QCPAbstractPlottable Class Reference

The abstract base class for all data representing objects in a plot. More...

#include <qcustomplot.h>

Inherits QObject.

Inherited by QCPBars, QCPCurve, QCPGraph, and QCPStatisticalBox.

Public Slots
QCustomPlot *	parentPlot () const
QString	name () const
bool	visible () const
QPen	pen () const
QBrush	brush () const
QCPAxis *	keyAxis () const
QCPAxis *	valueAxis () const
void	setName (const QString &name)
void	setVisible (bool visible)
void	setPen (const QPen &pen)
void	setBrush (const QBrush &brush)
void	setKeyAxis (QCPAxis *axis)
void	setValueAxis (QCPAxis *axis)
void	rescaleAxes (bool onlyEnlarge=false) const
void	rescaleKeyAxis (bool onlyEnlarge=false) const
void	rescaleValueAxis (bool onlyEnlarge=false) const
virtual void	clearData ()=0
virtual bool	addToLegend () const
virtual bool	removeFromLegend () const

Public Member Functions
	QCPAbstractPlottable (QCPAxis *keyAxis, QCPAxis *valueAxis)
virtual	~QCPAbstractPlottable ()

Protected Types
enum	SignDomain { SDNegative, SDBoth, SDPositive }

Protected Member Functions
virtual void	draw (QPainter *painter) const =0
virtual void	drawLegendIcon (QPainter *painter, const QRect &rect) const =0
virtual QCPRange	getKeyRange (bool &validRange, SignDomain inSignDomain=SDBoth) const =0
virtual QCPRange	getValueRange (bool &validRange, SignDomain inSignDomain=SDBoth) const =0
void	coordsToPixels (double key, double value, double &x, double &y) const
const QPointF	coordsToPixels (double key, double value) const

Protected Attributes
QCustomPlot *	mParentPlot
QString	mName
bool	mVisible
QPen	mPen
QBrush	mBrush
QCPAxis *	mKeyAxis
QCPAxis *	mValueAxis

Friends
class	QCustomPlot
class	QCPPlottableLegendItem

Detailed Description

The abstract base class for all data representing objects in a plot.

It defines a very basic interface like name, pen, brush, visibility etc. Since this class is abstract, it can't be instantiated. Use one of the subclasses or create a subclass yourself (see below), to create new ways of displaying data.

All further specifics are in the subclasses, for example:

• A normal graph with possibly a line, scatter points and error bars is displayed by QCPGraph (typically created with QCustomPlot::addGraph).
• A parametric curve can be displayed with QCPCurve.
• A stackable bar chart can be achieved with QCPBars.
• A box of a statistical box plot is created with QCPStatisticalBox.

Creating own plottables

To create an own plottable, you implement a subclass of QCPAbstractPlottable. These are the pure virtual functions, you must implement:

• clearData
• draw
• drawLegendIcon
• getKeyRange
• getValueRange

See the documentation of those functions for what they need to do.

For drawing your plot, you can use the coordsToPixels functions to translate a point in plot coordinates to pixel coordinates. This function is quite convenient, because it takes the orientation of the key and value axes into account for you (x and y are swapped when the key axis is vertical and the value axis horizontal). If you are worried about performance (i.e. you need to translate many points in a loop like QCPGraph), you can directly use QCPAxis::coordToPixel. However, you must then take care about the orientation of the axis yourself.

From QCPAbstractPlottable you inherit the following members you may use:

• QCustomPlot *mParentPlot: A pointer to the parent QCustomPlot instance. This is adopted from the axes that are passed in the constructor.
• QString mName: The name of the plottable.
• bool mVisible: Whether the plot is visible or not. When this is false, you shouldn't draw the data in the draw function (draw is always called, no matter what mVisible is).
• QPen mPen: The generic pen of the plottable. You should use this pen for the most prominent data representing lines in the plottable (e.g QCPGraph uses this pen for its graph lines and scatters)
• QBrush mBrush: The generic brush of the plottable. You should use this brush for the most prominent fillable structures in the plottable (e.g. QCPGraph uses this brush to control filling under the graph)
• QCPAxis *mKeyAxis, *mValueAxis: The key and value axes this plottable is attached to. Call their QCPAxis::coordToPixel functions to translate coordinates to pixels in either the key or value dimension.

Definition at line 112 of file qcustomplot.h.

Member Enumeration Documentation

SignDomain

enum QCPAbstractPlottable::SignDomain

protected

Represents negative and positive sign domain for passing to getKeyRange and getValueRange.

Enumerator
SDNegative	The negative sign domain, i.e. numbers smaller than zero.
SDBoth	Both sign domains, including zero, i.e. all (rational) numbers.
SDPositive	The positive sign domain, i.e. numbers greater than zero.

Definition at line 149 of file qcustomplot.h.

                  {SDNegative, 
                   SDBoth,     
                   SDPositive  
                  };

Constructor & Destructor Documentation

QCPAbstractPlottable()

QCPAbstractPlottable::QCPAbstractPlottable	(	QCPAxis *	keyAxis,
		QCPAxis *	valueAxis
	)

Constructs an abstract plottable which uses keyAxis as its key axis ("x") and valueAxis as its value axis ("y"). keyAxis and valueAxis must reside in the same QCustomPlot instance.

Since QCPAbstractPlottable is an abstract class that defines the basic interface to plottables (i.e. any form of data representation inside a plot, like graphs, curves etc.), it can't be directly instantiated.

You probably want one of the subclasses like QCPGraph and QCPCurve instead.

See also

setkeyAxis, setValueAxis

Definition at line 6092 of file qcustomplot.cc.

                                                                               :
  mParentPlot(keyAxis->parentPlot()),
  mName(""),
  mVisible(true),
  mPen(Qt::black),
  mBrush(Qt::NoBrush),
  mKeyAxis(keyAxis),
  mValueAxis(valueAxis)
{
  if (keyAxis->parentPlot() != valueAxis->parentPlot())
    qDebug() << FUNCNAME << "Parent plot of keyAxis is not the same as that of valueAxis.";
  if (keyAxis->orientation() == valueAxis->orientation())
    qDebug() << FUNCNAME << "keyAxis and valueAxis must be orthogonal to each other.";
}

~QCPAbstractPlottable()

virtual QCPAbstractPlottable::~QCPAbstractPlottable ( )

inlinevirtual

Definition at line 117 of file qcustomplot.h.

{}

Member Function Documentation

addToLegend

bool QCPAbstractPlottable::addToLegend ( ) const

virtualslot

Adds this plottable to the legend of the parent QCustomPlot.

Normally, a QCPPlottableLegendItem is created and inserted into the legend. If the plottable needs a more specialized representation in the plot, this function will take this into account and instead create the specialized subclass of QCPAbstractLegendItem.

Returns true on success, i.e. when a legend item associated with this plottable isn't already in the legend.

See also

removeFromLegend, QCPLegend::addItem

Definition at line 6260 of file qcustomplot.cc.

{
  if (!mParentPlot->legend->hasItemWithPlottable(this))
  {
    mParentPlot->legend->addItem(new QCPPlottableLegendItem(mParentPlot->legend, this));
    return true;
  } else
    return false;
}

brush

QBrush QCPAbstractPlottable::brush ( ) const

inlineslot

Definition at line 125 of file qcustomplot.h.

{ return mBrush; }

clearData

void QCPAbstractPlottable::clearData ( )

pure virtualslot

Clears all data in the plottable.

Implemented in QCPCurve.

coordsToPixels() [1/2]

void QCPAbstractPlottable::coordsToPixels ( double  key, double  value, double &  x, double &  y  ) const

protected

Definition at line 6298 of file qcustomplot.cc.

{
  if (mKeyAxis->orientation() == Qt::Horizontal)
  {
    x = mKeyAxis->coordToPixel(key);
    y = mValueAxis->coordToPixel(value);
  } else
  {
    y = mKeyAxis->coordToPixel(key);
    x = mValueAxis->coordToPixel(value);
  }
}

coordsToPixels() [2/2]

const QPointF QCPAbstractPlottable::coordsToPixels ( double  key, double  value  ) const

protected

Definition at line 6316 of file qcustomplot.cc.

{
  if (mKeyAxis->orientation() == Qt::Horizontal)
    return QPointF(mKeyAxis->coordToPixel(key), mValueAxis->coordToPixel(value));
  else
    return QPointF(mValueAxis->coordToPixel(value), mKeyAxis->coordToPixel(key));
}

draw()

void QCPAbstractPlottable::draw ( QPainter *  painter ) const

protectedpure virtual

Implemented in QCPStatisticalBox, QCPBars, QCPCurve, and QCPGraph.

drawLegendIcon()

void QCPAbstractPlottable::drawLegendIcon ( QPainter *  painter, const QRect &  rect  ) const

protectedpure virtual

Implemented in QCPStatisticalBox, QCPBars, QCPCurve, and QCPGraph.

getKeyRange()

QCPRange QCPAbstractPlottable::getKeyRange ( bool &  validRange, SignDomain  inSignDomain = SDBoth  ) const

protectedpure virtual

Implemented in QCPStatisticalBox, QCPBars, QCPCurve, and QCPGraph.

getValueRange()

QCPRange QCPAbstractPlottable::getValueRange ( bool &  validRange, SignDomain  inSignDomain = SDBoth  ) const

protectedpure virtual

Implemented in QCPStatisticalBox, QCPBars, QCPCurve, and QCPGraph.

keyAxis

QCPAxis* QCPAbstractPlottable::keyAxis ( ) const

inlineslot

Definition at line 126 of file qcustomplot.h.

{ return mKeyAxis; }

name

QString QCPAbstractPlottable::name ( ) const

inlineslot

Definition at line 122 of file qcustomplot.h.

{ return mName; }

parentPlot

QCustomPlot* QCPAbstractPlottable::parentPlot ( ) const

inlineslot

Definition at line 121 of file qcustomplot.h.

{ return mParentPlot; }

pen

QPen QCPAbstractPlottable::pen ( ) const

inlineslot

Definition at line 124 of file qcustomplot.h.

{ return mPen; }

removeFromLegend

bool QCPAbstractPlottable::removeFromLegend ( ) const

virtualslot

Removes the plottable from the legend of the parent QCustomPlot. This means the QCPAbstractLegendItem (usually a QCPPlottableLegendItem) that is associated with this plottable is removed.

Returns true on success, i.e. if a legend item associated with this plottable was found and removed from the legend.

See also

addToLegend, QCPLegend::removeItem

Definition at line 6280 of file qcustomplot.cc.

{
  if (QCPPlottableLegendItem *lip = mParentPlot->legend->itemWithPlottable(this))
    return mParentPlot->legend->removeItem(lip);
  else
    return false;
}

rescaleAxes

void QCPAbstractPlottable::rescaleAxes ( bool  onlyEnlarge = false ) const

slot

Rescales the key and value axes associated with this plottable to contain all displayed data, so the whole plottable is visible. If the scaling of an axis is logarithmic, rescaleAxes will make sure not to rescale to an illegal range i.e. a range containing different signs and/or zero. Instead it will stay in the current sign domain and ignore all entities of the plottable that lie outside of that domain.

onlyEnlarge makes sure the ranges are only expanded, never reduced. So it's possible to show multiple plottables in their entirety by multiple calls to rescaleAxes where the first call has onlyEnlarge set to false (the default), and all subsequent set to true.

Definition at line 6188 of file qcustomplot.cc.

{
  rescaleKeyAxis(onlyEnlarge);
  rescaleValueAxis(onlyEnlarge);
}

rescaleKeyAxis

void QCPAbstractPlottable::rescaleKeyAxis ( bool  onlyEnlarge = false ) const

slot

Rescales the key axis of the plottable so the whole plottable is visible.

See rescaleAxes for detailed behaviour.

Definition at line 6199 of file qcustomplot.cc.

{
  SignDomain signDomain = SDBoth;
  if (mKeyAxis->scaleType() == QCPAxis::STLogarithmic)
    signDomain = (mKeyAxis->range().upper < 0 ? SDNegative : SDPositive);
  
  bool validRange;
  QCPRange newRange = getKeyRange(validRange, signDomain);
  
  if (validRange)
  {
    if (onlyEnlarge)
    {
      if (mKeyAxis->range().lower < newRange.lower)
        newRange.lower = mKeyAxis->range().lower;
      if (mKeyAxis->range().upper > newRange.upper)
        newRange.upper = mKeyAxis->range().upper;
    }
    mKeyAxis->setRange(newRange);
  }
}

rescaleValueAxis

void QCPAbstractPlottable::rescaleValueAxis ( bool  onlyEnlarge = false ) const

slot

Rescales the value axis of the plottable so the whole plottable is visible.

See rescaleAxes for detailed behaviour.

Definition at line 6226 of file qcustomplot.cc.

{
  SignDomain signDomain = SDBoth;
  if (mValueAxis->scaleType() == QCPAxis::STLogarithmic)
    signDomain = (mValueAxis->range().upper < 0 ? SDNegative : SDPositive);
  
  bool validRange;
  QCPRange newRange = getValueRange(validRange, signDomain);
  
  if (validRange)
  {
    if (onlyEnlarge)
    {
      if (mValueAxis->range().lower < newRange.lower)
        newRange.lower = mValueAxis->range().lower;
      if (mValueAxis->range().upper > newRange.upper)
        newRange.upper = mValueAxis->range().upper;
    }
    mValueAxis->setRange(newRange);
  }
}

setBrush

void QCPAbstractPlottable::setBrush ( const QBrush &  brush )

slot

The brush is used to draw basic fills of the plottable representation in the plot. The Fill can be a color, gradient or texture, see the usage of QBrush.

For example, the QCPGraph subclass draws the fill under the graph with this brush, when it's not set to Qt::NoBrush.

See also

setPen

Definition at line 6148 of file qcustomplot.cc.

{
  mBrush = brush;
}

setKeyAxis

void QCPAbstractPlottable::setKeyAxis ( QCPAxis *  axis )

slot

The key axis of a plottable can be set to any axis of a QCustomPlot, as long as it is orthogonal to the plottable's value axis. The typical mathematical choice is to use the x-axis (QCustomPlot::xAxis) as key axis and the y-axis (QCustomPlot::yAxis) as value axis.

See also

setValueAxis

Definition at line 6160 of file qcustomplot.cc.

{
  mKeyAxis = axis;
}

setName

void QCPAbstractPlottable::setName ( const QString &  name )

slot

The name is the textual representation of this plottable as it is displayed in the QCPLegend of the parent QCustomPlot. It may contain any utf-8 characters, including newlines.

Definition at line 6111 of file qcustomplot.cc.

{
  mName = name;
}

setPen

void QCPAbstractPlottable::setPen ( const QPen &  pen )

slot

The pen is used to draw basic lines that make up the plottable representation in the plot.

For example, the QCPGraph subclass draws its graph lines and scatter points with this pen.

See also

setBrush

Definition at line 6134 of file qcustomplot.cc.

{
  mPen = pen;
}

setValueAxis

void QCPAbstractPlottable::setValueAxis ( QCPAxis *  axis )

slot

The value axis of a plottable can be set to any axis of a QCustomPlot, as long as it is orthogonal to the plottable's key axis. The typical mathematical choice is to use the x-axis (QCustomPlot::xAxis) as key axis and the y-axis (QCustomPlot::yAxis) as value axis.

See also

setKeyAxis

Definition at line 6172 of file qcustomplot.cc.

{
  mValueAxis = axis;
}

setVisible

void QCPAbstractPlottable::setVisible ( bool  visible )

slot

If the plottable visibility is set to false, it won't be drawn to the plot surface. It will still appear in a QCPLegend that it's associated with, though.

Definition at line 6120 of file qcustomplot.cc.

{
  mVisible = visible;
}

valueAxis

QCPAxis* QCPAbstractPlottable::valueAxis ( ) const

inlineslot

Definition at line 127 of file qcustomplot.h.

{ return mValueAxis; }

visible

bool QCPAbstractPlottable::visible ( ) const

inlineslot

Definition at line 123 of file qcustomplot.h.

{ return mVisible; }

Friends And Related Function Documentation

QCPPlottableLegendItem

friend class QCPPlottableLegendItem

friend

Definition at line 168 of file qcustomplot.h.

QCustomPlot

friend class QCustomPlot

friend

Definition at line 167 of file qcustomplot.h.

Member Data Documentation

mBrush

QBrush QCPAbstractPlottable::mBrush

protected

Definition at line 157 of file qcustomplot.h.

mKeyAxis

QCPAxis* QCPAbstractPlottable::mKeyAxis

protected

Definition at line 158 of file qcustomplot.h.

mName

QString QCPAbstractPlottable::mName

protected

Definition at line 154 of file qcustomplot.h.

mParentPlot

QCustomPlot* QCPAbstractPlottable::mParentPlot

protected

Definition at line 153 of file qcustomplot.h.

mPen

QPen QCPAbstractPlottable::mPen

protected

Definition at line 156 of file qcustomplot.h.

mValueAxis

QCPAxis * QCPAbstractPlottable::mValueAxis

protected

Definition at line 158 of file qcustomplot.h.

mVisible

bool QCPAbstractPlottable::mVisible

protected

Definition at line 155 of file qcustomplot.h.

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

• /build/rock-master-18.09-gui-rock-widget-collection-0.20180124/src/plot2d/qcustomplot.h
• /build/rock-master-18.09-gui-rock-widget-collection-0.20180124/src/plot2d/qcustomplot.cc