QwtPlotRescaler takes care of fixed aspect ratios for plot scales. More...

#include <qwt_plot_rescaler.h>

Inheritance diagram for QwtPlotRescaler:

Public Types
enum	RescalePolicy { Fixed, Expanding, Fitting }

enum	ExpandingDirection { ExpandUp, ExpandDown, ExpandBoth }

Public Member Functions
	QwtPlotRescaler (QWidget *canvas, int referenceAxis=QwtPlot::xBottom, RescalePolicy=Expanding)

virtual	~QwtPlotRescaler ()
	Destructor.

void	setEnabled (bool)
	En/disable the rescaler. More...

bool	isEnabled () const

void	setRescalePolicy (RescalePolicy)

RescalePolicy	rescalePolicy () const

void	setExpandingDirection (ExpandingDirection)

void	setExpandingDirection (int axis, ExpandingDirection)

ExpandingDirection	expandingDirection (int axis) const

void	setReferenceAxis (int axis)

int	referenceAxis () const

void	setAspectRatio (double ratio)

void	setAspectRatio (int axis, double ratio)

double	aspectRatio (int axis) const

void	setIntervalHint (int axis, const QwtInterval &)

QwtInterval	intervalHint (int axis) const

QWidget *	canvas ()

const QWidget *	canvas () const

QwtPlot *	plot ()

const QwtPlot *	plot () const

virtual bool	eventFilter (QObject , QEvent )
	Event filter for the plot canvas.

void	rescale () const
	Adjust the plot axes scales.

Protected Member Functions
virtual void	canvasResizeEvent (QResizeEvent *)

virtual void	rescale (const QSize &oldSize, const QSize &newSize) const

virtual QwtInterval	expandScale (int axis, const QSize &oldSize, const QSize &newSize) const

virtual QwtInterval	syncScale (int axis, const QwtInterval &reference, const QSize &size) const

virtual void	updateScales (QwtInterval intervals[QwtPlot::axisCnt]) const

Qt::Orientation	orientation (int axis) const

QwtInterval	interval (int axis) const

QwtInterval	expandInterval (const QwtInterval &, double width, ExpandingDirection) const

Detailed Description

QwtPlotRescaler takes care of fixed aspect ratios for plot scales.

QwtPlotRescaler auto adjusts the axes of a QwtPlot according to fixed aspect ratios.

Member Enumeration Documentation

enum QwtPlotRescaler::ExpandingDirection

When rescalePolicy() is set to Expanding its direction depends on ExpandingDirection

Enumerator
ExpandUp	The upper limit of the scale is adjusted.
ExpandDown	The lower limit of the scale is adjusted.
ExpandBoth	Both limits of the scale are adjusted.

enum QwtPlotRescaler::RescalePolicy

The rescale policy defines how to rescale the reference axis and their depending axes.

See also: ExpandingDirection, setIntervalHint()

Enumerator

Fixed

The interval of the reference axis remains unchanged, when the geometry of the canvas changes. All other axes will be adjusted according to their aspect ratio.

Expanding

The interval of the reference axis will be shrunk/expanded, when the geometry of the canvas changes. All other axes will be adjusted according to their aspect ratio.

The interval, that is represented by one pixel is fixed.

Fitting

The intervals of the axes are calculated, so that all axes include their interval hint.

Constructor & Destructor Documentation

QwtPlotRescaler::QwtPlotRescaler	(	QWidget *	canvas,
		int	referenceAxis = `QwtPlot::xBottom`,
		RescalePolicy	policy = `Expanding`
	)

explicit

Constructor

Parameters

canvas	Canvas
referenceAxis	Reference axis, see RescalePolicy
policy	Rescale policy

See also: setRescalePolicy(), setReferenceAxis()

Member Function Documentation

double QwtPlotRescaler::aspectRatio ( int axis ) const

Returns: Aspect ratio between an axis and the reference axis.

Parameters

axis	Axis index ( see QwtPlot::AxisId )

See also: setAspectRatio()

QWidget * QwtPlotRescaler::canvas ( )

Returns: plot canvas

const QWidget * QwtPlotRescaler::canvas ( ) const

Returns: plot canvas

void QwtPlotRescaler::canvasResizeEvent ( QResizeEvent * event )

protectedvirtual

Event handler for resize events of the plot canvas

Parameters

event Resize event

See also: rescale()

QwtPlotRescaler::ExpandingDirection QwtPlotRescaler::expandingDirection ( int axis ) const

Returns: Direction in which an axis should be expanded

Parameters

axis	Axis index ( see QwtPlot::AxisId )

See also: setExpandingDirection()

QwtInterval QwtPlotRescaler::expandInterval	(	const QwtInterval &	interval,
		double	width,
		ExpandingDirection	direction
	)		const

protected

Expand the interval

Parameters

interval	Interval to be expanded
width	Distance to be added to the interval
direction	Direction of the expand operation

Returns: Expanded interval

QwtInterval QwtPlotRescaler::expandScale	(	int	axis,
		const QSize &	oldSize,
		const QSize &	newSize
	)		const

protectedvirtual

Calculate the new scale interval of a plot axis

Parameters

axis	Axis index ( see QwtPlot::AxisId )
oldSize	Previous size of the canvas
newSize	New size of the canvas

Returns: Calculated new interval for the axis

QwtInterval QwtPlotRescaler::interval ( int axis ) const

protected

Parameters

axis	Axis index ( see QwtPlot::AxisId )

Returns: Normalized interval of an axis

QwtInterval QwtPlotRescaler::intervalHint ( int axis ) const

Parameters

axis	Axis, see QwtPlot::Axis

Returns: Interval hint

See also: setIntervalHint(), RescalePolicy

bool QwtPlotRescaler::isEnabled ( ) const

Returns: true when enabled, false otherwise

See also: setEnabled, eventFilter()

Qt::Orientation QwtPlotRescaler::orientation ( int axis ) const

protected

Returns: Orientation of an axis

Parameters

axis	Axis index ( see QwtPlot::AxisId )

QwtPlot * QwtPlotRescaler::plot ( )

Returns: plot widget

const QwtPlot * QwtPlotRescaler::plot ( ) const

Returns: plot widget

int QwtPlotRescaler::referenceAxis ( ) const

Returns: Reference axis ( see RescalePolicy )

See also: setReferenceAxis()

void QwtPlotRescaler::rescale	(	const QSize &	oldSize,
		const QSize &	newSize
	)		const

protectedvirtual

Adjust the plot axes scales

Parameters

oldSize	Previous size of the canvas
newSize	New size of the canvas

QwtPlotRescaler::RescalePolicy QwtPlotRescaler::rescalePolicy ( ) const

Returns: Rescale policy

See also: setRescalePolicy()

void QwtPlotRescaler::setAspectRatio ( double ratio )

Set the aspect ratio between the scale of the reference axis and the other scales. The default ratio is 1.0

Parameters

ratio Aspect ratio

See also: aspectRatio()

void QwtPlotRescaler::setAspectRatio	(	int	axis,
		double	ratio
	)

Set the aspect ratio between the scale of the reference axis and another scale. The default ratio is 1.0

Parameters

axis	Axis index ( see QwtPlot::AxisId )
ratio	Aspect ratio

See also: aspectRatio()

void QwtPlotRescaler::setEnabled ( bool on )

En/disable the rescaler.

When enabled is true an event filter is installed for the canvas, otherwise the event filter is removed.

Parameters

on	true or false

See also: isEnabled(), eventFilter()

void QwtPlotRescaler::setExpandingDirection ( ExpandingDirection direction )

Set the direction in which all axis should be expanded

Parameters

direction Direction

See also: expandingDirection()

void QwtPlotRescaler::setExpandingDirection	(	int	axis,
		ExpandingDirection	direction
	)

Set the direction in which an axis should be expanded

Parameters

axis	Axis index ( see QwtPlot::AxisId )
direction	Direction

See also: expandingDirection()

void QwtPlotRescaler::setIntervalHint	(	int	axis,
		const QwtInterval &	interval
	)

Set an interval hint for an axis

In Fitting mode, the hint is used as minimal interval that always needs to be displayed.

Parameters

axis	Axis, see QwtPlot::Axis
interval	Axis

See also: intervalHint(), RescalePolicy

void QwtPlotRescaler::setReferenceAxis ( int axis )

Set the reference axis ( see RescalePolicy )

Parameters

axis	Axis index ( QwtPlot::Axis )

See also: referenceAxis()

void QwtPlotRescaler::setRescalePolicy ( RescalePolicy policy )

Change the rescale policy

Parameters

policy Rescale policy

See also: rescalePolicy()

QwtInterval QwtPlotRescaler::syncScale	(	int	axis,
		const QwtInterval &	reference,
		const QSize &	size
	)		const

protectedvirtual

Synchronize an axis scale according to the scale of the reference axis

Parameters

axis	Axis index ( see QwtPlot::AxisId )
reference	Interval of the reference axis
size	Size of the canvas

Returns: New interval for axis

void QwtPlotRescaler::updateScales ( QwtInterval intervals[QwtPlot::axisCnt] ) const

protectedvirtual

Update the axes scales

Parameters

intervals Scale intervals

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation