QAbstractTransition Class▲
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Header: QAbstractTransition
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CMake:
find_package(Qt6 REQUIRED COMPONENTS StateMachine)
target_link_libraries(mytarget PRIVATE Qt6::StateMachine)
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qmake: QT += statemachine
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Inherits: QObject
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Inherited By: QEventTransition and QSignalTransition
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Group: QAbstractTransition is part of statemachine
Detailed Description▲
The QAbstractTransition class is the abstract base class of transitions between states (QAbstractState objects) of a QStateMachine. QAbstractTransition is part of Qt 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.
Member Type Documentation▲
enum QAbstractTransition::TransitionType▲
This enum specifies the kind of transition. By default, the type is an external transition.
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Constant |
Value |
Description |
|---|---|---|
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QAbstractTransition::ExternalTransition |
0 |
Any state that is the source state of a transition (which is not a target-less transition) is left, and re-entered when necessary. |
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QAbstractTransition::InternalTransition |
1 |
If the target state of a transition is a sub-state of a compound state, and that compound state is the source state, an internal transition will not leave the source state. |
See Also▲
See also QAbstractTransition::transitionType
Property Documentation▲
[read-only] sourceState : QState* const▲
This property holds the source state (parent) of this transition
Access functions:
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*sourceState() const
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:
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*targetState() const
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void setTargetState( *target)
Notifier signal:
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void targetStateChanged()
This is a private signal. It can be used in signal connections but cannot be emitted by the user.
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:
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< *> targetStates() const
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void setTargetStates(const < *> &targets)
Notifier signal:
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void targetStatesChanged()
This is a private signal. It can be used in signal connections but cannot be emitted by the user.
[bindable] transitionType : TransitionType▲
This property supports QProperty bindings.
indicates whether this transition is an internal transition, or an external transition.
Internal and external transitions behave the same, except for the case of a transition whose source state is a compound state and whose target(s) is a descendant of the source. In such a case, an internal transition will not exit and re-enter its source state, while an external one will.
By default, the type is an external transition.
Member Function Documentation▲
QAbstractTransition::QAbstractTransition(QState *sourceState = nullptr)▲
Constructs a new QAbstractTransition object with the given sourceState.
[virtual] QAbstractTransition::~QAbstractTransition()▲
Destroys this transition.
void QAbstractTransition::addAnimation(QAbstractAnimation *animation)▲
Adds the given animation to this transition. The transition does not take ownership of the animation.
See Also▲
See also removeAnimation(), 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▲
See also addAnimation()
[override virtual protected] bool QAbstractTransition::event(QEvent *e)▲
Reimplements: QObject::event(QEvent *e).
[pure virtual protected] bool QAbstractTransition::eventTest(QEvent *event)▲
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.
QStateMachine *QAbstractTransition::machine() const▲
Returns the state machine that this transition is part of, or nullptr 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 given event is what caused the transition to trigger. Reimplement this function to perform custom processing when the transition is triggered.
void QAbstractTransition::removeAnimation(QAbstractAnimation *animation)▲
void QAbstractTransition::setTargetState(QAbstractState *target)▲
Sets the target state of this transition.
Setter function for property targetState.
See Also▲
See also targetState()
void QAbstractTransition::setTargetStates(const QList<QAbstractState *> &targets)▲
Sets the target states of this transition to be the given targets.
Setter function for property targetStates.
See Also▲
See also targetStates()
void QAbstractTransition::setTransitionType(QAbstractTransition::TransitionType type)▲
Sets the type of the transition to type.
Setter function for property transitionType.
See Also▲
See also transitionType()
QState *QAbstractTransition::sourceState() const▲
Returns the source state of this transition, or nullptr if this transition has no source state.
Getter function for property sourceState.
QAbstractState *QAbstractTransition::targetState() const▲
Returns the target state of this transition, or nullptr if the transition has no target.
Getter function for property targetState.
See Also▲
See also setTargetState()
[since 5.4] void QAbstractTransition::targetStateChanged()▲
This signal is emitted when the targetState property is changed.
This is a private signal. It can be used in signal connections but cannot be emitted by the user.
Notifier signal for property targetState.
This function was introduced in Qt 5.4.
See Also▲
See also QAbstractTransition::targetState
QList<QAbstractState *> QAbstractTransition::targetStates() const▲
Returns the target states of this transition, or an empty list if this transition has no target states.
Getter function for property targetStates.
See Also▲
See also setTargetStates()
[since 5.4] void QAbstractTransition::targetStatesChanged()▲
This signal is emitted when the targetStates property is changed.
This is a private signal. It can be used in signal connections but cannot be emitted by the user.
Notifier signal for property targetStates.
This function was introduced in Qt 5.4.
See Also▲
See also QAbstractTransition::targetStates
QAbstractTransition::TransitionType QAbstractTransition::transitionType() const▲
Returns the type of the transition.
Getter function for property transitionType.
See Also▲
See also setTransitionType()
void QAbstractTransition::triggered()▲
This signal is emitted when the transition has been triggered (after onTransition() has been called).
This is a private signal. It can be used in signal connections but cannot be emitted by the user.