The QSignalTransition class provides a transition based on a Qt signal. More...
#include <QSignalTransition>
Inherits: QAbstractTransition.
This class was introduced in Qt 4.6.
QSignalTransition ( QState * sourceState = 0 ) | |
QSignalTransition ( QObject * sender, const char * signal, QState * sourceState = 0 ) | |
~QSignalTransition () | |
QObject * | senderObject () const |
void | setSenderObject ( QObject * sender ) |
void | setSignal ( const QByteArray & signal ) |
QByteArray | signal () const |
virtual bool | event ( QEvent * e ) |
virtual bool | eventTest ( QEvent * event ) |
virtual void | onTransition ( QEvent * event ) |
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);
This property holds the sender object that this signal transition is associated with.
Access functions:
QObject * | senderObject () const |
void | setSenderObject ( QObject * sender ) |
This property holds the signal that this signal transition is associated with.
Access functions:
QByteArray | signal () const |
void | setSignal ( const QByteArray & signal ) |
Constructs a new signal transition with the given sourceState.
Constructs a new signal transition associated with the given signal of the given sender, and with the given sourceState.
Destroys this signal transition.
Reimplemented from QObject::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.
Reimplemented from QAbstractTransition::onTransition().