Contents

• Properties
• Public Functions
• Signals
• Protected Functions
• Reimplemented Protected Functions
• Detailed Description
• Subclassing

Detailed Description

TheQAbstractTransition class is the base class of transitions betweenQAbstractState objects.

TheQAbstractTransition class is the abstract base class of transitions between states (QAbstractState objects) of aQStateMachine.QAbstractTransition is part ofThe State Machine Framework.

ThesourceState() function returns the source of the transition. ThetargetStates() function returns the targets of the transition. Themachine() function returns the state machine that the transition is part of.

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

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

Subclassing

TheeventTest() 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.

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

Property Documentation

sourceState :QState * const

This property holds the source state (parent) of this transition.

Access functions:

targetState :QAbstractState *

This property holds the target state of this transition.

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).

Access functions:

targetStates :QList<QAbstractState *>

This property holds the target states of this transition.

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

Access functions:

Member Function Documentation

QAbstractTransition::QAbstractTransition(QState * sourceState = 0)

Constructs a newQAbstractTransition object with the givensourceState.

[virtual]QAbstractTransition::~QAbstractTransition()

Destroys this transition.

void QAbstractTransition::addAnimation(QAbstractAnimation * animation)

Adds the givenanimation to this transition. The transition does not take ownership of the animation.

See alsoremoveAnimation() andanimations().

QList<QAbstractAnimation *> QAbstractTransition::animations() const

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

See alsoaddAnimation().

[virtual protected]bool QAbstractTransition::event(QEvent * e)

Reimplemented fromQObject::event().

[pure virtual protected]bool QAbstractTransition::eventTest(QEvent * event)

This function is called to determine whether the givenevent should cause this transition to trigger. Reimplement this function and return true if the event should trigger the transition, otherwise return false.

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.

[pure virtual protected]void QAbstractTransition::onTransition(QEvent * event)

This function is called when the transition is triggered. The givenevent is what caused the transition to trigger. Reimplement this function to perform custom processing when the transition is triggered.

void QAbstractTransition::removeAnimation(QAbstractAnimation * animation)

Removes the givenanimation from this transition.

See alsoaddAnimation().

[signal]void QAbstractTransition::triggered()

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