QwtPlotItem Class Reference

Base class for items on the plot canvas. More...

#include <qwt_plot_item.h>

Inheritance diagram for QwtPlotItem:

Inheritance graph
[legend]

List of all members.

Public Types

enum  ItemAttribute {
  Legend = 0x01,
  AutoScale = 0x02
}
typedef QFlags< ItemAttributeItemAttributes
enum  RenderHint { RenderAntialiased = 1 }
typedef QFlags< RenderHintRenderHints
enum  RttiValues {
  Rtti_PlotItem = 0,
  Rtti_PlotGrid,
  Rtti_PlotScale,
  Rtti_PlotMarker,
  Rtti_PlotCurve,
  Rtti_PlotSpectroCurve,
  Rtti_PlotIntervalCurve,
  Rtti_PlotHistogram,
  Rtti_PlotSpectrogram,
  Rtti_PlotSVG,
  Rtti_PlotUserItem = 1000
}

Public Member Functions

void attach (QwtPlot *plot)
virtual QRectF boundingRect () const
void detach ()
virtual void draw (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const =0
virtual void drawLegendIdentifier (QPainter *, const QRectF &) const
void hide ()
bool isVisible () const
virtual void itemChanged ()
virtual QWidget * legendItem () const
QRectF paintRect (const QwtScaleMap &, const QwtScaleMap &) const
QwtPlotplot () const
 QwtPlotItem (const QwtText &title=QwtText())
virtual int rtti () const
QRectF scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
void setAxes (int xAxis, int yAxis)
void setItemAttribute (ItemAttribute, bool on=true)
void setRenderHint (RenderHint, bool on=true)
void setTitle (const QwtText &title)
void setTitle (const QString &title)
virtual void setVisible (bool)
void setXAxis (int axis)
void setYAxis (int axis)
void setZ (double z)
void show ()
bool testItemAttribute (ItemAttribute) const
bool testRenderHint (RenderHint) const
const QwtTexttitle () const
virtual void updateLegend (QwtLegend *) const
virtual void updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &)
int xAxis () const
int yAxis () const
double z () const
virtual ~QwtPlotItem ()


Detailed Description

Base class for items on the plot canvas.

A plot item is "something", that can be painted on the plot canvas, or only affects the scales of the plot widget. They can be categorized as:

Depending on the QwtPlotItem::ItemAttribute flags, an item is included into autoscaling or has an entry on the legnd.

Before misusing the existing item classes it might be better to implement a new type of plot item ( don't implement a watermark as spectrogram ). Deriving a new type of QwtPlotItem primarily means to implement the YourPlotItem::draw() method.

See also:
The cpuplot example shows the implementation of additional plot items.

Member Typedef Documentation

Plot Item Attributes.

Render hints.


Member Enumeration Documentation

Plot Item Attributes

See also:
setItemAttribute(), testItemAttribute()
Enumerator:
Legend  The item is represented on the legend.
AutoScale  The boundingRect() of the item is included in the autoscaling calculation.

Render hints.

Enumerator:
RenderAntialiased  Enable antialiasing.

Runtime type information.

RttiValues is used to cast plot items, without having to enable runtime type information of the compiler.


Constructor & Destructor Documentation

QwtPlotItem::QwtPlotItem ( const QwtText title = QwtText()  )  [explicit]

Constructor

Parameters:
title Title of the item

QwtPlotItem::~QwtPlotItem (  )  [virtual]

Destroy the QwtPlotItem.


Member Function Documentation

void QwtPlotItem::attach ( QwtPlot plot  ) 

Attach the item to a plot.

This method will attach a QwtPlotItem to the QwtPlot argument. It will first detach the QwtPlotItem from any plot from a previous call to attach (if necessary). If a NULL argument is passed, it will detach from any QwtPlot it was attached to.

Parameters:
plot Plot widget
See also:
detach()

QRectF QwtPlotItem::boundingRect (  )  const [virtual]

void QwtPlotItem::detach (  ) 

This method detaches a QwtPlotItem from any QwtPlot it has been associated with.

detach() is equivalent to calling attach( NULL )

See also:
attach()

virtual void QwtPlotItem::draw ( QPainter *  painter,
const QwtScaleMap xMap,
const QwtScaleMap yMap,
const QRectF &  canvasRect 
) const [pure virtual]

Draw the item.

Parameters:
painter Painter
xMap Maps x-values into pixel coordinates.
yMap Maps y-values into pixel coordinates.
canvasRect Contents rect of the canvas in painter coordinates

Implemented in QwtPlotGrid, QwtPlotMarker, QwtPlotRasterItem, QwtPlotScaleItem, QwtPlotAbstractSeriesItem, QwtPlotSpectrogram, and QwtPlotSvgItem.

virtual void QwtLegendItemManager::drawLegendIdentifier ( QPainter *  ,
const QRectF &   
) const [inline, virtual, inherited]

QwtLegendItem can display an icon-identifier followed by a text. The icon helps to identify a plot item on the plot canvas and depends on the type of information, that is displayed.

The default implementation paints nothing.

Reimplemented in QwtPlotCurve, QwtPlotHistogram, QwtPlotIntervalCurve, and QwtPlotMarker.

void QwtPlotItem::hide (  ) 

Hide the item.

bool QwtPlotItem::isVisible (  )  const

Returns:
true if visible
See also:
setVisible(), show(), hide()

void QwtPlotItem::itemChanged (  )  [virtual]

Update the legend and call QwtPlot::autoRefresh for the parent plot.

See also:
updateLegend()

QWidget * QwtPlotItem::legendItem (  )  const [virtual]

Allocate the widget that represents the item on the legend.

The default implementation returns a QwtLegendItem(), but an item could be represented by any type of widget, by overloading legendItem() and updateLegend().

Returns:
QwtLegendItem()
See also:
updateLegend() QwtLegend()

Implements QwtLegendItemManager.

QRectF QwtPlotItem::paintRect ( const QwtScaleMap xMap,
const QwtScaleMap yMap 
) const

Calculate the bounding paint rect of 2 maps.

Parameters:
xMap X map
yMap X map
Returns:
Bounding paint rect of the scale maps, normalized

QwtPlot * QwtPlotItem::plot (  )  const

Return attached plot.

int QwtPlotItem::rtti (  )  const [virtual]

Return rtti for the specific class represented. QwtPlotItem is simply a virtual interface class, and base classes will implement this method with specific rtti values so a user can differentiate them.

The rtti value is useful for environments, where the runtime type information is disabled and it is not possible to do a dynamic_cast<...>.

Returns:
rtti value
See also:
RttiValues

Reimplemented in QwtPlotCurve, QwtPlotGrid, QwtPlotHistogram, QwtPlotIntervalCurve, QwtPlotMarker, QwtPlotScaleItem, QwtPlotSpectroCurve, QwtPlotSpectrogram, and QwtPlotSvgItem.

QRectF QwtPlotItem::scaleRect ( const QwtScaleMap xMap,
const QwtScaleMap yMap 
) const

Calculate the bounding scale rect of 2 maps.

Parameters:
xMap X map
yMap X map
Returns:
Bounding scale rect of the scale maps, normalized

void QwtPlotItem::setAxes ( int  xAxis,
int  yAxis 
)

Set X and Y axis

The item will painted according to the coordinates its Axes.

Parameters:
xAxis X Axis
yAxis Y Axis
See also:
setXAxis(), setYAxis(), xAxis(), yAxis()

void QwtPlotItem::setItemAttribute ( ItemAttribute  attribute,
bool  on = true 
)

Toggle an item attribute

Parameters:
attribute Attribute type
on true/false
See also:
testItemAttribute(), ItemAttribute

void QwtPlotItem::setRenderHint ( RenderHint  hint,
bool  on = true 
)

Toggle an render hint

Parameters:
hint Render hint
on true/false
See also:
testRenderHint(), RenderHint

void QwtPlotItem::setTitle ( const QwtText title  ) 

Set a new title

Parameters:
title Title
See also:
title()

void QwtPlotItem::setTitle ( const QString &  title  ) 

Set a new title

Parameters:
title Title
See also:
title()

void QwtPlotItem::setVisible ( bool  on  )  [virtual]

Show/Hide the item

Parameters:
on Show if true, otherwise hide
See also:
isVisible(), show(), hide()

void QwtPlotItem::setXAxis ( int  axis  ) 

Set the X axis

The item will painted according to the coordinates its Axes.

Parameters:
axis X Axis
See also:
setAxes(), setYAxis(), xAxis()

void QwtPlotItem::setYAxis ( int  axis  ) 

Set the Y axis

The item will painted according to the coordinates its Axes.

Parameters:
axis Y Axis
See also:
setAxes(), setXAxis(), yAxis()

void QwtPlotItem::setZ ( double  z  ) 

Set the z value.

Plot items are painted in increasing z-order.

Parameters:
z Z-value
See also:
z(), QwtPlotDict::itemList()

void QwtPlotItem::show (  ) 

Show the item.

bool QwtPlotItem::testItemAttribute ( ItemAttribute  attribute  )  const

Test an item attribute

Parameters:
attribute Attribute type
Returns:
true/false
See also:
setItemAttribute(), ItemAttribute

bool QwtPlotItem::testRenderHint ( RenderHint  hint  )  const

Test a render hint

Parameters:
hint Render hint
Returns:
true/false
See also:
setRenderHint(), RenderHint

const QwtText & QwtPlotItem::title (  )  const

Returns:
Title of the item
See also:
setTitle()

void QwtPlotItem::updateLegend ( QwtLegend legend  )  const [virtual]

Update the widget that represents the item on the legend.

updateLegend() is called from itemChanged() to adopt the widget representing the item on the legend to its new configuration.

The default implementation updates a QwtLegendItem(), but an item could be represented by any type of widget, by overloading legendItem() and updateLegend().

Parameters:
legend Legend
See also:
legendItem(), itemChanged(), QwtLegend()

Implements QwtLegendItemManager.

Reimplemented in QwtPlotCurve, and QwtPlotMarker.

void QwtPlotItem::updateScaleDiv ( const QwtScaleDiv xScaleDiv,
const QwtScaleDiv yScaleDiv 
) [virtual]

Update the item to changes of the axes scale division.

Update the item, when the axes of plot have changed. The default implementation does nothing, but items that depend on the scale division (like QwtPlotGrid()) have to reimplement updateScaleDiv()

Parameters:
xScaleDiv Scale division of the x-axis
yScaleDiv Scale division of the y-axis
See also:
QwtPlot::updateAxes()

Reimplemented in QwtPlotGrid, QwtPlotScaleItem, QwtPlotSeriesItem< T >, QwtPlotSeriesItem< QwtPoint3D >, QwtPlotSeriesItem< QPointF >, and QwtPlotSeriesItem< QwtIntervalSample >.

int QwtPlotItem::xAxis (  )  const

Return xAxis.

int QwtPlotItem::yAxis (  )  const

Return yAxis.

double QwtPlotItem::z (  )  const

Plot items are painted in increasing z-order.

Returns:
setZ(), QwtPlotDict::itemList()


Generated on Wed Jan 11 15:23:03 2012 for Qwt User's Guide by  doxygen 1.5.9