Qwt Polar User's Guide 1.0.0
Public Types | Public Slots | Signals | Public Member Functions | Protected Slots | Protected Member Functions

QwtPolarPlot Class Reference

A plotting widget, displaying a polar coordinate system. More...

#include <qwt_polar_plot.h>

Inheritance diagram for QwtPolarPlot:
Inheritance graph
[legend]

List of all members.

Public Types

enum  LegendPosition {
  LeftLegend,
  RightLegend,
  BottomLegend,
  TopLegend,
  ExternalLegend
}

Public Slots

virtual void replot ()
void autoRefresh ()
void setAzimuthOrigin (double)

Signals

void legendClicked (QwtPolarItem *plotItem)
void legendChecked (QwtPolarItem *plotItem, bool on)
void layoutChanged ()

Public Member Functions

 QwtPolarPlot (QWidget *parent=NULL)
 QwtPolarPlot (const QwtText &title, QWidget *parent=NULL)
virtual ~QwtPolarPlot ()
void setTitle (const QString &)
void setTitle (const QwtText &)
QwtText title () const
QwtTextLabel * titleLabel ()
const QwtTextLabel * titleLabel () const
void setAutoReplot (bool tf=true)
bool autoReplot () const
void setAutoScale (int scaleId)
bool hasAutoScale (int scaleId) const
void setScaleMaxMinor (int scaleId, int maxMinor)
int scaleMaxMinor (int scaleId) const
int scaleMaxMajor (int scaleId) const
void setScaleMaxMajor (int scaleId, int maxMajor)
QwtScaleEngine * scaleEngine (int scaleId)
const QwtScaleEngine * scaleEngine (int scaleId) const
void setScaleEngine (int scaleId, QwtScaleEngine *)
void setScale (int scaleId, double min, double max, double step=0)
void setScaleDiv (int scaleId, const QwtScaleDiv &)
const QwtScaleDiv * scaleDiv (int scaleId) const
QwtScaleDiv * scaleDiv (int scaleId)
QwtScaleMap scaleMap (int scaleId, double radius) const
QwtScaleMap scaleMap (int scaleId) const
void updateScale (int scaleId)
double azimuthOrigin () const
void zoom (const QwtPointPolar &, double factor)
void unzoom ()
QwtPointPolar zoomPos () const
double zoomFactor () const
QwtPolarCanvascanvas ()
const QwtPolarCanvascanvas () const
void setPlotBackground (const QBrush &c)
const QBrush & plotBackground () const
virtual void drawCanvas (QPainter *, const QRectF &) const
void insertLegend (QwtLegend *, LegendPosition=RightLegend, double ratio=-1.0)
QwtLegend * legend ()
const QwtLegend * legend () const
QwtPolarLayoutplotLayout ()
const QwtPolarLayoutplotLayout () const
QwtInterval visibleInterval () const
QRectF plotRect () const
QRectF plotRect (const QRectF &) const
int plotMarginHint () const

Protected Slots

virtual void legendItemClicked ()
virtual void legendItemChecked (bool)

Protected Member Functions

virtual bool event (QEvent *)
virtual void resizeEvent (QResizeEvent *)
virtual void updateLayout ()
virtual void drawItems (QPainter *painter, const QwtScaleMap &radialMap, const QwtScaleMap &azimuthMap, const QPointF &pole, double radius, const QRectF &canvasRect) const

Detailed Description

A plotting widget, displaying a polar coordinate system.

An unlimited number of plot items can be displayed on its canvas. Plot items might be curves (QwtPolarCurve), markers (QwtPolarMarker), the grid (QwtPolarGrid), or anything else derived from QwtPolarItem.

The coordinate system is defined by a radial and a azimuth scale. The scales at the axes can be explicitely set (QwtScaleDiv), or are calculated from the plot items, using algorithms (QwtScaleEngine) which can be configured separately for each axis. Autoscaling is supported for the radial scale.

In opposite to QwtPlot the scales might be different from the view, that is displayed on the canvas. The view can be changed by zooming - f.e. by using QwtPolarPanner or QwtPolarMaginfier.


Member Enumeration Documentation

Position of the legend, relative to the canvas.

See also:
insertLegend()
Enumerator:
LeftLegend 

The legend will be left from the canvas.

RightLegend 

The legend will be right from the canvas.

BottomLegend 

The legend will be below the canvas.

TopLegend 

The legend will be between canvas and title.

ExternalLegend 

External means that only the content of the legend will be handled by QwtPlot, but not its geometry. This might be interesting if an application wants to have a legend in an external window ( or on the canvas ).

Note:
The legend is not painted by QwtPolarRenderer

Constructor & Destructor Documentation

QwtPolarPlot::QwtPolarPlot ( QWidget *  parent = NULL) [explicit]

Constructor

Parameters:
parentParent widget
QwtPolarPlot::QwtPolarPlot ( const QwtText &  title,
QWidget *  parent = NULL 
)

Constructor

Parameters:
titleTitle text
parentParent widget
QwtPolarPlot::~QwtPolarPlot ( ) [virtual]

Destructor.


Member Function Documentation

void QwtPolarPlot::autoRefresh ( ) [slot]

Replots the plot if QwtPlot::autoReplot() is true.

bool QwtPolarPlot::autoReplot ( ) const
Returns:
true if the autoReplot option is set.
double QwtPolarPlot::azimuthOrigin ( ) const

The azimuth origin is the angle where the azimuth scale shows the value 0.0.

Returns:
Origin of the azimuth scale
See also:
setAzimuthOrigin()
QwtPolarCanvas * QwtPolarPlot::canvas ( )
Returns:
the plot's canvas
const QwtPolarCanvas * QwtPolarPlot::canvas ( ) const
Returns:
the plot's canvas
void QwtPolarPlot::drawCanvas ( QPainter *  painter,
const QRectF &  canvasRect 
) const [virtual]

Redraw the canvas.

Parameters:
painterPainter used for drawing
canvasRectContents rect of the canvas
void QwtPolarPlot::drawItems ( QPainter *  painter,
const QwtScaleMap &  azimuthMap,
const QwtScaleMap &  radialMap,
const QPointF &  pole,
double  radius,
const QRectF &  canvasRect 
) const [protected, virtual]

Redraw the canvas items.

Parameters:
painterPainter used for drawing
azimuthMapMaps azimuth values to values related to 0.0, M_2PI
radialMapMaps radius values into painter coordinates.
polePosition of the pole in painter coordinates
radiusRadius of the complete plot area in painter coordinates
canvasRectContents rect of the canvas in painter coordinates
bool QwtPolarPlot::event ( QEvent *  e) [protected, virtual]

Qt event handler.

Handles QEvent::LayoutRequest and QEvent::PolishRequest

Parameters:
eQt Event
Returns:
True, when the event was processed
bool QwtPolarPlot::hasAutoScale ( int  scaleId) const
Returns:
true if autoscaling is enabled
Parameters:
scaleIdScale index
See also:
setAutoScale()
void QwtPolarPlot::insertLegend ( QwtLegend *  legend,
QwtPolarPlot::LegendPosition  pos = RightLegend,
double  ratio = -1.0 
)

Insert a legend.

If the position legend is QwtPolarPlot::LeftLegend or QwtPolarPlot::RightLegend the legend will be organized in one column from top to down. Otherwise the legend items will be placed in a table with a best fit number of columns from left to right.

If pos != QwtPolarPlot::ExternalLegend the plot widget will become parent of the legend. It will be deleted when the plot is deleted, or another legend is set with insertLegend().

Parameters:
legendLegend
posThe legend's position. For top/left position the number of colums will be limited to 1, otherwise it will be set to unlimited.
ratioRatio between legend and the bounding rect of title, canvas and axes. The legend will be shrinked if it would need more space than the given ratio. The ratio is limited to ]0.0 .. 1.0]. In case of <= 0.0 it will be reset to the default ratio. The default vertical/horizontal ratio is 0.33/0.5.
See also:
legend(), QwtPolarLayout::legendPosition(), QwtPolarLayout::setLegendPosition()
void QwtPolarPlot::layoutChanged ( ) [signal]

A signal that is emitted, whenever the layout of the plot has been recalculated.

QwtLegend * QwtPolarPlot::legend ( )
Returns:
the plot's legend
See also:
insertLegend()
const QwtLegend * QwtPolarPlot::legend ( ) const
Returns:
the plot's legend
See also:
insertLegend()
void QwtPolarPlot::legendChecked ( QwtPolarItem plotItem,
bool  on 
) [signal]

A signal which is emitted when the user has clicked on a legend item, which is in QwtLegend::CheckableItem mode

Parameters:
plotItemCorresponding plot item of the selected legend item
onTrue when the legen item is checked
Note:
clicks are disabled as default
See also:
QwtLegend::setItemMode, QwtLegend::itemMode
void QwtPolarPlot::legendClicked ( QwtPolarItem plotItem) [signal]

A signal which is emitted when the user has clicked on a legend item, which is in QwtLegend::ClickableItem mode.

Parameters:
plotItemCorresponding plot item of the selected legend item
Note:
clicks are disabled as default
See also:
QwtLegend::setItemMode, QwtLegend::itemMode
void QwtPolarPlot::legendItemChecked ( bool  on) [protected, virtual, slot]

Called internally when the legend has been checked Emits a legendClicked() signal.

void QwtPolarPlot::legendItemClicked ( ) [protected, virtual, slot]

Called internally when the legend has been clicked on. Emits a legendClicked() signal.

const QBrush & QwtPolarPlot::plotBackground ( ) const
Returns:
plot background brush
See also:
plotBackground(), plotArea()
QwtPolarLayout * QwtPolarPlot::plotLayout ( )
Returns:
Layout, responsible for the geometry of the plot components
const QwtPolarLayout * QwtPolarPlot::plotLayout ( ) const
Returns:
Layout, responsible for the geometry of the plot components
int QwtPolarPlot::plotMarginHint ( ) const
Returns:
Maximum of all item margin hints.
See also:
QwtPolarItem::marginHint()
QRectF QwtPolarPlot::plotRect ( ) const

The plot area depends on the size of the canvas and the zoom parameters.

Returns:
Bounding rect of the plot area
QRectF QwtPolarPlot::plotRect ( const QRectF &  canvasRect) const

Calculate the bounding rect of the plot area.

The plot area depends on the zoom parameters.

Parameters:
canvasRectRectangle of the canvas
Returns:
Rectangle for displaying 100% of the plot
void QwtPolarPlot::replot ( ) [virtual, slot]

Redraw the plot.

If the autoReplot option is not set (which is the default) or if any curves are attached to raw data, the plot has to be refreshed explicitly in order to make changes visible.

See also:
setAutoReplot()
Warning:
Calls canvas()->repaint, take care of infinite recursions
void QwtPolarPlot::resizeEvent ( QResizeEvent *  e) [protected, virtual]

Resize and update internal layout.

const QwtScaleDiv * QwtPolarPlot::scaleDiv ( int  scaleId) const

Return the scale division of a specified scale.

scaleDiv(scaleId)->lBound(), scaleDiv(scaleId)->hBound() are the current limits of the scale.

Parameters:
scaleIdScale index
Returns:
Scale division
See also:
QwtScaleDiv, setScaleDiv(), setScale()
QwtScaleDiv * QwtPolarPlot::scaleDiv ( int  scaleId)

Return the scale division of a specified scale.

scaleDiv(scaleId)->lBound(), scaleDiv(scaleId)->hBound() are the current limits of the scale.

Parameters:
scaleIdScale index
Returns:
Scale division
See also:
QwtScaleDiv, setScaleDiv(), setScale()
QwtScaleEngine * QwtPolarPlot::scaleEngine ( int  scaleId)
Returns:
Scale engine for a specific scale
Parameters:
scaleIdScale index
See also:
setScaleEngine()
const QwtScaleEngine * QwtPolarPlot::scaleEngine ( int  scaleId) const
Returns:
Scale engine for a specific scale
Parameters:
scaleIdScale index
See also:
setScaleEngine()
QwtScaleMap QwtPolarPlot::scaleMap ( int  scaleId,
double  radius 
) const

Build a scale map

The azimuth map translates between the scale values and angles from [0.0, 2 * PI[. The radial map translates scale values into the distance from the pole.

Parameters:
scaleIdScale index
radiusRadius of the plot are in pixels
Returns:
Map for the scale on the canvas. With this map pixel coordinates can translated to plot coordinates and vice versa.
See also:
QwtScaleMap, transform(), invTransform()
QwtScaleMap QwtPolarPlot::scaleMap ( int  scaleId) const

Build a scale map

The azimuth map translates between the scale values and angles from [0.0, 2 * PI[. The radial map translates scale values into the distance from the pole. The radial map is calculated from the current geometry of the canvas.

Parameters:
scaleIdScale index
Returns:
Map for the scale on the canvas. With this map pixel coordinates can translated to plot coordinates and vice versa.
See also:
QwtScaleMap, transform(), invTransform()
int QwtPolarPlot::scaleMaxMajor ( int  scaleId) const
Returns:
the maximum number of major ticks for a specified axis
Parameters:
scaleIdScale index
See also:
setScaleMaxMajor()
int QwtPolarPlot::scaleMaxMinor ( int  scaleId) const
Returns:
the maximum number of minor ticks for a specified axis
Parameters:
scaleIdScale index
See also:
setScaleMaxMinor()
void QwtPolarPlot::setAutoReplot ( bool  enable = true)

Set or reset the autoReplot option.

If the autoReplot option is set, the plot will be updated implicitly by manipulating member functions. Since this may be time-consuming, it is recommended to leave this option switched off and call replot() explicitly if necessary.

The autoReplot option is set to false by default, which means that the user has to call replot() in order to make changes visible.

Parameters:
enabletrue or false. Defaults to true.
See also:
replot()
void QwtPolarPlot::setAutoScale ( int  scaleId)

Enable autoscaling.

This member function is used to switch back to autoscaling mode after a fixed scale has been set. Autoscaling calculates a useful scale division from the bounding interval of all plot items with the QwtPolarItem::AutoScale attribute.

Autoscaling is only supported for the radial scale and enabled as default.

Parameters:
scaleIdScale index
See also:
hasAutoScale(), setScale(), setScaleDiv(), QwtPolarItem::boundingInterval()
void QwtPolarPlot::setAzimuthOrigin ( double  origin) [slot]

Change the origin of the azimuth scale.

The azimuth origin is the angle where the azimuth scale shows the value 0.0. The default origin is 0.0.

Parameters:
originNew origin
See also:
azimuthOrigin()
void QwtPolarPlot::setPlotBackground ( const QBrush &  brush)

Set the background of the plot area.

The plot area is the circle around the pole. It's radius is defined by the radial scale.

Parameters:
brushBackground Brush
See also:
plotBackground(), plotArea()
void QwtPolarPlot::setScale ( int  scaleId,
double  min,
double  max,
double  stepSize = 0 
)

Disable autoscaling and specify a fixed scale for a selected scale.

Parameters:
scaleIdScale index
min
maxminimum and maximum of the scale
stepSizeMajor step size. If step == 0, the step size is calculated automatically using the maxMajor setting.
See also:
setScaleMaxMajor(), setAutoScale()
void QwtPolarPlot::setScaleDiv ( int  scaleId,
const QwtScaleDiv &  scaleDiv 
)

Disable autoscaling and specify a fixed scale for a selected scale.

Parameters:
scaleIdScale index
scaleDivScale division
See also:
setScale(), setAutoScale()
void QwtPolarPlot::setScaleEngine ( int  scaleId,
QwtScaleEngine *  scaleEngine 
)

Change the scale engine for an axis

Parameters:
scaleIdScale index
scaleEngineScale engine
See also:
axisScaleEngine()
void QwtPolarPlot::setScaleMaxMajor ( int  scaleId,
int  maxMajor 
)

Set the maximum number of major scale intervals for a specified scale

Parameters:
scaleIdScale index
maxMajormaximum number of major steps
See also:
scaleMaxMajor()
void QwtPolarPlot::setScaleMaxMinor ( int  scaleId,
int  maxMinor 
)

Set the maximum number of major scale intervals for a specified scale

Parameters:
scaleIdScale index
maxMinormaximum number of minor steps
See also:
scaleMaxMajor()
void QwtPolarPlot::setTitle ( const QwtText &  title)

Change the plot's title

Parameters:
titleNew title
void QwtPolarPlot::setTitle ( const QString &  title)

Change the plot's title

Parameters:
titleNew title
QwtText QwtPolarPlot::title ( ) const
Returns:
the plot's title
QwtTextLabel * QwtPolarPlot::titleLabel ( )
Returns:
the plot's title
const QwtTextLabel * QwtPolarPlot::titleLabel ( ) const
Returns:
the plot's titel label.
void QwtPolarPlot::unzoom ( )

Unzoom the plot

See also:
zoom()
void QwtPolarPlot::updateLayout ( ) [protected, virtual]

Rebuild the layout.

void QwtPolarPlot::updateScale ( int  scaleId)

Rebuild the scale

Parameters:
scaleIdScale index
QwtInterval QwtPolarPlot::visibleInterval ( ) const
Returns:
Bounding interval of the radial scale that is visible on the canvas.
void QwtPolarPlot::zoom ( const QwtPointPolar &  zoomPos,
double  zoomFactor 
)

Translate and in/decrease the zoom factor.

In zoom mode the zoom position is in the center of the canvas. The radius of the circle depends on the size of the plot canvas, that is devided by the zoom factor. Thus a factor < 1.0 zoom in.

Setting an invalid zoom position disables zooming.

Parameters:
zoomPosCenter of the translation
zoomFactorZoom factor
See also:
unzoom(), zoomPos(), zoomFactor()
double QwtPolarPlot::zoomFactor ( ) const
Returns:
Zoom factor
See also:
zoom(), zoomPos()
QwtPointPolar QwtPolarPlot::zoomPos ( ) const
Returns:
Zoom position
See also:
zoom(), zoomFactor()