The QGraphicsSceneIndex class provides a base class to implement a custom indexing algorithm for discovering items in QGraphicsScene. More...

#include <qgraphicssceneindex_p.h>

Inheritance diagram for QGraphicsSceneIndex:

Public Functions
virtual QList< QGraphicsItem * >	estimateItems (const QPointF &point, Qt::SortOrder order) const
	This virtual function return an estimation of items at position point. More...

virtual QList< QGraphicsItem * >	estimateItems (const QRectF &rect, Qt::SortOrder order) const =0

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

virtual QList< QGraphicsItem * >	items (Qt::SortOrder order=Qt::DescendingOrder) const =0
	This pure virtual function all items in the index and sort them using order. More...

virtual QList< QGraphicsItem * >	items (const QPointF &pos, Qt::ItemSelectionMode mode, Qt::SortOrder order, const QTransform &deviceTransform=QTransform()) const
	Returns all visible items that, depending on mode, are at the specified pos and return a list sorted using order. More...

virtual QList< QGraphicsItem * >	items (const QRectF &rect, Qt::ItemSelectionMode mode, Qt::SortOrder order, const QTransform &deviceTransform=QTransform()) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Returns all visible items that, depending on mode, are either inside or intersect with the specified rect and return a list sorted using order. More...

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
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Returns all visible items that, depending on mode, are either inside or intersect with the specified path and return a list sorted using order. More...

	QGraphicsSceneIndex (QGraphicsScene *scene=0)
	Constructs an abstract scene index for a given scene. More...

QGraphicsScene *	scene () const
	Returns the scene of this index. More...

virtual	~QGraphicsSceneIndex ()
	Destroys the scene index. 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 Slots
virtual void	updateSceneRect (const QRectF &rect)
	Notifies the index that the scene's scene rect has changed. More...

Protected Functions
virtual void	addItem (QGraphicsItem *item)=0
	This pure virtual function inserts an item to the scene index. More...

virtual void	clear ()
	This virtual function removes all items in the scene index. More...

virtual void	deleteItem (QGraphicsItem *item)
	This method is called when an item has been deleted. More...

virtual void	itemChange (const QGraphicsItem item, QGraphicsItem::GraphicsItemChange, const void const value)
	This virtual function is called by QGraphicsItem to notify the index that some part of the item 's state changes. More...

virtual void	prepareBoundingRectChange (const QGraphicsItem *item)
	Notify the index for a geometry change of an item. More...

	QGraphicsSceneIndex (QGraphicsSceneIndexPrivate &dd, QGraphicsScene *scene)

virtual void	removeItem (QGraphicsItem *item)=0
	This pure virtual function removes an item to the scene index. 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...

Friends
class	QGraphicsItem

class	QGraphicsItemPrivate

class	QGraphicsScene

class	QGraphicsSceneBspTreeIndex

class	QGraphicsScenePrivate

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	Schedules this object for deletion. 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...

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 QGraphicsSceneIndex class provides a base class to implement a custom indexing algorithm for discovering items in QGraphicsScene.

Since: 4.6

Warning: This function is not part of the public interface.

The QGraphicsSceneIndex class provides a base class to implement a custom indexing algorithm for discovering items in QGraphicsScene. You need to subclass it and reimplement addItem, removeItem, estimateItems and items in order to have an functional indexing.

See also: QGraphicsScene, QGraphicsView

Definition at line 81 of file qgraphicssceneindex_p.h.

Constructors and Destructors

◆ QGraphicsSceneIndex() [1/2]

QGraphicsSceneIndex::QGraphicsSceneIndex ( QGraphicsScene * scene = 0 )

Constructs an abstract scene index for a given scene.

Definition at line 373 of file qgraphicssceneindex.cpp.

 : QObject(*new QGraphicsSceneIndexPrivate(scene), scene)
 {
     d_func()->init();
 }

◆ ~QGraphicsSceneIndex()

QGraphicsSceneIndex::~QGraphicsSceneIndex ( )

virtual

Destroys the scene index.

Definition at line 391 of file qgraphicssceneindex.cpp.

 {
 
 }

◆ QGraphicsSceneIndex() [2/2]

QGraphicsSceneIndex::QGraphicsSceneIndex	(	QGraphicsSceneIndexPrivate &	dd,
		QGraphicsScene *	scene
	)

protected

Warning: This function is not part of the public interface.

Definition at line 382 of file qgraphicssceneindex.cpp.

     : QObject(dd, scene)
 {
     d_func()->init();
 }

Functions

◆ addItem()

void QGraphicsSceneIndex::addItem ( QGraphicsItem * item )

protectedpure virtual

This pure virtual function inserts an item to the scene index.

See also: removeItem(), deleteItem()

Implemented in QGraphicsSceneBspTreeIndex, and QGraphicsSceneLinearIndex.

◆ clear()

void QGraphicsSceneIndex::clear ( )

protectedvirtual

This virtual function removes all items in the scene index.

Reimplemented in QGraphicsSceneBspTreeIndex, and QGraphicsSceneLinearIndex.

Definition at line 586 of file qgraphicssceneindex.cpp.

 {
     const QList<QGraphicsItem *> allItems = items();
     for (int i = 0 ; i < allItems.size(); ++i)
         removeItem(allItems.at(i));
 }

◆ deleteItem()

void QGraphicsSceneIndex::deleteItem ( QGraphicsItem * item )

protectedvirtual

This method is called when an item has been deleted.

The default implementation call removeItem. Be carefull, if your implementation of removeItem use pure virtual method of QGraphicsItem like boundingRect(), then you should reimplement this method.

See also: addItem(), removeItem()

Definition at line 618 of file qgraphicssceneindex.cpp.

Referenced by QGraphicsScenePrivate::removeItemHelper().

 {
     removeItem(item);
 }

◆ estimateItems() [1/2]

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

virtual

This virtual function return an estimation of items at position point.

This method return a list sorted using order.

Definition at line 544 of file qgraphicssceneindex.cpp.

 {
     return estimateItems(QRectF(point, QSize(1, 1)), order);
 }

◆ estimateItems() [2/2]

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

pure virtual

Implemented in QGraphicsSceneBspTreeIndex, and QGraphicsSceneLinearIndex.

◆ estimateTopLevelItems()

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

virtual

Reimplemented in QGraphicsSceneBspTreeIndex.

Definition at line 549 of file qgraphicssceneindex.cpp.

 {
     Q_D(const QGraphicsSceneIndex);
     Q_UNUSED(rect);
     QGraphicsScenePrivate *scened = d->scene->d_func();
     scened->ensureSortedTopLevelItems();
     if (order == Qt::DescendingOrder) {
         QList<QGraphicsItem *> sorted;
         for (int i = scened->topLevelItems.size() - 1; i >= 0; --i)
             sorted << scened->topLevelItems.at(i);
         return sorted;
     }
     return scened->topLevelItems;
 }

◆ itemChange()

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

protectedvirtual

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 in QGraphicsSceneBspTreeIndex.

Definition at line 636 of file qgraphicssceneindex.cpp.

 {
     Q_UNUSED(item);
     Q_UNUSED(change);
     Q_UNUSED(value);
 }

◆ items() [1/5]

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

pure virtual

This pure virtual function all items in the index and sort them using order.

Implemented in QGraphicsSceneBspTreeIndex, and QGraphicsSceneLinearIndex.

Referenced by clear().

◆ items() [2/5]

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

virtual

Returns all visible items that, depending on mode, are at the specified pos and return a list sorted using order.

The default value for mode is Qt::IntersectsItemShape; all items whose exact shape intersects with pos are returned.

deviceTransform is the transformation apply to the view.

This method use the estimation of the index (estimateItems) and refine the list to get an exact result. If you want to implement your own refinement algorithm you can reimplement this method.

See also: estimateItems()

Definition at line 425 of file qgraphicssceneindex.cpp.

 {
 
     Q_D(const QGraphicsSceneIndex);
     QList<QGraphicsItem *> itemList;
     d->pointIntersector->scenePoint = pos;
     d->items_helper(QRectF(pos, QSizeF(1, 1)), d->pointIntersector, &itemList, deviceTransform, mode, order);
     return itemList;
 }

◆ items() [3/5]

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

virtual

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Returns all visible items that, depending on mode, are either inside or intersect with the specified rect and return a list sorted using order.

The default value for mode is Qt::IntersectsItemShape; all items whose exact shape intersects with or is contained by rect are returned.

deviceTransform is the transformation apply to the view.

This method use the estimation of the index (estimateItems) and refine the list to get an exact result. If you want to implement your own refinement algorithm you can reimplement this method.

See also: estimateItems()

Definition at line 458 of file qgraphicssceneindex.cpp.

 {
     Q_D(const QGraphicsSceneIndex);
     QRectF exposeRect = rect;
     _q_adjustRect(&exposeRect);
     QList<QGraphicsItem *> itemList;
     d->rectIntersector->sceneRect = rect;
     d->items_helper(exposeRect, d->rectIntersector, &itemList, deviceTransform, mode, order);
     return itemList;
 }

◆ items() [4/5]

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

virtual

Definition at line 492 of file qgraphicssceneindex.cpp.

 {
     Q_D(const QGraphicsSceneIndex);
     QList<QGraphicsItem *> itemList;
     QRectF exposeRect = polygon.boundingRect();
     _q_adjustRect(&exposeRect);
     QPainterPath path;
     path.addPolygon(polygon);
     d->pathIntersector->scenePath = path;
     d->items_helper(exposeRect, d->pathIntersector, &itemList, deviceTransform, mode, order);
     return itemList;
 }

◆ items() [5/5]

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

virtual

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Returns all visible items that, depending on mode, are either inside or intersect with the specified path and return a list sorted using order.

The default value for mode is Qt::IntersectsItemShape; all items whose exact shape intersects with or is contained by path are returned.

deviceTransform is the transformation apply to the view.

This method use the estimation of the index (estimateItems) and refine the list to get an exact result. If you want to implement your own refinement algorithm you can reimplement this method.

See also: estimateItems()

Definition at line 528 of file qgraphicssceneindex.cpp.

 {
     Q_D(const QGraphicsSceneIndex);
     QList<QGraphicsItem *> itemList;
     QRectF exposeRect = path.controlPointRect();
     _q_adjustRect(&exposeRect);
     d->pathIntersector->scenePath = path;
     d->items_helper(exposeRect, d->pathIntersector, &itemList, deviceTransform, mode, order);
     return itemList;
 }

◆ prepareBoundingRectChange()

void QGraphicsSceneIndex::prepareBoundingRectChange ( const QGraphicsItem * item )

protectedvirtual

Notify the index for a geometry change of an item.

See also: QGraphicsItem::prepareGeometryChange()

Reimplemented in QGraphicsSceneBspTreeIndex.

Definition at line 648 of file qgraphicssceneindex.cpp.

Referenced by QGraphicsItem::prepareGeometryChange().

 {
     Q_UNUSED(item);
 }

◆ removeItem()

void QGraphicsSceneIndex::removeItem ( QGraphicsItem * item )

protectedpure virtual

This pure virtual function removes an item to the scene index.

See also: addItem(), deleteItem()

Implemented in QGraphicsSceneBspTreeIndex, and QGraphicsSceneLinearIndex.

Referenced by clear(), deleteItem(), and QGraphicsScenePrivate::removeItemHelper().

◆ scene()

QGraphicsScene * QGraphicsSceneIndex::scene ( ) const

Returns the scene of this index.

Definition at line 399 of file qgraphicssceneindex.cpp.

 {
     Q_D(const QGraphicsSceneIndex);
     return d->scene;
 }

◆ updateSceneRect

void QGraphicsSceneIndex::updateSceneRect ( const QRectF & rect )

protectedvirtualslot

Notifies the index that the scene's scene rect has changed.

rect is thew new scene rect.

See also: QGraphicsScene::sceneRect()

Definition at line 578 of file qgraphicssceneindex.cpp.

 {
     Q_UNUSED(rect);
 }

Friends and Related Functions

◆ QGraphicsItem

friend class QGraphicsItem

friend

Definition at line 120 of file qgraphicssceneindex_p.h.

◆ QGraphicsItemPrivate

friend class QGraphicsItemPrivate

friend

Definition at line 121 of file qgraphicssceneindex_p.h.

◆ QGraphicsScene

friend class QGraphicsScene

friend

Definition at line 118 of file qgraphicssceneindex_p.h.

◆ QGraphicsSceneBspTreeIndex

friend class QGraphicsSceneBspTreeIndex

friend

Definition at line 122 of file qgraphicssceneindex_p.h.

◆ QGraphicsScenePrivate

friend class QGraphicsScenePrivate

friend

Definition at line 119 of file qgraphicssceneindex_p.h.

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

/src/gui/graphicsview/qgraphicssceneindex_p.h
/src/gui/graphicsview/qgraphicssceneindex.cpp

Public Functions

Protected Slots

Protected Functions

Friends

Additional Inherited Members

Detailed Description

Constructors and Destructors

◆ QGraphicsSceneIndex() [1/2]

◆ ~QGraphicsSceneIndex()

◆ QGraphicsSceneIndex() [2/2]

Functions

◆ addItem()

◆ clear()

◆ deleteItem()

◆ estimateItems() [1/2]

◆ estimateItems() [2/2]

◆ estimateTopLevelItems()

◆ itemChange()

◆ items() [1/5]

◆ items() [2/5]

◆ items() [3/5]

◆ items() [4/5]

◆ items() [5/5]

◆ prepareBoundingRectChange()

◆ removeItem()

◆ scene()

◆ updateSceneRect

Friends and Related Functions

◆ QGraphicsItem

◆ QGraphicsItemPrivate

◆ QGraphicsScene

◆ QGraphicsSceneBspTreeIndex

◆ QGraphicsScenePrivate