QAbstractTransition Class Reference

The QAbstractTransition class is the base class of transitions between QAbstractState objects. More...

#include <qabstracttransition.h>

Inheritance diagram for QAbstractTransition:

Signals
void	triggered ()
	This signal is emitted when the transition has been triggered (after onTransition() has been called). More...
Signals inherited from QObject
void	destroyed (QObject *=0)
	This signal is emitted immediately before the object obj is destroyed, and can not be blocked. More...

Public Functions
void	addAnimation (QAbstractAnimation *animation)
	Adds the given animation to this transition. More...
QList< QAbstractAnimation * >	animations () const
	Returns the list of animations associated with this transition, or an empty list if it has no animations. More...
QStateMachine *	machine () const
	Returns the state machine that this transition is part of, or 0 if the transition is not part of a state machine. More...
	QAbstractTransition (QState *sourceState=0)
	Constructs a new QAbstractTransition object with the given sourceState. More...
void	removeAnimation (QAbstractAnimation *animation)
	Removes the given animation from this transition. More...
void	setTargetState (QAbstractState *target)
	Sets the target state of this transition. More...
void	setTargetStates (const QList< QAbstractState *> &targets)
	Sets the target states of this transition to be the given targets. More...
QState *	sourceState () const
QAbstractState *	targetState () const
QList< QAbstractState * >	targetStates () const
virtual	~QAbstractTransition ()
	Destroys this transition. More...
Public Functions inherited from QObject
bool	blockSignals (bool b)
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). More...
const QObjectList &	children () const
	Returns a list of child objects. More...
bool	connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const
bool	disconnect (const char *signal=0, const QObject *receiver=0, const char *member=0)
bool	disconnect (const QObject *receiver, const char *member=0)
void	dumpObjectInfo ()
	Dumps information about signal connections, etc. More...
void	dumpObjectTree ()
	Dumps a tree of children to the debug output. More...
QList< QByteArray >	dynamicPropertyNames () const
	Returns the names of all properties that were dynamically added to the object using setProperty(). More...
virtual bool	eventFilter (QObject *, QEvent *)
	Filters events if this object has been installed as an event filter for the watched object. More...
template<typename T >
T	findChild (const QString &aName=QString()) const
	Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. More...
template<typename T >
QList< T >	findChildren (const QString &aName=QString()) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. More...
template<typename T >
QList< T >	findChildren (const QRegExp &re) const
bool	inherits (const char *classname) const
	Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false. More...
void	installEventFilter (QObject *)
	Installs an event filter filterObj on this object. More...
bool	isWidgetType () const
	Returns true if the object is a widget; otherwise returns false. More...
void	killTimer (int id)
	Kills the timer with timer identifier, id. More...
virtual const QMetaObject *	metaObject () const
	Returns a pointer to the meta-object of this object. More...
void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children. More...
QString	objectName () const
QObject *	parent () const
	Returns a pointer to the parent object. More...
QVariant	property (const char *name) const
	Returns the value of the object's name property. More...
Q_INVOKABLE	QObject (QObject *parent=0)
	Constructs an object with parent object parent. More...
void	removeEventFilter (QObject *)
	Removes an event filter object obj from this object. More...
void	setObjectName (const QString &name)
void	setParent (QObject *)
	Makes the object a child of parent. More...
bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value. More...
void	setUserData (uint id, QObjectUserData *data)
bool	signalsBlocked () const
	Returns true if signals are blocked; otherwise returns false. More...
int	startTimer (int interval)
	Starts a timer and returns a timer identifier, or returns zero if it could not start a timer. More...
QThread *	thread () const
	Returns the thread in which the object lives. More...
QObjectUserData *	userData (uint id) const
virtual	~QObject ()
	Destroys the object, deleting all its child objects. More...

Protected Functions
bool	event (QEvent *e)
	Reimplemented Function More...
virtual bool	eventTest (QEvent *event)=0
	This function is called to determine whether the given event should cause this transition to trigger. More...
virtual void	onTransition (QEvent *event)=0
	This function is called when the transition is triggered. More...
	QAbstractTransition (QAbstractTransitionPrivate &dd, QState *parent)
Protected Functions inherited from QObject
virtual void	childEvent (QChildEvent *)
	This event handler can be reimplemented in a subclass to receive child events. More...
virtual void	connectNotify (const char *signal)
	This virtual function is called when something has been connected to signal in this object. More...
virtual void	customEvent (QEvent *)
	This event handler can be reimplemented in a subclass to receive custom events. More...
virtual void	disconnectNotify (const char *signal)
	This virtual function is called when something has been disconnected from signal in this object. More...
	QObject (QObjectPrivate &dd, QObject *parent=0)
int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal. More...
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns 0. More...
int	senderSignalIndex () const
virtual void	timerEvent (QTimerEvent *)
	This event handler can be reimplemented in a subclass to receive timer events for the object. More...

Properties
QState *	sourceState
	the source state (parent) of this transition More...
QAbstractState *	targetState
	the target state of this transition More...
QList< QAbstractState * >	targetStates
	the target states of this transition More...

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	Schedules this object for deletion. More...
Static Public Functions inherited from QObject
static bool	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection)
	Creates a connection of the given type from the signal in the sender object to the method in the receiver object. More...
static bool	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)
static bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
	Disconnects signal in object sender from method in object receiver. More...
static bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member)
static uint	registerUserData ()
static QString	tr (const char *sourceText, const char *comment=0, int n=-1)
static QString	trUtf8 (const char *sourceText, const char *comment=0, int n=-1)
Static Public Variables inherited from QObject
static const QMetaObject	staticMetaObject
	This variable stores the meta-object for the class. More...
Protected Variables inherited from QObject
QScopedPointer< QObjectData >	d_ptr
Static Protected Variables inherited from QObject
static const QMetaObject	staticQtMetaObject
Related Functions inherited from QObject
T	qFindChildqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QRegExp &regExp)()
T *	qobject_cast (QObject *object)
	QObjectList
void *	qt_find_obj_child (QObject *parent, const char *type, const QString &name)
	Returns a pointer to the object named name that inherits type and with a given parent. More...

Detailed Description

The QAbstractTransition class is the base class of transitions between QAbstractState objects.

Since

4.6

The QAbstractTransition class is the abstract base class of transitions between states (QAbstractState objects) of a QStateMachine. QAbstractTransition is part of The State Machine Framework.

The sourceState() function returns the source of the transition. The targetStates() function returns the targets of the transition. The machine() function returns the state machine that the transition is part of.

The triggered() signal is emitted when the transition has been triggered.

Transitions can cause animations to be played. Use the addAnimation() function to add an animation to the transition.

Subclassing

The eventTest() function is called by the state machine to determine whether an event should trigger the transition. In your reimplementation you typically check the event type and cast the event object to the proper type, and check that one or more properties of the event meet your criteria.

The onTransition() function is called when the transition is triggered; reimplement this function to perform custom processing for the transition.

Definition at line 67 of file qabstracttransition.h.

Constructors and Destructors

QAbstractTransition() [1/2]

QAbstractTransition::QAbstractTransition

(

QState *

sourceState = 0

)

Constructs a new QAbstractTransition object with the given sourceState.

Definition at line 166 of file qabstracttransition.cpp.

    : QObject(*new QAbstractTransitionPrivate, sourceState)
{
}

~QAbstractTransition()

QAbstractTransition::~QAbstractTransition ( )

virtual

Destroys this transition.

Definition at line 183 of file qabstracttransition.cpp.

{
}

QAbstractTransition() [2/2]

QAbstractTransition::QAbstractTransition ( QAbstractTransitionPrivate &  dd, QState *  parent  )

protected

Warning

This function is not part of the public interface.

Definition at line 174 of file qabstracttransition.cpp.

    : QObject(dd, parent)
{
}

Functions

addAnimation()

void QAbstractTransition::addAnimation

(

QAbstractAnimation *

animation

)

Adds the given animation to this transition.

The transition does not take ownership of the animation.

See also

removeAnimation(), animations()

Definition at line 275 of file qabstracttransition.cpp.

{
    Q_D(QAbstractTransition);
    if (!animation) {
        qWarning("QAbstractTransition::addAnimation: cannot add null animation");
        return;
    }
    d->animations.append(animation);
}

animations()

QList< QAbstractAnimation * > QAbstractTransition::animations

(

)

const

Returns the list of animations associated with this transition, or an empty list if it has no animations.

See also

addAnimation()

Definition at line 306 of file qabstracttransition.cpp.

Referenced by QStateMachinePrivate::applyProperties().

{
    Q_D(const QAbstractTransition);
    return d->animations;
}

event()

bool QAbstractTransition::event ( QEvent *  e )

protectedvirtual

Reimplemented Function

Reimplemented from QObject.

Reimplemented in QEventTransition, and QSignalTransition.

Definition at line 343 of file qabstracttransition.cpp.

Referenced by QEventTransition::event(), QSignalTransition::event(), QBasicKeyEventTransition::eventTest(), and QBasicMouseEventTransition::eventTest().

{
    return QObject::event(e);
}

eventTest()

QAbstractTransition::eventTest ( QEvent *  event )

protectedpure virtual

This function is called to determine whether the given event should cause this transition to trigger.

Reimplement this function and return true if the event should trigger the transition, otherwise return false.

Implemented in _QStateMachine_Internal::GoToStateTransition, QBasicMouseEventTransition, QBasicKeyEventTransition, QMouseEventTransition, QKeyEventTransition, QEventTransition, and QSignalTransition.

machine()

QStateMachine * QAbstractTransition::machine

(

)

const

Returns the state machine that this transition is part of, or 0 if the transition is not part of a state machine.

Definition at line 261 of file qabstracttransition.cpp.

Referenced by QStateMachinePrivate::unregisterAllTransitions().

{
    Q_D(const QAbstractTransition);
    return d->machine();
}

onTransition()

QAbstractTransition::onTransition ( QEvent *  event )

protectedpure virtual

This function is called when the transition is triggered.

The given event is what caused the transition to trigger. Reimplement this function to perform custom processing when the transition is triggered.

Implemented in _QStateMachine_Internal::GoToStateTransition, QBasicMouseEventTransition, QBasicKeyEventTransition, QMouseEventTransition, QEventTransition, QSignalTransition, and QKeyEventTransition.

removeAnimation()

void QAbstractTransition::removeAnimation

(

QAbstractAnimation *

animation

)

Removes the given animation from this transition.

See also

addAnimation()

Definition at line 290 of file qabstracttransition.cpp.

{
    Q_D(QAbstractTransition);
    if (!animation) {
        qWarning("QAbstractTransition::removeAnimation: cannot remove null animation");
        return;
    }
    d->animations.removeOne(animation);
}

setTargetState()

void QAbstractTransition::setTargetState

(

QAbstractState *

target

)

Sets the target state of this transition.

Definition at line 212 of file qabstracttransition.cpp.

Referenced by QState::addTransition(), and QStateMachinePrivate::goToState().

{
    Q_D(QAbstractTransition);
    if (!target)
        d->targetStates.clear();
    else
        setTargetStates(QList<QAbstractState*>() << target);
}

setTargetStates()

void QAbstractTransition::setTargetStates

(

const QList< QAbstractState *> &

targets

)

Sets the target states of this transition to be the given targets.

Definition at line 240 of file qabstracttransition.cpp.

Referenced by setTargetState().

{
    Q_D(QAbstractTransition);

    for (int i = 0; i < targets.size(); ++i) {
        QAbstractState *target = targets.at(i);
        if (!target) {
            qWarning("QAbstractTransition::setTargetStates: target state(s) cannot be null");
            return;
        }
    }

    d->targetStates.clear();
    for (int i = 0; i < targets.size(); ++i)
        d->targetStates.append(targets.at(i));
}

sourceState()

QState* QAbstractTransition::sourceState

(

)

const

Referenced by QStateMachinePrivate::registerEventTransition(), QStateMachinePrivate::registerSignalTransition(), and ~QAbstractTransition().

targetState()

QAbstractState* QAbstractTransition::targetState

(

)

const

Referenced by ~QAbstractTransition().

targetStates()

QList<QAbstractState*> QAbstractTransition::targetStates

(

)

const

Referenced by QStateMachinePrivate::registerEventTransition(), QStateMachinePrivate::registerSignalTransition(), and setTargetState().

triggered

QAbstractTransition::triggered ( )

signal

This signal is emitted when the transition has been triggered (after onTransition() has been called).

Properties

sourceState

QState * QAbstractTransition::sourceState

private

the source state (parent) of this transition

Returns the source state of this transition, or 0 if this transition has no source state.

Definition at line 70 of file qabstracttransition.h.

Referenced by QStateMachinePrivate::applyProperties(), QStateMachinePrivate::enterStates(), QStateMachinePrivate::exitStates(), QStateMachinePrivate::isPreempted(), and QState::removeTransition().

targetState

QAbstractState * QAbstractTransition::targetState

private

the target state of this transition

Returns the target state of this transition, or 0 if the transition has no target.

If a transition has no target state, the transition may still be triggered, but this will not cause the state machine's configuration to change (i.e. the current state will not be exited and re-entered).

Definition at line 71 of file qabstracttransition.h.

targetStates

QList< QAbstractState * > QAbstractTransition::targetStates

private

the target states of this transition

Returns the target states of this transition, or an empty list if this transition has no target states.

If multiple states are specified, all must be descendants of the same parallel group state.

Definition at line 72 of file qabstracttransition.h.

Referenced by QStateMachinePrivate::applyProperties(), QStateMachinePrivate::enterStates(), QStateMachinePrivate::exitStates(), and QStateMachinePrivate::isPreempted().

---

The documentation for this class was generated from the following files:

• /src/corelib/statemachine/qabstracttransition.h
• /src/corelib/statemachine/qabstracttransition.cpp