diff options
Diffstat (limited to 'src/corelib/statemachine')
| -rw-r--r-- | src/corelib/statemachine/qstatemachine.cpp | 42 | ||||
| -rw-r--r-- | src/corelib/statemachine/qstatemachine.h | 3 | ||||
| -rw-r--r-- | src/corelib/statemachine/qstatemachine_p.h | 6 |
3 files changed, 43 insertions, 8 deletions
diff --git a/src/corelib/statemachine/qstatemachine.cpp b/src/corelib/statemachine/qstatemachine.cpp index be48dbc92f..e6dfacc0f5 100644 --- a/src/corelib/statemachine/qstatemachine.cpp +++ b/src/corelib/statemachine/qstatemachine.cpp @@ -140,6 +140,10 @@ QT_BEGIN_NAMESPACE no error state applies to the erroneous state, the machine will stop executing and an error message will be printed to the console. + \note Important: setting the \l{ChildMode} of a state machine to parallel (\l{ParallelStates}) + results in an invalid state machine. It can only be set to (or kept as) + \l{ExclusiveStates}. + \sa QAbstractState, QAbstractTransition, QState, {The State Machine Framework} */ @@ -519,7 +523,7 @@ bool QStateMachinePrivate::stateExitLessThan(QAbstractState *s1, QAbstractState } } -QState *QStateMachinePrivate::findLCA(const QList<QAbstractState*> &states, bool onlyCompound) const +QState *QStateMachinePrivate::findLCA(const QList<QAbstractState*> &states, bool onlyCompound) { if (states.isEmpty()) return 0; @@ -538,10 +542,16 @@ QState *QStateMachinePrivate::findLCA(const QList<QAbstractState*> &states, bool if (ok) return anc; } - return 0; + + // Oops, this should never happen! The state machine itself is a common ancestor of all states, + // no matter what. But, for the onlyCompound case: we probably have a state machine whose + // childMode is set to parallel, which is illegal. However, we're stuck with it (and with + // exposing this invalid/dangerous API to users), so recover in the least horrible way. + setError(QStateMachine::StateMachineChildModeSetToParallelError, q_func()); + return q_func(); // make the statemachine the LCA/LCCA (which it should have been anyway) } -QState *QStateMachinePrivate::findLCCA(const QList<QAbstractState*> &states) const +QState *QStateMachinePrivate::findLCCA(const QList<QAbstractState*> &states) { return findLCA(states, true); } @@ -903,7 +913,7 @@ function getTransitionDomain(t) */ QAbstractState *QStateMachinePrivate::getTransitionDomain(QAbstractTransition *t, const QList<QAbstractState *> &effectiveTargetStates, - CalculationCache *cache) const + CalculationCache *cache) { Q_ASSERT(cache); @@ -1484,6 +1494,14 @@ void QStateMachinePrivate::setError(QStateMachine::Error errorCode, QAbstractSta errorString = QStateMachine::tr("No common ancestor for targets and source of transition from state '%1'") .arg(currentContext->objectName()); break; + + case QStateMachine::StateMachineChildModeSetToParallelError: + Q_ASSERT(currentContext != nullptr); + + errorString = QStateMachine::tr("Child mode of state machine '%1' is not 'ExclusiveStates'!") + .arg(currentContext->objectName()); + break; + default: errorString = QStateMachine::tr("Unknown error"); }; @@ -2445,9 +2463,13 @@ QStateMachine::QStateMachine(QObject *parent) /*! \since 5.0 + \deprecated Constructs a new state machine with the given \a childMode and \a parent. + + \warning Do not set the \a childMode to anything else than \l{ExclusiveStates}, otherwise the + state machine is invalid, and might work incorrectly! */ QStateMachine::QStateMachine(QState::ChildMode childMode, QObject *parent) : QState(*new QStateMachinePrivate, /*parentState=*/0) @@ -2455,6 +2477,18 @@ QStateMachine::QStateMachine(QState::ChildMode childMode, QObject *parent) Q_D(QStateMachine); d->childMode = childMode; setParent(parent); // See comment in constructor above + + if (childMode != ExclusiveStates) { + //### FIXME for Qt6: remove this constructor completely, and hide the childMode property. + // Yes, the StateMachine itself is conceptually a state, but it should only expose a limited + // number of properties. The execution algorithm (in the URL below) treats a state machine + // as a state, but from an API point of view, it's questionable if the QStateMachine should + // inherit from QState. + // + // See function findLCCA in https://www.w3.org/TR/2014/WD-scxml-20140529/#AlgorithmforSCXMLInterpretation + // to see where setting childMode to parallel will break down. + qWarning() << "Invalid childMode for QStateMachine" << this; + } } /*! diff --git a/src/corelib/statemachine/qstatemachine.h b/src/corelib/statemachine/qstatemachine.h index e520285437..07781d09a4 100644 --- a/src/corelib/statemachine/qstatemachine.h +++ b/src/corelib/statemachine/qstatemachine.h @@ -106,7 +106,8 @@ public: NoError, NoInitialStateError, NoDefaultStateInHistoryStateError, - NoCommonAncestorForTransitionError + NoCommonAncestorForTransitionError, + StateMachineChildModeSetToParallelError }; explicit QStateMachine(QObject *parent = nullptr); diff --git a/src/corelib/statemachine/qstatemachine_p.h b/src/corelib/statemachine/qstatemachine_p.h index d6fdd72dc1..f140023e31 100644 --- a/src/corelib/statemachine/qstatemachine_p.h +++ b/src/corelib/statemachine/qstatemachine_p.h @@ -110,8 +110,8 @@ public: static QStateMachinePrivate *get(QStateMachine *q) { return q ? q->d_func() : nullptr; } - QState *findLCA(const QList<QAbstractState*> &states, bool onlyCompound = false) const; - QState *findLCCA(const QList<QAbstractState*> &states) const; + QState *findLCA(const QList<QAbstractState*> &states, bool onlyCompound = false); + QState *findLCCA(const QList<QAbstractState*> &states); static bool transitionStateEntryLessThan(QAbstractTransition *t1, QAbstractTransition *t2); static bool stateEntryLessThan(QAbstractState *s1, QAbstractState *s2); @@ -160,7 +160,7 @@ public: QSet<QAbstractState*> &statesForDefaultEntry, CalculationCache *cache); QAbstractState *getTransitionDomain(QAbstractTransition *t, const QList<QAbstractState *> &effectiveTargetStates, - CalculationCache *cache) const; + CalculationCache *cache); void addDescendantStatesToEnter(QAbstractState *state, QSet<QAbstractState*> &statesToEnter, QSet<QAbstractState*> &statesForDefaultEntry); |