The QGraphicsTransform class is an abstract base class for building advanced transformations on QGraphicsItems. More...

#include <qgraphicstransform.h>

Inheritance diagram for QGraphicsTransform:

Collaboration diagram for QGraphicsTransform:

Public Member Functions
	QGraphicsTransform (QObject *parent=nullptr)

	~QGraphicsTransform ()

virtual void	applyTo (QMatrix4x4 *matrix) const =0

Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)

virtual	~QObject ()

virtual bool	event (QEvent *event)

virtual bool	eventFilter (QObject watched, QEvent event)

QString	objectName () const

void	setObjectName (const QString &name)

QBindable< QString >	bindableObjectName ()

bool	isWidgetType () const

bool	isWindowType () const

bool	signalsBlocked () const noexcept

bool	blockSignals (bool b) noexcept

QThread *	thread () const

void	moveToThread (QThread *thread)

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)

template<typename T >
T	findChild (const QString &aName=QString(), Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<typename T >
QList< T >	findChildren (const QString &aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

const QObjectList &	children () const

void	setParent (QObject *parent)

void	installEventFilter (QObject *filterObj)

void	removeEventFilter (QObject *obj)

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

void	dumpObjectInfo () const

bool	setProperty (const char *name, const QVariant &value)

QVariant	property (const char *name) const

QList< QByteArray >	dynamicPropertyNames () const

QBindingStorage *	bindingStorage ()

const QBindingStorage *	bindingStorage () const

QObject *	parent () const

bool	inherits (const char *classname) const

Protected Slots
void	update ()

Protected Member Functions
	QGraphicsTransform (QGraphicsTransformPrivate &p, QObject *parent)

Protected Member Functions inherited from QObject
QObject *	sender () const

int	senderSignalIndex () const

int	receivers (const char *signal) const

bool	isSignalConnected (const QMetaMethod &signal) const

virtual void	timerEvent (QTimerEvent *event)

virtual void	childEvent (QChildEvent *event)

virtual void	customEvent (QEvent *event)

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

	QObject (QObjectPrivate &dd, QObject *parent=nullptr)

Friends
class	QGraphicsItem

class	QGraphicsItemPrivate

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()

Signals inherited from QObject
void	destroyed (QObject *=nullptr)

void	objectNameChanged (const QString &objectName, QPrivateSignal)

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)

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::FunctionPointer< Func2 >::Object receiver, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

static QMetaObject::Connection ::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 slot)

static QMetaObject::Connection ::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject context, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static std::enable_if< QtPrivate::FunctionPointer< Func2 >::ArgumentCount==-1 &&!std::is_convertible_v< Func2, const char * >, QMetaObject::Connection >::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 slot)

template<typename Func1 , typename Func2 >
static std::enable_if< QtPrivate::FunctionPointer< Func2 >::ArgumentCount==-1 &&!std::is_convertible_v< Func2, const char * >, QMetaObject::Connection >::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject context, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

static bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char member)

static bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &member)

static bool	disconnect (const QMetaObject::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 Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Properties inherited from QObject
QString	objectName
	the name of this object More...

Related Functions inherited from QObject
template< class T > T	qobject_cast (const QObject *object)

template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()

template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()

	QObjectList

Detailed Description

The QGraphicsTransform class is an abstract base class for building advanced transformations on QGraphicsItems.

Since: 4.6

\inmodule QtWidgets

As an alternative to QGraphicsItem::transform, QGraphicsTransform lets you create and control advanced transformations that can be configured independently using specialized properties.

QGraphicsItem allows you to assign any number of QGraphicsTransform instances to one QGraphicsItem. Each QGraphicsTransform is applied in order, one at a time, to the QGraphicsItem it's assigned to.

QGraphicsTransform is particularly useful for animations. Whereas QGraphicsItem::setTransform() lets you assign any transform directly to an item, there is no direct way to interpolate between two different transformations (e.g., when transitioning between two states, each for which the item has a different arbitrary transform assigned). Using QGraphicsTransform you can interpolate the property values of each independent transformation. The resulting operation is then combined into a single transform which is applied to QGraphicsItem.

Transformations are computed in true 3D space using QMatrix4x4. When the transformation is applied to a QGraphicsItem, it will be projected back to a 2D QTransform. When multiple QGraphicsTransform objects are applied to a QGraphicsItem, all of the transformations are computed in true 3D space, with the projection back to 2D only occurring after the last QGraphicsTransform is applied. The exception to this is QGraphicsRotation, which projects back to 2D after each rotation to preserve the perspective effect around the X and Y axes.

If you want to create your own configurable transformation, you can create a subclass of QGraphicsTransform (or any or the existing subclasses), and reimplement the pure virtual applyTo() function, which takes a pointer to a QMatrix4x4. Each operation you would like to apply should be exposed as properties (e.g., customTransform->setVerticalShear(2.5)). Inside you reimplementation of applyTo(), you can modify the provided transform respectively.

QGraphicsTransform can be used together with QGraphicsItem::setTransform(), QGraphicsItem::setRotation(), and QGraphicsItem::setScale().

See also: QGraphicsItem::transform(), QGraphicsScale, QGraphicsRotation

Definition at line 56 of file qgraphicstransform.h.

Constructor & Destructor Documentation

◆ QGraphicsTransform() [1/2]

QGraphicsTransform::QGraphicsTransform ( QObject * parent = nullptr )

Constructs a new QGraphicsTransform with the given parent.

Definition at line 130 of file qgraphicstransform.cpp.

◆ ~QGraphicsTransform()

QGraphicsTransform::~QGraphicsTransform ( )

Destroys the graphics transform.

Definition at line 138 of file qgraphicstransform.cpp.

◆ QGraphicsTransform() [2/2]

QGraphicsTransform::QGraphicsTransform	(	QGraphicsTransformPrivate &	p,
		QObject *	parent
	)

protected

Definition at line 147 of file qgraphicstransform.cpp.

Member Function Documentation

◆ applyTo()

void QGraphicsTransform::applyTo ( QMatrix4x4 * matrix ) const

pure virtual

This pure virtual method has to be reimplemented in derived classes.

It applies this transformation to matrix.

See also: QGraphicsItem::transform(), QMatrix4x4::toTransform()

Implemented in QGraphicsRotation, and QGraphicsScale.

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◆ update

void QGraphicsTransform::update ( )

protectedslot

Notifies that this transform operation has changed its parameters in such a way that applyTo() will return a different result than before.

When implementing you own custom graphics transform, you must call this function every time you change a parameter, to let QGraphicsItem know that its transformation needs to be updated.

See also: applyTo()

Definition at line 172 of file qgraphicstransform.cpp.

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Friends And Related Function Documentation

◆ QGraphicsItem

friend class QGraphicsItem

friend

Definition at line 72 of file qgraphicstransform.h.

◆ QGraphicsItemPrivate

friend class QGraphicsItemPrivate

friend

Definition at line 73 of file qgraphicstransform.h.

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

src/widgets/graphicsview/qgraphicstransform.h
src/widgets/graphicsview/qgraphicstransform.cpp

Public Member Functions

Protected Slots

Protected Member Functions

Friends

Additional Inherited Members