The QGraphicsBlurEffect class provides a blur effect. More...

#include <qgraphicseffect.h>

Inheritance diagram for QGraphicsBlurEffect:

Collaboration diagram for QGraphicsBlurEffect:

Public Types
enum	BlurHint { PerformanceHint = 0x00 , QualityHint = 0x01 , AnimationHint = 0x02 }
Public Types inherited from QGraphicsEffect
enum	ChangeFlag { SourceAttached = 0x1 , SourceDetached = 0x2 , SourceBoundingRectChanged = 0x4 , SourceInvalidated = 0x8 }
	This enum describes what has changed in QGraphicsEffectSource. More...
enum	PixmapPadMode { NoPad , PadToTransparentBorder , PadToEffectiveBoundingRect }
	This enum describes how the pixmap returned from sourcePixmap should be padded. More...

Public Slots
void	setBlurRadius (qreal blurRadius)
void	setBlurHints (BlurHints hints)
Public Slots inherited from QGraphicsEffect
void	setEnabled (bool enable)
void	update ()
	Schedules a redraw of the effect.
Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

Signals
void	blurRadiusChanged (qreal blurRadius)
	This signal is emitted whenever the effect's blur radius changes.
void	blurHintsChanged (BlurHints hints)
	This signal is emitted whenever the effect's blur hints changes.
Signals inherited from QGraphicsEffect
void	enabledChanged (bool enabled)
	This signal is emitted whenever the effect is enabled or disabled.
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
	QGraphicsBlurEffect (QObject *parent=nullptr)
	Constructs a new QGraphicsBlurEffect instance.
	~QGraphicsBlurEffect ()
	Destroys the effect.
QRectF	boundingRectFor (const QRectF &rect) const override
	\reimp
qreal	blurRadius () const
BlurHints	blurHints () const
Public Member Functions inherited from QGraphicsEffect
	QGraphicsEffect (QObject *parent=nullptr)
	Constructs a new QGraphicsEffect instance having the specified parent.
virtual	~QGraphicsEffect ()
	Removes the effect from the source, and destroys the graphics effect.
QRectF	boundingRect () const
	Returns the effective bounding rectangle for this effect, i.e., the bounding rectangle of the source in device coordinates, adjusted by any margins applied by the effect itself.
bool	isEnabled () const
QGraphicsEffectSource *	source () 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< QString >	bindableObjectName ()
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).
QThread *	thread () 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>
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>
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 QObjectList &	children () 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< QByteArray >	dynamicPropertyNames () const
QBindingStorage *	bindingStorage ()
const QBindingStorage *	bindingStorage () const
QObject *	parent () 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`.

Protected Member Functions
void	draw (QPainter *painter) override
	\reimp
Protected Member Functions inherited from QGraphicsEffect
	QGraphicsEffect (QGraphicsEffectPrivate &d, QObject *parent=nullptr)
virtual void	sourceChanged (ChangeFlags flags)
	This virtual function is called by QGraphicsEffect to notify the effect that the source has changed.
void	updateBoundingRect ()
	This function notifies the effect framework when the effect's bounding rectangle has changed.
bool	sourceIsPixmap () const
	Returns `true` if the source effectively is a pixmap, e.g., a QGraphicsPixmapItem.
QRectF	sourceBoundingRect (Qt::CoordinateSystem system=Qt::LogicalCoordinates) const
	Returns the bounding rectangle of the source mapped to the given system.
void	drawSource (QPainter *painter)
	Draws the source directly using the given painter.
QPixmap	sourcePixmap (Qt::CoordinateSystem system=Qt::LogicalCoordinates, QPoint *offset=nullptr, PixmapPadMode mode=PadToEffectiveBoundingRect) const
	Returns a pixmap with the source painted into it.
Protected Member Functions inherited from QObject
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 \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)

Properties
qreal	blurRadius
	the blur radius of the effect.
BlurHints	blurHints
	the blur hint of the effect.
Properties inherited from QGraphicsEffect
bool	enabled
	whether the effect is enabled or not.
Properties inherited from QObject
QString	objectName
	the name of this object

Additional Inherited Members
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 Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr
Related Symbols inherited from QObject
template< class T > T	qobject_cast (const QObject *object)
	Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.
template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()
template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()
	QObjectList
	\macro Q_CLASSINFO(Name, Value)

Detailed Description

The QGraphicsBlurEffect class provides a blur effect.

Since: 4.6 \inmodule QtWidgets

A blur effect blurs the source. This effect is useful for reducing details, such as when the source loses focus and you want to draw attention to other elements. The level of detail can be modified using the setBlurRadius() function. Use setBlurHints() to choose the blur hints.

By default, the blur radius is 5 pixels. The blur radius is specified in device coordinates.

{Blur effect on an image of a fish}

See also: QGraphicsDropShadowEffect, QGraphicsColorizeEffect, QGraphicsOpacityEffect

Definition at line 120 of file qgraphicseffect.h.

Member Enumeration Documentation

◆ BlurHint

enum QGraphicsBlurEffect::BlurHint

Since: 4.6

This enum describes the possible hints that can be used to control how blur effects are applied. The hints might not have an effect in all the paint engines.

\value PerformanceHint Indicates that rendering performance is the most important factor, at the potential cost of lower quality.

\value QualityHint Indicates that rendering quality is the most important factor, at the potential cost of lower performance.

\value AnimationHint Indicates that the blur radius is going to be animated, hinting that the implementation can keep a cache of blurred versions of the source. Do not use this hint if the source is going to be dynamically changing.

See also: blurHints(), setBlurHints()

Enumerator
PerformanceHint
QualityHint
AnimationHint

Definition at line 126 of file qgraphicseffect.h.

Constructor & Destructor Documentation

◆ QGraphicsBlurEffect()

QGraphicsBlurEffect::QGraphicsBlurEffect ( QObject * parent = nullptr )

Constructs a new QGraphicsBlurEffect instance.

The parent parameter is passed to QGraphicsEffect's constructor.

Definition at line 737 of file qgraphicseffect.cpp.

◆ ~QGraphicsBlurEffect()

QGraphicsBlurEffect::~QGraphicsBlurEffect ( )

Destroys the effect.

Definition at line 747 of file qgraphicseffect.cpp.

Member Function Documentation

◆ blurHints()

QGraphicsBlurEffect::BlurHints QGraphicsBlurEffect::blurHints ( ) const

Definition at line 797 of file qgraphicseffect.cpp.

◆ blurHintsChanged

void QGraphicsBlurEffect::blurHintsChanged ( BlurHints hints )

signal

This signal is emitted whenever the effect's blur hints changes.

The hints parameter holds the effect's new blur hints.

◆ blurRadius()

qreal QGraphicsBlurEffect::blurRadius ( ) const

Definition at line 763 of file qgraphicseffect.cpp.

◆ blurRadiusChanged

void QGraphicsBlurEffect::blurRadiusChanged ( qreal radius )

signal

This signal is emitted whenever the effect's blur radius changes.

The radius parameter holds the effect's new blur radius.

◆ boundingRectFor()

QRectF QGraphicsBlurEffect::boundingRectFor ( const QRectF & rect ) const

overridevirtual

\reimp

Reimplemented from QGraphicsEffect.

Definition at line 823 of file qgraphicseffect.cpp.

◆ draw()

void QGraphicsBlurEffect::draw ( QPainter * painter )

overrideprotectedvirtual

\reimp

Implements QGraphicsEffect.

Definition at line 832 of file qgraphicseffect.cpp.

◆ setBlurHints

void QGraphicsBlurEffect::setBlurHints ( BlurHints hints )

slot

Definition at line 803 of file qgraphicseffect.cpp.

◆ setBlurRadius

void QGraphicsBlurEffect::setBlurRadius ( qreal blurRadius )

slot

Definition at line 769 of file qgraphicseffect.cpp.

Property Documentation

◆ blurHints

BlurHints QGraphicsBlurEffect::blurHints

readwrite

the blur hint of the effect.

Use the PerformanceHint hint to say that you want a faster blur, the QualityHint hint to say that you prefer a higher quality blur, or the AnimationHint when you want to animate the blur radius.

By default, the blur hint is PerformanceHint.

Definition at line 124 of file qgraphicseffect.h.

◆ blurRadius

qreal QGraphicsBlurEffect::blurRadius

readwrite

the blur radius of the effect.

Using a smaller radius results in a sharper appearance, whereas a bigger radius results in a more blurred appearance.

By default, the blur radius is 5 pixels.

The radius is given in device coordinates, meaning it is unaffected by scale.

Definition at line 123 of file qgraphicseffect.h.

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

qtbase/src/widgets/effects/qgraphicseffect.h (500399473f9a80b801119ff645e77dfbf3101149)
qtbase/src/widgets/effects/qgraphicseffect.cpp (87806f5cad6e4ce75a899598c15c126995682562)

Public Types

Public Slots

Signals

Public Member Functions

Protected Member Functions

Properties

Additional Inherited Members