#include <qwt_plot_item.h>

Inheritance diagram for QwtPlotItem:

Public Types
enum	ItemAttribute { Legend = 1, AutoScale = 2 }
enum	RenderHint { RenderAntialiased = 1 }
enum	RttiValues { Rtti_PlotItem = 0, Rtti_PlotGrid, Rtti_PlotScale, Rtti_PlotMarker, Rtti_PlotCurve, Rtti_PlotHistogram, Rtti_PlotSpectrogram, Rtti_PlotSVG, Rtti_PlotUserItem = 1000 }

Public Member Functions
	QwtPlotItem (const QwtText &title=QwtText())
virtual	~QwtPlotItem ()
void	attach (QwtPlot *plot)
virtual QwtDoubleRect	boundingRect () const
void	detach ()
virtual void	draw (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRect &canvasRect) const =0
void	hide ()
QwtDoubleRect	invTransform (const QwtScaleMap &, const QwtScaleMap &, const QRect &) const
bool	isVisible () const
virtual void	itemChanged ()
virtual QWidget *	legendItem () const
QRect	paintRect (const QwtScaleMap &, const QwtScaleMap &) const
QwtPlot *	plot () const
virtual int	rtti () const
QwtDoubleRect	scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
void	setAxis (int xAxis, int yAxis)
void	setItemAttribute (ItemAttribute, bool on=true)
void	setRenderHint (RenderHint, bool on=true)
void	setTitle (const QString &title)
void	setTitle (const QwtText &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 QwtText &	title () const
QRect	transform (const QwtScaleMap &, const QwtScaleMap &, const QwtDoubleRect &) const
virtual void	updateLegend (QwtLegend *) const
virtual void	updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &)
int	xAxis () const
int	yAxis () const
double	z () const
Public Member Functions inherited from QwtLegendItemManager
	QwtLegendItemManager ()
virtual	~QwtLegendItemManager ()

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:

Representator
A "Representator" is an item that represents some sort of data on the plot canvas. The different representator classes are organized according to the characteristics of the data:
- QwtPlotMarker Represents a point or a horizontal/vertical coordinate
- QwtPlotCurve Represents a series of points
- QwtPlotSpectrogram ( QwtPlotRasterItem ) Represents raster data
- ...

Decorators
A "Decorator" is an item, that displays additional information, that is not related to any data:
- QwtPlotGrid
- QwtPlotScaleItem
- QwtPlotSvgItem
- ...

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 Enumeration Documentation

enum QwtPlotItem::ItemAttribute

Plot Item Attributes

Legend
The item is represented on the legend.
AutoScale
The boundingRect() of the item is included in the autoscaling calculation.

See also:: setItemAttribute(), testItemAttribute()

enum QwtPlotItem::RttiValues

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

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:: QwtPlotItem::detach()

QwtDoubleRect QwtPlotItem::boundingRect ( ) const

virtual

Returns:: An invalid bounding rect: QwtDoubleRect(1.0, 1.0, -2.0, -2.0)

Reimplemented in QwtPlotCurve, QwtPlotMarker, QwtPlotSpectrogram, and QwtPlotSvgItem.

void QwtPlotItem::detach ( )

inline

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

detach() is equivalent to calling attach( NULL )

See also:: attach( QwtPlot* plot )

virtual void QwtPlotItem::draw	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRect &	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 QwtPlotCurve, QwtPlotMarker, QwtPlotScaleItem, QwtPlotSpectrogram, QwtPlotRasterItem, QwtPlotGrid, and QwtPlotSvgItem.

QwtDoubleRect QwtPlotItem::invTransform	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRect &	rect
	)		const

Transform a rectangle from paint to scale coordinates

Parameters:

xMap	X map
yMap	Y map
rect	Rectangle in paint coordinates

Returns:: Rectangle in scale coordinates

See also:: transform()

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 is made for QwtPlotCurve and 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.

QRect 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 rect of the scale maps

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, QwtPlotSpectrogram, QwtPlotMarker, QwtPlotScaleItem, QwtPlotSvgItem, and QwtPlotGrid.

QwtDoubleRect 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 rect of the scale maps

void QwtPlotItem::setAxis	(	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 QString & title )

Set a new title

Parameters:

title Title

See also:: title()

void QwtPlotItem::setTitle ( const QwtText & 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:: setAxis(), 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:: setAxis(), 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()

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()

QRect QwtPlotItem::transform	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QwtDoubleRect &	rect
	)		const

Transform a rectangle

Parameters:

xMap	X map
yMap	Y map
rect	Rectangle in scale coordinates

Returns:: Rectangle in paint coordinates

See also:: invTransform()

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 is made for QwtPlotCurve and 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.

void QwtPlotItem::updateScaleDiv	(	const QwtScaleDiv &	,
		const QwtScaleDiv &
	)

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 QwtPlotScaleItem, and QwtPlotGrid.

double QwtPlotItem::z ( ) const

Plot items are painted in increasing z-order.

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

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation