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Internal/Contributor docs for the Qt SDK. <b>Note:</b> These are NOT official API docs; those are found <a href='https://doc.qt.io/'>here</a>.
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Public Types | Public Slots | Signals | Public Member Functions | Protected Member Functions | Properties | List of all members
QGraphicsBlurEffect Class Reference

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 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
 Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.
 
 
 
 \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.

See also
QGraphicsDropShadowEffect, QGraphicsColorizeEffect, QGraphicsOpacityEffect

Definition at line 119 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 125 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 728 of file qgraphicseffect.cpp.

References d, and PerformanceHint.

◆ ~QGraphicsBlurEffect()

QGraphicsBlurEffect::~QGraphicsBlurEffect ( )

Destroys the effect.

Definition at line 738 of file qgraphicseffect.cpp.

Member Function Documentation

◆ blurHints()

QGraphicsBlurEffect::BlurHints QGraphicsBlurEffect::blurHints ( ) const

Definition at line 788 of file qgraphicseffect.cpp.

References d.

◆ 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().

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◆ blurRadius()

qreal QGraphicsBlurEffect::blurRadius ( ) const

Definition at line 754 of file qgraphicseffect.cpp.

References d.

◆ 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().

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◆ boundingRectFor()

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

\reimp

Reimplemented from QGraphicsEffect.

Definition at line 814 of file qgraphicseffect.cpp.

References d, and rect.

◆ draw()

void QGraphicsBlurEffect::draw ( QPainter * painter)
overrideprotectedvirtual

\reimp

Implements QGraphicsEffect.

Definition at line 823 of file qgraphicseffect.cpp.

References d, QGraphicsEffect::drawSource(), Qt::LogicalCoordinates, QGraphicsEffect::PadToEffectiveBoundingRect, painter, pixmap, and QGraphicsEffect::sourcePixmap().

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◆ setBlurHints

void QGraphicsBlurEffect::setBlurHints ( BlurHints hints)
slot

Definition at line 794 of file qgraphicseffect.cpp.

References blurHintsChanged(), d, and emit.

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◆ setBlurRadius

void QGraphicsBlurEffect::setBlurRadius ( qreal blurRadius)
slot

Definition at line 760 of file qgraphicseffect.cpp.

References blurRadiusChanged(), d, emit, qFuzzyCompare(), and QGraphicsEffect::updateBoundingRect().

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Property Documentation

◆ 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 123 of file qgraphicseffect.h.

◆ blurRadius

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 122 of file qgraphicseffect.h.

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