qt6-bb10/src/corelib/statemachine/qeventtransition.cpp

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/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
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** This file is part of the QtCore module of the Qt Toolkit.
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#include "qeventtransition.h"
#ifndef QT_NO_STATEMACHINE
#include "qeventtransition_p.h"
#include "qstate.h"
#include "qstate_p.h"
#include "qstatemachine.h"
#include "qstatemachine_p.h"
#include <qdebug.h>
QT_BEGIN_NAMESPACE
/*!
\class QEventTransition
\brief The QEventTransition class provides a QObject-specific transition for Qt events.
\since 4.6
\ingroup statemachine
A QEventTransition object binds an event to a particular QObject.
QEventTransition is part of \l{The State Machine Framework}.
Example:
\code
QPushButton *button = ...;
QState *s1 = ...;
QState *s2 = ...;
// If in s1 and the button receives an Enter event, transition to s2
QEventTransition *enterTransition = new QEventTransition(button, QEvent::Enter);
enterTransition->setTargetState(s2);
s1->addTransition(enterTransition);
// If in s2 and the button receives an Exit event, transition back to s1
QEventTransition *leaveTransition = new QEventTransition(button, QEvent::Leave);
leaveTransition->setTargetState(s1);
s2->addTransition(leaveTransition);
\endcode
\section1 Subclassing
When reimplementing the eventTest() function, you should first call the base
implementation to verify that the event is a QStateMachine::WrappedEvent for
the proper object and event type. You may then cast the event to a
QStateMachine::WrappedEvent and get the original event by calling
QStateMachine::WrappedEvent::event(), and perform additional checks on that
object.
\sa QState::addTransition()
*/
/*!
\property QEventTransition::eventSource
\brief the event source that this event transition is associated with
*/
/*!
\property QEventTransition::eventType
\brief the type of event that this event transition is associated with
*/
QEventTransitionPrivate::QEventTransitionPrivate()
{
object = 0;
eventType = QEvent::None;
registered = false;
}
QEventTransitionPrivate *QEventTransitionPrivate::get(QEventTransition *q)
{
return q->d_func();
}
void QEventTransitionPrivate::unregister()
{
Q_Q(QEventTransition);
if (!registered || !machine())
return;
QStateMachinePrivate::get(machine())->unregisterEventTransition(q);
}
void QEventTransitionPrivate::maybeRegister()
{
Q_Q(QEventTransition);
if (!machine() || !machine()->configuration().contains(sourceState()))
return;
QStateMachinePrivate::get(machine())->registerEventTransition(q);
}
/*!
Constructs a new QEventTransition object with the given \a sourceState.
*/
QEventTransition::QEventTransition(QState *sourceState)
: QAbstractTransition(*new QEventTransitionPrivate, sourceState)
{
}
/*!
Constructs a new QEventTransition object associated with events of the given
\a type for the given \a object, and with the given \a sourceState.
*/
QEventTransition::QEventTransition(QObject *object, QEvent::Type type,
QState *sourceState)
: QAbstractTransition(*new QEventTransitionPrivate, sourceState)
{
Q_D(QEventTransition);
d->registered = false;
d->object = object;
d->eventType = type;
}
/*!
\internal
*/
QEventTransition::QEventTransition(QEventTransitionPrivate &dd, QState *parent)
: QAbstractTransition(dd, parent)
{
}
/*!
\internal
*/
QEventTransition::QEventTransition(QEventTransitionPrivate &dd, QObject *object,
QEvent::Type type, QState *parent)
: QAbstractTransition(dd, parent)
{
Q_D(QEventTransition);
d->registered = false;
d->object = object;
d->eventType = type;
}
/*!
Destroys this QObject event transition.
*/
QEventTransition::~QEventTransition()
{
}
/*!
Returns the event type that this event transition is associated with.
*/
QEvent::Type QEventTransition::eventType() const
{
Q_D(const QEventTransition);
return d->eventType;
}
/*!
Sets the event \a type that this event transition is associated with.
*/
void QEventTransition::setEventType(QEvent::Type type)
{
Q_D(QEventTransition);
if (d->eventType == type)
return;
d->unregister();
d->eventType = type;
d->maybeRegister();
}
/*!
Returns the event source associated with this event transition.
*/
QObject *QEventTransition::eventSource() const
{
Q_D(const QEventTransition);
return d->object;
}
/*!
Sets the event source associated with this event transition to be the given
\a object.
*/
void QEventTransition::setEventSource(QObject *object)
{
Q_D(QEventTransition);
if (d->object == object)
return;
d->unregister();
d->object = object;
d->maybeRegister();
}
/*!
\reimp
*/
bool QEventTransition::eventTest(QEvent *event)
{
Q_D(const QEventTransition);
if (event->type() == QEvent::StateMachineWrapped) {
QStateMachine::WrappedEvent *we = static_cast<QStateMachine::WrappedEvent*>(event);
return (we->object() == d->object)
&& (we->event()->type() == d->eventType);
}
return false;
}
/*!
\reimp
*/
void QEventTransition::onTransition(QEvent *event)
{
Q_UNUSED(event);
}
/*!
\reimp
*/
bool QEventTransition::event(QEvent *e)
{
return QAbstractTransition::event(e);
}
QT_END_NAMESPACE
#endif //QT_NO_STATEMACHINE