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Internal/Contributor docs for the Qt SDK. Note: These are NOT official API docs; those are found at https://doc.qt.io/
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QQuickState Class Reference

#include <qquickstate_p.h>

Inheritance diagram for QQuickState:
Collaboration diagram for QQuickState:

Signals

void completed ()
Signals inherited from QObject
void destroyed (QObject *=nullptr)
 This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked.
void objectNameChanged (const QString &objectName, QPrivateSignal)
 This signal is emitted after the object's name has been changed.

Public Member Functions

 QQuickState (QObject *parent=nullptr)
 \qmltype State \nativetype QQuickState \inqmlmodule QtQuick
 ~QQuickState () override
QString name () const
 \qmlproperty string QtQuick::State::name This property holds the name of the state.
void setName (const QString &)
bool isNamed () const
bool isWhenKnown () const
bool when () const
void setWhen (bool)
QString extends () const
 \qmlproperty string QtQuick::State::extend This property holds the state that this state extends.
void setExtends (const QString &)
QQmlListProperty< QQuickStateOperationchanges ()
int operationCount () const
QQuickStateOperationoperationAt (int) const
QQuickStateoperator<< (QQuickStateOperation *)
void apply (QQuickTransition *, QQuickState *revert)
void cancel ()
QQuickStateGroupstateGroup () const
void setStateGroup (QQuickStateGroup *)
bool containsPropertyInRevertList (QObject *target, const QString &name) const
bool changeValueInRevertList (QObject *target, const QString &name, const QVariant &revertValue)
bool changeBindingInRevertList (QObject *target, const QString &name, QQmlAnyBinding binding)
bool removeEntryFromRevertList (QObject *target, const QString &name)
void addEntryToRevertList (const QQuickStateAction &action)
void removeAllEntriesFromRevertList (QObject *target)
void addEntriesToRevertList (const QList< QQuickStateAction > &actions)
QVariant valueInRevertList (QObject *target, const QString &name) const
QQmlAnyBinding bindingInRevertList (QObject *target, const QString &name) const
bool isStateActive () const
Public Member Functions inherited from QObject
Q_INVOKABLE QObject (QObject *parent=nullptr)
 Constructs an object with parent object parent.
virtual ~QObject ()
 Destroys the object, deleting all its child objects.
virtual bool event (QEvent *event)
 This virtual function receives events to an object and should return true if the event e was recognized and processed.
virtual bool eventFilter (QObject *watched, QEvent *event)
 Filters events if this object has been installed as an event filter for the watched object.
QString objectName () const
Q_WEAK_OVERLOAD void setObjectName (const QString &name)
 Sets the object's name to name.
void setObjectName (QAnyStringView name)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
QBindable< QStringbindableObjectName ()
bool isWidgetType () const
 Returns true if the object is a widget; otherwise returns false.
bool isWindowType () const
 Returns true if the object is a window; otherwise returns false.
bool isQuickItemType () const
 Returns true if the object is a QQuickItem; otherwise returns false.
bool isQmlObjectType () const
 Returns whether the object has been created by the QML engine or ownership has been explicitly set via QJSEngine::setObjectOwnership().
bool signalsBlocked () const noexcept
 Returns true if signals are blocked; otherwise returns false.
bool blockSignals (bool b) noexcept
 If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it).
QThreadthread () const
 Returns the thread in which the object lives.
bool moveToThread (QThread *thread QT6_DECL_NEW_OVERLOAD_TAIL)
 Changes the thread affinity for this object and its children and returns true on success.
int startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
 This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds.
int startTimer (std::chrono::nanoseconds time, Qt::TimerType timerType=Qt::CoarseTimer)
void killTimer (int id)
 Kills the timer with timer identifier, id.
void killTimer (Qt::TimerId id)
template<typename T>
findChild (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
 Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object.
template<typename T>
QList< T > findChildren (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) 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.
template<typename T>
findChild (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
template<typename T>
QList< T > findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
const QObjectListchildren () const
 Returns a list of child objects.
void setParent (QObject *parent)
 Makes the object a child of parent.
void installEventFilter (QObject *filterObj)
 Installs an event filter filterObj on this object.
void removeEventFilter (QObject *obj)
 Removes an event filter object obj from this object.
QMetaObject::Connection connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const
bool disconnect (const char *signal=nullptr, const QObject *receiver=nullptr, const char *member=nullptr) const
bool disconnect (const QObject *receiver, const char *member=nullptr) const
void dumpObjectTree () const
 Dumps a tree of children to the debug output.
void dumpObjectInfo () const
 Dumps information about signal connections, etc.
bool setProperty (const char *name, const QVariant &value)
 Sets the value of the object's name property to value.
bool setProperty (const char *name, QVariant &&value)
QVariant property (const char *name) const
 Returns the value of the object's name property.
QList< QByteArraydynamicPropertyNames () const
QBindingStoragebindingStorage ()
const QBindingStoragebindingStorage () const
QObjectparent () const
 Returns a pointer to the parent object.
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.

Properties

QString name
bool when
QString extend
QQmlListProperty< QQuickStateOperationchanges
 \qmlproperty list<Change> QtQuick::State::changes This property holds the changes to apply for this state \qmldefault
Properties inherited from QObject
QString objectName
 the name of this object

Additional Inherited Members

Public Slots inherited from QObject
void deleteLater ()
 \threadsafe
Static Public Member Functions inherited from QObject
static QMetaObject::Connection connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection)
 \threadsafe
static QMetaObject::Connection connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)
template<typename Func1, typename Func2>
static QMetaObject::Connection connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType *context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection)
template<typename Func1, typename Func2>
static QMetaObject::Connection connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot)
static bool disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
 \threadsafe
static bool disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member)
static bool disconnect (const QMetaObject::Connection &)
 Disconnect a connection.
template<typename Func1, typename Func2>
static bool disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object *receiver, Func2 slot)
template<typename Func1>
static bool disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const QObject *receiver, void **zero)
Protected Member Functions inherited from QObject
QObjectsender () const
 Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr.
int senderSignalIndex () const
int receivers (const char *signal) const
 Returns the number of receivers connected to the signal.
bool isSignalConnected (const QMetaMethod &signal) const
virtual void timerEvent (QTimerEvent *event)
 This event handler can be reimplemented in a subclass to receive timer events for the object.
virtual void childEvent (QChildEvent *event)
 This event handler can be reimplemented in a subclass to receive child events.
virtual void customEvent (QEvent *event)
 This event handler can be reimplemented in a subclass to receive custom events.
virtual void connectNotify (const QMetaMethod &signal)
virtual void disconnectNotify (const QMetaMethod &signal)
 QObject (QObjectPrivate &dd, QObject *parent=nullptr)
Protected Attributes inherited from QObject
QScopedPointer< QObjectDatad_ptr

Detailed Description

Definition at line 122 of file qquickstate_p.h.

Constructor & Destructor Documentation

◆ QQuickState()

QQuickState::QQuickState ( QObject * parent = nullptr)

\qmltype State \nativetype QQuickState \inqmlmodule QtQuick

Defines configurations of objects and properties.

A state is a set of batched changes from the default configuration.

All items have a default state that defines the default configuration of objects and property values. New states can be defined by adding State items to the \l {Item::states}{states} property to allow items to switch between different configurations. These configurations can, for example, be used to apply different sets of property values or execute different scripts.

The following example displays a single \l Rectangle. In the default state, the rectangle is colored black. In the "clicked" state, a PropertyChanges object changes the rectangle's color to red. Clicking within the MouseArea toggles the rectangle's state between the default state and the "clicked" state, thus toggling the color of the rectangle between black and red.

import QtQuick
Rectangle {
id: myRect
width: 100; height: 100
color: "black"
MouseArea {
id: mouseArea
anchors.fill: parent
onClicked: myRect.state == 'clicked' ? myRect.state = "" : myRect.state = 'clicked';
}
states: [
State {
name: "clicked"
PropertyChanges { target: myRect; color: "red" }
}
]
}

Notice the default state is referred to using an empty string ("").

States are commonly used together with \l{Animation and Transitions in Qt Quick}{Transitions} to provide animations when state changes occur.

Note
Setting the state of an object from within another state of the same object is not allowed.
See also
{Qt Quick Examples - Animation#States}{States example}, {Qt Quick States}, {Animation and Transitions in Qt Quick}{Transitions}, {Qt Qml}

Definition at line 118 of file qquickstate.cpp.

◆ ~QQuickState()

QQuickState::~QQuickState ( )
override

Definition at line 125 of file qquickstate.cpp.

Member Function Documentation

◆ addEntriesToRevertList()

void QQuickState::addEntriesToRevertList ( const QList< QQuickStateAction > & actions)

Definition at line 444 of file qquickstate.cpp.

◆ addEntryToRevertList()

void QQuickState::addEntryToRevertList ( const QQuickStateAction & action)

Definition at line 412 of file qquickstate.cpp.

◆ apply()

void QQuickState::apply ( QQuickTransition * trans,
QQuickState * revert )

Definition at line 497 of file qquickstate.cpp.

◆ bindingInRevertList()

QQmlAnyBinding QQuickState::bindingInRevertList ( QObject * target,
const QString & name ) const

Definition at line 478 of file qquickstate.cpp.

◆ cancel()

void QQuickState::cancel ( )

Definition at line 325 of file qquickstate.cpp.

◆ changeBindingInRevertList()

bool QQuickState::changeBindingInRevertList ( QObject * target,
const QString & name,
QQmlAnyBinding binding )

Definition at line 371 of file qquickstate.cpp.

◆ changes()

QQmlListProperty< QQuickStateOperation > QQuickState::changes ( )

◆ changeValueInRevertList()

bool QQuickState::changeValueInRevertList ( QObject * target,
const QString & name,
const QVariant & revertValue )

Definition at line 355 of file qquickstate.cpp.

◆ completed

void QQuickState::completed ( )
signal

◆ containsPropertyInRevertList()

bool QQuickState::containsPropertyInRevertList ( QObject * target,
const QString & name ) const

Definition at line 341 of file qquickstate.cpp.

◆ extends()

QString QQuickState::extends ( ) const

\qmlproperty string QtQuick::State::extend This property holds the state that this state extends.

When a state extends another state, it inherits all the changes of that state.

The state being extended is treated as the base state in regards to the changes specified by the extending state.

Definition at line 211 of file qquickstate.cpp.

◆ isNamed()

bool QQuickState::isNamed ( ) const

Definition at line 151 of file qquickstate.cpp.

◆ isStateActive()

bool QQuickState::isStateActive ( ) const

Definition at line 492 of file qquickstate.cpp.

◆ isWhenKnown()

bool QQuickState::isWhenKnown ( ) const

Definition at line 157 of file qquickstate.cpp.

◆ name()

QString QQuickState::name ( ) const

\qmlproperty string QtQuick::State::name This property holds the name of the state.

Each state should have a unique name within its item.

Definition at line 138 of file qquickstate.cpp.

◆ operationAt()

QQuickStateOperation * QQuickState::operationAt ( int index) const

Definition at line 250 of file qquickstate.cpp.

◆ operationCount()

int QQuickState::operationCount ( ) const

Definition at line 244 of file qquickstate.cpp.

◆ operator<<()

QQuickState & QQuickState::operator<< ( QQuickStateOperation * op)

Definition at line 256 of file qquickstate.cpp.

◆ removeAllEntriesFromRevertList()

void QQuickState::removeAllEntriesFromRevertList ( QObject * target)

Definition at line 421 of file qquickstate.cpp.

◆ removeEntryFromRevertList()

bool QQuickState::removeEntryFromRevertList ( QObject * target,
const QString & name )

Definition at line 387 of file qquickstate.cpp.

◆ setExtends()

void QQuickState::setExtends ( const QString & extends)

Definition at line 217 of file qquickstate.cpp.

◆ setName()

void QQuickState::setName ( const QString & n)

Definition at line 144 of file qquickstate.cpp.

◆ setStateGroup()

void QQuickState::setStateGroup ( QQuickStateGroup * group)

Definition at line 319 of file qquickstate.cpp.

◆ setWhen()

void QQuickState::setWhen ( bool when)

Definition at line 193 of file qquickstate.cpp.

◆ stateGroup()

QQuickStateGroup * QQuickState::stateGroup ( ) const

Definition at line 313 of file qquickstate.cpp.

◆ valueInRevertList()

QVariant QQuickState::valueInRevertList ( QObject * target,
const QString & name ) const

Definition at line 464 of file qquickstate.cpp.

◆ when()

bool QQuickState::when ( ) const
\qmlproperty bool QtQuick::State::when
This property holds when the state should be applied.

This should be set to an expression that evaluates to \c true when you want the state to
be applied. For example, the following \l Rectangle changes in and out of the "hidden"
state when the \l MouseArea is pressed:

\snippet qml/state-when.qml 0

If multiple states in a group have \c when clauses that evaluate to \c true
at the same time, the first matching state will be applied. For example, in
the following snippet \c state1 will always be selected rather than
\c state2 when sharedCondition becomes \c true.
\qml
Item {
    states: [
        State { name: "state1"; when: sharedCondition },
        State { name: "state2"; when: sharedCondition }
    ]

... } \endqml

Definition at line 187 of file qquickstate.cpp.

Property Documentation

◆ changes

QQmlListProperty< QQuickStateOperation > QQuickState::changes
read

\qmlproperty list<Change> QtQuick::State::changes This property holds the changes to apply for this state \qmldefault

By default these changes are applied against the default state. If the state extends another state, then the changes are applied against the state being extended.

Definition at line 129 of file qquickstate_p.h.

◆ extend

QString QQuickState::extend
readwrite

Definition at line 128 of file qquickstate_p.h.

◆ name

QString QQuickState::name
readwrite

◆ when

bool QQuickState::when
readwrite

Definition at line 127 of file qquickstate_p.h.


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