A curved line from one point to another. More...

Inheritance diagram for QCPlot::QCPItemCurve:

Public Member Functions
	QCPItemCurve (QCustomPlot *parentPlot)
	Creates a curve item and sets default values. More...

QPen	pen () const

QPen	selectedPen () const

QCPLineEnding	head () const

QCPLineEnding	tail () const

void	setPen (const QPen &pen)
	Sets the pen that will be used to draw the line. More...

void	setSelectedPen (const QPen &pen)
	Sets the pen that will be used to draw the line when selected. More...

void	setHead (const QCPLineEnding &head)
	Sets the line ending style of the head. More...

void	setTail (const QCPLineEnding &tail)
	Sets the line ending style of the tail. More...

virtual double	selectTest (const QPointF &pos) const
	This function is used to decide whether a click hits an item or not. More...

Public Member Functions inherited from QCPlot::QCPAbstractItem
	QCPAbstractItem (QCustomPlot *parentPlot)
	Base class constructor which initializes base class members.

bool	clipToAxisRect () const

QCPAxis *	clipKeyAxis () const

QCPAxis *	clipValueAxis () const

bool	selectable () const

bool	selected () const

void	setClipToAxisRect (bool clip)
	Sets whether the item shall be clipped to the axis rect or whether it shall be visible on the entire QCustomPlot. More...

void	setClipAxes (QCPAxis keyAxis, QCPAxis valueAxis)
	Sets both clip axes. More...

void	setClipKeyAxis (QCPAxis *axis)
	Sets the clip key axis. More...

void	setClipValueAxis (QCPAxis *axis)
	Sets the clip value axis. More...

void	setSelectable (bool selectable)
	Sets whether the user can (de-)select this item by clicking on the QCustomPlot surface. More...

void	setSelected (bool selected)
	Sets whether this item is selected or not. More...

QList< QCPItemPosition * >	positions () const
	Returns all positions of the item in a list. More...

QList< QCPItemAnchor * >	anchors () const
	Returns all anchors of the item in a list. More...

QCPItemPosition *	position (const QString &name) const
	Returns the QCPItemPosition with the specified name. More...

QCPItemAnchor *	anchor (const QString &name) const
	Returns the QCPItemAnchor with the specified name. More...

bool	hasAnchor (const QString &name) const
	Returns whether this item has an anchor with the specified name. More...

Public Member Functions inherited from QCPlot::QCPLayerable
	QCPLayerable (QCustomPlot *parentPlot)
	Creates a new QCPLayerable instance. More...

bool	visible () const

QCustomPlot *	parentPlot () const

QCPLayer *	layer () const

bool	antialiased () const

void	setVisible (bool on)
	Sets the visibility of this layerable object. More...

bool	setLayer (QCPLayer *layer)
	Sets the layer of this layerable object. More...

bool	setLayer (const QString &layerName)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Sets the layer of this layerable object by name. More...

void	setAntialiased (bool enabled)
	Sets whether this object will be drawn antialiased or not. More...

Public Attributes
QCPItemPosition *const	start

QCPItemPosition *const	startDir

QCPItemPosition *const	endDir

QCPItemPosition *const	end

Protected Member Functions
virtual void	draw (QCPPainter *painter)

QPen	mainPen () const

Protected Member Functions inherited from QCPlot::QCPAbstractItem
virtual QRect	clipRect () const

virtual void	applyDefaultAntialiasingHint (QCPPainter *painter) const

double	distSqrToLine (const QPointF &start, const QPointF &end, const QPointF &point) const

double	rectSelectTest (const QRectF &rect, const QPointF &pos, bool filledRect) const

virtual QPointF	anchorPixelPoint (int anchorId) const

QCPItemPosition *	createPosition (const QString &name)

QCPItemAnchor *	createAnchor (const QString &name, int anchorId)

Protected Member Functions inherited from QCPlot::QCPLayerable
bool	moveToLayer (QCPLayer *layer, bool prepend)

void	applyAntialiasingHint (QCPPainter *painter, bool localAntialiased, QCP::AntialiasedElement overrideElement) const

Protected Attributes
QPen	mPen

QPen	mSelectedPen

QCPLineEnding	mHead

QCPLineEnding	mTail

Protected Attributes inherited from QCPlot::QCPAbstractItem
bool	mClipToAxisRect

QCPAxis *	mClipKeyAxis

QCPAxis *	mClipValueAxis

bool	mSelectable

bool	mSelected

QList< QCPItemPosition * >	mPositions

QList< QCPItemAnchor * >	mAnchors

Protected Attributes inherited from QCPlot::QCPLayerable
bool	mVisible

QCustomPlot *	mParentPlot

QCPLayer *	mLayer

bool	mAntialiased

Additional Inherited Members
Signals inherited from QCPlot::QCPAbstractItem
void	selectionChanged (bool selected)
	This signal is emitted when the selection state of this item has changed, either by user interaction or by a direct call to setSelected.

Detailed Description

A curved line from one point to another.

Curve example. Blue dotted circles are anchors, solid blue discs are positions.

It has four positions, start and end, which define the end points of the line, and two control points which define the direction the line exits from the start and the direction from which it approaches the end: startDir and endDir.

With setHead and setTail you may set different line ending styles, e.g. to create an arrow.

Often it is desirable for the control points to stay at fixed relative positions to the start/end point. This can be achieved by setting the parent anchor e.g. of startDir simply to start, and then specify the desired pixel offset with QCPItemPosition::setCoords on startDir.

Constructor & Destructor Documentation

QCPlot::QCPItemCurve::QCPItemCurve ( QCustomPlot * parentPlot )

Creates a curve item and sets default values.

The constructed item can be added to the plot with QCustomPlot::addItem.

Member Function Documentation

double QCPlot::QCPItemCurve::selectTest ( const QPointF & pos ) const

virtual

This function is used to decide whether a click hits an item or not.

pos is a point in pixel coordinates on the QCustomPlot surface. This function returns the shortest pixel distance of this point to the item. If the item is either invisible or the distance couldn't be determined, -1.0 is returned. setSelectable has no influence on the return value of this function.

If the item is represented not by single lines but by an area like QCPItemRect or QCPItemText, a click inside the area returns a constant value greater zero (typically 99% of the selectionTolerance of the parent QCustomPlot). If the click lies outside the area, this function returns -1.0.

Providing a constant value for area objects allows selecting line objects even when they are obscured by such area objects, by clicking close to the lines (i.e. closer than 0.99*selectionTolerance).

The actual setting of the selection state is not done by this function. This is handled by the parent QCustomPlot when the mouseReleaseEvent occurs.