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().