QSignalTransition¶

PyQt5.QtCore.QSignalTransition: Inherits from QAbstractTransition.

Description¶

The QSignalTransition class provides a transition based on a Qt signal.

Typically you would use the overload of 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 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);

Methods¶

__init__(sourceState: QState = None): Constructs a new signal transition with the given sourceState.

__init__(pyqtBoundSignal, sourceState: QState = None): TODO

event(QEvent) → bool: TODO

eventTest(QEvent) → bool: TODO

onTransition(QEvent): TODO

senderObject() → QObject: Returns the sender object associated with this signal transition.

See also

setSenderObject().

setSenderObject(QObject): Sets the sender object associated with this signal transition.

See also

senderObject().

setSignal(Union[QByteArray, bytes, bytearray]): Sets the signal associated with this signal transition.

See also

signal().

signal() → QByteArray: Returns the signal associated with this signal transition.

See also

setSignal().

Signals¶

senderObjectChanged(): TODO

signalChanged(): TODO