine.init()¶

Return type: bool

Initializes the state machine.

State machine initialization consists of calling 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.

PySide6.QtScxml.QScxmlStateMachine.initialValues()¶

Return type

This property holds The initial values to be used for setting up the data model..

See also

init() QScxmlDataModel

PySide6.QtScxml.QScxmlStateMachine.initialValuesChanged(initialValues)¶

Parameters: initialValues –

PySide6.QtScxml.QScxmlStateMachine.initializedChanged(initialized)¶

Parameters: initialized – bool

PySide6.QtScxml.QScxmlStateMachine.invokedServices()¶

Return type

This property holds A list of SCXML services that were invoked from the main state machine (possibly recursively)..

PySide6.QtScxml.QScxmlStateMachine.invokedServicesChanged(invokedServices)¶

Parameters: invokedServices –

PySide6.QtScxml.QScxmlStateMachine.isActive(scxmlStateName)¶

Parameters: scxmlStateName – str
Return type: bool

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

PySide6.QtScxml.QScxmlStateMachine.isActive(stateIndex)

Parameters: stateIndex – int
Return type: bool

Returns true if the state with the ID stateIndex is active.

This method is part of the interface to the compiled representation of SCXML state machines. It should only be used internally and by state machines compiled from SCXML documents.

PySide6.QtScxml.QScxmlStateMachine.isDispatchableTarget(target)¶

Parameters: target – str
Return type: bool

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

PySide6.QtScxml.QScxmlStateMachine.isInitialized()¶

Return type: bool

This property holds Whether the state machine has been initialized..

It is true if the state machine has been initialized, false otherwise.

See also

init() QScxmlDataModel

PySide6.QtScxml.QScxmlStateMachine.isInvoked()¶

Return type: bool

This property holds Whether the state machine was invoked from an outer state machine..

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

PySide6.QtScxml.QScxmlStateMachine.isRunning()¶

Return type: bool

This property holds the running state of this state machine.

See also

start()

PySide6.QtScxml.QScxmlStateMachine.loader()¶

Return type: PySide6.QtScxml.QScxmlCompiler.Loader

This property holds The loader that is currently used to resolve and load URIs for the state machine..

PySide6.QtScxml.QScxmlStateMachine.loaderChanged(loader)¶

Parameters: loader – PySide6.QtScxml.QScxmlCompiler.Loader

PySide6.QtScxml.QScxmlStateMachine.log(label, msg)¶

Parameters

label – str
msg – str

PySide6.QtScxml.QScxmlStateMachine.name()¶

Return type: str

This property holds The name of the state machine as set by the name attribute of the <scxml> tag..

PySide6.QtScxml.QScxmlStateMachine.parseErrors()¶

Return type

This property holds The list of parse errors that occurred while creating a state machine from an SCXML file..

PySide6.QtScxml.QScxmlStateMachine.reachedStableState()¶

PySide6.QtScxml.QScxmlStateMachine.runningChanged(running)¶

Parameters: running – bool

PySide6.QtScxml.QScxmlStateMachine.sessionId()¶

Return type: str

This property holds The session ID of 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

invokeId()

PySide6.QtScxml.QScxmlStateMachine.setDataModel(model)¶

Parameters: model – PySide6.QtScxml.QScxmlDataModel

This property holds The data model to be used for this state machine..

SCXML data models are described in SCXML Specification - 5 Data Model and Data Manipulation . For more information about supported data models, see SCXML Compliance .

Changing the data model when the state machine has been initialized is not specified in the SCXML standard and leads to undefined behavior.

See also

QScxmlDataModel QScxmlNullDataModel QScxmlCppDataModel

PySide6.QtScxml.QScxmlStateMachine.setInitialValues(initialValues)¶

Parameters: initialValues –

This property holds The initial values to be used for setting up the data model..

See also

init() QScxmlDataModel

PySide6.QtScxml.QScxmlStateMachine.setLoader(loader)¶

Parameters: loader – PySide6.QtScxml.QScxmlCompiler.Loader

This property holds The loader that is currently used to resolve and load URIs for the state machine..

PySide6.QtScxml.QScxmlStateMachine.setRunning(running)¶

Parameters: running – bool

This property holds the running state of this state machine.

See also

start()

PySide6.QtScxml.QScxmlStateMachine.setTableData(tableData)¶

Parameters: tableData – PySide6.QtScxml.QScxmlTableData

This property holds The table data that is used when generating C++ from an SCXML file..

The class implementing the state machine will use this property to assign the generated table data. The state machine does not assume ownership of the table data.

PySide6.QtScxml.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 exec() or exec() .

Table of Contents

Previous topic

Next topic

QScxmlStateMachine¶

Synopsis¶

Functions¶

Slots¶

Signals¶

Static functions¶

Detailed Description¶