QCPItemAnchor Class Reference

Inheritance diagram for QCPItemAnchor:

Public Member Functions
	QCPItemAnchor (QCustomPlot *parentPlot, QCPAbstractItem *parentItem, const QString &name, int anchorId=-1)
QString	name () const
virtual QPointF	pixelPosition () const

Protected Member Functions
void	addChildX (QCPItemPosition *pos)
void	addChildY (QCPItemPosition *pos)
void	removeChildX (QCPItemPosition *pos)
void	removeChildY (QCPItemPosition *pos)
virtual QCPItemPosition *	toQCPItemPosition ()

Protected Attributes
int	mAnchorId
QSet< QCPItemPosition * >	mChildrenX
QSet< QCPItemPosition * >	mChildrenY
QString	mName
QCPAbstractItem *	mParentItem
QCustomPlot *	mParentPlot

Detailed Description

An anchor of an item to which positions can be attached to.

An item (QCPAbstractItem) may have one or more anchors. Unlike QCPItemPosition, an anchor doesn't control anything on its item, but provides a way to tie other items via their positions to the anchor.

For example, a QCPItemRect is defined by its positions topLeft and bottomRight. Additionally it has various anchors like top, topRight or bottomLeft etc. So you can attach the start (which is a QCPItemPosition) of a QCPItemLine to one of the anchors by calling QCPItemPosition::setParentAnchor on start, passing the wanted anchor of the QCPItemRect. This way the start of the line will now always follow the respective anchor location on the rect item.

Note that QCPItemPosition derives from QCPItemAnchor, so every position can also serve as an anchor to other positions.

To learn how to provide anchors in your own item subclasses, see the subclassing section of the QCPAbstractItem documentation.

Definition at line 3605 of file qcustomplot.h.

Constructor & Destructor Documentation

QCPItemAnchor()

QCPItemAnchor::QCPItemAnchor	(	QCustomPlot *	parentPlot,
		QCPAbstractItem *	parentItem,
		const QString &	name,
		int	anchorId = -1 )

Creates a new QCPItemAnchor. You shouldn't create QCPItemAnchor instances directly, even if you want to make a new item subclass. Use QCPAbstractItem::createAnchor instead, as explained in the subclassing section of the QCPAbstractItem documentation.

Definition at line 12044 of file qcustomplot.cpp.

~QCPItemAnchor()

QCPItemAnchor::~QCPItemAnchor ( )

virtual

Definition at line 12052 of file qcustomplot.cpp.

Member Function Documentation

addChildX()

void QCPItemAnchor::addChildX ( QCPItemPosition * pos )

protected

Adds pos to the childX list of this anchor, which keeps track of which children use this anchor as parent anchor for the respective coordinate. This is necessary to notify the children prior to destruction of the anchor.

Note that this function does not change the parent setting in pos.

Definition at line 12100 of file qcustomplot.cpp.

addChildY()

void QCPItemAnchor::addChildY ( QCPItemPosition * pos )

protected

Adds pos to the childY list of this anchor, which keeps track of which children use this anchor as parent anchor for the respective coordinate. This is necessary to notify the children prior to destruction of the anchor.

Note that this function does not change the parent setting in pos.

Definition at line 12128 of file qcustomplot.cpp.

name()

QString QCPItemAnchor::name ( ) const

inline

Definition at line 3613 of file qcustomplot.h.

pixelPosition()

QPointF QCPItemAnchor::pixelPosition ( ) const

virtual

Returns the final absolute pixel position of the QCPItemAnchor on the QCustomPlot surface.

The pixel information is internally retrieved via QCPAbstractItem::anchorPixelPosition of the parent item, QCPItemAnchor is just an intermediary.

Reimplemented in QCPItemPosition.

Definition at line 12073 of file qcustomplot.cpp.

removeChildX()

void QCPItemAnchor::removeChildX ( QCPItemPosition * pos )

protected

Removes pos from the childX list of this anchor.

Note that this function does not change the parent setting in pos.

Definition at line 12114 of file qcustomplot.cpp.

removeChildY()

void QCPItemAnchor::removeChildY ( QCPItemPosition * pos )

protected

Removes pos from the childY list of this anchor.

Note that this function does not change the parent setting in pos.

Definition at line 12142 of file qcustomplot.cpp.

toQCPItemPosition()

virtual QCPItemPosition * QCPItemAnchor::toQCPItemPosition ( )

inlineprotectedvirtual

Returns nullptr if this instance is merely a QCPItemAnchor, and a valid pointer of type QCPItemPosition* if it actually is a QCPItemPosition (which is a subclass of QCPItemAnchor).

This safe downcast functionality could also be achieved with a dynamic_cast. However, QCustomPlot avoids dynamic_cast to work with projects that don't have RTTI support enabled (e.g. -fno-rtti flag with gcc compiler).

Reimplemented in QCPItemPosition.

Definition at line 3627 of file qcustomplot.h.

Member Data Documentation

mAnchorId

int QCPItemAnchor::mAnchorId

protected

Definition at line 3623 of file qcustomplot.h.

mChildrenX

QSet<QCPItemPosition*> QCPItemAnchor::mChildrenX

protected

Definition at line 3624 of file qcustomplot.h.

mChildrenY

QSet<QCPItemPosition*> QCPItemAnchor::mChildrenY

protected

Definition at line 3624 of file qcustomplot.h.

mName

QString QCPItemAnchor::mName

protected

Definition at line 3618 of file qcustomplot.h.

mParentItem

QCPAbstractItem* QCPItemAnchor::mParentItem

protected

Definition at line 3622 of file qcustomplot.h.

mParentPlot

QCustomPlot* QCPItemAnchor::mParentPlot

protected

Definition at line 3621 of file qcustomplot.h.

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

• qcustomplot.h
• qcustomplot.cpp