The QSGContext holds the scene graph entry points for one QML engine. More...

#include <qsgcontext_p.h>

Inheritance diagram for QSGContext:

Collaboration diagram for QSGContext:

Public Types
enum	AntialiasingMethod { UndecidedAntialiasing , VertexAntialiasing , MsaaAntialiasing }

Public Member Functions
	QSGContext (QObject *parent=nullptr)

	~QSGContext () override

virtual void	renderContextInitialized (QSGRenderContext *renderContext)

virtual void	renderContextInvalidated (QSGRenderContext *renderContext)

virtual QSGRenderContext *	createRenderContext ()=0

QSGInternalRectangleNode *	createInternalRectangleNode (const QRectF &rect, const QColor &c)
	Convenience factory function for creating a colored rectangle with the given geometry.

virtual QSGInternalRectangleNode *	createInternalRectangleNode ()=0

virtual QSGInternalImageNode *	createInternalImageNode (QSGRenderContext *renderContext)=0

virtual QSGPainterNode *	createPainterNode (QQuickPaintedItem *item)=0

virtual QSGGlyphNode *	createGlyphNode (QSGRenderContext *rc, bool preferNativeGlyphNode, int renderTypeQuality)=0

virtual QSGLayer *	createLayer (QSGRenderContext *renderContext)=0

virtual QSGGuiThreadShaderEffectManager *	createGuiThreadShaderEffectManager ()
	Creates a new shader effect helper instance.

virtual QSGShaderEffectNode *	createShaderEffectNode (QSGRenderContext *renderContext)
	Creates a new shader effect node.

virtual QAnimationDriver *	createAnimationDriver (QObject *parent)
	Creates a new animation driver.

virtual float	vsyncIntervalForAnimationDriver (QAnimationDriver *driver)

virtual bool	isVSyncDependent (QAnimationDriver *driver)

virtual QSize	minimumFBOSize () const

virtual QSurfaceFormat	defaultSurfaceFormat () const =0

virtual QSGRendererInterface *	rendererInterface (QSGRenderContext *renderContext)
	Returns a pointer to the (presumably) global renderer interface.

virtual QSGRectangleNode *	createRectangleNode ()=0

virtual QSGImageNode *	createImageNode ()=0

virtual QSGNinePatchNode *	createNinePatchNode ()=0

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.

void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children.

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::milliseconds time, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)
	Kills the timer with timer identifier, id.

template<typename T >
T	findChild (const QString &aName=QString(), 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 (const QString &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 >
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`.

Static Public Member Functions
static QSGContext *	createDefaultContext ()
	Creates a default scene graph context for the current hardware.

static QQuickTextureFactory *	createTextureFactoryFromImage (const QImage &image)
	Calls into the scene graph adaptation if available and creates a texture factory.

static QSGRenderLoop *	createWindowManager ()
	Calls into the scene graph adaptation if available and creates a hardware specific window manager.

static void	setBackend (const QString &backend)

static QString	backend ()

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)

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

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.

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)

Protected Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Properties inherited from QObject
QString	objectName
	the name of this object

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 QSGContext holds the scene graph entry points for one QML engine.

The context is not ready for use until it has a QRhi. Once that happens, the scene graph population can start.

Definition at line 73 of file qsgcontext_p.h.

Member Enumeration Documentation

◆ AntialiasingMethod

enum QSGContext::AntialiasingMethod

Enumerator
UndecidedAntialiasing
VertexAntialiasing
MsaaAntialiasing

Definition at line 78 of file qsgcontext_p.h.

Constructor & Destructor Documentation

◆ QSGContext()

QSGContext::QSGContext ( QObject * parent = nullptr )

explicit

Definition at line 302 of file qsgcontext.cpp.

◆ ~QSGContext()

QSGContext::~QSGContext ( )

override

Definition at line 307 of file qsgcontext.cpp.

Member Function Documentation

◆ backend()

QString QSGContext::backend ( )

static

Definition at line 221 of file qsgcontextplugin.cpp.

References QSGAdaptationBackendData::name, QSGAdaptationBackendData::quickWindowBackendRequest, and QSGAdaptationBackendData::tried.

Referenced by QGeoMapMapboxGLPrivate::updateSceneGraph().

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◆ createAnimationDriver()

QAnimationDriver * QSGContext::createAnimationDriver ( QObject * parent )

virtual

Creates a new animation driver.

Definition at line 355 of file qsgcontext.cpp.

References QObject::parent().

Referenced by QSGSoftwareThreadedRenderLoop::QSGSoftwareThreadedRenderLoop(), QSGThreadedRenderLoop::QSGThreadedRenderLoop(), QSGSoftwareRenderThread::run(), and QSGRenderThread::run().

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◆ createDefaultContext()

QSGContext * QSGContext::createDefaultContext ( )

static

Creates a default scene graph context for the current hardware.

This may load a device-specific plugin.

Definition at line 173 of file qsgcontextplugin.cpp.

References contextFactory(), QSGContextFactoryInterface::create(), QSGAdaptationBackendData::factory, and QSGAdaptationBackendData::name.

Referenced by QQuickRenderControlPrivate::QQuickRenderControlPrivate(), QSGGuiThreadRenderLoop::QSGGuiThreadRenderLoop(), and QSGOpenVGRenderLoop::QSGOpenVGRenderLoop().

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◆ createGlyphNode()

virtual QSGGlyphNode * QSGContext::createGlyphNode	(	QSGRenderContext *	rc,
		bool	preferNativeGlyphNode,
		int	renderTypeQuality
	)

pure virtual

Implemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

Referenced by QQuickTextNode::addGlyphs().

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◆ createGuiThreadShaderEffectManager()

QSGGuiThreadShaderEffectManager * QSGContext::createGuiThreadShaderEffectManager ( )

virtual

Creates a new shader effect helper instance.

This function is called on the GUI thread, unlike the others. This is necessary in order to provide adaptable, backend-specific shader effect functionality to the GUI thread too.

Reimplemented in QSGDefaultContext.

Definition at line 337 of file qsgcontext.cpp.

◆ createImageNode()

virtual QSGImageNode * QSGContext::createImageNode ( )

pure virtual

Implemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

◆ createInternalImageNode()

virtual QSGInternalImageNode * QSGContext::createInternalImageNode ( QSGRenderContext * renderContext )

pure virtual

Implemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

Referenced by QQuickTextNode::addImage(), and QQuickCanvasItem::updatePaintNode().

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◆ createInternalRectangleNode() [1/2]

virtual QSGInternalRectangleNode * QSGContext::createInternalRectangleNode ( )

pure virtual

Implemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

Referenced by createInternalRectangleNode().

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◆ createInternalRectangleNode() [2/2]

QSGInternalRectangleNode * QSGContext::createInternalRectangleNode	(	const QRectF &	rect,
		const QColor &	c
	)

Convenience factory function for creating a colored rectangle with the given geometry.

Definition at line 323 of file qsgcontext.cpp.

References createInternalRectangleNode(), rect, QSGInternalRectangleNode::setColor(), QSGInternalRectangleNode::setRect(), and QSGInternalRectangleNode::update().

Referenced by QQuickTextNode::addRectangleNode(), QQuickTextNode::setCursor(), and QQuickMultiPointTouchArea::updatePaintNode().

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◆ createLayer()

virtual QSGLayer * QSGContext::createLayer ( QSGRenderContext * renderContext )

pure virtual

Implemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

Referenced by QQuickDesignerSupport::refFromEffectItem(), and QQuick3DTexture::updateSpatialNode().

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◆ createNinePatchNode()

virtual QSGNinePatchNode * QSGContext::createNinePatchNode ( )

pure virtual

Implemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

◆ createPainterNode()

virtual QSGPainterNode * QSGContext::createPainterNode ( QQuickPaintedItem * item )

pure virtual

Implemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

◆ createRectangleNode()

virtual QSGRectangleNode * QSGContext::createRectangleNode ( )

pure virtual

Implemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

◆ createRenderContext()

virtual QSGRenderContext * QSGContext::createRenderContext ( )

pure virtual

Implemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

Referenced by QQuickRenderControlPrivate::QQuickRenderControlPrivate(), QSGOpenVGRenderLoop::QSGOpenVGRenderLoop(), QSGSoftwareRenderLoop::QSGSoftwareRenderLoop(), QSGGuiThreadRenderLoop::createRenderContext(), and QSGThreadedRenderLoop::createRenderContext().

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◆ createShaderEffectNode()

QSGShaderEffectNode * QSGContext::createShaderEffectNode ( QSGRenderContext * renderContext )

virtual

Creates a new shader effect node.

The default of returning nullptr is valid as long as the backend does not claim SupportsShaderEffectNode or ignoring ShaderEffect elements is acceptable.

Reimplemented in QSGDefaultContext.

Definition at line 347 of file qsgcontext.cpp.

Referenced by QQuickShaderEffectPrivate::handleUpdatePaintNode().

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◆ createTextureFactoryFromImage()

QQuickTextureFactory * QSGContext::createTextureFactoryFromImage ( const QImage & image )

static

Calls into the scene graph adaptation if available and creates a texture factory.

The primary purpose of this function is to reimplement hardware specific asynchronous texture frameskip-less uploads that can happen on the image providers thread.

Definition at line 190 of file qsgcontextplugin.cpp.

References contextFactory(), QSGContextFactoryInterface::createTextureFactoryFromImage(), and QSGAdaptationBackendData::factory.

Referenced by BackendSupport::BackendSupport(), and QQuickTextureFactory::textureFactoryForImage().

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◆ createWindowManager()

QSGRenderLoop * QSGContext::createWindowManager ( )

static

Calls into the scene graph adaptation if available and creates a hardware specific window manager.

Definition at line 204 of file qsgcontextplugin.cpp.

References contextFactory(), QSGContextFactoryInterface::createWindowManager(), and QSGAdaptationBackendData::factory.

Referenced by QSGRenderLoop::instance().

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◆ defaultSurfaceFormat()

virtual QSurfaceFormat QSGContext::defaultSurfaceFormat ( ) const

pure virtual

Implemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

Referenced by QQuickWindowPrivate::init().

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◆ isVSyncDependent()

bool QSGContext::isVSyncDependent ( QAnimationDriver * driver )

virtual

Returns: true if driver relies on vsync-based throttling in some form.

Definition at line 375 of file qsgcontext.cpp.

References isVSyncDependent().

Referenced by QSGThreadedRenderLoop::event(), and isVSyncDependent().

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◆ minimumFBOSize()

QSize QSGContext::minimumFBOSize ( ) const

virtual

Definition at line 380 of file qsgcontext.cpp.

◆ renderContextInitialized()

void QSGContext::renderContextInitialized ( QSGRenderContext * renderContext )

virtual

Reimplemented in QSGDefaultContext.

Definition at line 311 of file qsgcontext.cpp.

Referenced by QSGDefaultRenderContext::initialize().

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◆ renderContextInvalidated()

void QSGContext::renderContextInvalidated ( QSGRenderContext * renderContext )

virtual

Reimplemented in QSGDefaultContext.

Definition at line 315 of file qsgcontext.cpp.

Referenced by QSGSoftwareRenderContext::invalidate(), and QSGDefaultRenderContext::invalidate().

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◆ rendererInterface()

QSGRendererInterface * QSGContext::rendererInterface ( QSGRenderContext * renderContext )

virtual

Returns a pointer to the (presumably) global renderer interface.

Note: This function may be called on the GUI thread in order to get access to QSGRendererInterface::graphicsApi() and other getters.; it is expected that the simple queries (graphicsApi, shaderType, etc.) are available regardless of the render context validity (i.e. scenegraph status). This does not apply to engine-specific getters like getResource(). In the end this means that this function must always return a valid object in subclasses, even when renderContext->isValid() is false. The typical pattern is to implement the QSGRendererInterface in the QSGContext or QSGRenderContext subclass itself, whichever is more suitable.

Reimplemented in QSGOpenVGContext, QSGSoftwareContext, and QSGDefaultContext.

Definition at line 399 of file qsgcontext.cpp.

References Q_UNUSED, and qWarning.

Referenced by isOpenGL(), QQuickWindowPrivate::openglContext(), and QQuickImageParticle::updatePaintNode().

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◆ setBackend()

void QSGContext::setBackend ( const QString & backend )

static

Definition at line 212 of file qsgcontextplugin.cpp.

References QSGAdaptationBackendData::quickWindowBackendRequest, qWarning, and QSGAdaptationBackendData::tried.

◆ vsyncIntervalForAnimationDriver()

float QSGContext::vsyncIntervalForAnimationDriver ( QAnimationDriver * driver )

virtual

Returns: the vsync rate (such as, 16.68 ms or similar), if applicable, for the driver that was created by createAnimationDriver().

Definition at line 367 of file qsgcontext.cpp.

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

qtdeclarative/src/quick/scenegraph/qsgcontext_p.h
qtdeclarative/src/quick/scenegraph/qsgcontext.cpp
qtdeclarative/src/quick/scenegraph/qsgcontextplugin.cpp

Public Types

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ AntialiasingMethod

Constructor & Destructor Documentation

◆ QSGContext()

◆ ~QSGContext()

Member Function Documentation

◆ backend()

◆ createAnimationDriver()

◆ createDefaultContext()

◆ createGlyphNode()

◆ createGuiThreadShaderEffectManager()

◆ createImageNode()

◆ createInternalImageNode()

◆ createInternalRectangleNode() [1/2]

◆ createInternalRectangleNode() [2/2]

◆ createLayer()

◆ createNinePatchNode()

◆ createPainterNode()

◆ createRectangleNode()

◆ createRenderContext()

◆ createShaderEffectNode()

◆ createTextureFactoryFromImage()

◆ createWindowManager()

◆ defaultSurfaceFormat()

◆ isVSyncDependent()

◆ minimumFBOSize()

◆ renderContextInitialized()

◆ renderContextInvalidated()

◆ rendererInterface()

◆ setBackend()

◆ vsyncIntervalForAnimationDriver()