The QGraphicsRotation class provides a rotation transformation around a given axis. More...

#include <qgraphicstransform.h>

Inheritance diagram for QGraphicsRotation:

Signals
void	angleChanged ()
	This signal is emitted whenever the angle has changed. More...

void	axisChanged ()
	This signal is emitted whenever the axis of the object changes. More...

void	originChanged ()
	This signal is emitted whenever the origin has changed. 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
qreal	angle () const

void	applyTo (QMatrix4x4 *matrix) const
	Reimplemented Function More...

QVector3D	axis () const

QVector3D	origin () const

	QGraphicsRotation (QObject *parent=0)
	Constructs a new QGraphicsRotation with the given parent. More...

void	setAngle (qreal)

void	setAxis (const QVector3D &axis)

void	setAxis (Qt::Axis axis)
	Convenience function to set the axis to axis. More...

void	setOrigin (const QVector3D &point)

	~QGraphicsRotation ()
	Destroys the graphics rotation. More...

Public Functions inherited from QGraphicsTransform
	QGraphicsTransform (QObject *parent=0)
	Constructs a new QGraphicsTransform with the given parent. More...

	~QGraphicsTransform ()
	Destroys the graphics transform. 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	event (QEvent *)
	This virtual function receives events to an object and should return true if the event e was recognized and processed. 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...

Properties
qreal	angle
	the angle for clockwise rotation, in degrees. More...

QVector3D	axis
	a rotation axis, specified by a vector in 3D space. More...

QVector3D	origin
	the origin of the rotation in 3D space. 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 Slots inherited from QGraphicsTransform
void	update ()
	Notifies that this transform operation has changed its parameters in such a way that applyTo() will return a different result than before. More...

Protected Functions inherited from QGraphicsTransform
	QGraphicsTransform (QGraphicsTransformPrivate &p, QObject *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...

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 QGraphicsRotation class provides a rotation transformation around a given axis.

Since: 4.6

You can provide the desired axis by assigning a QVector3D to the axis property or by passing a member if Qt::Axis to the setAxis convenience function. By default the axis is (0, 0, 1) i.e., rotation around the Z axis.

The angle property, which is provided by QGraphicsRotation, now describes the number of degrees to rotate around this axis.

QGraphicsRotation provides certain parameters to help control how the rotation should be applied.

The origin is the point that the item is rotated around (i.e., it stays fixed relative to the parent as the rest of the item is rotated). By default the origin is QPointF(0, 0).

The angle property provides the number of degrees to rotate the item clockwise around the origin. This value also be negative, indicating a counter-clockwise rotation. For animation purposes it may also be useful to provide rotation angles exceeding (-360, 360) degrees, for instance to animate how an item rotates several times.

Note: the final rotation is the combined effect of a rotation in 3D space followed by a projection back to 2D. If several rotations are performed in succession, they will not behave as expected unless they were all around the Z axis.

See also: QGraphicsTransform, QGraphicsItem::setRotation(), QTransform::rotate()

Definition at line 122 of file qgraphicstransform.h.

Constructors and Destructors

◆ QGraphicsRotation()

QGraphicsRotation::QGraphicsRotation ( QObject * parent = 0 )

Constructs a new QGraphicsRotation with the given parent.

Definition at line 462 of file qgraphicstransform.cpp.

     : QGraphicsTransform(*new QGraphicsRotationPrivate, parent)
 {
 }

◆ ~QGraphicsRotation()

QGraphicsRotation::~QGraphicsRotation ( )

Destroys the graphics rotation.

Definition at line 470 of file qgraphicstransform.cpp.

471 {

472 }

Functions

◆ angle()

qreal QGraphicsRotation::angle ( ) const

Referenced by setAngle(), and setOrigin().

◆ angleChanged

void QGraphicsRotation::angleChanged ( )

signal

This signal is emitted whenever the angle has changed.

See also: QGraphicsRotation::angle

Referenced by setAngle().

◆ applyTo()

void QGraphicsRotation::applyTo ( QMatrix4x4 * matrix ) const

virtual

Reimplemented Function

Implements QGraphicsTransform.

Definition at line 625 of file qgraphicstransform.cpp.

 {
     Q_D(const QGraphicsRotation);
 
     if (d->angle == 0. || d->axis.isNull() || qIsNaN(d->angle))
         return;
 
     matrix->translate(d->origin);
     matrix->projectedRotate(d->angle, d->axis.x(), d->axis.y(), d->axis.z());
     matrix->translate(-d->origin);
 }

◆ axis()

QVector3D QGraphicsRotation::axis ( ) const

Referenced by setAngle(), and setAxis().

◆ axisChanged

void QGraphicsRotation::axisChanged ( )

signal

This signal is emitted whenever the axis of the object changes.

See also: QGraphicsRotation::axis

Referenced by setAxis().

◆ origin()

QVector3D QGraphicsRotation::origin ( ) const

Referenced by ~QGraphicsRotation().

◆ originChanged

QGraphicsRotation::originChanged ( )

signal

This signal is emitted whenever the origin has changed.

See also: QGraphicsRotation::origin

Referenced by setOrigin().

◆ setAngle()

void QGraphicsRotation::setAngle ( qreal angle )

Definition at line 522 of file qgraphicstransform.cpp.

 {
     Q_D(QGraphicsRotation);
     if (d->angle == angle)
         return;
     d->angle = angle;
     update();
     emit angleChanged();
 }

◆ setAxis() [1/2]

void QGraphicsRotation::setAxis ( const QVector3D & axis )

Definition at line 574 of file qgraphicstransform.cpp.

Referenced by setAxis().

 {
     Q_D(QGraphicsRotation);
     if (d->axis == axis)
          return;
     d->axis = axis;
     update();
     emit axisChanged();
 }

◆ setAxis() [2/2]

void QGraphicsRotation::setAxis ( Qt::Axis axis )

Convenience function to set the axis to axis.

Note: the Qt::YAxis rotation for QTransform is inverted from the correct mathematical rotation in 3D space. The QGraphicsRotation class implements a correct mathematical rotation. The following two sequences of code will perform the same transformation:

QTransform t;
t.rotate(45, Qt::YAxis);
QGraphicsRotation r;
r.setAxis(Qt::YAxis);
r.setAngle(-45);

Definition at line 606 of file qgraphicstransform.cpp.

 {
     switch (axis)
     {
     case Qt::XAxis:
         setAxis(QVector3D(1, 0, 0));
         break;
     case Qt::YAxis:
         setAxis(QVector3D(0, 1, 0));
         break;
     case Qt::ZAxis:
         setAxis(QVector3D(0, 0, 1));
         break;
     }
 }

◆ setOrigin()

void QGraphicsRotation::setOrigin ( const QVector3D & point )

Definition at line 491 of file qgraphicstransform.cpp.

 {
     Q_D(QGraphicsRotation);
     if (d->origin == point)
         return;
     d->origin = point;
     update();
     emit originChanged();
 }

Properties

◆ angle

qreal QGraphicsRotation::angle

private

the angle for clockwise rotation, in degrees.

The angle can be any real number; the default value is 0.0. A value of 180 will rotate 180 degrees, clockwise. If you provide a negative number, the item will be rotated counter-clockwise. Normally the rotation angle will be in the range (-360, 360), but you can also provide numbers outside of this range (e.g., a angle of 370 degrees gives the same result as 10 degrees). Setting the angle to NaN results in no rotation.

See also: origin

Definition at line 127 of file qgraphicstransform.h.

◆ axis

QVector3D QGraphicsRotation::axis

private

a rotation axis, specified by a vector in 3D space.

This can be any axis in 3D space. By default the axis is (0, 0, 1), which is aligned with the Z axis. If you provide another axis, QGraphicsRotation will provide a transformation that rotates around this axis. For example, if you would like to rotate an item around its X axis, you could pass (1, 0, 0) as the axis.

See also: QTransform, QGraphicsRotation::angle

Definition at line 128 of file qgraphicstransform.h.

◆ origin

QVector3D QGraphicsRotation::origin

private

the origin of the rotation in 3D space.

All rotations will be done relative to this point (i.e., this point will stay fixed, relative to the parent, when the item is rotated).

See also: angle

Definition at line 126 of file qgraphicstransform.h.

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

/src/gui/graphicsview/qgraphicstransform.h
/src/gui/graphicsview/qgraphicstransform.cpp

Signals

Public Functions

Properties

Additional Inherited Members

Detailed Description

Constructors and Destructors

◆ QGraphicsRotation()

◆ ~QGraphicsRotation()

Functions

◆ angle()

◆ angleChanged

◆ applyTo()

◆ axis()

◆ axisChanged

◆ origin()

◆ originChanged

◆ setAngle()

◆ setAxis() [1/2]

◆ setAxis() [2/2]

◆ setOrigin()

Properties

◆ angle

◆ axis

◆ origin