A 2-D plotting widget. More...

#include <qwt_plot.h>

Inheritance diagram for QwtPlot:

Public Types
enum	Axis { yLeft, yRight, xBottom, xTop, axisCnt }
	Axis index. More...

enum	LegendPosition { LeftLegend, RightLegend, BottomLegend, TopLegend }

Public Slots
virtual void	replot ()
	Redraw the plot. More...

void	autoRefresh ()
	Replots the plot if autoReplot() is `true`.

Signals
void	itemAttached (QwtPlotItem *plotItem, bool on)

void	legendDataChanged (const QVariant &itemInfo, const QList< QwtLegendData > &data)

Public Member Functions
	QwtPlot (QWidget *=NULL)
	Constructor. More...

	QwtPlot (const QwtText &title, QWidget *=NULL)
	Constructor. More...

virtual	~QwtPlot ()
	Destructor.

void	applyProperties (const QString &)

QString	grabProperties () const

void	setAutoReplot (bool=true)
	Set or reset the autoReplot option. More...

bool	autoReplot () const

void	setPlotLayout (QwtPlotLayout *)
	Assign a new plot layout. More...

QwtPlotLayout *	plotLayout ()

const QwtPlotLayout *	plotLayout () const

void	setTitle (const QString &)

void	setTitle (const QwtText &)

QwtText	title () const

QwtTextLabel *	titleLabel ()

const QwtTextLabel *	titleLabel () const

void	setFooter (const QString &)

void	setFooter (const QwtText &)

QwtText	footer () const

QwtTextLabel *	footerLabel ()

const QwtTextLabel *	footerLabel () const

void	setCanvas (QWidget *)
	Set the drawing canvas of the plot widget. More...

QWidget *	canvas ()

const QWidget *	canvas () const

void	setCanvasBackground (const QBrush &)
	Change the background of the plotting area. More...

QBrush	canvasBackground () const

virtual QwtScaleMap	canvasMap (int axisId) const

double	invTransform (int axisId, int pos) const

double	transform (int axisId, double value) const
	Transform a value into a coordinate in the plotting region. More...

QwtScaleEngine *	axisScaleEngine (int axisId)

const QwtScaleEngine *	axisScaleEngine (int axisId) const

void	setAxisScaleEngine (int axisId, QwtScaleEngine *)

void	setAxisAutoScale (int axisId, bool on=true)
	Enable autoscaling for a specified axis. More...

bool	axisAutoScale (int axisId) const

void	enableAxis (int axisId, bool tf=true)
	Enable or disable a specified axis. More...

bool	axisEnabled (int axisId) const

void	setAxisFont (int axisId, const QFont &)
	Change the font of an axis. More...

QFont	axisFont (int axisId) const

void	setAxisScale (int axisId, double min, double max, double stepSize=0)
	Disable autoscaling and specify a fixed scale for a selected axis. More...

void	setAxisScaleDiv (int axisId, const QwtScaleDiv &)
	Disable autoscaling and specify a fixed scale for a selected axis. More...

void	setAxisScaleDraw (int axisId, QwtScaleDraw *)
	Set a scale draw. More...

double	axisStepSize (int axisId) const
	Return the step size parameter that has been set in setAxisScale. More...

QwtInterval	axisInterval (int axisId) const
	Return the current interval of the specified axis. More...

const QwtScaleDiv &	axisScaleDiv (int axisId) const
	Return the scale division of a specified axis. More...

const QwtScaleDraw *	axisScaleDraw (int axisId) const
	Return the scale draw of a specified axis. More...

QwtScaleDraw *	axisScaleDraw (int axisId)
	Return the scale draw of a specified axis. More...

const QwtScaleWidget *	axisWidget (int axisId) const

QwtScaleWidget *	axisWidget (int axisId)

void	setAxisLabelAlignment (int axisId, Qt::Alignment)

void	setAxisLabelRotation (int axisId, double rotation)

void	setAxisTitle (int axisId, const QString &)
	Change the title of a specified axis. More...

void	setAxisTitle (int axisId, const QwtText &)
	Change the title of a specified axis. More...

QwtText	axisTitle (int axisId) const

void	setAxisMaxMinor (int axisId, int maxMinor)

int	axisMaxMinor (int axisId) const

void	setAxisMaxMajor (int axisId, int maxMajor)

int	axisMaxMajor (int axisId) const

void	insertLegend (QwtAbstractLegend *, LegendPosition=QwtPlot::RightLegend, double ratio=-1.0)
	Insert a legend. More...

QwtAbstractLegend *	legend ()

const QwtAbstractLegend *	legend () const

void	updateLegend ()

void	updateLegend (const QwtPlotItem *)

virtual QSize	sizeHint () const

virtual QSize	minimumSizeHint () const
	Return a minimum size hint.

virtual void	updateLayout ()
	Adjust plot content to its current size. More...

virtual void	drawCanvas (QPainter *)

void	updateAxes ()
	Rebuild the axes scales. More...

void	updateCanvasMargins ()
	Update the canvas margins. More...

virtual void	getCanvasMarginsHint (const QwtScaleMap maps[], const QRectF &canvasRect, double &left, double &top, double &right, double &bottom) const
	Calculate the canvas margins. More...

virtual bool	event (QEvent *)
	Adds handling of layout requests. More...

virtual bool	eventFilter (QObject , QEvent )
	Event filter. More...

virtual void	drawItems (QPainter *, const QRectF &, const QwtScaleMap maps[axisCnt]) const

virtual QVariant	itemToInfo (QwtPlotItem *) const
	Build an information, that can be used to identify a plot item on the legend. More...

virtual QwtPlotItem *	infoToItem (const QVariant &) const
	Identify the plot item according to an item info object, that has bee generated from itemToInfo(). More...

Public Member Functions inherited from QwtPlotDict
	QwtPlotDict ()

virtual	~QwtPlotDict ()

void	setAutoDelete (bool)

bool	autoDelete () const

const QwtPlotItemList &	itemList () const
	A QwtPlotItemList of all attached plot items. More...

QwtPlotItemList	itemList (int rtti) const

void	detachItems (int rtti=QwtPlotItem::Rtti_PlotItem, bool autoDelete=true)

Protected Member Functions
virtual void	resizeEvent (QResizeEvent *e)

Protected Member Functions inherited from QwtPlotDict
void	insertItem (QwtPlotItem *)

void	removeItem (QwtPlotItem *)

Static Protected Member Functions
static bool	axisValid (int axisId)

Detailed Description

A 2-D plotting widget.

QwtPlot is a widget for plotting two-dimensional graphs. An unlimited number of plot items can be displayed on its canvas. Plot items might be curves (QwtPlotCurve), markers (QwtPlotMarker), the grid (QwtPlotGrid), or anything else derived from QwtPlotItem. A plot can have up to four axes, with each plot item attached to an x- and a y axis. The scales at the axes can be explicitly set (QwtScaleDiv), or are calculated from the plot items, using algorithms (QwtScaleEngine) which can be configured separately for each axis.

The simpleplot example is a good starting point to see how to set up a plot widget.

Example: The following example shows (schematically) the most simple way to use QwtPlot. By default, only the left and bottom axes are visible and their scales are computed automatically.
#include <qwt_plot.h>

#include <qwt_plot_curve.h>

QwtPlot *myPlot = new QwtPlot( "Two Curves", parent );

// add curves

QwtPlotCurve *curve1 = new QwtPlotCurve( "Curve 1" );

QwtPlotCurve *curve2 = new QwtPlotCurve( "Curve 2" );

// connect or copy the data to the curves

curve1->setData( ... );

curve2->setData( ... );

curve1->attach( myPlot );

curve2->attach( myPlot );

// finally, refresh the plot

myPlot->replot();

\endpar

Member Enumeration Documentation

◆ Axis

enum QwtPlot::Axis

Axis index.

Enumerator
yLeft	Y axis left of the canvas.
yRight	Y axis right of the canvas.
xBottom	X axis below the canvas.
xTop	X axis above the canvas.
axisCnt	Number of axes.

◆ LegendPosition

enum QwtPlot::LegendPosition

Position of the legend, relative to the canvas.

See also: insertLegend()

Enumerator
LeftLegend	The legend will be left from the QwtPlot::yLeft axis.
RightLegend	The legend will be right from the QwtPlot::yRight axis.
BottomLegend	The legend will be below the footer.
TopLegend	The legend will be above the title.

Constructor & Destructor Documentation

◆ QwtPlot() [1/2]

QwtPlot::QwtPlot ( QWidget * parent = NULL )

explicit

Constructor.

Parameters

parent Parent widget

◆ QwtPlot() [2/2]

QwtPlot::QwtPlot	(	const QwtText &	title,
		QWidget *	parent = `NULL`
	)

explicit

Constructor.

Parameters

title	Title text
parent	Parent widget

Member Function Documentation

◆ applyProperties()

void QwtPlot::applyProperties ( const QString & )

This method is intended for manipulating the plot widget from a specific editor in the Qwt designer plugin.

Warning: The plot editor has never been implemented.

◆ autoReplot()

bool QwtPlot::autoReplot ( ) const

Returns: true if the autoReplot option is set.

See also: setAutoReplot()

◆ axisAutoScale()

bool QwtPlot::axisAutoScale ( int axisId ) const

Returns: True, if autoscaling is enabled

Parameters

axisId Axis index

◆ axisEnabled()

bool QwtPlot::axisEnabled ( int axisId ) const

Returns: True, if a specified axis is enabled

Parameters

axisId Axis index

◆ axisFont()

QFont QwtPlot::axisFont ( int axisId ) const

Returns: The font of the scale labels for a specified axis

Parameters

axisId Axis index

◆ axisInterval()

QwtInterval QwtPlot::axisInterval ( int axisId ) const

Return the current interval of the specified axis.

This is only a convenience function for axisScaleDiv( axisId )->interval();

Parameters

axisId Axis index

Returns: Scale interval

See also: QwtScaleDiv, axisScaleDiv()

◆ axisMaxMajor()

int QwtPlot::axisMaxMajor ( int axisId ) const

Returns: The maximum number of major ticks for a specified axis

Parameters

axisId Axis index

See also: setAxisMaxMajor(), QwtScaleEngine::divideScale()

◆ axisMaxMinor()

int QwtPlot::axisMaxMinor ( int axisId ) const

Returns: the maximum number of minor ticks for a specified axis

Parameters

axisId Axis index

See also: setAxisMaxMinor(), QwtScaleEngine::divideScale()

◆ axisScaleDiv()

const QwtScaleDiv & QwtPlot::axisScaleDiv ( int axisId ) const

Return the scale division of a specified axis.

axisScaleDiv(axisId).lowerBound(), axisScaleDiv(axisId).upperBound() are the current limits of the axis scale.

Parameters

axisId Axis index

Returns: Scale division

See also: QwtScaleDiv, setAxisScaleDiv(), QwtScaleEngine::divideScale()

◆ axisScaleDraw() [1/2]

QwtScaleDraw * QwtPlot::axisScaleDraw ( int axisId )

Return the scale draw of a specified axis.

Parameters

axisId Axis index

Returns: Specified scaleDraw for axis, or NULL if axis is invalid.

◆ axisScaleDraw() [2/2]

const QwtScaleDraw * QwtPlot::axisScaleDraw ( int axisId ) const

Return the scale draw of a specified axis.

Parameters

axisId Axis index

Returns: Specified scaleDraw for axis, or NULL if axis is invalid.

◆ axisScaleEngine() [1/2]

QwtScaleEngine * QwtPlot::axisScaleEngine ( int axisId )

Parameters

axisId Axis index

Returns: Scale engine for a specific axis

◆ axisScaleEngine() [2/2]

const QwtScaleEngine * QwtPlot::axisScaleEngine ( int axisId ) const

Parameters

axisId Axis index

Returns: Scale engine for a specific axis

◆ axisStepSize()

double QwtPlot::axisStepSize ( int axisId ) const

Return the step size parameter that has been set in setAxisScale.

This doesn't need to be the step size of the current scale.

Parameters

axisId Axis index

Returns: step size parameter value

See also: setAxisScale(), QwtScaleEngine::divideScale()

◆ axisTitle()

QwtText QwtPlot::axisTitle ( int axisId ) const

Returns: Title of a specified axis

Parameters

axisId Axis index

◆ axisValid()

bool QwtPlot::axisValid ( int axisId )

staticprotected

Returns: true if the specified axis exists, otherwise false

Parameters

axisId axis index

◆ axisWidget() [1/2]

QwtScaleWidget * QwtPlot::axisWidget ( int axisId )

Returns: Scale widget of the specified axis, or NULL if axisId is invalid.

Parameters

axisId Axis index

◆ axisWidget() [2/2]

const QwtScaleWidget * QwtPlot::axisWidget ( int axisId ) const

Returns: Scale widget of the specified axis, or NULL if axisId is invalid.

Parameters

axisId Axis index

◆ canvas() [1/2]

QWidget * QwtPlot::canvas ( )

Returns: the plot's canvas

◆ canvas() [2/2]

const QWidget * QwtPlot::canvas ( ) const

Returns: the plot's canvas

◆ canvasBackground()

QBrush QwtPlot::canvasBackground ( ) const

Nothing else than: canvas()->palette().brush( QPalette::Normal, QPalette::Window);

Returns: Background brush of the plotting area.

See also: setCanvasBackground()

◆ canvasMap()

QwtScaleMap QwtPlot::canvasMap ( int axisId ) const

virtual

Parameters

axisId Axis

Returns: Map for the axis on the canvas. With this map pixel coordinates can translated to plot coordinates and vice versa.

See also: QwtScaleMap, transform(), invTransform()

◆ drawCanvas()

void QwtPlot::drawCanvas ( QPainter * painter )

virtual

Redraw the canvas.

Parameters

painter Painter used for drawing

Warning: drawCanvas calls drawItems what is also used for printing. Applications that like to add individual plot items better overload drawItems()

See also: drawItems()

◆ drawItems()

void QwtPlot::drawItems	(	QPainter *	painter,
		const QRectF &	canvasRect,
		const QwtScaleMap	maps[axisCnt]
	)		const

virtual

Redraw the canvas items.

Parameters

painter	Painter used for drawing
canvasRect	Bounding rectangle where to paint
maps	QwtPlot::axisCnt maps, mapping between plot and paint device coordinates

Note: Usually canvasRect is contentsRect() of the plot canvas. Due to a bug in Qt this rectangle might be wrong for certain frame styles ( f.e QFrame::Box ) and it might be necessary to fix the margins manually using QWidget::setContentsMargins()

◆ enableAxis()

void QwtPlot::enableAxis	(	int	axisId,
		bool	tf = `true`
	)

Enable or disable a specified axis.

When an axis is disabled, this only means that it is not visible on the screen. Curves, markers and can be attached to disabled axes, and transformation of screen coordinates into values works as normal.

Only xBottom and yLeft are enabled by default.

Parameters

axisId	Axis index
tf	`true` (enabled) or `false` (disabled)

◆ event()

bool QwtPlot::event ( QEvent * event )

virtual

Adds handling of layout requests.

Parameters

event Event

Returns: See QFrame::event()

◆ eventFilter()

bool QwtPlot::eventFilter	(	QObject *	object,
		QEvent *	event
	)

virtual

Event filter.

The plot handles the following events for the canvas:

QEvent::Resize The canvas margins might depend on its size
QEvent::ContentsRectChange The layout needs to be recalculated

Parameters

object	Object to be filtered
event	Event

Returns: See QFrame::eventFilter()

See also: updateCanvasMargins(), updateLayout()

◆ footer()

QwtText QwtPlot::footer ( ) const

Returns: Text of the footer

◆ footerLabel() [1/2]

QwtTextLabel * QwtPlot::footerLabel ( )

Returns: Footer label widget.

◆ footerLabel() [2/2]

const QwtTextLabel * QwtPlot::footerLabel ( ) const

Returns: Footer label widget.

◆ getCanvasMarginsHint()

void QwtPlot::getCanvasMarginsHint	(	const QwtScaleMap	maps[],
		const QRectF &	canvasRect,
		double &	left,
		double &	top,
		double &	right,
		double &	bottom
	)		const

virtual

Calculate the canvas margins.

Parameters

maps	QwtPlot::axisCnt maps, mapping between plot and paint device coordinates
canvasRect	Bounding rectangle where to paint
left	Return parameter for the left margin
top	Return parameter for the top margin
right	Return parameter for the right margin
bottom	Return parameter for the bottom margin

Plot items might indicate, that they need some extra space at the borders of the canvas by the QwtPlotItem::Margins flag.

updateCanvasMargins(), QwtPlotItem::getCanvasMarginHint()

◆ grabProperties()

QString QwtPlot::grabProperties ( ) const

This method is intended for manipulating the plot widget from a specific editor in the Qwt designer plugin.

Returns: QString()

Warning: The plot editor has never been implemented.

◆ infoToItem()

QwtPlotItem * QwtPlot::infoToItem ( const QVariant & itemInfo ) const

virtual

Identify the plot item according to an item info object, that has bee generated from itemToInfo().

The default implementation simply tries to unwrap a QwtPlotItem pointer:

if ( itemInfo.canConvert<QwtPlotItem *>() )

return qvariant_cast<QwtPlotItem *>( itemInfo );

Parameters

itemInfo Plot item

Returns: A plot item, when successful, otherwise a NULL pointer.

See also: itemToInfo()

◆ insertLegend()

void QwtPlot::insertLegend	(	QwtAbstractLegend *	legend,
		QwtPlot::LegendPosition	pos = `QwtPlot::RightLegend`,
		double	ratio = `-1.0`
	)

Insert a legend.

If the position legend is QwtPlot::LeftLegend or QwtPlot::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.

insertLegend() will set the plot widget as parent for the legend. The legend will be deleted in the destructor of the plot or when another legend is inserted.

Legends, that are not inserted into the layout of the plot widget need to connect to the legendDataChanged() signal. Calling updateLegend() initiates this signal for an initial update. When the application code wants to implement its own layout this also needs to be done for rendering plots to a document ( see QwtPlotRenderer ).

Parameters

legend	Legend
pos	The legend's position. For top/left position the number of columns will be limited to 1, otherwise it will be set to unlimited.
ratio	Ratio between legend and the bounding rectangle of title, canvas and axes. The legend will be shrunk 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(), QwtPlotLayout::legendPosition(), QwtPlotLayout::setLegendPosition()

◆ invTransform()

double QwtPlot::invTransform	(	int	axisId,
		int	pos
	)		const

Transform the x or y coordinate of a position in the drawing region into a value.

Parameters

axisId	Axis index
pos	position

Returns: Position as axis coordinate

Warning: The position can be an x or a y coordinate, depending on the specified axis.

◆ itemAttached

void QwtPlot::itemAttached	(	QwtPlotItem *	plotItem,
		bool	on
	)

signal

A signal indicating, that an item has been attached/detached

Parameters

plotItem	Plot item
on	Attached/Detached

◆ itemToInfo()

QVariant QwtPlot::itemToInfo ( QwtPlotItem * plotItem ) const

virtual

Build an information, that can be used to identify a plot item on the legend.

The default implementation simply wraps the plot item into a QVariant object. When overloading itemToInfo() usually infoToItem() needs to reimplemeted too.

QVariant itemInfo;

qVariantSetValue( itemInfo, plotItem );

Parameters

plotItem Plot item

Returns: Plot item embedded in a QVariant

See also: infoToItem()

◆ legend() [1/2]

QwtAbstractLegend * QwtPlot::legend ( )

Returns: the plot's legend

See also: insertLegend()

◆ legend() [2/2]

const QwtAbstractLegend * QwtPlot::legend ( ) const

Returns: the plot's legend

See also: insertLegend()

◆ legendDataChanged

void QwtPlot::legendDataChanged	(	const QVariant &	itemInfo,
		const QList< QwtLegendData > &	data
	)

signal

A signal with the attributes how to update the legend entries for a plot item.

Parameters

itemInfo	Info about a plot item, build from itemToInfo()
data	Attributes of the entries ( usually <= 1 ) for the plot item.

See also: itemToInfo(), infoToItem(), QwtAbstractLegend::updateLegend()

◆ plotLayout() [1/2]

QwtPlotLayout * QwtPlot::plotLayout ( )

Returns: the plot's layout

◆ plotLayout() [2/2]

const QwtPlotLayout * QwtPlot::plotLayout ( ) const

Returns: the plot's layout

◆ replot

void QwtPlot::replot ( )

virtualslot

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: updateAxes(), setAutoReplot()

◆ resizeEvent()

void QwtPlot::resizeEvent ( QResizeEvent * e )

protectedvirtual

Resize and update internal layout

Parameters

e	Resize event

◆ setAutoReplot()

void QwtPlot::setAutoReplot ( bool tf = 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

tf	`true` or `false`. Defaults to `true`.

See also: replot()

◆ setAxisAutoScale()

void QwtPlot::setAxisAutoScale	(	int	axisId,
		bool	on = `true`
	)

Enable autoscaling for a specified axis.

This member function is used to switch back to autoscaling mode after a fixed scale has been set. Autoscaling is enabled by default.

Parameters

axisId	Axis index
on	On/Off

See also: setAxisScale(), setAxisScaleDiv(), updateAxes()

Note: The autoscaling flag has no effect until updateAxes() is executed ( called by replot() ).

◆ setAxisFont()

void QwtPlot::setAxisFont	(	int	axisId,
		const QFont &	font
	)

Change the font of an axis.

Parameters

axisId	Axis index
font	Font

Warning: This function changes the font of the tick labels, not of the axis title.

◆ setAxisLabelAlignment()

void QwtPlot::setAxisLabelAlignment	(	int	axisId,
		Qt::Alignment	alignment
	)

Change the alignment of the tick labels

Parameters

axisId	Axis index
alignment	Or'd Qt::AlignmentFlags see <qnamespace.h>

See also: QwtScaleDraw::setLabelAlignment()

◆ setAxisLabelRotation()

void QwtPlot::setAxisLabelRotation	(	int	axisId,
		double	rotation
	)

Rotate all tick labels

Parameters

axisId	Axis index
rotation	Angle in degrees. When changing the label rotation, the label alignment might be adjusted too.

See also: QwtScaleDraw::setLabelRotation(), setAxisLabelAlignment()

◆ setAxisMaxMajor()

void QwtPlot::setAxisMaxMajor	(	int	axisId,
		int	maxMajor
	)

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

Parameters

axisId	Axis index
maxMajor	Maximum number of major steps

See also: axisMaxMajor()

◆ setAxisMaxMinor()

void QwtPlot::setAxisMaxMinor	(	int	axisId,
		int	maxMinor
	)

Set the maximum number of minor scale intervals for a specified axis

Parameters

axisId	Axis index
maxMinor	Maximum number of minor steps

See also: axisMaxMinor()

◆ setAxisScale()

void QwtPlot::setAxisScale	(	int	axisId,
		double	min,
		double	max,
		double	stepSize = `0`
	)

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

In updateAxes() the scale engine calculates a scale division from the specified parameters, that will be assigned to the scale widget. So updates of the scale widget usually happen delayed with the next replot.

Parameters

axisId	Axis index
min	Minimum of the scale
max	Maximum of the scale
stepSize	Major step size. If `step == 0`, the step size is calculated automatically using the maxMajor setting.

See also: setAxisMaxMajor(), setAxisAutoScale(), axisStepSize(), QwtScaleEngine::divideScale()

◆ setAxisScaleDiv()

void QwtPlot::setAxisScaleDiv	(	int	axisId,
		const QwtScaleDiv &	scaleDiv
	)

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

The scale division will be stored locally only until the next call of updateAxes(). So updates of the scale widget usually happen delayed with the next replot.

Parameters

axisId	Axis index
scaleDiv	Scale division

See also: setAxisScale(), setAxisAutoScale()

◆ setAxisScaleDraw()

void QwtPlot::setAxisScaleDraw	(	int	axisId,
		QwtScaleDraw *	scaleDraw
	)

Set a scale draw.

Parameters

axisId	Axis index
scaleDraw	Object responsible for drawing scales.

By passing scaleDraw it is possible to extend QwtScaleDraw functionality and let it take place in QwtPlot. Please note that scaleDraw has to be created with new and will be deleted by the corresponding QwtScale member ( like a child object ).

See also: QwtScaleDraw, QwtScaleWidget

Warning: The attributes of scaleDraw will be overwritten by those of the previous QwtScaleDraw.

◆ setAxisScaleEngine()

void QwtPlot::setAxisScaleEngine	(	int	axisId,
		QwtScaleEngine *	scaleEngine
	)

Change the scale engine for an axis

Parameters

axisId	Axis index
scaleEngine	Scale engine

See also: axisScaleEngine()

◆ setAxisTitle() [1/2]

void QwtPlot::setAxisTitle	(	int	axisId,
		const QString &	title
	)

Change the title of a specified axis.

Parameters

axisId	Axis index
title	axis title

◆ setAxisTitle() [2/2]

void QwtPlot::setAxisTitle	(	int	axisId,
		const QwtText &	title
	)

Change the title of a specified axis.

Parameters

axisId	Axis index
title	Axis title

◆ setCanvas()

void QwtPlot::setCanvas ( QWidget * canvas )

Set the drawing canvas of the plot widget.

QwtPlot invokes methods of the canvas as meta methods ( see QMetaObject ). In opposite to using conventional C++ techniques like virtual methods they allow to use canvas implementations that are derived from QWidget or QGLWidget.

The following meta methods could be implemented:

replot() When the canvas doesn't offer a replot method, QwtPlot calls update() instead.
borderPath() The border path is necessary to clip the content of the canvas When the canvas doesn't have any special border ( f.e rounded corners ) it is o.k. not to implement this method.

The default canvas is a QwtPlotCanvas

Parameters

canvas Canvas Widget

See also: canvas()

◆ setCanvasBackground()

void QwtPlot::setCanvasBackground ( const QBrush & brush )

Change the background of the plotting area.

Sets brush to QPalette::Window of all color groups of the palette of the canvas. Using canvas()->setPalette() is a more powerful way to set these colors.

Parameters

brush New background brush

See also: canvasBackground()

◆ setFooter() [1/2]

void QwtPlot::setFooter ( const QString & text )

Change the text the footer

Parameters

text	New text of the footer

◆ setFooter() [2/2]

void QwtPlot::setFooter ( const QwtText & text )

Change the text the footer

Parameters

text	New text of the footer

◆ setPlotLayout()

void QwtPlot::setPlotLayout ( QwtPlotLayout * layout )

Assign a new plot layout.

Parameters

layout Layout()

See also: plotLayout()

◆ setTitle() [1/2]

void QwtPlot::setTitle ( const QString & title )

Change the plot's title

Parameters

title New title

◆ setTitle() [2/2]

void QwtPlot::setTitle ( const QwtText & title )

Change the plot's title

Parameters

title New title

◆ sizeHint()

QSize QwtPlot::sizeHint ( ) const

virtual

Returns: Size hint for the plot widget

See also: minimumSizeHint()

◆ title()

QwtText QwtPlot::title ( ) const

Returns: Title of the plot

◆ titleLabel() [1/2]

QwtTextLabel * QwtPlot::titleLabel ( )

Returns: Title label widget.

◆ titleLabel() [2/2]

const QwtTextLabel * QwtPlot::titleLabel ( ) const

Returns: Title label widget.

◆ transform()

double QwtPlot::transform	(	int	axisId,
		double	value
	)		const

Transform a value into a coordinate in the plotting region.

Parameters

axisId	Axis index
value	value

Returns: X or Y coordinate in the plotting region corresponding to the value.

◆ updateAxes()

void QwtPlot::updateAxes ( )

Rebuild the axes scales.

In case of autoscaling the boundaries of a scale are calculated from the bounding rectangles of all plot items, having the QwtPlotItem::AutoScale flag enabled ( QwtScaleEngine::autoScale() ). Then a scale division is calculated ( QwtScaleEngine::didvideScale() ) and assigned to scale widget.

When the scale boundaries have been assigned with setAxisScale() a scale division is calculated ( QwtScaleEngine::didvideScale() ) for this interval and assigned to the scale widget.

When the scale has been set explicitly by setAxisScaleDiv() the locally stored scale division gets assigned to the scale widget.

The scale widget indicates modifications by emitting a QwtScaleWidget::scaleDivChanged() signal.

updateAxes() is usually called by replot().

See also: setAxisAutoScale(), setAxisScale(), setAxisScaleDiv(), replot() QwtPlotItem::boundingRect()

◆ updateCanvasMargins()

void QwtPlot::updateCanvasMargins ( )

Update the canvas margins.

Plot items might indicate, that they need some extra space at the borders of the canvas by the QwtPlotItem::Margins flag.

getCanvasMarginsHint(), QwtPlotItem::getCanvasMarginHint()

◆ updateLayout()

void QwtPlot::updateLayout ( )

virtual

Adjust plot content to its current size.

See also: resizeEvent()

◆ updateLegend() [1/2]

void QwtPlot::updateLegend ( )

Emit legendDataChanged() for all plot item

See also: QwtPlotItem::legendData(), legendDataChanged()

◆ updateLegend() [2/2]

void QwtPlot::updateLegend ( const QwtPlotItem * plotItem )

Emit legendDataChanged() for a plot item

Parameters

plotItem Plot item

See also: QwtPlotItem::legendData(), legendDataChanged()

Public Types

Public Slots

Signals

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ Axis

◆ LegendPosition

Constructor & Destructor Documentation

◆ QwtPlot() [1/2]

◆ QwtPlot() [2/2]

Member Function Documentation

◆ applyProperties()

◆ autoReplot()

◆ axisAutoScale()

◆ axisEnabled()

◆ axisFont()

◆ axisInterval()

◆ axisMaxMajor()

◆ axisMaxMinor()

◆ axisScaleDiv()

◆ axisScaleDraw() [1/2]

◆ axisScaleDraw() [2/2]

◆ axisScaleEngine() [1/2]

◆ axisScaleEngine() [2/2]

◆ axisStepSize()

◆ axisTitle()

◆ axisValid()

◆ axisWidget() [1/2]

◆ axisWidget() [2/2]

◆ canvas() [1/2]

◆ canvas() [2/2]

◆ canvasBackground()

◆ canvasMap()

◆ drawCanvas()

◆ drawItems()

◆ enableAxis()

◆ event()

◆ eventFilter()

◆ footer()

◆ footerLabel() [1/2]

◆ footerLabel() [2/2]

◆ getCanvasMarginsHint()

◆ grabProperties()

◆ infoToItem()

◆ insertLegend()

◆ invTransform()

◆ itemAttached

◆ itemToInfo()

◆ legend() [1/2]

◆ legend() [2/2]

◆ legendDataChanged

◆ plotLayout() [1/2]

◆ plotLayout() [2/2]

◆ replot

◆ resizeEvent()

◆ setAutoReplot()

◆ setAxisAutoScale()

◆ setAxisFont()

◆ setAxisLabelAlignment()

◆ setAxisLabelRotation()

◆ setAxisMaxMajor()

◆ setAxisMaxMinor()

◆ setAxisScale()

◆ setAxisScaleDiv()

◆ setAxisScaleDraw()

◆ setAxisScaleEngine()

◆ setAxisTitle() [1/2]

◆ setAxisTitle() [2/2]

◆ setCanvas()

◆ setCanvasBackground()

◆ setFooter() [1/2]

◆ setFooter() [2/2]

◆ setPlotLayout()

◆ setTitle() [1/2]

◆ setTitle() [2/2]

◆ sizeHint()

◆ title()