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

#include <qgraphicseffect.h>

Inheritance diagram for QGraphicsBlurEffect:

Public Types
enum	BlurHint { PerformanceHint = 0x00, QualityHint = 0x01, AnimationHint = 0x02 }
	This enum describes the possible hints that can be used to control how blur effects are applied. More...

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	setBlurHints (BlurHints hints)

void	setBlurRadius (qreal blurRadius)

Public Slots inherited from QGraphicsEffect
void	setEnabled (bool enable)

void	update ()
	Schedules a redraw of the effect. More...

Public Slots inherited from QObject
void	deleteLater ()
	Schedules this object for deletion. More...

Signals
void	blurHintsChanged (BlurHints hints)
	This signal is emitted whenever the effect's blur hints changes. More...

void	blurRadiusChanged (qreal blurRadius)
	This signal is emitted whenever the effect's blur radius changes. More...

Signals inherited from QGraphicsEffect
void	enabledChanged (bool enabled)
	This signal is emitted whenever the effect is enabled or disabled. 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
BlurHints	blurHints () const

qreal	blurRadius () const

QRectF	boundingRectFor (const QRectF &rect) const
	Reimplemented Function More...

	QGraphicsBlurEffect (QObject *parent=0)
	Constructs a new QGraphicsBlurEffect instance. More...

	~QGraphicsBlurEffect ()
	Destroys the effect. More...

Public Functions inherited from QGraphicsEffect
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. More...

bool	isEnabled () const

	QGraphicsEffect (QObject *parent=0)
	Constructs a new QGraphicsEffect instance having the specified parent. More...

QGraphicsEffectSource *	source () const
	Returns a pointer to the source, which provides extra context information that can be useful for the effect. More...

virtual	~QGraphicsEffect ()
	Removes the effect from the source, and destroys the graphics effect. 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...

Protected Functions
void	draw (QPainter *painter)
	Reimplemented Function More...

Protected Functions inherited from QGraphicsEffect
void	drawSource (QPainter *painter)
	Draws the source directly using the given painter. More...

	QGraphicsEffect (QGraphicsEffectPrivate &d, QObject *parent=0)

QRectF	sourceBoundingRect (Qt::CoordinateSystem system=Qt::LogicalCoordinates) const
	Returns the bounding rectangle of the source mapped to the given system. More...

virtual void	sourceChanged (ChangeFlags flags)
	This virtual function is called by QGraphicsEffect to notify the effect that the source has changed. More...

bool	sourceIsPixmap () const
	Returns true if the source effectively is a pixmap, e.g., a QGraphicsPixmapItem. More...

QPixmap	sourcePixmap (Qt::CoordinateSystem system=Qt::LogicalCoordinates, QPoint *offset=0, PixmapPadMode mode=PadToEffectiveBoundingRect) const
	Returns a pixmap with the source painted into it. More...

void	updateBoundingRect ()
	This function notifies the effect framework when the effect's bounding rectangle has changed. More...

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...

Properties
BlurHints	blurHints
	the blur hint of the effect. More...

qreal	blurRadius
	the blur radius of the effect. More...

Additional Inherited Members
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 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 QGraphicsBlurEffect class provides a blur effect.

Since: 4.6

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.

See also: QGraphicsDropShadowEffect, QGraphicsColorizeEffect, QGraphicsOpacityEffect

Definition at line 159 of file qgraphicseffect.h.

Enumerations

◆ BlurHint

enum QGraphicsBlurEffect::BlurHint

This enum describes the possible hints that can be used to control how blur effects are applied.

Since: 4.6

The hints might not have an effect in all the paint engines.

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

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

AnimationHint Indicates that the blur radius is going to be animated, hinting that the implementation can keep a cache of blurred verisons 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 166 of file qgraphicseffect.h.

                   {
         PerformanceHint = 0x00,
         QualityHint = 0x01,
         AnimationHint = 0x02
     };

Constructors and Destructors

◆ QGraphicsBlurEffect()

QGraphicsBlurEffect::QGraphicsBlurEffect ( QObject * parent = 0 )

Constructs a new QGraphicsBlurEffect instance.

The parent parameter is passed to QGraphicsEffect's constructor.

Definition at line 802 of file qgraphicseffect.cpp.

     : QGraphicsEffect(*new QGraphicsBlurEffectPrivate, parent)
 {
     Q_D(QGraphicsBlurEffect);
     d->filter->setBlurHints(QGraphicsBlurEffect::PerformanceHint);
 }

◆ ~QGraphicsBlurEffect()

QGraphicsBlurEffect::~QGraphicsBlurEffect ( )

Destroys the effect.

Definition at line 812 of file qgraphicseffect.cpp.

813 {

814 }

Functions

◆ blurHints()

BlurHints QGraphicsBlurEffect::blurHints ( ) const

Referenced by setBlurRadius().

◆ 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.

Referenced by setBlurHints().

◆ blurRadius()

qreal QGraphicsBlurEffect::blurRadius ( ) const

Referenced by ~QGraphicsBlurEffect().

◆ 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.

Referenced by setBlurRadius().

◆ boundingRectFor()

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

virtual

Reimplemented Function

Reimplemented from QGraphicsEffect.

Definition at line 900 of file qgraphicseffect.cpp.

 {
     Q_D(const QGraphicsBlurEffect);
     return d->filter->boundingRectFor(rect);
 }

◆ draw()

void QGraphicsBlurEffect::draw ( QPainter * painter )

protectedvirtual

Reimplemented Function

Implements QGraphicsEffect.

Definition at line 909 of file qgraphicseffect.cpp.

 {
     Q_D(QGraphicsBlurEffect);
     if (d->filter->radius() < 1) {
         drawSource(painter);
         return;
     }
 
     PixmapPadMode mode = PadToEffectiveBoundingRect;
     if (painter->paintEngine()->type() == QPaintEngine::OpenGL2)
         mode = NoPad;
 
     QPoint offset;
     QPixmap pixmap = sourcePixmap(Qt::LogicalCoordinates, &offset, mode);
     if (pixmap.isNull())
         return;
 
     d->filter->draw(painter, offset, pixmap);
 }

◆ setBlurHints

void QGraphicsBlurEffect::setBlurHints ( BlurHints hints )

slot

Definition at line 877 of file qgraphicseffect.cpp.

 {
     Q_D(QGraphicsBlurEffect);
     if (d->filter->blurHints() == hints)
         return;
 
     d->filter->setBlurHints(hints);
     emit blurHintsChanged(hints);
 }

◆ setBlurRadius

void QGraphicsBlurEffect::setBlurRadius ( qreal blurRadius )

slot

Definition at line 837 of file qgraphicseffect.cpp.

 {
     Q_D(QGraphicsBlurEffect);
     if (qFuzzyCompare(d->filter->radius(), radius))
         return;
 
     d->filter->setRadius(radius);
     updateBoundingRect();
     emit blurRadiusChanged(radius);
 }

Properties

◆ blurHints

QGraphicsBlurEffect::BlurHints QGraphicsBlurEffect::blurHints

private

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 164 of file qgraphicseffect.h.

◆ blurRadius

qreal QGraphicsBlurEffect::blurRadius

private

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 163 of file qgraphicseffect.h.

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

/src/gui/effects/qgraphicseffect.h
/src/gui/effects/qgraphicseffect.cpp

Public Types

Public Slots

Signals

Public Functions

Protected Functions

Properties

Additional Inherited Members

Detailed Description

Enumerations

◆ BlurHint

Constructors and Destructors

◆ QGraphicsBlurEffect()

◆ ~QGraphicsBlurEffect()

Functions

◆ blurHints()

◆ blurHintsChanged

◆ blurRadius()

◆ blurRadiusChanged

◆ boundingRectFor()

◆ draw()

◆ setBlurHints

◆ setBlurRadius

Properties

◆ blurHints

◆ blurRadius