The QGraphicsItemGroup class provides a container that treats a group of items as a single item. More...

#include <qgraphicsitem.h>

Inheritance diagram for QGraphicsItemGroup:

Collaboration diagram for QGraphicsItemGroup:

Public Types
enum	{ Type = 10 }

Public Types inherited from QGraphicsItem
enum	GraphicsItemFlag { ItemIsMovable = 0x1 , ItemIsSelectable = 0x2 , ItemIsFocusable = 0x4 , ItemClipsToShape = 0x8 , ItemClipsChildrenToShape = 0x10 , ItemIgnoresTransformations = 0x20 , ItemIgnoresParentOpacity = 0x40 , ItemDoesntPropagateOpacityToChildren = 0x80 , ItemStacksBehindParent = 0x100 , ItemUsesExtendedStyleOption = 0x200 , ItemHasNoContents = 0x400 , ItemSendsGeometryChanges = 0x800 , ItemAcceptsInputMethod = 0x1000 , ItemNegativeZStacksBehindParent = 0x2000 , ItemIsPanel = 0x4000 , ItemIsFocusScope = 0x8000 , ItemSendsScenePositionChanges = 0x10000 , ItemStopsClickFocusPropagation = 0x20000 , ItemStopsFocusHandling = 0x40000 , ItemContainsChildrenInShape = 0x80000 }

enum	GraphicsItemChange { ItemPositionChange , ItemVisibleChange = 2 , ItemEnabledChange , ItemSelectedChange , ItemParentChange , ItemChildAddedChange , ItemChildRemovedChange , ItemTransformChange , ItemPositionHasChanged , ItemTransformHasChanged , ItemSceneChange , ItemVisibleHasChanged , ItemEnabledHasChanged , ItemSelectedHasChanged , ItemParentHasChanged , ItemSceneHasChanged , ItemCursorChange , ItemCursorHasChanged , ItemToolTipChange , ItemToolTipHasChanged , ItemFlagsChange , ItemFlagsHaveChanged , ItemZValueChange , ItemZValueHasChanged , ItemOpacityChange , ItemOpacityHasChanged , ItemScenePositionHasChanged , ItemRotationChange , ItemRotationHasChanged , ItemScaleChange , ItemScaleHasChanged , ItemTransformOriginPointChange , ItemTransformOriginPointHasChanged }

enum	CacheMode { NoCache , ItemCoordinateCache , DeviceCoordinateCache }

enum	PanelModality { NonModal , PanelModal , SceneModal }

enum	{ Type = 1 , UserType = 65536 }

Public Member Functions
	QGraphicsItemGroup (QGraphicsItem *parent=nullptr)

	~QGraphicsItemGroup ()

void	addToGroup (QGraphicsItem *item)

void	removeFromGroup (QGraphicsItem *item)

QRectF	boundingRect () const override

void	paint (QPainter painter, const QStyleOptionGraphicsItem option, QWidget *widget=nullptr) override

bool	isObscuredBy (const QGraphicsItem *item) const override

QPainterPath	opaqueArea () const override

int	type () const override

Public Member Functions inherited from QGraphicsItem
	QGraphicsItem (QGraphicsItem *parent=nullptr)

virtual	~QGraphicsItem ()

QGraphicsScene *	scene () const

QGraphicsItem *	parentItem () const

QGraphicsItem *	topLevelItem () const

QGraphicsObject *	parentObject () const

QGraphicsWidget *	parentWidget () const

QGraphicsWidget *	topLevelWidget () const

QGraphicsWidget *	window () const

QGraphicsItem *	panel () const

void	setParentItem (QGraphicsItem *parent)

QList< QGraphicsItem * >	childItems () const

bool	isWidget () const

bool	isWindow () const

bool	isPanel () const

QGraphicsObject *	toGraphicsObject ()

const QGraphicsObject *	toGraphicsObject () const

QGraphicsItemGroup *	group () const

void	setGroup (QGraphicsItemGroup *group)

GraphicsItemFlags	flags () const

void	setFlag (GraphicsItemFlag flag, bool enabled=true)

void	setFlags (GraphicsItemFlags flags)

CacheMode	cacheMode () const

void	setCacheMode (CacheMode mode, const QSize &cacheSize=QSize())

PanelModality	panelModality () const

void	setPanelModality (PanelModality panelModality)

bool	isBlockedByModalPanel (QGraphicsItem **blockingPanel=nullptr) const

QCursor	cursor () const

void	setCursor (const QCursor &cursor)

bool	hasCursor () const

void	unsetCursor ()

bool	isVisible () const

bool	isVisibleTo (const QGraphicsItem *parent) const

void	setVisible (bool visible)

void	hide ()

void	show ()

bool	isEnabled () const

void	setEnabled (bool enabled)

bool	isSelected () const

void	setSelected (bool selected)

bool	acceptDrops () const

void	setAcceptDrops (bool on)

qreal	opacity () const

qreal	effectiveOpacity () const

void	setOpacity (qreal opacity)

Qt::MouseButtons	acceptedMouseButtons () const

void	setAcceptedMouseButtons (Qt::MouseButtons buttons)

bool	acceptHoverEvents () const

void	setAcceptHoverEvents (bool enabled)

bool	acceptTouchEvents () const

void	setAcceptTouchEvents (bool enabled)

bool	filtersChildEvents () const

void	setFiltersChildEvents (bool enabled)

bool	handlesChildEvents () const

void	setHandlesChildEvents (bool enabled)

bool	isActive () const

void	setActive (bool active)

bool	hasFocus () const

void	setFocus (Qt::FocusReason focusReason=Qt::OtherFocusReason)

void	clearFocus ()

QGraphicsItem *	focusProxy () const

void	setFocusProxy (QGraphicsItem *item)

QGraphicsItem *	focusItem () const

QGraphicsItem *	focusScopeItem () const

void	grabMouse ()

void	ungrabMouse ()

void	grabKeyboard ()

void	ungrabKeyboard ()

QPointF	pos () const

qreal	x () const

void	setX (qreal x)

qreal	y () const

void	setY (qreal y)

QPointF	scenePos () const

void	setPos (const QPointF &pos)

void	setPos (qreal x, qreal y)

void	moveBy (qreal dx, qreal dy)

void	ensureVisible (const QRectF &rect=QRectF(), int xmargin=50, int ymargin=50)

void	ensureVisible (qreal x, qreal y, qreal w, qreal h, int xmargin=50, int ymargin=50)

QTransform	transform () const

QTransform	sceneTransform () const

QTransform	deviceTransform (const QTransform &viewportTransform) const

QTransform	itemTransform (const QGraphicsItem other, bool ok=nullptr) const

void	setTransform (const QTransform &matrix, bool combine=false)

void	resetTransform ()

void	setRotation (qreal angle)

qreal	rotation () const

void	setScale (qreal scale)

qreal	scale () const

QList< QGraphicsTransform * >	transformations () const

void	setTransformations (const QList< QGraphicsTransform * > &transformations)

QPointF	transformOriginPoint () const

void	setTransformOriginPoint (const QPointF &origin)

void	setTransformOriginPoint (qreal ax, qreal ay)

virtual void	advance (int phase)

qreal	zValue () const

void	setZValue (qreal z)

void	stackBefore (const QGraphicsItem *sibling)

QRectF	childrenBoundingRect () const

QRectF	sceneBoundingRect () const

virtual QPainterPath	shape () const

bool	isClipped () const

QPainterPath	clipPath () const

virtual bool	contains (const QPointF &point) const

virtual bool	collidesWithItem (const QGraphicsItem *other, Qt::ItemSelectionMode mode=Qt::IntersectsItemShape) const

virtual bool	collidesWithPath (const QPainterPath &path, Qt::ItemSelectionMode mode=Qt::IntersectsItemShape) const

QList< QGraphicsItem * >	collidingItems (Qt::ItemSelectionMode mode=Qt::IntersectsItemShape) const

bool	isObscured (const QRectF &rect=QRectF()) const

bool	isObscured (qreal x, qreal y, qreal w, qreal h) const

QRegion	boundingRegion (const QTransform &itemToDeviceTransform) const

qreal	boundingRegionGranularity () const

void	setBoundingRegionGranularity (qreal granularity)

void	update (const QRectF &rect=QRectF())

void	update (qreal x, qreal y, qreal width, qreal height)

void	scroll (qreal dx, qreal dy, const QRectF &rect=QRectF())

QPointF	mapToItem (const QGraphicsItem *item, const QPointF &point) const

QPointF	mapToParent (const QPointF &point) const

QPointF	mapToScene (const QPointF &point) const

QPolygonF	mapToItem (const QGraphicsItem *item, const QRectF &rect) const

QPolygonF	mapToParent (const QRectF &rect) const

QPolygonF	mapToScene (const QRectF &rect) const

QRectF	mapRectToItem (const QGraphicsItem *item, const QRectF &rect) const

QRectF	mapRectToParent (const QRectF &rect) const

QRectF	mapRectToScene (const QRectF &rect) const

QPolygonF	mapToItem (const QGraphicsItem *item, const QPolygonF &polygon) const

QPolygonF	mapToParent (const QPolygonF &polygon) const

QPolygonF	mapToScene (const QPolygonF &polygon) const

QPainterPath	mapToItem (const QGraphicsItem *item, const QPainterPath &path) const

QPainterPath	mapToParent (const QPainterPath &path) const

QPainterPath	mapToScene (const QPainterPath &path) const

QPointF	mapFromItem (const QGraphicsItem *item, const QPointF &point) const

QPointF	mapFromParent (const QPointF &point) const

QPointF	mapFromScene (const QPointF &point) const

QPolygonF	mapFromItem (const QGraphicsItem *item, const QRectF &rect) const

QPolygonF	mapFromParent (const QRectF &rect) const

QPolygonF	mapFromScene (const QRectF &rect) const

QRectF	mapRectFromItem (const QGraphicsItem *item, const QRectF &rect) const

QRectF	mapRectFromParent (const QRectF &rect) const

QRectF	mapRectFromScene (const QRectF &rect) const

QPolygonF	mapFromItem (const QGraphicsItem *item, const QPolygonF &polygon) const

QPolygonF	mapFromParent (const QPolygonF &polygon) const

QPolygonF	mapFromScene (const QPolygonF &polygon) const

QPainterPath	mapFromItem (const QGraphicsItem *item, const QPainterPath &path) const

QPainterPath	mapFromParent (const QPainterPath &path) const

QPainterPath	mapFromScene (const QPainterPath &path) const

QPointF	mapToItem (const QGraphicsItem *item, qreal x, qreal y) const

QPointF	mapToParent (qreal x, qreal y) const

QPointF	mapToScene (qreal x, qreal y) const

QPolygonF	mapToItem (const QGraphicsItem *item, qreal x, qreal y, qreal w, qreal h) const

QPolygonF	mapToParent (qreal x, qreal y, qreal w, qreal h) const

QPolygonF	mapToScene (qreal x, qreal y, qreal w, qreal h) const

QRectF	mapRectToItem (const QGraphicsItem *item, qreal x, qreal y, qreal w, qreal h) const

QRectF	mapRectToParent (qreal x, qreal y, qreal w, qreal h) const

QRectF	mapRectToScene (qreal x, qreal y, qreal w, qreal h) const

QPointF	mapFromItem (const QGraphicsItem *item, qreal x, qreal y) const

QPointF	mapFromParent (qreal x, qreal y) const

QPointF	mapFromScene (qreal x, qreal y) const

QPolygonF	mapFromItem (const QGraphicsItem *item, qreal x, qreal y, qreal w, qreal h) const

QPolygonF	mapFromParent (qreal x, qreal y, qreal w, qreal h) const

QPolygonF	mapFromScene (qreal x, qreal y, qreal w, qreal h) const

QRectF	mapRectFromItem (const QGraphicsItem *item, qreal x, qreal y, qreal w, qreal h) const

QRectF	mapRectFromParent (qreal x, qreal y, qreal w, qreal h) const

QRectF	mapRectFromScene (qreal x, qreal y, qreal w, qreal h) const

bool	isAncestorOf (const QGraphicsItem *child) const

QGraphicsItem *	commonAncestorItem (const QGraphicsItem *other) const

bool	isUnderMouse () const

QVariant	data (int key) const

void	setData (int key, const QVariant &value)

Qt::InputMethodHints	inputMethodHints () const

void	setInputMethodHints (Qt::InputMethodHints hints)

void	installSceneEventFilter (QGraphicsItem *filterItem)

void	removeSceneEventFilter (QGraphicsItem *filterItem)

Additional Inherited Members
Protected Types inherited from QGraphicsItem
enum	Extension { UserExtension = 0x80000000 }

Protected Member Functions inherited from QGraphicsItem
void	updateMicroFocus ()

virtual bool	sceneEventFilter (QGraphicsItem watched, QEvent event)

virtual bool	sceneEvent (QEvent *event)

virtual void	contextMenuEvent (QGraphicsSceneContextMenuEvent *event)

virtual void	dragEnterEvent (QGraphicsSceneDragDropEvent *event)

virtual void	dragLeaveEvent (QGraphicsSceneDragDropEvent *event)

virtual void	dragMoveEvent (QGraphicsSceneDragDropEvent *event)

virtual void	dropEvent (QGraphicsSceneDragDropEvent *event)

virtual void	focusInEvent (QFocusEvent *event)

virtual void	focusOutEvent (QFocusEvent *event)

virtual void	hoverEnterEvent (QGraphicsSceneHoverEvent *event)

virtual void	hoverMoveEvent (QGraphicsSceneHoverEvent *event)

virtual void	hoverLeaveEvent (QGraphicsSceneHoverEvent *event)

virtual void	keyPressEvent (QKeyEvent *event)

virtual void	keyReleaseEvent (QKeyEvent *event)

virtual void	mousePressEvent (QGraphicsSceneMouseEvent *event)

virtual void	mouseMoveEvent (QGraphicsSceneMouseEvent *event)

virtual void	mouseReleaseEvent (QGraphicsSceneMouseEvent *event)

virtual void	mouseDoubleClickEvent (QGraphicsSceneMouseEvent *event)

virtual void	wheelEvent (QGraphicsSceneWheelEvent *event)

virtual void	inputMethodEvent (QInputMethodEvent *event)

virtual QVariant	inputMethodQuery (Qt::InputMethodQuery query) const

virtual QVariant	itemChange (GraphicsItemChange change, const QVariant &value)

virtual bool	supportsExtension (Extension extension) const

virtual void	setExtension (Extension extension, const QVariant &variant)

virtual QVariant	extension (const QVariant &variant) const

	QGraphicsItem (QGraphicsItemPrivate &dd, QGraphicsItem *parent)

void	addToIndex ()

void	removeFromIndex ()

void	prepareGeometryChange ()

Protected Attributes inherited from QGraphicsItem
QScopedPointer< QGraphicsItemPrivate >	d_ptr

Related Functions inherited from QGraphicsItem
T	qgraphicsitem_cast (QGraphicsItem *item)

Detailed Description

The QGraphicsItemGroup class provides a container that treats a group of items as a single item.

Since: 4.2

\inmodule QtWidgets

A QGraphicsItemGroup is a special type of compound item that treats itself and all its children as one item (i.e., all events and geometries for all children are merged together). It's common to use item groups in presentation tools, when the user wants to group several smaller items into one big item in order to simplify moving and copying of items.

If all you want is to store items inside other items, you can use any QGraphicsItem directly by passing a suitable parent to setParentItem().

The boundingRect() function of QGraphicsItemGroup returns the bounding rectangle of all items in the item group. QGraphicsItemGroup ignores the ItemIgnoresTransformations flag on its children (i.e., with respect to the geometry of the group item, the children are treated as if they were transformable).

There are two ways to construct an item group. The easiest and most common approach is to pass a list of items (e.g., all selected items) to QGraphicsScene::createItemGroup(), which returns a new QGraphicsItemGroup item. The other approach is to manually construct a QGraphicsItemGroup item, add it to the scene calling QGraphicsScene::addItem(), and then add items to the group manually, one at a time by calling addToGroup(). To dismantle ("ungroup") an item group, you can either call QGraphicsScene::destroyItemGroup(), or you can manually remove all items from the group by calling removeFromGroup().

The operation of adding and removing items preserves the items' scene-relative position and transformation, as opposed to calling setParentItem(), where only the child item's parent-relative position and transformation are kept.

The addtoGroup() function reparents the target item to this item group, keeping the item's position and transformation intact relative to the scene. Visually, this means that items added via addToGroup() will remain completely unchanged as a result of this operation, regardless of the item or the group's current position or transformation; although the item's position and matrix are likely to change.

The removeFromGroup() function has similar semantics to setParentItem(); it reparents the item to the parent item of the item group. As with addToGroup(), the item's scene-relative position and transformation remain intact.

See also: QGraphicsItem, {Graphics View Framework}

Definition at line 985 of file qgraphicsitem.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Enumerator
Type

Definition at line 1000 of file qgraphicsitem.h.

Constructor & Destructor Documentation

◆ QGraphicsItemGroup()

QGraphicsItemGroup::QGraphicsItemGroup ( QGraphicsItem * parent = nullptr )

explicit

Constructs a QGraphicsItemGroup. parent is passed to QGraphicsItem's constructor.

See also: QGraphicsScene::addItem()

Definition at line 10919 of file qgraphicsitem.cpp.

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◆ ~QGraphicsItemGroup()

QGraphicsItemGroup::~QGraphicsItemGroup ( )

Destroys the QGraphicsItemGroup.

Definition at line 10928 of file qgraphicsitem.cpp.

Member Function Documentation

◆ addToGroup()

void QGraphicsItemGroup::addToGroup ( QGraphicsItem * item )

Adds the given item and item's child items to this item group. The item and child items will be reparented to this group, but its position and transformation relative to the scene will stay intact.

See also: removeFromGroup(), QGraphicsScene::createItemGroup()

Definition at line 10939 of file qgraphicsitem.cpp.

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◆ boundingRect()

QRectF QGraphicsItemGroup::boundingRect ( ) const

overridevirtual

\reimp

Returns the bounding rect of this group item, and all its children.

Implements QGraphicsItem.

Reimplemented in CustomGroup.

Definition at line 11051 of file qgraphicsitem.cpp.

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◆ isObscuredBy()

bool QGraphicsItemGroup::isObscuredBy ( const QGraphicsItem * item ) const

overridevirtual

\reimp

Reimplemented from QGraphicsItem.

Definition at line 11074 of file qgraphicsitem.cpp.

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◆ opaqueArea()

QPainterPath QGraphicsItemGroup::opaqueArea ( ) const

overridevirtual

\reimp

Reimplemented from QGraphicsItem.

Definition at line 11082 of file qgraphicsitem.cpp.

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◆ paint()

void QGraphicsItemGroup::paint	(	QPainter *	painter,
		const QStyleOptionGraphicsItem *	option,
		QWidget *	widget = `nullptr`
	)

overridevirtual

\reimp

Implements QGraphicsItem.

Reimplemented in CustomGroup.

Definition at line 11060 of file qgraphicsitem.cpp.

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◆ removeFromGroup()

void QGraphicsItemGroup::removeFromGroup ( QGraphicsItem * item )

Removes the specified item from this group. The item will be reparented to this group's parent item, or to 0 if this group has no parent. Its position and transformation relative to the scene will stay intact.

See also: addToGroup(), QGraphicsScene::destroyItemGroup()

Definition at line 10997 of file qgraphicsitem.cpp.

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◆ type()

int QGraphicsItemGroup::type ( ) const

overridevirtual

\reimp

Reimplemented from QGraphicsItem.

Definition at line 11090 of file qgraphicsitem.cpp.

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

src/widgets/graphicsview/qgraphicsitem.h
src/widgets/graphicsview/qgraphicsitem.cpp

Public Types

Public Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ QGraphicsItemGroup()

◆ ~QGraphicsItemGroup()

Member Function Documentation

◆ addToGroup()

◆ boundingRect()

◆ isObscuredBy()

◆ opaqueArea()

◆ paint()

◆ removeFromGroup()

◆ type()