Item that sticks to QCPGraph data points. More...

#include <plot2d.h>

Inheritance diagram for QCPItemTracer:

Public Types
enum	TracerStyle { tsNone, tsPlus, tsCrosshair, tsCircle, tsSquare }

Public Member Functions
	QCPItemTracer (QCustomPlot *parentPlot)

virtual	~QCPItemTracer ()

QPen	pen () const

QPen	selectedPen () const

QBrush	brush () const

QBrush	selectedBrush () const

double	size () const

TracerStyle	style () const

QCPGraph *	graph () const

double	graphKey () const

bool	interpolating () const

void	setPen (const QPen &pen)

void	setSelectedPen (const QPen &pen)

void	setBrush (const QBrush &brush)

void	setSelectedBrush (const QBrush &brush)

void	setSize (double size)

void	setStyle (TracerStyle style)

void	setGraph (QCPGraph *graph)

void	setGraphKey (double key)

void	setInterpolating (bool enabled)

virtual double	selectTest (const QPointF &pos) const

void	updatePosition ()

Public Member Functions inherited from QCPAbstractItem
	QCPAbstractItem (QCustomPlot *parentPlot)

virtual	~QCPAbstractItem ()

bool	clipToAxisRect () const

QCPAxis *	clipKeyAxis () const

QCPAxis *	clipValueAxis () const

bool	selectable () const

bool	selected () const

void	setClipToAxisRect (bool clip)

void	setClipAxes (QCPAxis keyAxis, QCPAxis valueAxis)

void	setClipKeyAxis (QCPAxis *axis)

void	setClipValueAxis (QCPAxis *axis)

void	setSelectable (bool selectable)

void	setSelected (bool selected)

QList< QCPItemPosition * >	positions () const

QList< QCPItemAnchor * >	anchors () const

QCPItemPosition *	position (const QString &name) const

QCPItemAnchor *	anchor (const QString &name) const

bool	hasAnchor (const QString &name) const

Public Member Functions inherited from QCPLayerable
	QCPLayerable (QCustomPlot *parentPlot)

	~QCPLayerable ()

bool	visible () const

QCustomPlot *	parentPlot () const

QCPLayer *	layer () const

bool	antialiased () const

void	setVisible (bool on)

bool	setLayer (QCPLayer *layer)

bool	setLayer (const QString &layerName)

void	setAntialiased (bool enabled)

Public Attributes
QCPItemPosition *const	position

Protected Member Functions
virtual void	draw (QCPPainter *painter)

QPen	mainPen () const

QBrush	mainBrush () const

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

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

Protected Attributes
QPen	mPen

QPen	mSelectedPen

QBrush	mBrush

QBrush	mSelectedBrush

double	mSize

TracerStyle	mStyle

QCPGraph *	mGraph

double	mGraphKey

bool	mInterpolating

Protected Attributes inherited from QCPAbstractItem
bool	mClipToAxisRect

QCPAxis *	mClipKeyAxis

QCPAxis *	mClipValueAxis

bool	mSelectable

bool	mSelected

QList< QCPItemPosition * >	mPositions

QList< QCPItemAnchor * >	mAnchors

Protected Attributes inherited from QCPLayerable
bool	mVisible

QCustomPlot *	mParentPlot

QCPLayer *	mLayer

bool	mAntialiased

Additional Inherited Members
Signals inherited from QCPAbstractItem
void	selectionChanged (bool selected)

Detailed Description

Item that sticks to QCPGraph data points.

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

The tracer can be connected with a QCPGraph via setGraph. Then it will automatically adopt the coordinate axes of the graph and update its position to be on the graph's data. This means the key stays controllable via setGraphKey, but the value will follow the graph data. If a QCPGraph is connected, note that setting the coordinates directly via position will have no effect, i.e. be overriden in the next redraw (this is when the coodinate update happens).

If the specified key in setGraphKey is outside the key bounds of the graph, the tracer will stay at the respective end of the graph.

With setInterpolating you may specify whether the tracer may only stay exactly on data points or whether it interpolates data points linearly, if given a key that lies between two data points of the graph.

The tracer has different visual styles, see setStyle. It is also possible to make the tracer have no own visual appearance (set the style to tsNone), and just connect other item positions to the tracer position (used as an anchor) via QCPItemPosition::setParentAnchor.

Note: The tracer position is only automatically updated upon redraws. This means when, for example, the data of the graph changes and you immediately afterwards (without a redraw) read the position coordinates of the tracer, they will not reflect the updated data of the graph. In this case you should call updatePosition manually, prior to reading the tracer coordinates.

Member Enumeration Documentation

enum QCPItemTracer::TracerStyle

The different visual appearances a tracer item can have. Some styles size may be controlled with setSize.

See Also: setStyle

Enumerator
tsNone	The tracer is not visible.
tsPlus	A plus shaped crosshair with limited size.
tsCrosshair	A plus shaped crosshair which spans the complete axis rect.
tsCircle	A circle.
tsSquare	A square.

Constructor & Destructor Documentation

QCPItemTracer::QCPItemTracer ( QCustomPlot * parentPlot )

Creates a tracer item and sets default values.

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

QCPItemTracer::~QCPItemTracer ( )

virtual

Member Function Documentation

QBrush QCPItemTracer::brush ( ) const

inline

void QCPItemTracer::draw ( QCPPainter * painter )

protectedvirtual

Implements QCPAbstractItem.

QCPGraph* QCPItemTracer::graph ( ) const

inline

double QCPItemTracer::graphKey ( ) const

inline

bool QCPItemTracer::interpolating ( ) const

inline

QBrush QCPItemTracer::mainBrush ( ) const

protected

QPen QCPItemTracer::mainPen ( ) const

protected

QPen QCPItemTracer::pen ( ) const

inline

QBrush QCPItemTracer::selectedBrush ( ) const

inline

QPen QCPItemTracer::selectedPen ( ) const

inline

double QCPItemTracer::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.

See Also: setSelected, QCustomPlot::setInteractions

Implements QCPAbstractItem.

void QCPItemTracer::setBrush ( const QBrush & brush )

Sets the brush that will be used to draw any fills of the tracer

See Also: setSelectedBrush, setPen

void QCPItemTracer::setGraph ( QCPGraph * graph )

Sets the QCPGraph this tracer sticks to. The tracer position will be set to type QCPItemPosition::ptPlotCoords and the axes will be set to the axes of graph.

To free the tracer from any graph, set graph to 0. The tracer position can then be placed freely like any other item position. This is the state the tracer will assume when its graph gets deleted while still attached to it.

See Also: setGraphKey

void QCPItemTracer::setGraphKey ( double key )

Sets the key of the graph's data point the tracer will be positioned at. This is the only free cordinate of a tracer when attached to a graph.

Depending on setInterpolating, the tracer will be either positioned on the data point closest to key, or will stay exactly at key and interpolate the value linearly.

See Also: setGraph, setInterpolating

void QCPItemTracer::setInterpolating ( bool enabled )

Sets whether the value of the graph's data points shall be interpolated, when positioning the tracer.

If enabled is set to false and a key is given with setGraphKey, the tracer is placed on the data point of the graph which is closest to the key, but which is not necessarily exactly there. If enabled is true, the tracer will be positioned exactly at the specified key, and the appropriate value will be interpolated from the graph's data points linearly.

See Also: setGraph, setGraphKey

void QCPItemTracer::setPen ( const QPen & pen )

Sets the pen that will be used to draw the line of the tracer

See Also: setSelectedPen, setBrush

void QCPItemTracer::setSelectedBrush ( const QBrush & brush )

Sets the brush that will be used to draw any fills of the tracer, when selected.

See Also: setBrush, setSelected

void QCPItemTracer::setSelectedPen ( const QPen & pen )

Sets the pen that will be used to draw the line of the tracer when selected

See Also: setPen, setSelected

void QCPItemTracer::setSize ( double size )

Sets the size of the tracer in pixels, if the style supports setting a size (e.g. tsSquare does, tsCrosshair does not).

void QCPItemTracer::setStyle ( QCPItemTracer::TracerStyle style )

Sets the style/visual appearance of the tracer.

If you only want to use the tracer position as an anchor for other items, set style to tsNone.

double QCPItemTracer::size ( ) const

inline

TracerStyle QCPItemTracer::style ( ) const

inline

void QCPItemTracer::updatePosition ( )

If the tracer is connected with a graph (setGraph), this function updates the tracer's position to reside on the graph data, depending on the configured key (setGraphKey).

It is called automatically on every redraw and normally doesn't need to be called manually. One exception is when you want to read the tracer coordinates via position and are not sure that the graph's data (or the tracer key with setGraphKey) hasn't changed since the last redraw. In that situation, call this function before accessing position, to make sure you don't get out-of-date coordinates.

If there is no graph set on this tracer, this function does nothing.

Member Data Documentation

QBrush QCPItemTracer::mBrush

protected

QCPGraph* QCPItemTracer::mGraph

protected

double QCPItemTracer::mGraphKey

protected

bool QCPItemTracer::mInterpolating

protected

QPen QCPItemTracer::mPen

protected

QBrush QCPItemTracer::mSelectedBrush

protected

QPen QCPItemTracer::mSelectedPen

protected

double QCPItemTracer::mSize

protected

TracerStyle QCPItemTracer::mStyle

protected

QCPItemPosition* const QCPItemTracer::position

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

C:/Users/mpeniak/Dropbox/Aquila/trunk/aquila/include/plot2d.h
C:/Users/mpeniak/Dropbox/Aquila/trunk/aquila/src/plot2d.cpp

Public Types

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation