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 |
This class was introduced in Qt 4.6.
Properties
- senderObject : QObject*
- signal : QByteArray
Public Functions
QSignalTransition(const QObject *sender, PointerToMemberFunction signal, QState *sourceState = nullptr) | |
QSignalTransition(const QObject *sender, const char *signal, QState *sourceState = nullptr) | |
QSignalTransition(QState *sourceState = nullptr) | |
virtual | ~QSignalTransition() |
QObject * | senderObject() const |
void | setSenderObject(const QObject *sender) |
void | setSignal(const QByteArray &signal) |
QByteArray | signal() const |
Signals
void | senderObjectChanged() |
void | signalChanged() |
Reimplemented Protected Functions
virtual bool | event(QEvent *e) override |
virtual bool | eventTest(QEvent *event) override |
virtual void | onTransition(QEvent *event) override |
Detailed Description
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:
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
template <typename PointerToMemberFunction> QSignalTransition::QSignalTransition(const QObject *sender, PointerToMemberFunction signal, QState *sourceState = 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(const QObject *sender, const char *signal, QState *sourceState = nullptr)
Constructs a new signal transition associated with the given signal of the given sender, and with the given sourceState.
QSignalTransition::QSignalTransition(QState *sourceState = nullptr)
Constructs a new signal transition with the given sourceState.
[signal]
void QSignalTransition::senderObjectChanged()
This signal is emitted when the senderObject property is changed.
Note: This is a private signal. It can be used in signal connections but cannot be emitted by the user.
Note: Notifier signal for property senderObject.
This function was introduced in Qt 5.4.
See also QSignalTransition::senderObject.
[signal]
void QSignalTransition::signalChanged()
This signal is emitted when the signal property is changed.
Note: This is a private signal. It can be used in signal connections but cannot be emitted by the user.
Note: Notifier signal for property signal.
This function was introduced in Qt 5.4.
See also QSignalTransition::signal.
[virtual]
QSignalTransition::~QSignalTransition()
Destroys this signal transition.
[override virtual protected]
bool QSignalTransition::event(QEvent *e)
Reimplements: QAbstractTransition::event(QEvent *e).
[override virtual protected]
bool QSignalTransition::eventTest(QEvent *event)
Reimplements: QAbstractTransition::eventTest(QEvent *event).
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.
[override virtual protected]
void QSignalTransition::onTransition(QEvent *event)
Reimplements: QAbstractTransition::onTransition(QEvent *event).
QObject *QSignalTransition::senderObject() const
Returns the sender object associated with this signal transition.
Note: Getter function for property senderObject.
See also setSenderObject().
void QSignalTransition::setSenderObject(const QObject *sender)
Sets the sender object associated with this signal transition.
Note: Setter function for property senderObject.
See also senderObject().
void QSignalTransition::setSignal(const QByteArray &signal)
Sets the signal associated with this signal transition.
Note: Setter function for property signal.
See also signal().
QByteArray QSignalTransition::signal() const
Returns the signal associated with this signal transition.
Note: Getter function for property signal.
See also setSignal().