Main Page · Class Overview · Hierarchy · All Classes
Public Functions | Signals | Protected Types | Protected Functions
QCPAbstractPlottable Class Reference

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

Inheritance diagram for QCPAbstractPlottable:
Inheritance graph

Public Functions

 QCPAbstractPlottable (QCPAxis *keyAxis, QCPAxis *valueAxis)
QString name () const
bool antialiasedFill () const
bool antialiasedScatters () const
bool antialiasedErrorBars () const
QPen pen () const
QPen selectedPen () const
QBrush brush () const
QBrush selectedBrush () const
QCPAxiskeyAxis () const
QCPAxisvalueAxis () const
bool selectable () const
bool selected () const
void setName (const QString &name)
void setAntialiasedFill (bool enabled)
void setAntialiasedScatters (bool enabled)
void setAntialiasedErrorBars (bool enabled)
void setPen (const QPen &pen)
void setSelectedPen (const QPen &pen)
void setBrush (const QBrush &brush)
void setSelectedBrush (const QBrush &brush)
void setKeyAxis (QCPAxis *axis)
void setValueAxis (QCPAxis *axis)
void setSelectable (bool selectable)
void setSelected (bool selected)
void rescaleAxes (bool onlyEnlarge=false) const
void rescaleKeyAxis (bool onlyEnlarge=false) const
void rescaleValueAxis (bool onlyEnlarge=false) const
virtual void clearData ()=0
virtual double selectTest (const QPointF &pos) const =0
virtual bool addToLegend ()
virtual bool removeFromLegend () const
bool visible () const
QCustomPlotparentPlot () const
QCPLayerlayer () const
bool antialiased () const
void setVisible (bool on)
bool setLayer (QCPLayer *layer)
bool setLayer (const QString &layerName)
void setAntialiased (bool enabled)

Signals

void selectionChanged (bool selected)

Protected Types

enum  SignDomain

Protected Functions

virtual QRect clipRect () const
virtual void draw (QCPPainter *painter)=0
virtual void drawLegendIcon (QCPPainter *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
void pixelsToCoords (double x, double y, double &key, double &value) const
void pixelsToCoords (const QPointF &pixelPos, double &key, double &value) const
QPen mainPen () const
QBrush mainBrush () const
void applyDefaultAntialiasingHint (QCPPainter *painter) const
void applyFillAntialiasingHint (QCPPainter *painter) const
void applyScattersAntialiasingHint (QCPPainter *painter) const
void applyErrorBarsAntialiasingHint (QCPPainter *painter) const
double distSqrToLine (const QPointF &start, const QPointF &end, const QPointF &point) const
bool moveToLayer (QCPLayer *layer, bool prepend)
void applyAntialiasingHint (QCPPainter *painter, bool localAntialiased, QCP::AntialiasedElement overrideElement) const

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:

Creating own plottables

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

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)
QPen mSelectedPen The generic pen that should be used when the plottable is selected (hint: mainPen gives you the right pen, depending on selection state).
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)
QBrush mSelectedBrush The generic brush that should be used when the plottable is selected (hint: mainBrush gives you the right brush, depending on selection state).
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.
bool mSelected indicates whether the plottable is selected or not.

Member Enumeration Documentation

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.


Constructor & Destructor Documentation

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 and not have the same orientation. If either of these restrictions is violated, a corresponding message is printed to the debug output (qDebug), the construction is not aborted, though.

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

Member Function Documentation

void QCPAbstractPlottable::setName ( const QString &  name)

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.

Sets whether fills of this plottable is drawn antialiased or not.

Note that this setting may be overridden by QCustomPlot::setAntialiasedElements and QCustomPlot::setNotAntialiasedElements.

Sets whether the scatter symbols of this plottable are drawn antialiased or not.

Note that this setting may be overridden by QCustomPlot::setAntialiasedElements and QCustomPlot::setNotAntialiasedElements.

Sets whether the error bars of this plottable are drawn antialiased or not.

Note that this setting may be overridden by QCustomPlot::setAntialiasedElements and QCustomPlot::setNotAntialiasedElements.

void QCPAbstractPlottable::setPen ( const QPen &  pen)

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
void QCPAbstractPlottable::setSelectedPen ( const QPen &  pen)

When the plottable is selected, this pen is used to draw basic lines instead of the normal pen set via setPen.

See also:
setSelected, setSelectable, setSelectedBrush, selectTest
void QCPAbstractPlottable::setBrush ( const QBrush &  brush)

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
void QCPAbstractPlottable::setSelectedBrush ( const QBrush &  brush)

When the plottable is selected, this brush is used to draw fills instead of the normal brush set via setBrush.

See also:
setSelected, setSelectable, setSelectedPen, selectTest

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. This function performs no checks to make sure this is the case. The typical mathematical choice is to use the x-axis (QCustomPlot::xAxis) as key axis and the y-axis (QCustomPlot::yAxis) as value axis.

Normally, the key and value axes are set in the constructor of the plottable (or QCustomPlot::addGraph when working with QCPGraphs through the dedicated graph interface).

See also:
setValueAxis

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. This function performs no checks to make sure this is the case. The typical mathematical choice is to use the x-axis (QCustomPlot::xAxis) as key axis and the y-axis (QCustomPlot::yAxis) as value axis.

Normally, the key and value axes are set in the constructor of the plottable (or QCustomPlot::addGraph when working with QCPGraphs through the dedicated graph interface).

See also:
setKeyAxis
void QCPAbstractPlottable::setSelectable ( bool  selectable)

Sets whether the user can (de-)select this plottable by clicking on the QCustomPlot surface. (When QCustomPlot::setInteractions contains iSelectPlottables.)

However, even when selectable was set to false, it is possible to set the selection manually, by calling setSelected directly.

See also:
setSelected
void QCPAbstractPlottable::setSelected ( bool  selected)

Sets whether this plottable is selected or not. When selected, it uses a different pen and brush to draw its lines and fills, see setSelectedPen and setSelectedBrush.

The entire selection mechanism for plottables is handled automatically when QCustomPlot::setInteractions contains iSelectPlottables. You only need to call this function when you wish to change the selection state manually.

This function can change the selection state even when setSelectable was set to false.

emits the selectionChanged signal when selected is different from the previous selection state.

See also:
selectTest
void QCPAbstractPlottable::rescaleAxes ( bool  onlyEnlarge = false) const

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 parts 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.

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

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

See rescaleAxes for detailed behaviour.

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

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

See rescaleAxes for detailed behaviour.

void QCPAbstractPlottable::clearData ( ) [pure virtual]

Clears all data in the plottable.

Implemented in QCPStatisticalBox, QCPBars, QCPCurve, and QCPGraph.

double QCPAbstractPlottable::selectTest ( const QPointF &  pos) const [pure virtual]

This function is used to decide whether a click hits a plottable 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 plottable (e.g. to the scatters/lines of a graph). If the plottable is either invisible, contains no data or the distance couldn't be determined, -1.0 is returned. setSelectable has no influence on the return value of this function.

If the plottable is represented not by single lines but by an area like QCPBars or QCPStatisticalBox, 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

Implemented in QCPStatisticalBox, QCPBars, QCPCurve, and QCPGraph.

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
bool QCPAbstractPlottable::removeFromLegend ( ) const [virtual]

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
void QCPAbstractPlottable::selectionChanged ( bool  selected) [signal]

This signal is emitted when the selection state of this plottable has changed, either by user interaction or by a direct call to setSelected.

QRect QCPAbstractPlottable::clipRect ( ) const [protected, virtual]

Returns the clipping rectangle of this layerable object. By default, this is the viewport of the parent QCustomPlot. Specific subclasses may reimplement this function to provide different clipping rects.

The returned clipping rect is set on the painter before the draw function of the respective object is called.

Reimplemented from QCPLayerable.

void QCPAbstractPlottable::draw ( QCPPainter painter) [protected, pure virtual]

Draws this plottable with the provided painter. Called by QCustomPlot::draw on all its visible plottables.

The cliprect of the provided painter is set to the axis rect of the key/value axis of this plottable (what clipRect returns), before this function is called.

Implements QCPLayerable.

Implemented in QCPStatisticalBox, QCPBars, QCPCurve, and QCPGraph.

void QCPAbstractPlottable::drawLegendIcon ( QCPPainter painter,
const QRect &  rect 
) const [protected, pure virtual]

called by QCPLegend::draw (via QCPPlottableLegendItem::draw) to create a graphical representation of this plottable inside rect, next to the plottable name.

Implemented in QCPStatisticalBox, QCPBars, QCPCurve, and QCPGraph.

QCPRange QCPAbstractPlottable::getKeyRange ( bool &  validRange,
SignDomain  inSignDomain = sdBoth 
) const [protected, pure virtual]

called by rescaleAxes functions to get the full data key bounds. For logarithmic plots, one can set inSignDomain to either sdNegative or sdPositive in order to restrict the returned range to that sign domain. E.g. when only negative range is wanted, set inSignDomain to sdNegative and all positive points will be ignored for range calculation. For no restriction, just set inSignDomain to sdBoth (default). validRange is an output parameter that indicates whether a proper range could be found or not. If this is false, you shouldn't use the returned range (e.g. no points in data).

See also:
rescaleAxes, getValueRange

Implemented in QCPStatisticalBox, QCPBars, QCPCurve, and QCPGraph.

QCPRange QCPAbstractPlottable::getValueRange ( bool &  validRange,
SignDomain  inSignDomain = sdBoth 
) const [protected, pure virtual]

called by rescaleAxes functions to get the full data value bounds. For logarithmic plots, one can set inSignDomain to either sdNegative or sdPositive in order to restrict the returned range to that sign domain. E.g. when only negative range is wanted, set inSignDomain to sdNegative and all positive points will be ignored for range calculation. For no restriction, just set inSignDomain to sdBoth (default). validRange is an output parameter that indicates whether a proper range could be found or not. If this is false, you shouldn't use the returned range (e.g. no points in data).

See also:
rescaleAxes, getKeyRange

Implemented in QCPStatisticalBox, QCPBars, QCPCurve, and QCPGraph.

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

Convenience function for transforming a key/value pair to pixels on the QCustomPlot surface, taking the orientations of the axes associated with this plottable into account (e.g. whether key represents x or y).

key and value are transformed to the coodinates in pixels and are written to x and y.

See also:
pixelsToCoords, QCPAxis::coordToPixel
const QPointF QCPAbstractPlottable::coordsToPixels ( double  key,
double  value 
) const [protected]

This is an overloaded function.

Returns the input as pixel coordinates in a QPointF.

void QCPAbstractPlottable::pixelsToCoords ( double  x,
double  y,
double &  key,
double &  value 
) const [protected]

Convenience function for transforming a x/y pixel pair on the QCustomPlot surface to plot coordinates, taking the orientations of the axes associated with this plottable into account (e.g. whether key represents x or y).

x and y are transformed to the plot coodinates and are written to key and value.

See also:
coordsToPixels, QCPAxis::coordToPixel
void QCPAbstractPlottable::pixelsToCoords ( const QPointF &  pixelPos,
double &  key,
double &  value 
) const [protected]

This is an overloaded function.

Returns the pixel input pixelPos as plot coordinates key and value.

QPen QCPAbstractPlottable::mainPen ( ) const [protected]

Returns the pen that should be used for drawing lines of the plottable. Returns mPen when the graph is not selected and mSelectedPen when it is.

QBrush QCPAbstractPlottable::mainBrush ( ) const [protected]

Returns the brush that should be used for drawing fills of the plottable. Returns mBrush when the graph is not selected and mSelectedBrush when it is.

void QCPAbstractPlottable::applyDefaultAntialiasingHint ( QCPPainter painter) const [protected, virtual]

A convenience function to easily set the QPainter::Antialiased hint on the provided painter before drawing plottable lines.

This is the antialiasing state the painter passed to the draw method is in by default.

This function takes into account the local setting of the antialiasing flag as well as the overrides set e.g. with QCustomPlot::setNotAntialiasedElements.

See also:
setAntialiased, applyFillAntialiasingHint, applyScattersAntialiasingHint, applyErrorBarsAntialiasingHint

Implements QCPLayerable.

void QCPAbstractPlottable::applyFillAntialiasingHint ( QCPPainter painter) const [protected]

A convenience function to easily set the QPainter::Antialiased hint on the provided painter before drawing plottable fills.

This function takes into account the local setting of the fill antialiasing flag as well as the overrides set e.g. with QCustomPlot::setNotAntialiasedElements.

See also:
setAntialiased, applyDefaultAntialiasingHint, applyScattersAntialiasingHint, applyErrorBarsAntialiasingHint
void QCPAbstractPlottable::applyScattersAntialiasingHint ( QCPPainter painter) const [protected]

A convenience function to easily set the QPainter::Antialiased hint on the provided painter before drawing plottable scatter points.

This function takes into account the local setting of the scatters antialiasing flag as well as the overrides set e.g. with QCustomPlot::setNotAntialiasedElements.

See also:
setAntialiased, applyFillAntialiasingHint, applyDefaultAntialiasingHint, applyErrorBarsAntialiasingHint

A convenience function to easily set the QPainter::Antialiased hint on the provided painter before drawing plottable error bars.

This function takes into account the local setting of the error bars antialiasing flag as well as the overrides set e.g. with QCustomPlot::setNotAntialiasedElements.

See also:
setAntialiased, applyFillAntialiasingHint, applyScattersAntialiasingHint, applyDefaultAntialiasingHint
double QCPAbstractPlottable::distSqrToLine ( const QPointF &  start,
const QPointF &  end,
const QPointF &  point 
) const [protected]

Finds the shortest squared distance of point to the line segment defined by start and end.

This function may be used to help with the implementation of the selectTest function for specific plottables.

Note:
This function is identical to QCPAbstractItem::distSqrToLine
void QCPLayerable::setVisible ( bool  on) [inherited]

Sets the visibility of this layerable object. If an object is not visible, it will not be drawn on the QCustomPlot surface, and user interaction with it (e.g. click/selection) is not possible.

bool QCPLayerable::setLayer ( QCPLayer layer) [inherited]

Sets the layer of this layerable object. The object will be placed on top of the other objects already on layer.

Returns true on success, i.e. if layer is a valid layer.

bool QCPLayerable::setLayer ( const QString &  layerName) [inherited]

This is an overloaded function.

Sets the layer of this layerable object by name

Returns true on success, i.e. if layerName is a valid layer name.

void QCPLayerable::setAntialiased ( bool  enabled) [inherited]

Sets whether this object will be drawn antialiased or not.

Note that antialiasing settings may be overridden by QCustomPlot::setAntialiasedElements and QCustomPlot::setNotAntialiasedElements.

bool QCPLayerable::moveToLayer ( QCPLayer layer,
bool  prepend 
) [protected, inherited]

Moves this layerable object to layer. If prepend is true, this object will be prepended to the new layer's list, i.e. it will be drawn below the objects already on the layer. If it is false, the object will be appended.

Returns true on success, i.e. if layer is a valid layer.

void QCPLayerable::applyAntialiasingHint ( QCPPainter painter,
bool  localAntialiased,
QCP::AntialiasedElement  overrideElement 
) const [protected, inherited]

Sets the QPainter::Antialiasing render hint on the provided painter, depending on the localAntialiased value as well as the overrides QCustomPlot::setAntialiasedElements and QCustomPlot::setNotAntialiasedElements. Which override enum this function takes into account is controlled via overrideElement.


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