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
()
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)
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 aQEventLoop
to work correctly. The event loop is used to implement thedelay
attribute for events and to schedule the processing of a state machine when events are received from nested (or parent) state machines.
-
class
PySide2.QtScxml.
QScxmlStateMachine
(metaObject[, parent=None])¶ - Parameters
parent –
PySide2.QtCore.QObject
metaObject –
PySide2.QtCore.QMetaObject
-
PySide2.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
istrue
(the default), the parent states will be filtered out and only the leaf states will be returned. When it isfalse
, the full list of active states will be returned.
-
PySide2.QtScxml.QScxmlStateMachine.
cancelDelayedEvent
(sendId)¶ - Parameters
sendId – str
Cancels a delayed event with the specified
sendId
.
-
PySide2.QtScxml.QScxmlStateMachine.
connectToEvent
(scxmlEventSpec, receiver, method[, type=Qt.AutoConnection])¶ - Parameters
scxmlEventSpec – str
receiver –
PySide2.QtCore.QObject
method – str
type –
ConnectionType
- Return type
-
PySide2.QtScxml.QScxmlStateMachine.
connectToState
(scxmlStateName, receiver, method[, type=Qt.AutoConnection])¶ - Parameters
scxmlStateName – str
receiver –
PySide2.QtCore.QObject
method – str
type –
ConnectionType
- Return type
-
PySide2.QtScxml.QScxmlStateMachine.
dataModel
()¶ - Return type
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.
-
PySide2.QtScxml.QScxmlStateMachine.
dataModelChanged
(model)¶ - Parameters
model –
PySide2.QtScxml.QScxmlDataModel
-
PySide2.QtScxml.QScxmlStateMachine.
finished
()¶
-
static
PySide2.QtScxml.QScxmlStateMachine.
fromData
(data[, fileName=""])¶ - Parameters
data –
PySide2.QtCore.QIODevice
fileName – str
- Return type
Creates a state machine by reading from the
QIODevice
specified bydata
.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 theparseErrors()
method.See also
-
static
PySide2.QtScxml.QScxmlStateMachine.
fromFile
(fileName)¶ - Parameters
fileName – str
- Return type
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
-
PySide2.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 theinitialValues
property.Returns
false
if parse errors occur or if any of the initialization steps fail. Returnstrue
otherwise.
-
PySide2.QtScxml.QScxmlStateMachine.
initialValues
()¶ - Return type
This property holds The initial values to be used for setting up the data model..
See also
-
PySide2.QtScxml.QScxmlStateMachine.
initialValuesChanged
(initialValues)¶ - Parameters
initialValues –
-
PySide2.QtScxml.QScxmlStateMachine.
initializedChanged
(initialized)¶ - Parameters
initialized – bool
-
PySide2.QtScxml.QScxmlStateMachine.
invokedServices
()¶ - Return type
This property holds A list of SCXML services that were invoked from the main state machine (possibly recursively)..
-
PySide2.QtScxml.QScxmlStateMachine.
invokedServicesChanged
(invokedServices)¶ - Parameters
invokedServices –
-
PySide2.QtScxml.QScxmlStateMachine.
isActive
(scxmlStateName)¶ - Parameters
scxmlStateName – str
- Return type
bool
-
PySide2.QtScxml.QScxmlStateMachine.
isActive
(stateIndex) - Parameters
stateIndex – int
- Return type
bool
Returns
true
if the state with the IDstateIndex
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.
-
PySide2.QtScxml.QScxmlStateMachine.
isDispatchableTarget
(target)¶ - Parameters
target – str
- Return type
bool
Returns
true
if a message totarget
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
, wheresessionid
is the session ID of the current state machine#_servicename
, whereservicename
is the ID or name of a service started with<invoke>
by this state machine
-
PySide2.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
-
PySide2.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.
-
PySide2.QtScxml.QScxmlStateMachine.
isRunning
()¶ - Return type
bool
This property holds the running state of this state machine.
See also
-
PySide2.QtScxml.QScxmlStateMachine.
loader
()¶ - Return type
This property holds The loader that is currently used to resolve and load URIs for the state machine..
-
PySide2.QtScxml.QScxmlStateMachine.
loaderChanged
(loader)¶ - Parameters
loader –
PySide2.QtScxml.Loader
-
PySide2.QtScxml.QScxmlStateMachine.
log
(label, msg)¶ - Parameters
label – str
msg – str
-
PySide2.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..
-
PySide2.QtScxml.QScxmlStateMachine.
parseErrors
()¶ - Return type
This property holds The list of parse errors that occurred while creating a state machine from an SCXML file..
-
PySide2.QtScxml.QScxmlStateMachine.
reachedStableState
()¶
-
PySide2.QtScxml.QScxmlStateMachine.
runningChanged
(running)¶ - Parameters
running – bool
-
PySide2.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 theinvokeid
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
-
PySide2.QtScxml.QScxmlStateMachine.
setDataModel
(model)¶ - Parameters
model –
PySide2.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.
-
PySide2.QtScxml.QScxmlStateMachine.
setInitialValues
(initialValues)¶ - Parameters
initialValues –
This property holds The initial values to be used for setting up the data model..
See also
-
PySide2.QtScxml.QScxmlStateMachine.
setLoader
(loader)¶ - Parameters
loader –
PySide2.QtScxml.Loader
This property holds The loader that is currently used to resolve and load URIs for the state machine..
-
PySide2.QtScxml.QScxmlStateMachine.
setRunning
(running)¶ - Parameters
running – bool
This property holds the running state of this state machine.
See also
-
PySide2.QtScxml.QScxmlStateMachine.
setTableData
(tableData)¶ - Parameters
tableData –
PySide2.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.
-
PySide2.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()
orexec()
.See also
-
PySide2.QtScxml.QScxmlStateMachine.
stateNames
([compress=true])¶ - Parameters
compress – bool
- Return type
list of strings
Retrieves a list of state names of all states.
When
compress
istrue
(the default), the states that contain child states will be filtered out and only the leaf states will be returned. When it isfalse
, the full list of all states will be returned.The returned list does not contain the states of possible nested state machines.
Note
The order of the state names in the list is the order in which the states occurred in the SCXML document.
-
PySide2.QtScxml.QScxmlStateMachine.
stop
()¶ Stops this state machine. The machine will not execute any further state transitions. Its
running
property is set tofalse
.See also
-
PySide2.QtScxml.QScxmlStateMachine.
submitEvent
(event)¶ - Parameters
event –
PySide2.QtScxml.QScxmlEvent
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. The state machine takes ownership of
event
and deletes it after processing.
-
PySide2.QtScxml.QScxmlStateMachine.
submitEvent
(eventName) - Parameters
eventName – str
-
PySide2.QtScxml.QScxmlStateMachine.
submitEvent
(eventName, data) - Parameters
eventName – str
data – object
A utility method to create and submit an external event with the specified
eventName
as the name anddata
as the payload data.
-
PySide2.QtScxml.QScxmlStateMachine.
tableData
()¶ - Return type
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.
-
PySide2.QtScxml.QScxmlStateMachine.
tableDataChanged
(tableData)¶ - Parameters
tableData –
PySide2.QtScxml.QScxmlTableData
© 2020 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.