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Internal/Contributor docs for the Qt SDK. Note: These are NOT official API docs; those are found at https://doc.qt.io/
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MyGraphicsEffect Class Reference
Inheritance diagram for MyGraphicsEffect:
Collaboration diagram for MyGraphicsEffect:

Public Member Functions

void draw (QPainter *painter) override
 [0]
void draw (QPainter *painter) override
 This pure virtual function draws the effect and is called whenever the source needs to be drawn.
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.
virtual QRectF boundingRectFor (const QRectF &sourceRect) const
 Returns the effective bounding rectangle for this effect, given the provided rect in the device coordinates.
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
QGraphicsEffectSourcesource () 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< QStringbindableObjectName ()
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).
QThreadthread () 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>
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>
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 QObjectListchildren () 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< QByteArraydynamicPropertyNames () const
QBindingStoragebindingStorage ()
const QBindingStoragebindingStorage () const
QObjectparent () 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.

Additional Inherited Members

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 inherited from QGraphicsEffect
void setEnabled (bool enable)
void update ()
 Schedules a redraw of the effect.
Public Slots inherited from QObject
void deleteLater ()
 \threadsafe
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.
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 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
QObjectsender () 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)
Protected Attributes inherited from QObject
QScopedPointer< QObjectDatad_ptr
Properties inherited from QGraphicsEffect
bool enabled
 whether the effect is enabled or not.
Properties inherited from QObject
QString objectName
 the name of this object

Detailed Description

Definition at line 10 of file src_gui_effects_qgraphicseffect.cpp.

Member Function Documentation

◆ draw() [1/2]

void MyGraphicsEffect::draw ( QPainter * painter)
overridevirtual

[0]

[1]

Implements QGraphicsEffect.

Definition at line 39 of file src_gui_effects_qgraphicseffect.cpp.

◆ draw() [2/2]

void MyGraphicsEffect::draw ( QPainter * painter)
overridevirtual

This pure virtual function draws the effect and is called whenever the source needs to be drawn.

Reimplement this function in a QGraphicsEffect subclass to provide the effect's drawing implementation, using painter.

For example:

{
//...
QPoint offset;
if (sourceIsPixmap()) {
// No point in drawing in device coordinates (pixmap will be scaled anyways).
//...
} else {
// Draw pixmap in device coordinates to avoid pixmap scaling;
painter->setWorldTransform(QTransform());
//...
}
//...
}

This function should not be called explicitly by the user, since it is meant for reimplementation purposes only.

Implements QGraphicsEffect.


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