QtGui.QGraphicsScene Class Reference

The QGraphicsScene class provides a surface for managing a large number of 2D graphical items. More...

Inheritance diagram for QtGui.QGraphicsScene:

Collaboration diagram for QtGui.QGraphicsScene:

Public Types
enum	ItemIndexMethod { BspTreeIndex = 0, NoIndex = -1 }
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enum	SceneLayer { AllLayers = 65535, BackgroundLayer = 2, ForegroundLayer = 4, ItemLayer = 1 }
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Public Member Functions
	QGraphicsScene (QObject parent=null)
	QGraphicsScene (QRectF sceneRect, QObject parent=null)
	QGraphicsScene (double x, double y, double width, double height, QObject parent=null)
override void	CreateProxy ()
new QGraphicsEllipseItem	AddEllipse (QRectF rect)
new QGraphicsEllipseItem	AddEllipse (QRectF rect, QPen pen)
new QGraphicsEllipseItem	AddEllipse (QRectF rect, QPen pen, QBrush brush)
new QGraphicsEllipseItem	AddEllipse (double x, double y, double w, double h)
new QGraphicsEllipseItem	AddEllipse (double x, double y, double w, double h, QPen pen)
new QGraphicsEllipseItem	AddEllipse (double x, double y, double w, double h, QPen pen, QBrush brush)
new void	AddItem (IQGraphicsItem item)
new QGraphicsLineItem	AddLine (QLineF line)
new QGraphicsLineItem	AddLine (QLineF line, QPen pen)
new QGraphicsLineItem	AddLine (double x1, double y1, double x2, double y2)
new QGraphicsLineItem	AddLine (double x1, double y1, double x2, double y2, QPen pen)
new QGraphicsPathItem	AddPath (QPainterPath path)
new QGraphicsPathItem	AddPath (QPainterPath path, QPen pen)
new QGraphicsPathItem	AddPath (QPainterPath path, QPen pen, QBrush brush)
new QGraphicsPixmapItem	AddPixmap (QPixmap pixmap)
new QGraphicsPolygonItem	AddPolygon (QPolygonF polygon)
new QGraphicsPolygonItem	AddPolygon (QPolygonF polygon, QPen pen)
new QGraphicsPolygonItem	AddPolygon (QPolygonF polygon, QPen pen, QBrush brush)
new QGraphicsRectItem	AddRect (QRectF rect)
new QGraphicsRectItem	AddRect (QRectF rect, QPen pen)
new QGraphicsRectItem	AddRect (QRectF rect, QPen pen, QBrush brush)
new QGraphicsRectItem	AddRect (double x, double y, double w, double h)
new QGraphicsRectItem	AddRect (double x, double y, double w, double h, QPen pen)
new QGraphicsRectItem	AddRect (double x, double y, double w, double h, QPen pen, QBrush brush)
new QGraphicsSimpleTextItem	AddSimpleText (string text)
new QGraphicsSimpleTextItem	AddSimpleText (string text, QFont font)
new QGraphicsTextItem	AddText (string text)
new QGraphicsTextItem	AddText (string text, QFont font)
new QGraphicsProxyWidget	AddWidget (QWidget widget, Qt.WindowType wFlags=0)
new void	Advance ()
new void	Clear ()
new void	ClearFocus ()
new void	ClearSelection ()
new System.Collections.Generic.List < IQGraphicsItem >	CollidingItems (IQGraphicsItem item, Qt.ItemSelectionMode mode=Qt.ItemSelectionMode.IntersectsItemShape)
new QGraphicsItemGroup	CreateItemGroup (System.Collections.Generic.List< IQGraphicsItem > items)
new void	DestroyItemGroup (QGraphicsItemGroup group)
override bool	OnEvent (QEvent @event)
override bool	EventFilter (QObject watched, QEvent @event)
new bool	HasFocus ()
new double	Height ()
virtual object	InputMethodQuery (Qt.InputMethodQuery query)
new void	Invalidate ()
new void	Invalidate (QRectF rect, QGraphicsScene.SceneLayer layers=QGraphicsScene.SceneLayer.AllLayers)
new void	Invalidate (double x, double y, double w, double h, QGraphicsScene.SceneLayer layers=QGraphicsScene.SceneLayer.AllLayers)
new bool	IsActive ()
new IQGraphicsItem	ItemAt (QPointF pos)
new IQGraphicsItem	ItemAt (QPointF pos, QTransform deviceTransform)
new IQGraphicsItem	ItemAt (double x, double y)
new IQGraphicsItem	ItemAt (double x, double y, QTransform deviceTransform)
new System.Collections.Generic.List < IQGraphicsItem >	Items ()
new System.Collections.Generic.List < IQGraphicsItem >	Items (QPointF pos)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QRectF rect, Qt.ItemSelectionMode mode=Qt.ItemSelectionMode.IntersectsItemShape)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QPolygonF polygon, Qt.ItemSelectionMode mode=Qt.ItemSelectionMode.IntersectsItemShape)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QPainterPath path, Qt.ItemSelectionMode mode=Qt.ItemSelectionMode.IntersectsItemShape)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QPointF pos, Qt.ItemSelectionMode mode, Qt.SortOrder order)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QRectF rect, Qt.ItemSelectionMode mode, Qt.SortOrder order)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QPolygonF polygon, Qt.ItemSelectionMode mode, Qt.SortOrder order)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QPainterPath path, Qt.ItemSelectionMode mode, Qt.SortOrder order)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QPointF pos, Qt.ItemSelectionMode mode, Qt.SortOrder order, QTransform deviceTransform)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QRectF rect, Qt.ItemSelectionMode mode, Qt.SortOrder order, QTransform deviceTransform)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QPolygonF polygon, Qt.ItemSelectionMode mode, Qt.SortOrder order, QTransform deviceTransform)
new System.Collections.Generic.List < IQGraphicsItem >	Items (QPainterPath path, Qt.ItemSelectionMode mode, Qt.SortOrder order, QTransform deviceTransform)
new System.Collections.Generic.List < IQGraphicsItem >	Items (Qt.SortOrder order)
new System.Collections.Generic.List < IQGraphicsItem >	Items (double x, double y, double w, double h, Qt.ItemSelectionMode mode=Qt.ItemSelectionMode.IntersectsItemShape)
new System.Collections.Generic.List < IQGraphicsItem >	Items (double x, double y, double w, double h, Qt.ItemSelectionMode mode, Qt.SortOrder order)
new System.Collections.Generic.List < IQGraphicsItem >	Items (double x, double y, double w, double h, Qt.ItemSelectionMode mode, Qt.SortOrder order, QTransform deviceTransform)
new QRectF	ItemsBoundingRect ()
new IQGraphicsItem	MouseGrabberItem ()
new void	RemoveItem (IQGraphicsItem item)
new void	Render (QPainter painter)
new void	Render (QPainter painter, QRectF target)
new void	Render (QPainter painter, QRectF target, QRectF source, Qt.AspectRatioMode aspectRatioMode=Qt.AspectRatioMode.KeepAspectRatio)
new System.Collections.Generic.List < IQGraphicsItem >	SelectedItems ()
new bool	OnSendEvent (IQGraphicsItem item, QEvent @event)
new void	SetFocus (Qt.FocusReason focusReason=Qt.FocusReason.OtherFocusReason)
new void	SetFocusItem (IQGraphicsItem item, Qt.FocusReason focusReason=Qt.FocusReason.OtherFocusReason)
new void	SetSceneRect (double x, double y, double w, double h)
new void	SetSelectionArea (QPainterPath path, QTransform deviceTransform)
new void	SetSelectionArea (QPainterPath path, Qt.ItemSelectionMode mode)
new void	SetSelectionArea (QPainterPath path, Qt.ItemSelectionMode mode, QTransform deviceTransform)
new void	Update ()
new void	Update (QRectF rect)
new void	Update (double x, double y, double w, double h)
new System.Collections.Generic.List < QGraphicsView >	Views ()
new double	Width ()
new void	Dispose ()
Public Member Functions inherited from QtCore.QObject
	QObject (QObject parent=null)
new bool	BlockSignals (bool b)
new System.Collections.Generic.List < QObject >	Children ()
new bool	Connect (QObject sender, string signal, string member, Qt.ConnectionType type=Qt.ConnectionType.AutoConnection)
new void	DeleteLater ()
new bool	Disconnect (QObject receiver, string member=null)
new bool	Disconnect (string signal=null, QObject receiver=null, string member=null)
new void	DumpObjectInfo ()
new void	DumpObjectTree ()
new System.Collections.Generic.List < QByteArray >	DynamicPropertyNames ()
virtual bool	OnEvent (QEvent arg1)
virtual bool	EventFilter (QObject arg1, QEvent arg2)
new bool	Inherits (string classname)
new void	InstallEventFilter (QObject arg1)
new bool	IsWidgetType ()
new void	KillTimer (int id)
new object	Property (string name)
new void	RemoveEventFilter (QObject arg1)
new bool	SetProperty (string name, object value)
new void	SetUserData (uint id, QObjectUserData data)
new bool	SignalsBlocked ()
new int	StartTimer (int interval)
new QObjectUserData	UserData (uint id)
new void	Dispose ()
Public Member Functions inherited from QtCore.Qt
delegate QTextStream	FuncQTextStreamQTextStream (QTextStream qTextStream)
delegate string	FuncStringQByteArray (QByteArray qByteArray)
delegate QByteArray	FuncQByteArrayString (string @string)
delegate void	ActionQtMsgTypeString (QtMsgType qtMsgType, string @string)
delegate QObject	FuncQObject ()

Static Public Member Functions
static string	Tr (string s, string c=null)
static string	Tr (string s, string c, int n)
static string	TrUtf8 (string s, string c=null)
static string	TrUtf8 (string s, string c, int n)
Static Public Member Functions inherited from QtCore.QObject
static bool	Connect (QObject sender, QMetaMethod signal, QObject receiver, QMetaMethod method, Qt.ConnectionType type=Qt.ConnectionType.AutoConnection)
static bool	Connect (QObject sender, string signal, QObject receiver, string member, Qt.ConnectionType arg5=Qt.ConnectionType.AutoConnection)
static bool	Disconnect (QObject sender, QMetaMethod signal, QObject receiver, QMetaMethod member)
static bool	Disconnect (QObject sender, string signal, QObject receiver, string member)
static uint	RegisterUserData ()
static string	Tr (string s, string c=null)
static string	Tr (string s, string c, int n)
static string	TrUtf8 (string s, string c=null)
static string	TrUtf8 (string s, string c, int n)
Static Public Member Functions inherited from QtCore.Qt
static QDataStream	Write (QDataStream s, object p)
static QDataStream	Write (QDataStream arg1, QSizeF arg2)
static QTextStream	Write (QTextStream s, Qt.FuncQTextStreamQTextStream f)
static QDataStream	Write (QDataStream arg1, QPoint arg2)
static QDataStream	Write (QDataStream arg1, QLineF arg2)
static QDataStream	Write (QDataStream arg1, QPointF arg2)
static QDataStream	Write (QDataStream arg1, QChar arg2)
static QDataStream	Write (QDataStream arg1, QByteArray arg2)
static QDataStream	Write (QDataStream arg1, QEasingCurve arg2)
static QDataStream	Write (QDataStream arg1, QRectF arg2)
static QDataStream	Write (QDataStream arg1, QDateTime arg2)
static QDataStream	Write (QDataStream arg1, QUrl arg2)
static QDataStream	Write (QDataStream arg1, QTime arg2)
static QDataStream	Write (QDataStream arg1, QLocale arg2)
static QDataStream	Write (QDataStream arg1, QBitArray arg2)
static QDataStream	Write (QDataStream arg1, QUuid arg2)
static QDataStream	Write (QDataStream arg1, QLine arg2)
static QDataStream	Write (QDataStream arg1, QDate arg2)
static QDataStream	Write (QDataStream @out, QRegExp regExp)
static QDataStream	Write (QDataStream arg1, QRect arg2)
static QDataStream	Write (QDataStream arg1, QSize arg2)
static QDataStream	Write (QDataStream s, QVariant.Type p)
static QDataStream	Write (QDataStream arg1, string arg2)
static QDataStream	Write (QDataStream @out, System.Collections.Generic.List< string > list)
static QDataStream	Read (QDataStream arg1, QChar arg2)
static QDataStream	Read (QDataStream arg1, QLocale arg2)
static QDataStream	Read (QDataStream arg1, QRect arg2)
static QDataStream	Read (QDataStream arg1, QEasingCurve arg2)
static QDataStream	Read (QDataStream arg1, QDate arg2)
static QDataStream	Read (QDataStream arg1, QUrl arg2)
static QDataStream	Read (QDataStream arg1, QUuid arg2)
static QTextStream	Read (QTextStream s, Qt.FuncQTextStreamQTextStream f)
static QDataStream	Read (QDataStream arg1, QLineF arg2)
static QDataStream	Read (QDataStream arg1, QRectF arg2)
static QDataStream	Read (QDataStream arg1, QPointF arg2)
static QDataStream	Read (QDataStream arg1, QLine arg2)
static QDataStream	Read (QDataStream arg1, QBitArray arg2)
static QDataStream	Read (QDataStream arg1, QSize arg2)
static QDataStream	Read (QDataStream arg1, QDateTime arg2)
static QDataStream	Read (QDataStream arg1, QTime arg2)
static QDataStream	Read (QDataStream arg1, QPoint arg2)
static QDataStream	Read (QDataStream @in, QRegExp regExp)
static QDataStream	Read (QDataStream s, object p)
static QDataStream	Read (QDataStream arg1, QByteArray arg2)
static QDataStream	Read (QDataStream arg1, QSizeF arg2)
static QDataStream	Read (QDataStream arg1, string arg2)
static QDataStream	Read (QDataStream s, QVariant.Type p)
static QDataStream	Read (QDataStream @in, System.Collections.Generic.List< string > list)
static double	qAcos (double v)
static void	qAddPostRoutine (System.Action arg1)
static string	qAppName ()
static double	qAsin (double v)
static double	qAtan (double v)
static double	qAtan2 (double x, double y)
static void	qBadAlloc ()
static int	qCeil (double v)
static ushort	qChecksum (string s, uint len)
static QByteArray	qCompress (QByteArray data)
static QByteArray	qCompress (QByteArray data, int compressionLevel=-1)
static QByteArray	qCompress (Pointer< byte > data, int nbytes)
static QByteArray	qCompress (Pointer< byte > data, int nbytes, int compressionLevel=-1)
static double	qCos (double v)
static double	qExp (double v)
static double	qFabs (double v)
static double	qFastCos (double x)
static double	qFastSin (double x)
static string	qFlagLocation (string method)
static int	qFloor (double v)
static bool	qFuzzyCompare (double p1, double p2)
static bool	qFuzzyCompare (float p1, float p2)
static bool	qFuzzyIsNull (double d)
static bool	qFuzzyIsNull (float f)
static uint	qHash (QBitArray key)
static uint	qHash (QChar key)
static uint	qHash (QStringRef key)
static uint	qHash (QUrl url)
static uint	qHash (QPersistentModelIndex index)
static uint	qHash (QByteArray key)
static uint	qHash (QModelIndex index)
static uint	qHash (uint key)
static uint	qHash (sbyte key)
static uint	qHash (byte key)
static uint	qHash (short key)
static uint	qHash (NativeLong key)
static uint	qHash (ushort key)
static uint	qHash (long key)
static uint	qHash (ulong key)
static uint	qHash (int key)
static uint	qHash (string key)
static uint	qHash (NativeULong key)
static double	qInf ()
static Qt.ActionQtMsgTypeString	qInstallMsgHandler (Qt.ActionQtMsgTypeString arg1)
static int	qIntCast (float f)
static int	qIntCast (double f)
static bool	qIsFinite (double d)
static bool	qIsFinite (float f)
static bool	qIsInf (float f)
static bool	qIsInf (double d)
static bool	qIsNaN (float f)
static bool	qIsNaN (double d)
static bool	qIsNull (float f)
static bool	qIsNull (double d)
static double	qLn (double v)
static double	qPow (double x, double y)
static double	qQNaN ()
static void	qRegisterStaticPluginInstanceFunction (Qt.FuncQObject function)
static void	qRemovePostRoutine (System.Action arg1)
static int	qRound (double d)
static long	qRound64 (double d)
static double	qSNaN ()
static bool	qSharedBuild ()
static double	qSin (double v)
static double	qSqrt (double v)
static bool	qStringComparisonHelper (QStringRef s1, string s2)
static double	qTan (double v)
static QByteArray	qUncompress (QByteArray data)
static QByteArray	qUncompress (Pointer< byte > data, int nbytes)
static string	qVersion ()
static void	Qbswap_helper (Pointer< byte > src, Pointer< byte > dest, int size)
static QByteArray	Qgetenv (string varName)
static bool	Qputenv (string varName, QByteArray value)
static int	Qrand ()
static void	Qsrand (uint seed)
static int	Qstrcmp (QByteArray str1, QByteArray str2)
static int	Qstrcmp (QByteArray str1, string str2)
static int	Qstrcmp (string str1, QByteArray str2)
static int	Qstrcmp (string str1, string str2)
static Pointer< sbyte >	Qstrcpy (Pointer< sbyte > dst, string src)
static Pointer< sbyte >	Qstrdup (string arg1)
static int	Qstricmp (string arg1, string arg2)
static uint	Qstrlen (string str)
static int	Qstrncmp (string str1, string str2, uint len)
static Pointer< sbyte >	Qstrncpy (Pointer< sbyte > dst, string src, uint len)
static int	Qstrnicmp (string arg1, string arg2, uint len)
static uint	Qstrnlen (string str, uint maxlen)
static string	QtTrId (string id, int n=-1)

Protected Member Functions
	QGraphicsScene (System.Type dummy)
new void	OnChanged (System.Collections.Generic.List< QRectF > region)
virtual void	OnContextMenuEvent (QGraphicsSceneContextMenuEvent @event)
virtual void	OnDragEnterEvent (QGraphicsSceneDragDropEvent @event)
virtual void	OnDragLeaveEvent (QGraphicsSceneDragDropEvent @event)
virtual void	OnDragMoveEvent (QGraphicsSceneDragDropEvent @event)
virtual void	DrawBackground (QPainter painter, QRectF rect)
virtual void	DrawForeground (QPainter painter, QRectF rect)
virtual void	DrawItems (QPainter painter, int numItems, IQGraphicsItem items, QStyleOptionGraphicsItem options, QWidget widget=null)
virtual void	OnDropEvent (QGraphicsSceneDragDropEvent @event)
virtual void	OnFocusInEvent (QFocusEvent @event)
new bool	FocusNextPrevChild (bool next)
virtual void	OnFocusOutEvent (QFocusEvent @event)
virtual void	OnHelpEvent (QGraphicsSceneHelpEvent @event)
virtual void	OnInputMethodEvent (QInputMethodEvent @event)
virtual void	OnKeyPressEvent (QKeyEvent @event)
virtual void	OnKeyReleaseEvent (QKeyEvent @event)
virtual void	OnMouseDoubleClickEvent (QGraphicsSceneMouseEvent @event)
virtual void	OnMouseMoveEvent (QGraphicsSceneMouseEvent @event)
virtual void	OnMousePressEvent (QGraphicsSceneMouseEvent @event)
virtual void	OnMouseReleaseEvent (QGraphicsSceneMouseEvent @event)
new void	OnSceneRectChanged (QRectF rect)
new void	OnSelectionChanged ()
virtual void	OnWheelEvent (QGraphicsSceneWheelEvent @event)
Protected Member Functions inherited from QtCore.QObject
	QObject (System.Type dummy)
virtual void	OnChildEvent (QChildEvent arg1)
virtual void	ConnectNotify (string signal)
virtual void	OnCustomEvent (QEvent arg1)
new void	OnDestroyed (QObject arg1=null)
virtual void	DisconnectNotify (string signal)
new int	Receivers (string signal)
new QObject	Sender ()
new int	SenderSignalIndex ()
virtual void	OnTimerEvent (QTimerEvent arg1)

Properties
Slot < System.Collections.Generic.List < QRectF > >	Changed
Slot< QRectF >	SceneRectChanged
Slot	SelectionChanged
new IQGraphicsItem	ActivePanel [get, set]
new QGraphicsWidget	ActiveWindow [get, set]
new QPainterPath	SelectionArea [get, set]
new QStyle	Style [get, set]
new IQGraphicsItem	FocusItem [get]
new QBrush	BackgroundBrush [get, set]
new QBrush	ForegroundBrush [get, set]
new ItemIndexMethod	itemIndexMethod [get, set]
new QRectF	SceneRect [get, set]
new int	BspTreeDepth [get, set]
new QPalette	Palette [get, set]
new QFont	Font [get, set]
new bool	SortCacheEnabled [get, set]
new bool	StickyFocus [get, set]
static new QMetaObject	StaticMetaObject [get]
new IQGraphicsSceneSignals	Emit [get]
Properties inherited from QtCore.QObject
virtual EventHandler < QEventArgs< QChildEvent > >	ChildEvent
virtual EventHandler < QEventArgs< QEvent > >	CustomEvent
virtual EventHandler < QEventArgs< QEvent > >	Event
virtual EventHandler < QEventArgs< QTimerEvent > >	TimerEvent
Slot< QObject >	DestroyedQObject
Slot	Destroyed
new QObject	Parent [get, set]
virtual System.IntPtr	SmokeObject [get, set]
new string	ObjectName [get, set]
static new QMetaObject	StaticMetaObject [get]
static new QMetaObject	StaticQtMetaObject [get]
new IQObjectSignals	Emit [get]

Additional Inherited Members
Protected Attributes inherited from QtCore.QObject
object	Q_EMIT = null
SmokeInvocation	interceptor
readonly List< QEventHandler >	eventFilters = new List<QEventHandler>()

Detailed Description

The QGraphicsScene class provides a surface for managing a large number of 2D graphical items.

The class serves as a container for QGraphicsItems. It is used together with QGraphicsView for visualizing graphical items, such as lines, rectangles, text, or even custom items, on a 2D surface. QGraphicsScene is part of the Graphics View Framework.

QGraphicsScene also provides functionality that lets you efficiently determine both the location of items, and for determining what items are visible within an arbitrary area on the scene. With the QGraphicsView widget, you can either visualize the whole scene, or zoom in and view only parts of the scene.

Example:

QGraphicsScene scene;

scene.addText("Hello, world!");

QGraphicsView view(&scene);

view.show();

Note that QGraphicsScene has no visual appearance of its own; it only manages the items. You need to create a QGraphicsView widget to visualize the scene.

To add items to a scene, you start off by constructing a QGraphicsScene object. Then, you have two options: either add your existing QGraphicsItem objects by calling addItem(), or you can call one of the convenience functions addEllipse(), addLine(), addPath(), addPixmap(), addPolygon(), addRect(), or addText(), which all return a pointer to the newly added item. The dimensions of the items added with these functions are relative to the item's coordinate system, and the items position is initialized to (0, 0) in the scene.

You can then visualize the scene using QGraphicsView. When the scene changes, (e.g., when an item moves or is transformed) QGraphicsScene emits the changed() signal. To remove an item, call removeItem().

QGraphicsScene uses an indexing algorithm to manage the location of items efficiently. By default, a BSP (Binary Space Partitioning) tree is used; an algorithm suitable for large scenes where most items remain static (i.e., do not move around). You can choose to disable this index by calling setItemIndexMethod(). For more information about the available indexing algorithms, see the itemIndexMethod property.

The scene's bounding rect is set by calling setSceneRect(). Items can be placed at any position on the scene, and the size of the scene is by default unlimited. The scene rect is used only for internal bookkeeping, maintaining the scene's item index. If the scene rect is unset, QGraphicsScene will use the bounding area of all items, as returned by itemsBoundingRect(), as the scene rect. However, itemsBoundingRect() is a relatively time consuming function, as it operates by collecting positional information for every item on the scene. Because of this, you should always set the scene rect when operating on large scenes.

One of QGraphicsScene's greatest strengths is its ability to efficiently determine the location of items. Even with millions of items on the scene, the items() functions can determine the location of an item within few milliseconds. There are several overloads to items(): one that finds items at a certain position, one that finds items inside or intersecting with a polygon or a rectangle, and more. The list of returned items is sorted by stacking order, with the topmost item being the first item in the list. For convenience, there is also an itemAt() function that returns the topmost item at a given position.

QGraphicsScene maintains selection information for the scene. To select items, call setSelectionArea(), and to clear the current selection, call clearSelection(). Call selectedItems() to get the list of all selected items.

Event Handling and Propagation

Another responsibility that QGraphicsScene has, is to propagate events from QGraphicsView. To send an event to a scene, you construct an event that inherits QEvent, and then send it using, for example, QApplication::sendEvent(). event() is responsible for dispatching the event to the individual items. Some common events are handled by convenience event handlers. For example, key press events are handled by keyPressEvent(), and mouse press events are handled by mousePressEvent().

Key events are delivered to the focus item. To set the focus item, you can either call setFocusItem(), passing an item that accepts focus, or the item itself can call QGraphicsItem::setFocus(). Call focusItem() to get the current focus item. For compatibility with widgets, the scene also maintains its own focus information. By default, the scene does not have focus, and all key events are discarded. If setFocus() is called, or if an item on the scene gains focus, the scene automatically gains focus. If the scene has focus, hasFocus() will return true, and key events will be forwarded to the focus item, if any. If the scene loses focus, (i.e., someone calls clearFocus()) while an item has focus, the scene will maintain its item focus information, and once the scene regains focus, it will make sure the last focus item regains focus.

For mouse-over effects, QGraphicsScene dispatches hover events. If an item accepts hover events (see QGraphicsItem::acceptHoverEvents()), it will receive a GraphicsSceneHoverEnter event when the mouse enters its area. As the mouse continues moving inside the item's area, QGraphicsScene will send it GraphicsSceneHoverMove events. When the mouse leaves the item's area, the item will receive a GraphicsSceneHoverLeave event.

All mouse events are delivered to the current mouse grabber item. An item becomes the scene's mouse grabber if it accepts mouse events (see QGraphicsItem::acceptedMouseButtons()) and it receives a mouse press. It stays the mouse grabber until it receives a mouse release when no other mouse buttons are pressed. You can call mouseGrabberItem() to determine what item is currently grabbing the mouse.

See also QGraphicsItem and QGraphicsView.

Member Enumeration Documentation

enum QtGui.QGraphicsScene.ItemIndexMethod

This enum describes the indexing algorithms QGraphicsScene provides for managing positional information about items on the scene.

See also setItemIndexMethod() and bspTreeDepth.

Enumerator:

BspTreeIndex	A Binary Space Partitioning tree is applied. All QGraphicsScene's item location algorithms are of an order close to logarithmic complexity, by making use of binary search. Adding, moving and removing items is logarithmic. This approach is best for static scenes (i.e., scenes where most items do not move).
NoIndex	No index is applied. Item location is of linear complexity, as all items on the scene are searched. Adding, moving and removing items, however, is done in constant time. This approach is ideal for dynamic scenes, where many items are added, moved or removed continuously.

enum QtGui.QGraphicsScene.SceneLayer

This enum describes the rendering layers in a QGraphicsScene. When QGraphicsScene draws the scene contents, it renders each of these layers separately, in order.

Each layer represents a flag that can be OR'ed together when calling functions such as invalidate() or QGraphicsView::invalidateScene().

This enum was introduced or modified in Qt 4.3.

See also invalidate() and QGraphicsView::invalidateScene().

Enumerator:

AllLayers	All layers; this value represents a combination of all three layers.
BackgroundLayer	The background layer. QGraphicsScene renders the scene's background in this layer by calling the virtual function drawBackground(). The background layer is drawn first of all layers.
ForegroundLayer	The foreground layer. QGraphicsScene renders the scene's foreground in this layer by calling the virtual function drawForeground(). The foreground layer is drawn last of all layers.
ItemLayer	The item layer. QGraphicsScene renders all items are in this layer by calling the virtual function drawItems(). The item layer is drawn after the background layer, but before the foreground layer.

Constructor & Destructor Documentation

QtGui.QGraphicsScene.QGraphicsScene ( System.Type  dummy )

protected

QtGui.QGraphicsScene.QGraphicsScene

(

QObject

parent = null

)

Constructs a QGraphicsScene object. The parent parameter is passed to QObject's constructor.

QtGui.QGraphicsScene.QGraphicsScene	(	QRectF	sceneRect,
		QObject	parent = null
	)

Constructs a QGraphicsScene object, using sceneRect for its scene rectangle. The parent parameter is passed to QObject's constructor.

See also sceneRect.

QtGui.QGraphicsScene.QGraphicsScene	(	double	x,
		double	y,
		double	width,
		double	height,
		QObject	parent = null
	)

Constructs a QGraphicsScene object. The parent parameter is passed to QObject's constructor.

Member Function Documentation

new QGraphicsEllipseItem QtGui.QGraphicsScene.AddEllipse

(

QRectF

rect

)

Creates and adds an ellipse item to the scene, and returns the item pointer. The geometry of the ellipse is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addLine(), addPath(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsEllipseItem QtGui.QGraphicsScene.AddEllipse	(	QRectF	rect,
		QPen	pen
	)

Creates and adds an ellipse item to the scene, and returns the item pointer. The geometry of the ellipse is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addLine(), addPath(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsEllipseItem QtGui.QGraphicsScene.AddEllipse	(	QRectF	rect,
		QPen	pen,
		QBrush	brush
	)

Creates and adds an ellipse item to the scene, and returns the item pointer. The geometry of the ellipse is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addLine(), addPath(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsEllipseItem QtGui.QGraphicsScene.AddEllipse	(	double	x,
		double	y,
		double	w,
		double	h
	)

Creates and adds an ellipse item to the scene, and returns the item pointer. The geometry of the ellipse is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addLine(), addPath(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsEllipseItem QtGui.QGraphicsScene.AddEllipse	(	double	x,
		double	y,
		double	w,
		double	h,
		QPen	pen
	)

Creates and adds an ellipse item to the scene, and returns the item pointer. The geometry of the ellipse is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addLine(), addPath(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsEllipseItem QtGui.QGraphicsScene.AddEllipse	(	double	x,
		double	y,
		double	w,
		double	h,
		QPen	pen,
		QBrush	brush
	)

Creates and adds an ellipse item to the scene, and returns the item pointer. The geometry of the ellipse is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addLine(), addPath(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new void QtGui.QGraphicsScene.AddItem

(

IQGraphicsItem

item

)

Adds or moves the item and all its childen to this scene. This scene takes ownership of the item.

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

If the item is already in a different scene, it will first be removed from its old scene, and then added to this scene as a top-level.

QGraphicsScene will send ItemSceneChange notifications to item while it is added to the scene. If item does not currently belong to a scene, only one notification is sent. If it does belong to scene already (i.e., it is moved to this scene), QGraphicsScene will send an addition notification as the item is removed from its previous scene.

If the item is a panel, the scene is active, and there is no active panel in the scene, then the item will be activated.

See also removeItem(), addEllipse(), addLine(), addPath(), addPixmap(), addRect(), addText(), addWidget(), and Sorting.

new QGraphicsLineItem QtGui.QGraphicsScene.AddLine

(

QLineF

line

)

Creates and adds a line item to the scene, and returns the item pointer. The geometry of the line is defined by line, and its pen is initialized to pen.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addPath(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsLineItem QtGui.QGraphicsScene.AddLine	(	QLineF	line,
		QPen	pen
	)

Creates and adds a line item to the scene, and returns the item pointer. The geometry of the line is defined by line, and its pen is initialized to pen.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addPath(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsLineItem QtGui.QGraphicsScene.AddLine	(	double	x1,
		double	y1,
		double	x2,
		double	y2
	)

Creates and adds a line item to the scene, and returns the item pointer. The geometry of the line is defined by line, and its pen is initialized to pen.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addPath(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsLineItem QtGui.QGraphicsScene.AddLine	(	double	x1,
		double	y1,
		double	x2,
		double	y2,
		QPen	pen
	)

Creates and adds a line item to the scene, and returns the item pointer. The geometry of the line is defined by line, and its pen is initialized to pen.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addPath(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsPathItem QtGui.QGraphicsScene.AddPath

(

QPainterPath

path

)

Creates and adds a path item to the scene, and returns the item pointer. The geometry of the path is defined by path, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsPathItem QtGui.QGraphicsScene.AddPath	(	QPainterPath	path,
		QPen	pen
	)

Creates and adds a path item to the scene, and returns the item pointer. The geometry of the path is defined by path, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsPathItem QtGui.QGraphicsScene.AddPath	(	QPainterPath	path,
		QPen	pen,
		QBrush	brush
	)

Creates and adds a path item to the scene, and returns the item pointer. The geometry of the path is defined by path, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsPixmapItem QtGui.QGraphicsScene.AddPixmap

(

QPixmap

pixmap

)

Creates and adds a pixmap item to the scene, and returns the item pointer. The pixmap is defined by pixmap.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPath(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsPolygonItem QtGui.QGraphicsScene.AddPolygon

(

QPolygonF

polygon

)

Creates and adds a polygon item to the scene, and returns the item pointer. The polygon is defined by polygon, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPath(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsPolygonItem QtGui.QGraphicsScene.AddPolygon	(	QPolygonF	polygon,
		QPen	pen
	)

Creates and adds a polygon item to the scene, and returns the item pointer. The polygon is defined by polygon, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPath(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsPolygonItem QtGui.QGraphicsScene.AddPolygon	(	QPolygonF	polygon,
		QPen	pen,
		QBrush	brush
	)

Creates and adds a polygon item to the scene, and returns the item pointer. The polygon is defined by polygon, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPath(), addRect(), addText(), addItem(), and addWidget().

new QGraphicsRectItem QtGui.QGraphicsScene.AddRect

(

QRectF

rect

)

Creates and adds a rectangle item to the scene, and returns the item pointer. The geometry of the rectangle is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0). For example, if a QRect(50, 50, 100, 100) is added, its top-left corner will be at (50, 50) relative to the origin in the items coordinate system.

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addText(), addItem(), and addWidget().

new QGraphicsRectItem QtGui.QGraphicsScene.AddRect	(	QRectF	rect,
		QPen	pen
	)

Creates and adds a rectangle item to the scene, and returns the item pointer. The geometry of the rectangle is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0). For example, if a QRect(50, 50, 100, 100) is added, its top-left corner will be at (50, 50) relative to the origin in the items coordinate system.

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addText(), addItem(), and addWidget().

new QGraphicsRectItem QtGui.QGraphicsScene.AddRect	(	QRectF	rect,
		QPen	pen,
		QBrush	brush
	)

Creates and adds a rectangle item to the scene, and returns the item pointer. The geometry of the rectangle is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0). For example, if a QRect(50, 50, 100, 100) is added, its top-left corner will be at (50, 50) relative to the origin in the items coordinate system.

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addText(), addItem(), and addWidget().

new QGraphicsRectItem QtGui.QGraphicsScene.AddRect	(	double	x,
		double	y,
		double	w,
		double	h
	)

Creates and adds a rectangle item to the scene, and returns the item pointer. The geometry of the rectangle is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0). For example, if a QRect(50, 50, 100, 100) is added, its top-left corner will be at (50, 50) relative to the origin in the items coordinate system.

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addText(), addItem(), and addWidget().

new QGraphicsRectItem QtGui.QGraphicsScene.AddRect	(	double	x,
		double	y,
		double	w,
		double	h,
		QPen	pen
	)

Creates and adds a rectangle item to the scene, and returns the item pointer. The geometry of the rectangle is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0). For example, if a QRect(50, 50, 100, 100) is added, its top-left corner will be at (50, 50) relative to the origin in the items coordinate system.

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addText(), addItem(), and addWidget().

new QGraphicsRectItem QtGui.QGraphicsScene.AddRect	(	double	x,
		double	y,
		double	w,
		double	h,
		QPen	pen,
		QBrush	brush
	)

Creates and adds a rectangle item to the scene, and returns the item pointer. The geometry of the rectangle is defined by rect, and its pen and brush are initialized to pen and brush.

Note that the item's geometry is provided in item coordinates, and its position is initialized to (0, 0). For example, if a QRect(50, 50, 100, 100) is added, its top-left corner will be at (50, 50) relative to the origin in the items coordinate system.

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addText(), addItem(), and addWidget().

new QGraphicsSimpleTextItem QtGui.QGraphicsScene.AddSimpleText

(

string

text

)

Creates and adds a QGraphicsSimpleTextItem to the scene, and returns the item pointer. The text string is initialized to text, and its font is initialized to font.

The item's position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addRect(), addItem(), and addWidget().

new QGraphicsSimpleTextItem QtGui.QGraphicsScene.AddSimpleText	(	string	text,
		QFont	font
	)

Creates and adds a QGraphicsSimpleTextItem to the scene, and returns the item pointer. The text string is initialized to text, and its font is initialized to font.

The item's position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addRect(), addItem(), and addWidget().

new QGraphicsTextItem QtGui.QGraphicsScene.AddText

(

string

text

)

Creates and adds a text item to the scene, and returns the item pointer. The text string is initialized to text, and its font is initialized to font.

The item's position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addRect(), addItem(), and addWidget().

new QGraphicsTextItem QtGui.QGraphicsScene.AddText	(	string	text,
		QFont	font
	)

Creates and adds a text item to the scene, and returns the item pointer. The text string is initialized to text, and its font is initialized to font.

The item's position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addRect(), addItem(), and addWidget().

new QGraphicsProxyWidget QtGui.QGraphicsScene.AddWidget	(	QWidget	widget,
		Qt.WindowType	wFlags = 0
	)

Creates a new QGraphicsProxyWidget for widget, adds it to the scene, and returns a pointer to the proxy. wFlags set the default window flags for the embedding proxy widget.

The item's position is initialized to (0, 0).

If the item is visible (i.e., QGraphicsItem::isVisible() returns true), QGraphicsScene will emit changed() once control goes back to the event loop.

Note that widgets with the Qt::WA_PaintOnScreen widget attribute set and widgets that wrap an external application or controller are not supported. Examples are QGLWidget and QAxWidget.

See also addEllipse(), addLine(), addPixmap(), addPixmap(), addRect(), addText(), addSimpleText(), and addItem().

new void QtGui.QGraphicsScene.Advance

(

)

This slot advances the scene by one step, by calling QGraphicsItem::advance() for all items on the scene. This is done in two phases: in the first phase, all items are notified that the scene is about to change, and in the second phase all items are notified that they can move. In the first phase, QGraphicsItem::advance() is called passing a value of 0 as an argument, and 1 is passed in the second phase.

See also QGraphicsItem::advance(), QGraphicsItemAnimation, and QTimeLine.

new void QtGui.QGraphicsScene.Clear

(

)

Removes and deletes all items from the scene, but otherwise leaves the state of the scene unchanged.

This function was introduced in Qt 4.4.

See also addItem().

new void QtGui.QGraphicsScene.ClearFocus

(

)

Clears focus from the scene. If any item has focus when this function is called, it will lose focus, and regain focus again once the scene regains focus.

A scene that does not have focus ignores key events.

See also hasFocus(), setFocus(), and setFocusItem().

new void QtGui.QGraphicsScene.ClearSelection

(

)

Clears the current selection.

See also setSelectionArea() and selectedItems().

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.CollidingItems	(	IQGraphicsItem	item,
		Qt.ItemSelectionMode	mode = Qt.ItemSelectionMode.IntersectsItemShape
	)

Returns a list of all items that collide with item. Collisions are determined by calling QGraphicsItem::collidesWithItem(); the collision detection is determined by mode. By default, all items whose shape intersects item or is contained inside item's shape are returned.

The items are returned in descending stacking order (i.e., the first item in the list is the uppermost item, and the last item is the lowermost item).

See also items(), itemAt(), QGraphicsItem::collidesWithItem(), and Sorting.

new QGraphicsItemGroup QtGui.QGraphicsScene.CreateItemGroup

(

System.Collections.Generic.List< IQGraphicsItem >

items

)

Groups all items in items into a new QGraphicsItemGroup, and returns a pointer to the group. The group is created with the common ancestor of items as its parent, and with position (0, 0). The items are all reparented to the group, and their positions and transformations are mapped to the group. If items is empty, this function will return an empty top-level QGraphicsItemGroup.

QGraphicsScene has ownership of the group item; you do not need to delete it. To dismantle (ungroup) a group, call destroyItemGroup().

See also destroyItemGroup() and QGraphicsItemGroup::addToGroup().

override void QtGui.QGraphicsScene.CreateProxy ( )

virtual

Reimplemented from QtCore.QObject.

new void QtGui.QGraphicsScene.DestroyItemGroup

(

QGraphicsItemGroup

group

)

Reparents all items in group to group's parent item, then removes group from the scene, and finally deletes it. The items' positions and transformations are mapped from the group to the group's parent.

See also createItemGroup() and QGraphicsItemGroup::removeFromGroup().

new void QtGui.QGraphicsScene.Dispose

(

)

virtual void QtGui.QGraphicsScene.DrawBackground ( QPainter  painter, QRectF  rect  )

protectedvirtual

Draws the background of the scene using painter, before any items and the foreground are drawn. Reimplement this function to provide a custom background for the scene.

All painting is done in scene coordinates. The rect parameter is the exposed rectangle.

If all you want is to define a color, texture, or gradient for the background, you can call setBackgroundBrush() instead.

See also drawForeground() and drawItems().

virtual void QtGui.QGraphicsScene.DrawForeground ( QPainter  painter, QRectF  rect  )

protectedvirtual

Draws the foreground of the scene using painter, after the background and all items have been drawn. Reimplement this function to provide a custom foreground for the scene.

All painting is done in scene coordinates. The rect parameter is the exposed rectangle.

If all you want is to define a color, texture or gradient for the foreground, you can call setForegroundBrush() instead.

See also drawBackground() and drawItems().

virtual void QtGui.QGraphicsScene.DrawItems ( QPainter  painter, int  numItems, IQGraphicsItem  items, QStyleOptionGraphicsItem  options, QWidget  widget = null  )

protectedvirtual

Paints the given items using the provided painter, after the background has been drawn, and before the foreground has been drawn. All painting is done in scene coordinates. Before drawing each item, the painter must be transformed using QGraphicsItem::sceneTransform().

The options parameter is the list of style option objects for each item in items. The numItems parameter is the number of items in items and options in options. The widget parameter is optional; if specified, it should point to the widget that is being painted on.

The default implementation prepares the painter matrix, and calls QGraphicsItem::paint() on all items. Reimplement this function to provide custom painting of all items for the scene; gaining complete control over how each item is drawn. In some cases this can increase drawing performance significantly.

Example:

void CustomScene::drawItems(QPainter *painter, int numItems,

QGraphicsItem *items[],

const QStyleOptionGraphicsItem options[],

QWidget *widget)

{

for (int i = 0; i < numItems; ++i) {

// Draw the item

painter->save();

painter->setMatrix(items[i]->sceneMatrix(), true);

items[i]->paint(painter, &options[i], widget);

painter->restore();

}

}

Since Qt 4.6, this function is not called anymore unless the QGraphicsView::IndirectPainting flag is given as an Optimization flag.

See also drawBackground() and drawForeground().

override bool QtGui.QGraphicsScene.EventFilter	(	QObject	watched,
		QEvent @	event
	)

Reimplemented from QObject::eventFilter().

QGraphicsScene filters QApplication's events to detect palette and font changes.

new bool QtGui.QGraphicsScene.FocusNextPrevChild ( bool  next )

protected

Finds a new widget to give the keyboard focus to, as appropriate for Tab and Shift+Tab, and returns true if it can find a new widget, or false if it cannot. If next is true, this function searches forward; if next is false, it searches backward.

You can reimplement this function in a subclass of QGraphicsScene to provide fine-grained control over how tab focus passes inside your scene. The default implementation is based on the tab focus chain defined by QGraphicsWidget::setTabOrder().

This function was introduced in Qt 4.4.

new bool QtGui.QGraphicsScene.HasFocus

(

)

Returns true if the scene has focus; otherwise returns false. If the scene has focus, it will will forward key events from QKeyEvent to any item that has focus.

See also setFocus() and setFocusItem().

new double QtGui.QGraphicsScene.Height

(

)

This convenience function is equivalent to calling sceneRect().height().

See also width().

virtual object QtGui.QGraphicsScene.InputMethodQuery ( Qt.InputMethodQuery  query )

virtual

This method is used by input methods to query a set of properties of the scene to be able to support complex input method operations as support for surrounding text and reconversions.

The query parameter specifies which property is queried.

See also QWidget::inputMethodQuery().

new void QtGui.QGraphicsScene.Invalidate

(

)

Invalidates and schedules a redraw of the layers in rect on the scene. Any cached content in layers is unconditionally invalidated and redrawn.

You can use this function overload to notify QGraphicsScene of changes to the background or the foreground of the scene. This function is commonly used for scenes with tile-based backgrounds to notify changes when QGraphicsView has enabled CacheBackground.

Example:

QRectF TileScene::rectForTile(int x, int y) const

{

// Return the rectangle for the tile at position (x, y).

return QRectF(x * tileWidth, y * tileHeight, tileWidth, tileHeight);

}

void TileScene::setTile(int x, int y, const QPixmap &pixmap)

{

// Sets or replaces the tile at position (x, y) with pixmap.

if (x >= 0 && x < numTilesH && y >= 0 && y < numTilesV) {

tiles[y][x] = pixmap;

invalidate(rectForTile(x, y), BackgroundLayer);

}

}

void TileScene::drawBackground(QPainter *painter, const QRectF &exposed)

{

// Draws all tiles that intersect the exposed area.

for (int y = 0; y < numTilesV; ++y) {

for (int x = 0; x < numTilesH; ++x) {

QRectF rect = rectForTile(x, y);

if (exposed.intersects(rect))

painter->drawPixmap(rect.topLeft(), tiles[y][x]);

}

}

}

Note that QGraphicsView currently supports background caching only (see QGraphicsView::CacheBackground). This function is equivalent to calling update() if any layer but BackgroundLayer is passed.

See also QGraphicsView::resetCachedContent().

new void QtGui.QGraphicsScene.Invalidate	(	QRectF	rect,
		QGraphicsScene.SceneLayer	layers = QGraphicsScene.SceneLayer.AllLayers
	)

Invalidates and schedules a redraw of the layers in rect on the scene. Any cached content in layers is unconditionally invalidated and redrawn.

You can use this function overload to notify QGraphicsScene of changes to the background or the foreground of the scene. This function is commonly used for scenes with tile-based backgrounds to notify changes when QGraphicsView has enabled CacheBackground.

Example:

QRectF TileScene::rectForTile(int x, int y) const

{

// Return the rectangle for the tile at position (x, y).

return QRectF(x * tileWidth, y * tileHeight, tileWidth, tileHeight);

}

void TileScene::setTile(int x, int y, const QPixmap &pixmap)

{

// Sets or replaces the tile at position (x, y) with pixmap.

if (x >= 0 && x < numTilesH && y >= 0 && y < numTilesV) {

tiles[y][x] = pixmap;

invalidate(rectForTile(x, y), BackgroundLayer);

}

}

void TileScene::drawBackground(QPainter *painter, const QRectF &exposed)

{

// Draws all tiles that intersect the exposed area.

for (int y = 0; y < numTilesV; ++y) {

for (int x = 0; x < numTilesH; ++x) {

QRectF rect = rectForTile(x, y);

if (exposed.intersects(rect))

painter->drawPixmap(rect.topLeft(), tiles[y][x]);

}

}

}

Note that QGraphicsView currently supports background caching only (see QGraphicsView::CacheBackground). This function is equivalent to calling update() if any layer but BackgroundLayer is passed.

See also QGraphicsView::resetCachedContent().

new void QtGui.QGraphicsScene.Invalidate	(	double	x,
		double	y,
		double	w,
		double	h,
		QGraphicsScene.SceneLayer	layers = QGraphicsScene.SceneLayer.AllLayers
	)

Invalidates and schedules a redraw of the layers in rect on the scene. Any cached content in layers is unconditionally invalidated and redrawn.

You can use this function overload to notify QGraphicsScene of changes to the background or the foreground of the scene. This function is commonly used for scenes with tile-based backgrounds to notify changes when QGraphicsView has enabled CacheBackground.

Example:

QRectF TileScene::rectForTile(int x, int y) const

{

// Return the rectangle for the tile at position (x, y).

return QRectF(x * tileWidth, y * tileHeight, tileWidth, tileHeight);

}

void TileScene::setTile(int x, int y, const QPixmap &pixmap)

{

// Sets or replaces the tile at position (x, y) with pixmap.

if (x >= 0 && x < numTilesH && y >= 0 && y < numTilesV) {

tiles[y][x] = pixmap;

invalidate(rectForTile(x, y), BackgroundLayer);

}

}

void TileScene::drawBackground(QPainter *painter, const QRectF &exposed)

{

// Draws all tiles that intersect the exposed area.

for (int y = 0; y < numTilesV; ++y) {

for (int x = 0; x < numTilesH; ++x) {

QRectF rect = rectForTile(x, y);

if (exposed.intersects(rect))

painter->drawPixmap(rect.topLeft(), tiles[y][x]);

}

}

}

Note that QGraphicsView currently supports background caching only (see QGraphicsView::CacheBackground). This function is equivalent to calling update() if any layer but BackgroundLayer is passed.

See also QGraphicsView::resetCachedContent().

new bool QtGui.QGraphicsScene.IsActive

(

)

Returns true if the scene is active (e.g., it's viewed by at least one QGraphicsView that is active); otherwise returns false.

This function was introduced in Qt 4.6.

See also QGraphicsItem::isActive() and QWidget::isActiveWindow().

new IQGraphicsItem QtGui.QGraphicsScene.ItemAt

(

QPointF

pos

)

Returns the topmost visible item at the specified position, or 0 if there are no items at this position.

deviceTransform is the transformation that applies to the view, and needs to be provided if the scene contains items that ignore transformations.

This function was introduced in Qt 4.6.

See also items(), collidingItems(), and Sorting.

new IQGraphicsItem QtGui.QGraphicsScene.ItemAt	(	QPointF	pos,
		QTransform	deviceTransform
	)

Returns the topmost visible item at the specified position, or 0 if there are no items at this position.

deviceTransform is the transformation that applies to the view, and needs to be provided if the scene contains items that ignore transformations.

This function was introduced in Qt 4.6.

See also items(), collidingItems(), and Sorting.

new IQGraphicsItem QtGui.QGraphicsScene.ItemAt	(	double	x,
		double	y
	)

Returns the topmost visible item at the specified position, or 0 if there are no items at this position.

deviceTransform is the transformation that applies to the view, and needs to be provided if the scene contains items that ignore transformations.

This function was introduced in Qt 4.6.

See also items(), collidingItems(), and Sorting.

new IQGraphicsItem QtGui.QGraphicsScene.ItemAt	(	double	x,
		double	y,
		QTransform	deviceTransform
	)

Returns the topmost visible item at the specified position, or 0 if there are no items at this position.

deviceTransform is the transformation that applies to the view, and needs to be provided if the scene contains items that ignore transformations.

This function was introduced in Qt 4.6.

See also items(), collidingItems(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items

(

)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items

(

QPointF

pos

)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QRectF	rect,
		Qt.ItemSelectionMode	mode = Qt.ItemSelectionMode.IntersectsItemShape
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QPolygonF	polygon,
		Qt.ItemSelectionMode	mode = Qt.ItemSelectionMode.IntersectsItemShape
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QPainterPath	path,
		Qt.ItemSelectionMode	mode = Qt.ItemSelectionMode.IntersectsItemShape
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QPointF	pos,
		Qt.ItemSelectionMode	mode,
		Qt.SortOrder	order
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QRectF	rect,
		Qt.ItemSelectionMode	mode,
		Qt.SortOrder	order
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QPolygonF	polygon,
		Qt.ItemSelectionMode	mode,
		Qt.SortOrder	order
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QPainterPath	path,
		Qt.ItemSelectionMode	mode,
		Qt.SortOrder	order
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QPointF	pos,
		Qt.ItemSelectionMode	mode,
		Qt.SortOrder	order,
		QTransform	deviceTransform
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QRectF	rect,
		Qt.ItemSelectionMode	mode,
		Qt.SortOrder	order,
		QTransform	deviceTransform
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QPolygonF	polygon,
		Qt.ItemSelectionMode	mode,
		Qt.SortOrder	order,
		QTransform	deviceTransform
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	QPainterPath	path,
		Qt.ItemSelectionMode	mode,
		Qt.SortOrder	order,
		QTransform	deviceTransform
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items

(

Qt.SortOrder

order

)

Returns an ordered list of all items on the scene. order decides the stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	double	x,
		double	y,
		double	w,
		double	h,
		Qt.ItemSelectionMode	mode = Qt.ItemSelectionMode.IntersectsItemShape
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	double	x,
		double	y,
		double	w,
		double	h,
		Qt.ItemSelectionMode	mode,
		Qt.SortOrder	order
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.Items	(	double	x,
		double	y,
		double	w,
		double	h,
		Qt.ItemSelectionMode	mode,
		Qt.SortOrder	order,
		QTransform	deviceTransform
	)

Returns a list of all items in the scene in descending stacking order.

See also addItem(), removeItem(), and Sorting.

new QRectF QtGui.QGraphicsScene.ItemsBoundingRect

(

)

Calculates and returns the bounding rect of all items on the scene. This function works by iterating over all items, and because if this, it can be slow for large scenes.

See also sceneRect().

new IQGraphicsItem QtGui.QGraphicsScene.MouseGrabberItem

(

)

Returns the current mouse grabber item, or 0 if no item is currently grabbing the mouse. The mouse grabber item is the item that receives all mouse events sent to the scene.

An item becomes a mouse grabber when it receives and accepts a mouse press event, and it stays the mouse grabber until either of the following events occur:

If the item receives a mouse release event when there are no other buttons pressed, it loses the mouse grab.

If the item becomes invisible (i.e., someone calls item->setVisible(false)), or if it becomes disabled (i.e., someone calls item->setEnabled(false)), it loses the mouse grab.

If the item is removed from the scene, it loses the mouse grab.

If the item loses its mouse grab, the scene will ignore all mouse events until a new item grabs the mouse (i.e., until a new item receives a mouse press event).

new void QtGui.QGraphicsScene.OnChanged ( System.Collections.Generic.List< QRectF >  region )

protected

This signal is emitted by QGraphicsScene when control reaches the event loop, if the scene content changes. The region parameter contains a list of scene rectangles that indicate the area that has been changed.

See also QGraphicsView::updateScene().

virtual void QtGui.QGraphicsScene.OnContextMenuEvent ( QGraphicsSceneContextMenuEvent @  event )

protectedvirtual

This event handler, for event contextMenuEvent, can be reimplemented in a subclass to receive context menu events. The default implementation forwards the event to the topmost item that accepts context menu events at the position of the event. If no items accept context menu events at this position, the event is ignored.

See also QGraphicsItem::contextMenuEvent().

virtual void QtGui.QGraphicsScene.OnDragEnterEvent ( QGraphicsSceneDragDropEvent @  event )

protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive drag enter events for the scene.

The default implementation accepts the event and prepares the scene to accept drag move events.

See also QGraphicsItem::dragEnterEvent(), dragMoveEvent(), dragLeaveEvent(), and dropEvent().

virtual void QtGui.QGraphicsScene.OnDragLeaveEvent ( QGraphicsSceneDragDropEvent @  event )

protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive drag leave events for the scene.

See also QGraphicsItem::dragLeaveEvent(), dragEnterEvent(), dragMoveEvent(), and dropEvent().

virtual void QtGui.QGraphicsScene.OnDragMoveEvent ( QGraphicsSceneDragDropEvent @  event )

protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive drag move events for the scene.

See also QGraphicsItem::dragMoveEvent(), dragEnterEvent(), dragLeaveEvent(), and dropEvent().

virtual void QtGui.QGraphicsScene.OnDropEvent ( QGraphicsSceneDragDropEvent @  event )

protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive drop events for the scene.

See also QGraphicsItem::dropEvent(), dragEnterEvent(), dragMoveEvent(), and dragLeaveEvent().

override bool QtGui.QGraphicsScene.OnEvent

(

QEvent @

event

)

Reimplemented from QObject::event().

Processes the event event, and dispatches it to the respective event handlers.

In addition to calling the convenience event handlers, this function is responsible for converting mouse move events to hover events for when there is no mouse grabber item. Hover events are delivered directly to items; there is no convenience function for them.

Unlike QWidget, QGraphicsScene does not have the convenience functions enterEvent() and leaveEvent(). Use this function to obtain those events instead.

See also contextMenuEvent(), keyPressEvent(), keyReleaseEvent(), mousePressEvent(), mouseMoveEvent(), mouseReleaseEvent(), mouseDoubleClickEvent(), focusInEvent(), and focusOutEvent().

virtual void QtGui.QGraphicsScene.OnFocusInEvent ( QFocusEvent @  event )

protectedvirtual

This event handler, for event focusEvent, can be reimplemented in a subclass to receive focus in events.

The default implementation sets focus on the scene, and then on the last focus item.

See also QGraphicsItem::focusOutEvent().

virtual void QtGui.QGraphicsScene.OnFocusOutEvent ( QFocusEvent @  event )

protectedvirtual

This event handler, for event focusEvent, can be reimplemented in a subclass to receive focus out events.

The default implementation removes focus from any focus item, then removes focus from the scene.

See also QGraphicsItem::focusInEvent().

virtual void QtGui.QGraphicsScene.OnHelpEvent ( QGraphicsSceneHelpEvent @  event )

protectedvirtual

This event handler, for event helpEvent, can be reimplemented in a subclass to receive help events. The events are of type QEvent::ToolTip, which are created when a tooltip is requested.

The default implementation shows the tooltip of the topmost item, i.e., the item with the highest z-value, at the mouse cursor position. If no item has a tooltip set, this function does nothing.

See also QGraphicsItem::toolTip() and QGraphicsSceneHelpEvent.

virtual void QtGui.QGraphicsScene.OnInputMethodEvent ( QInputMethodEvent @  event )

protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive input method events for the scene.

The default implementation forwards the event to the focusItem(). If no item currently has focus or the current focus item does not accept input methods, this function does nothing.

See also QGraphicsItem::inputMethodEvent().

virtual void QtGui.QGraphicsScene.OnKeyPressEvent ( QKeyEvent @  event )

protectedvirtual

This event handler, for event keyEvent, can be reimplemented in a subclass to receive keypress events. The default implementation forwards the event to current focus item.

See also QGraphicsItem::keyPressEvent() and focusItem().

virtual void QtGui.QGraphicsScene.OnKeyReleaseEvent ( QKeyEvent @  event )

protectedvirtual

This event handler, for event keyEvent, can be reimplemented in a subclass to receive key release events. The default implementation forwards the event to current focus item.

See also QGraphicsItem::keyReleaseEvent() and focusItem().

virtual void QtGui.QGraphicsScene.OnMouseDoubleClickEvent ( QGraphicsSceneMouseEvent @  event )

protectedvirtual

This event handler, for event mouseEvent, can be reimplemented in a subclass to receive mouse doubleclick events for the scene.

If someone doubleclicks on the scene, the scene will first receive a mouse press event, followed by a release event (i.e., a click), then a doubleclick event, and finally a release event. If the doubleclick event is delivered to a different item than the one that received the first press and release, it will be delivered as a press event. However, tripleclick events are not delivered as doubleclick events in this case.

The default implementation is similar to mousePressEvent().

See also QGraphicsItem::mousePressEvent(), QGraphicsItem::mouseMoveEvent(), QGraphicsItem::mouseReleaseEvent(), and QGraphicsItem::setAcceptedMouseButtons().

virtual void QtGui.QGraphicsScene.OnMouseMoveEvent ( QGraphicsSceneMouseEvent @  event )

protectedvirtual

This event handler, for event mouseEvent, can be reimplemented in a subclass to receive mouse move events for the scene.

The default implementation depends on the mouse grabber state. If there is a mouse grabber item, the event is sent to the mouse grabber. If there are any items that accept hover events at the current position, the event is translated into a hover event and accepted; otherwise it's ignored.

See also QGraphicsItem::mousePressEvent(), QGraphicsItem::mouseReleaseEvent(), QGraphicsItem::mouseDoubleClickEvent(), and QGraphicsItem::setAcceptedMouseButtons().

virtual void QtGui.QGraphicsScene.OnMousePressEvent ( QGraphicsSceneMouseEvent @  event )

protectedvirtual

This event handler, for event mouseEvent, can be reimplemented in a subclass to receive mouse press events for the scene.

The default implementation depends on the state of the scene. If there is a mouse grabber item, then the event is sent to the mouse grabber. Otherwise, it is forwarded to the topmost item that accepts mouse events at the scene position from the event, and that item promptly becomes the mouse grabber item.

If there is no item at the given position on the scene, the selection area is reset, any focus item loses its input focus, and the event is then ignored.

See also QGraphicsItem::mousePressEvent() and QGraphicsItem::setAcceptedMouseButtons().

virtual void QtGui.QGraphicsScene.OnMouseReleaseEvent ( QGraphicsSceneMouseEvent @  event )

protectedvirtual

This event handler, for event mouseEvent, can be reimplemented in a subclass to receive mouse release events for the scene.

The default implementation depends on the mouse grabber state. If there is no mouse grabber, the event is ignored. Otherwise, if there is a mouse grabber item, the event is sent to the mouse grabber. If this mouse release represents the last pressed button on the mouse, the mouse grabber item then loses the mouse grab.

See also QGraphicsItem::mousePressEvent(), QGraphicsItem::mouseMoveEvent(), QGraphicsItem::mouseDoubleClickEvent(), and QGraphicsItem::setAcceptedMouseButtons().

new void QtGui.QGraphicsScene.OnSceneRectChanged ( QRectF  rect )

protected

This signal is emitted by QGraphicsScene whenever the scene rect changes. The rect parameter is the new scene rectangle.

See also QGraphicsView::updateSceneRect().

new void QtGui.QGraphicsScene.OnSelectionChanged ( )

protected

This signal is emitted by QGraphicsScene whenever the selection changes. You can call selectedItems() to get the new list of selected items.

The selection changes whenever an item is selected or unselected, a selection area is set, cleared or otherwise changed, if a preselected item is added to the scene, or if a selected item is removed from the scene.

QGraphicsScene emits this signal only once for group selection operations. For example, if you set a selection area, select or unselect a QGraphicsItemGroup, or if you add or remove from the scene a parent item that contains several selected items, selectionChanged() is emitted only once after the operation has completed (instead of once for each item).

This function was introduced in Qt 4.3.

See also setSelectionArea(), selectedItems(), and QGraphicsItem::setSelected().

new bool QtGui.QGraphicsScene.OnSendEvent	(	IQGraphicsItem	item,
		QEvent @	event
	)

Sends event event to item item through possible event filters.

The event is sent only if the item is enabled.

Returns false if the event was filtered or if the item is disabled. Otherwise returns the value that was returned from the event handler.

This function was introduced in Qt 4.6.

See also QGraphicsItem::sceneEvent() and QGraphicsItem::sceneEventFilter().

virtual void QtGui.QGraphicsScene.OnWheelEvent ( QGraphicsSceneWheelEvent @  event )

protectedvirtual

This event handler, for event wheelEvent, can be reimplemented in a subclass to receive mouse wheel events for the scene.

By default, the event is delivered to the topmost visible item under the cursor. If ignored, the event propagates to the item beneath, and again until the event is accepted, or it reaches the scene. If no items accept the event, it is ignored.

See also QGraphicsItem::wheelEvent().

new void QtGui.QGraphicsScene.RemoveItem

(

IQGraphicsItem

item

)

Removes the item item and all its children from the scene. The ownership of item is passed on to the caller (i.e., QGraphicsScene will no longer delete item when destroyed).

See also addItem().

new void QtGui.QGraphicsScene.Render

(

QPainter

painter

)

Renders the source rect from scene into target, using painter. This function is useful for capturing the contents of the scene onto a paint device, such as a QImage (e.g., to take a screenshot), or for printing with QPrinter. For example:

QGraphicsScene scene;

scene.addItem(...

...

QPrinter printer(QPrinter::HighResolution);

printer.setPaperSize(QPrinter::A4);

QPainter painter(&printer);

scene.render(&painter);

If source is a null rect, this function will use sceneRect() to determine what to render. If target is a null rect, the dimensions of painter's paint device will be used.

The source rect contents will be transformed according to aspectRatioMode to fit into the target rect. By default, the aspect ratio is kept, and source is scaled to fit in target.

See also QGraphicsView::render().

new void QtGui.QGraphicsScene.Render	(	QPainter	painter,
		QRectF	target
	)

Renders the source rect from scene into target, using painter. This function is useful for capturing the contents of the scene onto a paint device, such as a QImage (e.g., to take a screenshot), or for printing with QPrinter. For example:

QGraphicsScene scene;

scene.addItem(...

...

QPrinter printer(QPrinter::HighResolution);

printer.setPaperSize(QPrinter::A4);

QPainter painter(&printer);

scene.render(&painter);

If source is a null rect, this function will use sceneRect() to determine what to render. If target is a null rect, the dimensions of painter's paint device will be used.

The source rect contents will be transformed according to aspectRatioMode to fit into the target rect. By default, the aspect ratio is kept, and source is scaled to fit in target.

See also QGraphicsView::render().

new void QtGui.QGraphicsScene.Render	(	QPainter	painter,
		QRectF	target,
		QRectF	source,
		Qt.AspectRatioMode	aspectRatioMode = Qt.AspectRatioMode.KeepAspectRatio
	)

Renders the source rect from scene into target, using painter. This function is useful for capturing the contents of the scene onto a paint device, such as a QImage (e.g., to take a screenshot), or for printing with QPrinter. For example:

QGraphicsScene scene;

scene.addItem(...

...

QPrinter printer(QPrinter::HighResolution);

printer.setPaperSize(QPrinter::A4);

QPainter painter(&printer);

scene.render(&painter);

If source is a null rect, this function will use sceneRect() to determine what to render. If target is a null rect, the dimensions of painter's paint device will be used.

The source rect contents will be transformed according to aspectRatioMode to fit into the target rect. By default, the aspect ratio is kept, and source is scaled to fit in target.

See also QGraphicsView::render().

new System.Collections.Generic.List<IQGraphicsItem> QtGui.QGraphicsScene.SelectedItems

(

)

Returns a list of all currently selected items. The items are returned in no particular order.

See also setSelectionArea().

new void QtGui.QGraphicsScene.SetFocus

(

Qt.FocusReason

focusReason = Qt.FocusReason.OtherFocusReason

)

Sets focus on the scene by sending a QFocusEvent to the scene, passing focusReason as the reason. If the scene regains focus after having previously lost it while an item had focus, the last focus item will receive focus with focusReason as the reason.

If the scene already has focus, this function does nothing.

See also hasFocus(), clearFocus(), and setFocusItem().

new void QtGui.QGraphicsScene.SetFocusItem	(	IQGraphicsItem	item,
		Qt.FocusReason	focusReason = Qt.FocusReason.OtherFocusReason
	)

Sets the scene's focus item to item, with the focus reason focusReason, after removing focus from any previous item that may have had focus.

If item is 0, or if it either does not accept focus (i.e., it does not have the QGraphicsItem::ItemIsFocusable flag enabled), or is not visible or not enabled, this function only removes focus from any previous focusitem.

If item is not 0, and the scene does not currently have focus (i.e., hasFocus() returns false), this function will call setFocus() automatically.

See also focusItem(), hasFocus(), and setFocus().

new void QtGui.QGraphicsScene.SetSceneRect	(	double	x,
		double	y,
		double	w,
		double	h
	)

new void QtGui.QGraphicsScene.SetSelectionArea	(	QPainterPath	path,
		QTransform	deviceTransform
	)

Sets the selection area to path. All items within this area are immediately selected, and all items outside are unselected. You can get the list of all selected items by calling selectedItems().

deviceTransform is the transformation that applies to the view, and needs to be provided if the scene contains items that ignore transformations.

For an item to be selected, it must be marked as selectable (QGraphicsItem::ItemIsSelectable).

This function was introduced in Qt 4.6.

See also clearSelection() and selectionArea().

new void QtGui.QGraphicsScene.SetSelectionArea	(	QPainterPath	path,
		Qt.ItemSelectionMode	mode
	)

Sets the selection area to path. All items within this area are immediately selected, and all items outside are unselected. You can get the list of all selected items by calling selectedItems().

deviceTransform is the transformation that applies to the view, and needs to be provided if the scene contains items that ignore transformations.

For an item to be selected, it must be marked as selectable (QGraphicsItem::ItemIsSelectable).

This function was introduced in Qt 4.6.

See also clearSelection() and selectionArea().

new void QtGui.QGraphicsScene.SetSelectionArea	(	QPainterPath	path,
		Qt.ItemSelectionMode	mode,
		QTransform	deviceTransform
	)

This is an overloaded function.

Sets the selection area to path using mode to determine if items are included in the selection area.

deviceTransform is the transformation that applies to the view, and needs to be provided if the scene contains items that ignore transformations.

This function was introduced in Qt 4.6.

See also clearSelection() and selectionArea().

static string QtGui.QGraphicsScene.Tr ( string  s, string  c = null  )

static

static string QtGui.QGraphicsScene.Tr ( string  s, string  c, int  n  )

static

static string QtGui.QGraphicsScene.TrUtf8 ( string  s, string  c = null  )

static

static string QtGui.QGraphicsScene.TrUtf8 ( string  s, string  c, int  n  )

static

new void QtGui.QGraphicsScene.Update

(

)

Schedules a redraw of the area rect on the scene.

See also sceneRect() and changed().

new void QtGui.QGraphicsScene.Update

(

QRectF

rect

)

Schedules a redraw of the area rect on the scene.

See also sceneRect() and changed().

new void QtGui.QGraphicsScene.Update	(	double	x,
		double	y,
		double	w,
		double	h
	)

Schedules a redraw of the area rect on the scene.

See also sceneRect() and changed().

new System.Collections.Generic.List<QGraphicsView> QtGui.QGraphicsScene.Views

(

)

Returns a list of all the views that display this scene.

See also QGraphicsView::scene().

new double QtGui.QGraphicsScene.Width

(

)

This convenience function is equivalent to calling sceneRect().width().

See also height().

Property Documentation

new IQGraphicsItem QtGui.QGraphicsScene.ActivePanel

getset

Returns the current active panel, or 0 if no panel is currently active.

This function was introduced in Qt 4.6.

Activates item, which must be an item in this scene. You can also pass 0 for item, in which case QGraphicsScene will deactivate any currently active panel.

If the scene is currently inactive, item remains inactive until the scene becomes active (or, ir item is 0, no item will be activated).

This function was introduced in Qt 4.6.

new QGraphicsWidget QtGui.QGraphicsScene.ActiveWindow

getset

Returns the current active window, or 0 if no window is currently active.

This function was introduced in Qt 4.4.

Activates widget, which must be a widget in this scene. You can also pass 0 for widget, in which case QGraphicsScene will deactivate any currently active window.

This function was introduced in Qt 4.4.

new QBrush QtGui.QGraphicsScene.BackgroundBrush

getset

This property holds the background brush of the scene.

Set this property to changes the scene's background to a different color, gradient or texture. The default background brush is Qt::NoBrush. The background is drawn before (behind) the items.

Example:

QGraphicsScene scene;

QGraphicsView view(&scene);

view.show();

// a blue background

scene.setBackgroundBrush(Qt::blue);

// a gradient background

QRadialGradient gradient(0, 0, 10);

gradient.setSpread(QGradient::RepeatSpread);

scene.setBackgroundBrush(gradient);

QGraphicsScene::render() calls drawBackground() to draw the scene background. For more detailed control over how the background is drawn, you can reimplement drawBackground() in a subclass of QGraphicsScene.

new int QtGui.QGraphicsScene.BspTreeDepth

getset

This property holds the depth of QGraphicsScene's BSP index tree.

This property has no effect when NoIndex is used.

This value determines the depth of QGraphicsScene's BSP tree. The depth directly affects QGraphicsScene's performance and memory usage; the latter growing exponentially with the depth of the tree. With an optimal tree depth, QGraphicsScene 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 QGraphicsScene 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:

QSizeF segmentSize = sceneRect().size() / pow(2, depth - 1);

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

This property was introduced in Qt 4.3.

Slot<System.Collections.Generic.List<QRectF> > QtGui.QGraphicsScene.Changed

addremove

This signal is emitted by QGraphicsScene when control reaches the event loop, if the scene content changes. The region parameter contains a list of scene rectangles that indicate the area that has been changed.

See also QGraphicsView::updateScene().

new IQGraphicsSceneSignals QtGui.QGraphicsScene.Emit

getprotected

new IQGraphicsItem QtGui.QGraphicsScene.FocusItem

get

When the scene is active, this functions returns the scene's current focus item, or 0 if no item currently has focus. When the scene is inactive, this functions returns the item that will gain input focus when the scene becomes active.

The focus item receives keyboard input when the scene receives a key event.

See also setFocusItem(), QGraphicsItem::hasFocus(), and isActive().

new QFont QtGui.QGraphicsScene.Font

getset

This property holds the scene's default font.

This property provides the scene's font. The scene font defaults to, and resolves all its entries from, QApplication::font.

If the scene's font changes, either directly through setFont() or indirectly when the application font changes, QGraphicsScene first sends itself a FontChange event, and it then sends FontChange events to all top-level widget items in the scene. These items respond by resolving their own fonts to the scene, and they then notify their children, who again notify their children, and so on, until all widget items have updated their fonts.

Changing the scene font, (directly or indirectly through QApplication::setFont(),) automatically schedules a redraw the entire scene.

This property was introduced in Qt 4.4.

new QBrush QtGui.QGraphicsScene.ForegroundBrush

getset

This property holds the foreground brush of the scene.

Change this property to set the scene's foreground to a different color, gradient or texture.

The foreground is drawn after (on top of) the items. The default foreground brush is Qt::NoBrush ( i.e. the foreground is not drawn).

Example:

QGraphicsScene scene;

QGraphicsView view(&scene);

view.show();

// a white semi-transparent foreground

scene.setForegroundBrush(QColor(255, 255, 255, 127));

// a grid foreground

scene.setForegroundBrush(QBrush(Qt::lightGray, Qt::CrossPattern));

QGraphicsScene::render() calls drawForeground() to draw the scene foreground. For more detailed control over how the foreground is drawn, you can reimplement the drawForeground() function in a QGraphicsScene subclass.

new ItemIndexMethod QtGui.QGraphicsScene.itemIndexMethod

getset

This property holds the item indexing method.

QGraphicsScene applies an indexing algorithm to the scene, to speed up item discovery functions like items() and itemAt(). Indexing is most efficient for static scenes (i.e., where items don't move around). For dynamic scenes, or scenes with many animated items, the index bookkeeping can outweight the fast lookup speeds.

For the common case, the default index method BspTreeIndex works fine. If your scene uses many animations and you are experiencing slowness, you can disable indexing by calling setItemIndexMethod(NoIndex).

new QPalette QtGui.QGraphicsScene.Palette

getset

This property holds the scene's default palette.

This property provides the scene's palette. The scene palette defaults to, and resolves all its entries from, QApplication::palette.

If the scene's palette changes, either directly through setPalette() or indirectly when the application palette changes, QGraphicsScene first sends itself a PaletteChange event, and it then sends PaletteChange events to all top-level widget items in the scene. These items respond by resolving their own palettes to the scene, and they then notify their children, who again notify their children, and so on, until all widget items have updated their palettes.

Changing the scene palette, (directly or indirectly through QApplication::setPalette(),) automatically schedules a redraw the entire scene.

This property was introduced in Qt 4.4.

new QRectF QtGui.QGraphicsScene.SceneRect

getset

This property holds the scene rectangle; the bounding rectangle of the scene.

The scene rectangle defines the extent of the scene. It is primarily used by QGraphicsView to determine the view's default scrollable area, and by QGraphicsScene to manage item indexing.

If unset, or if set to a null QRectF, sceneRect() will return the largest bounding rect of all items on the scene since the scene was created (i.e., a rectangle that grows when items are added to or moved in the scene, but never shrinks).

Slot<QRectF> QtGui.QGraphicsScene.SceneRectChanged

addremove

This signal is emitted by QGraphicsScene whenever the scene rect changes. The rect parameter is the new scene rectangle.

See also QGraphicsView::updateSceneRect().

new QPainterPath QtGui.QGraphicsScene.SelectionArea

getset

Returns the selection area that was previously set with setSelectionArea(), or an empty QPainterPath if no selection area has been set.

Sets the selection area to path. All items within this area are immediately selected, and all items outside are unselected. You can get the list of all selected items by calling selectedItems().

deviceTransform is the transformation that applies to the view, and needs to be provided if the scene contains items that ignore transformations.

For an item to be selected, it must be marked as selectable (QGraphicsItem::ItemIsSelectable).

This function was introduced in Qt 4.6.

Slot QtGui.QGraphicsScene.SelectionChanged

addremove

This signal is emitted by QGraphicsScene whenever the selection changes. You can call selectedItems() to get the new list of selected items.

The selection changes whenever an item is selected or unselected, a selection area is set, cleared or otherwise changed, if a preselected item is added to the scene, or if a selected item is removed from the scene.

QGraphicsScene emits this signal only once for group selection operations. For example, if you set a selection area, select or unselect a QGraphicsItemGroup, or if you add or remove from the scene a parent item that contains several selected items, selectionChanged() is emitted only once after the operation has completed (instead of once for each item).

This function was introduced in Qt 4.3.

See also setSelectionArea(), selectedItems(), and QGraphicsItem::setSelected().

new bool QtGui.QGraphicsScene.SortCacheEnabled

getset

This property holds whether sort caching is enabled.

Since Qt 4.6, this property has no effect.

This property was introduced in Qt 4.5.

new QMetaObject QtGui.QGraphicsScene.StaticMetaObject

staticget

new bool QtGui.QGraphicsScene.StickyFocus

getset

This property holds whether clicking into the scene background will clear focus.

In a QGraphicsScene with stickyFocus set to true, focus will remain unchanged when the user clicks into the scene background or on an item that does not accept focus. Otherwise, focus will be cleared.

By default, this property is false.

Focus changes in response to a mouse press. You can reimplement mousePressEvent() in a subclass of QGraphicsScene to toggle this property based on where the user has clicked.

This property was introduced in Qt 4.6.

new QStyle QtGui.QGraphicsScene.Style

getset

Returns the scene's style, or the same as QApplication::style() if the scene has not been explicitly assigned a style.

This function was introduced in Qt 4.4.

Sets or replaces the style of the scene to style, and reparents the style to this scene. Any previously assigned style is deleted. The scene's style defaults to QApplication::style(), and serves as the default for all QGraphicsWidget items in the scene.

Changing the style, either directly by calling this function, or indirectly by calling QApplication::setStyle(), will automatically update the style for all widgets in the scene that do not have a style explicitly assigned to them.

If style is 0, QGraphicsScene will revert to QApplication::style().

This function was introduced in Qt 4.4.