QCPItemAnchor

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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 QCPItemPositiontoQCPItemPosition ()
 

Protected Attributes

int mAnchorId
 
QSet< QCPItemPosition * > mChildrenX
 
QSet< QCPItemPosition * > mChildrenY
 
QString mName
 
QCPAbstractItemmParentItem
 
QCustomPlotmParentPlot
 

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 3550 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 12026 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 12082 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 12110 of file qcustomplot.cpp.

◆ 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 12055 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 12096 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 12124 of file qcustomplot.cpp.

◆ toQCPItemPosition()

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 3572 of file qcustomplot.h.


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