QSignalTransition Class
The QSignalTransition class provides a transition based on a Qt signal. More...
Header: | #include <QSignalTransition> |
qmake: | QT += core |
Since: | Qt 4.6 |
Inherits: | QAbstractTransition |
Properties
- senderObject : QObject *
- signal : QByteArray
- 4 properties inherited from QAbstractTransition
- 1 property inherited from QObject
Public Functions
QSignalTransition(QState * sourceState = Q_NULLPTR) | |
QSignalTransition(const QObject * sender, const char * signal, QState * sourceState = Q_NULLPTR) | |
QSignalTransition(const QObject * sender, PointerToMemberFunction signal, QState * sourceState = Q_NULLPTR) | |
~QSignalTransition() | |
QObject * | senderObject() const |
void | setSenderObject(const QObject * sender) |
void | setSignal(const QByteArray & signal) |
QByteArray | signal() const |
- 11 public functions inherited from QAbstractTransition
- 31 public functions inherited from QObject
Signals
void | senderObjectChanged() |
void | signalChanged() |
- 3 signals inherited from QAbstractTransition
- 2 signals inherited from QObject
Reimplemented Protected Functions
virtual bool | event(QEvent * e) |
virtual bool | eventTest(QEvent * event) |
virtual void | onTransition(QEvent * event) |
- 3 protected functions inherited from QAbstractTransition
- 9 protected functions inherited from QObject
Additional Inherited Members
- 1 public slot inherited from QObject
- 11 static public members inherited from QObject
- 3 protected functions inherited from QAbstractTransition
- 9 protected functions inherited from QObject
Detailed Description
The QSignalTransition class provides a transition based on a Qt signal.
Typically you would use the overload of QState::addTransition() that takes a sender and signal as arguments, rather than creating QSignalTransition objects directly. QSignalTransition is part of The State Machine Framework.
You can subclass QSignalTransition and reimplement eventTest() to make a signal transition conditional; the event object passed to eventTest() will be a QStateMachine::SignalEvent object. Example:
class CheckedTransition : public QSignalTransition { public: CheckedTransition(QCheckBox *check) : QSignalTransition(check, SIGNAL(stateChanged(int))) {} protected: bool eventTest(QEvent *e) { if (!QSignalTransition::eventTest(e)) return false; QStateMachine::SignalEvent *se = static_cast<QStateMachine::SignalEvent*>(e); return (se->arguments().at(0).toInt() == Qt::Checked); } }; ... QCheckBox *check = new QCheckBox(); check->setTristate(true); QState *s1 = new QState(); QState *s2 = new QState(); CheckedTransition *t1 = new CheckedTransition(check); t1->setTargetState(s2); s1->addTransition(t1);
Property Documentation
senderObject : QObject *
This property holds the sender object that this signal transition is associated with.
Access functions:
QObject * | senderObject() const |
void | setSenderObject(const QObject * sender) |
Notifier signal:
void | senderObjectChanged() | [see note below] |
Note: This is a private signal. It can be used in signal connections but cannot be emitted by the user.
signal : QByteArray
This property holds the signal that this signal transition is associated with.
Access functions:
QByteArray | signal() const |
void | setSignal(const QByteArray & signal) |
Notifier signal:
void | signalChanged() | [see note below] |
Note: This is a private signal. It can be used in signal connections but cannot be emitted by the user.
Member Function Documentation
QSignalTransition::QSignalTransition(QState * sourceState = Q_NULLPTR)
Constructs a new signal transition with the given sourceState.
QSignalTransition::QSignalTransition(const QObject * sender, const char * signal, QState * sourceState = Q_NULLPTR)
Constructs a new signal transition associated with the given signal of the given sender, and with the given sourceState.
QSignalTransition::QSignalTransition(const QObject * sender, PointerToMemberFunction signal, QState * sourceState = Q_NULLPTR)
This is an overloaded function.
Constructs a new signal transition associated with the given signal of the given sender object and with the given sourceState. This constructor is enabled if the compiler supports delegating constructors, as indicated by the presence of the macro Q_COMPILER_DELEGATING_CONSTRUCTORS.
This function was introduced in Qt 5.7.
QSignalTransition::~QSignalTransition()
Destroys this signal transition.
[virtual protected]
bool QSignalTransition::event(QEvent * e)
Reimplemented from QObject::event().
[virtual protected]
bool QSignalTransition::eventTest(QEvent * event)
Reimplemented from QAbstractTransition::eventTest().
The default implementation returns true
if the event is a QStateMachine::SignalEvent object and the event's sender and signal index match this transition, and returns false
otherwise.
[virtual protected]
void QSignalTransition::onTransition(QEvent * event)
Reimplemented from QAbstractTransition::onTransition().