The QGraphicsSceneBspTreeIndex class provides an implementation of a BSP indexing algorithm for discovering items in QGraphicsScene. More...

#include <qgraphicsscenebsptreeindex_p.h>

Inheritance diagram for QGraphicsSceneBspTreeIndex:

[legend]

Collaboration diagram for QGraphicsSceneBspTreeIndex:

[legend]

Public Member Functions
	QGraphicsSceneBspTreeIndex (QGraphicsScene *scene=nullptr)

	~QGraphicsSceneBspTreeIndex ()

QList< QGraphicsItem * >	estimateItems (const QRectF &rect, Qt::SortOrder order) const override

QList< QGraphicsItem * >	estimateTopLevelItems (const QRectF &rect, Qt::SortOrder order) const override

QList< QGraphicsItem * >	items (Qt::SortOrder order=Qt::DescendingOrder) const override

int	bspTreeDepth () const

void	setBspTreeDepth (int depth)

Public Member Functions inherited from QGraphicsSceneIndex
	QGraphicsSceneIndex (QGraphicsScene *scene=nullptr)

virtual	~QGraphicsSceneIndex ()

QGraphicsScene *	scene () const

virtual QList< QGraphicsItem * >	items (const QPointF &pos, Qt::ItemSelectionMode mode, Qt::SortOrder order, const QTransform &deviceTransform=QTransform()) const

virtual QList< QGraphicsItem * >	items (const QRectF &rect, Qt::ItemSelectionMode mode, Qt::SortOrder order, const QTransform &deviceTransform=QTransform()) const

virtual QList< QGraphicsItem * >	items (const QPolygonF &polygon, Qt::ItemSelectionMode mode, Qt::SortOrder order, const QTransform &deviceTransform=QTransform()) const

virtual QList< QGraphicsItem * >	items (const QPainterPath &path, Qt::ItemSelectionMode mode, Qt::SortOrder order, const QTransform &deviceTransform=QTransform()) const

virtual QList< QGraphicsItem * >	estimateItems (const QPointF &point, Qt::SortOrder order) const

Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)

virtual	~QObject ()

virtual bool	eventFilter (QObject watched, QEvent event)

QString	objectName () const

void	setObjectName (const QString &name)

QBindable< QString >	bindableObjectName ()

bool	isWidgetType () const

bool	isWindowType () const

bool	signalsBlocked () const noexcept

bool	blockSignals (bool b) noexcept

QThread *	thread () const

void	moveToThread (QThread *thread)

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)

template<typename T >
T	findChild (const QString &aName=QString(), Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<typename T >
QList< T >	findChildren (const QString &aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

const QObjectList &	children () const

void	setParent (QObject *parent)

void	installEventFilter (QObject *filterObj)

void	removeEventFilter (QObject *obj)

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

void	dumpObjectInfo () const

bool	setProperty (const char *name, const QVariant &value)

QVariant	property (const char *name) const

QList< QByteArray >	dynamicPropertyNames () const

QBindingStorage *	bindingStorage ()

const QBindingStorage *	bindingStorage () const

QObject *	parent () const

bool	inherits (const char *classname) const

Protected Slots
void	updateSceneRect (const QRectF &rect) override

Protected Slots inherited from QGraphicsSceneIndex
virtual void	updateSceneRect (const QRectF &rect)

Protected Member Functions
bool	event (QEvent *event) override

void	clear () override

void	addItem (QGraphicsItem *item) override

void	removeItem (QGraphicsItem *item) override

void	prepareBoundingRectChange (const QGraphicsItem *item) override

void	itemChange (const QGraphicsItem item, QGraphicsItem::GraphicsItemChange change, const void const value) override

Protected Member Functions inherited from QGraphicsSceneIndex
virtual void	deleteItem (QGraphicsItem *item)

	QGraphicsSceneIndex (QGraphicsSceneIndexPrivate &dd, QGraphicsScene *scene)

Protected Member Functions inherited from QObject
QObject *	sender () const

int	senderSignalIndex () const

int	receivers (const char *signal) const

bool	isSignalConnected (const QMetaMethod &signal) const

virtual void	timerEvent (QTimerEvent *event)

virtual void	childEvent (QChildEvent *event)

virtual void	customEvent (QEvent *event)

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

	QObject (QObjectPrivate &dd, QObject *parent=nullptr)

Properties
int	bspTreeDepth
	the depth of the BSP index tree More...

Properties inherited from QObject
QString	objectName
	the name of this object More...

Friends
class	QGraphicsScenePrivate

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

Signals inherited from QObject
void	destroyed (QObject *=nullptr)

void	objectNameChanged (const QString &objectName, QPrivateSignal)

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)

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::FunctionPointer< Func2 >::Object receiver, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

static QMetaObject::Connection ::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 slot)

static QMetaObject::Connection ::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject context, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static std::enable_if< QtPrivate::FunctionPointer< Func2 >::ArgumentCount==-1 &&!std::is_convertible_v< Func2, const char * >, QMetaObject::Connection >::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 slot)

template<typename Func1 , typename Func2 >
static std::enable_if< QtPrivate::FunctionPointer< Func2 >::ArgumentCount==-1 &&!std::is_convertible_v< Func2, const char * >, QMetaObject::Connection >::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject context, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

static bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char member)

static bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &member)

static bool	disconnect (const QMetaObject::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 Functions inherited from QObject
template< class T > T	qobject_cast (const QObject *object)

template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()

template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()

	QObjectList

Detailed Description

The QGraphicsSceneBspTreeIndex class provides an implementation of a BSP indexing algorithm for discovering items in QGraphicsScene.

Since: 4.6

Definition at line 72 of file qgraphicsscenebsptreeindex_p.h.

Constructor & Destructor Documentation

◆ QGraphicsSceneBspTreeIndex()

QGraphicsSceneBspTreeIndex::QGraphicsSceneBspTreeIndex ( QGraphicsScene * scene = nullptr )

Constructs a BSP scene index for the given scene.

Definition at line 444 of file qgraphicsscenebsptreeindex.cpp.

◆ ~QGraphicsSceneBspTreeIndex()

QGraphicsSceneBspTreeIndex::~QGraphicsSceneBspTreeIndex ( )

Definition at line 450 of file qgraphicsscenebsptreeindex.cpp.

Member Function Documentation

◆ addItem()

void QGraphicsSceneBspTreeIndex::addItem ( QGraphicsItem * item )

overrideprotectedvirtual

Add the item into the BSP index.

Implements QGraphicsSceneIndex.

Definition at line 488 of file qgraphicsscenebsptreeindex.cpp.

◆ bspTreeDepth()

int QGraphicsSceneBspTreeIndex::bspTreeDepth ( ) const

Definition at line 597 of file qgraphicsscenebsptreeindex.cpp.

◆ clear()

void QGraphicsSceneBspTreeIndex::clear ( )

overrideprotectedvirtual

This virtual function removes all items in the scene index.

Reimplemented from QGraphicsSceneIndex.

Definition at line 466 of file qgraphicsscenebsptreeindex.cpp.

◆ estimateItems()

QList< QGraphicsItem * > QGraphicsSceneBspTreeIndex::estimateItems	(	const QRectF &	rect,
		Qt::SortOrder	order
	)		const

overridevirtual

Returns an estimation visible items that are either inside or intersect with the specified rect and return a list sorted using order.

deviceTransform is the transformation apply to the view.

Implements QGraphicsSceneIndex.

Definition at line 532 of file qgraphicsscenebsptreeindex.cpp.

Here is the caller graph for this function:

◆ estimateTopLevelItems()

QList< QGraphicsItem * > QGraphicsSceneBspTreeIndex::estimateTopLevelItems	(	const QRectF &	rect,
		Qt::SortOrder	order
	)		const

overridevirtual

Reimplemented from QGraphicsSceneIndex.

Definition at line 538 of file qgraphicsscenebsptreeindex.cpp.

Here is the call graph for this function:

◆ event()

bool QGraphicsSceneBspTreeIndex::event ( QEvent * event )

overrideprotectedvirtual

\reimp

Used to catch the timer event.

Reimplemented from QObject.

Definition at line 692 of file qgraphicsscenebsptreeindex.cpp.

Here is the call graph for this function:

◆ itemChange()

void QGraphicsSceneBspTreeIndex::itemChange	(	const QGraphicsItem *	item,
		QGraphicsItem::GraphicsItemChange	change,
		const void *const	value
	)

overrideprotectedvirtual

This virtual function is called by QGraphicsItem to notify the index that some part of the item 's state changes. By reimplementing this function, your can react to a change, and in some cases, (depending on change,) adjustments in the index can be made.

change is the parameter of the item that is changing. value is the value that changed; the type of the value depends on change.

The default implementation does nothing.

See also: QGraphicsItem::GraphicsItemChange

Reimplemented from QGraphicsSceneIndex.

Definition at line 631 of file qgraphicsscenebsptreeindex.cpp.

Here is the call graph for this function:

◆ items()

QList< QGraphicsItem * > QGraphicsSceneBspTreeIndex::items ( Qt::SortOrder order = Qt::DescendingOrder ) const

overridevirtual

Return all items in the BSP index and sort them using order.

Implements QGraphicsSceneIndex.

Definition at line 549 of file qgraphicsscenebsptreeindex.cpp.

◆ prepareBoundingRectChange()

void QGraphicsSceneBspTreeIndex::prepareBoundingRectChange ( const QGraphicsItem * item )

overrideprotectedvirtual

Notify the index for a geometry change of an item.

See also: QGraphicsItem::prepareGeometryChange()

Reimplemented from QGraphicsSceneIndex.

Definition at line 507 of file qgraphicsscenebsptreeindex.cpp.

Here is the call graph for this function:

◆ removeItem()

void QGraphicsSceneBspTreeIndex::removeItem ( QGraphicsItem * item )

overrideprotectedvirtual

Remove the item from the BSP index.

Implements QGraphicsSceneIndex.

Definition at line 497 of file qgraphicsscenebsptreeindex.cpp.

◆ setBspTreeDepth()

void QGraphicsSceneBspTreeIndex::setBspTreeDepth ( int depth )

Definition at line 603 of file qgraphicsscenebsptreeindex.cpp.

Here is the caller graph for this function:

◆ updateSceneRect

void QGraphicsSceneBspTreeIndex::updateSceneRect ( const QRectF & rect )

overrideprotectedslot

Definition at line 618 of file qgraphicsscenebsptreeindex.cpp.

Friends And Related Function Documentation

◆ QGraphicsScenePrivate

friend class QGraphicsScenePrivate

friend

Definition at line 107 of file qgraphicsscenebsptreeindex_p.h.

Property Documentation

◆ bspTreeDepth

QGraphicsSceneBspTreeIndex::bspTreeDepth

readwrite

the depth of the BSP index tree

Since: 4.6

This value determines the depth of BSP tree. The depth directly affects performance and memory usage; the latter growing exponentially with the depth of the tree. With an optimal tree depth, the index can instantly determine the locality of items, even for scenes with thousands or millions of items. This also greatly improves rendering performance.

By default, the value is 0, in which case Qt will guess a reasonable default depth based on the size, location and number of items in the scene. If these parameters change frequently, however, you may experience slowdowns as the index retunes the depth internally. You can avoid potential slowdowns by fixating the tree depth through setting this property.

The depth of the tree and the size of the scene rectangle decide the granularity of the scene's partitioning. The size of each scene segment is determined by the following algorithm:

The BSP tree has an optimal size when each segment contains between 0 and 10 items.

Definition at line 200 of file qgraphicsscenebsptreeindex_p.h.

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

src/widgets/graphicsview/qgraphicsscenebsptreeindex_p.h
src/widgets/graphicsview/qgraphicsscenebsptreeindex.cpp

Public Member Functions

Protected Slots

Protected Member Functions

Properties

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QGraphicsSceneBspTreeIndex()

◆ ~QGraphicsSceneBspTreeIndex()

Member Function Documentation

◆ addItem()

◆ bspTreeDepth()

◆ clear()

◆ estimateItems()

◆ estimateTopLevelItems()

◆ event()

◆ itemChange()

◆ items()

◆ prepareBoundingRectChange()

◆ removeItem()

◆ setBspTreeDepth()

◆ updateSceneRect

Friends And Related Function Documentation

◆ QGraphicsScenePrivate

Property Documentation

◆ bspTreeDepth