QwtPlotRescaler Class Reference

#include <qwt_plot_rescaler.h>

List of all members.

Public Types
enum	ExpandingDirection {   ExpandUp,   ExpandDown,   ExpandBoth }
enum	RescalePolicy {   Fixed,   Expanding,   Fitting }

Public Member Functions
	QwtPlotRescaler (QwtPlotCanvas *, int referenceAxis=QwtPlot::xBottom, RescalePolicy=Expanding)
virtual	~QwtPlotRescaler ()
double	aspectRatio (int axis) const
QwtPlotCanvas *	canvas ()
const QwtPlotCanvas *	canvas () const
virtual bool	eventFilter (QObject *, QEvent *)
ExpandingDirection	expandingDirection (int axis) const
QwtDoubleInterval	intervalHint (int axis) const
bool	isEnabled () const
QwtPlot *	plot ()
const QwtPlot *	plot () const
int	referenceAxis () const
void	rescale () const
RescalePolicy	rescalePolicy () const
void	setAspectRatio (double ratio)
void	setAspectRatio (int axis, double ratio)
void	setEnabled (bool)
void	setExpandingDirection (ExpandingDirection)
void	setExpandingDirection (int axis, ExpandingDirection)
void	setIntervalHint (int axis, const QwtDoubleInterval &)
void	setReferenceAxis (int axis)
void	setRescalePolicy (RescalePolicy)

Protected Member Functions
virtual void	canvasResizeEvent (QResizeEvent *)
QwtDoubleInterval	expandInterval (const QwtDoubleInterval &, double width, ExpandingDirection) const
virtual QwtDoubleInterval	expandScale (int axis, const QSize &oldSize, const QSize &newSize) const
QwtDoubleInterval	interval (int axis) const
Qt::Orientation	orientation (int axis) const
virtual void	rescale (const QSize &oldSize, const QSize &newSize) const
virtual QwtDoubleInterval	syncScale (int axis, const QwtDoubleInterval &reference, const QSize &size) const
virtual void	updateScales (QwtDoubleInterval intervals[QwtPlot::axisCnt]) const

---

Detailed Description

QwtPlotRescaler takes care of fixed aspect ratios for plot scales.

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

---

Member Enumeration Documentation

enum QwtPlotRescaler::RescalePolicy

Rescale Policy.

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

• 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 shrinked/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 minimal interval.

---

Constructor & Destructor Documentation

QwtPlotRescaler::QwtPlotRescaler ( QwtPlotCanvas *  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

Return aspect ratio between an axis and the reference axis.

Parameters:

axis	Axis index ( see QwtPlot::AxisId )

See also:

setAspectRatio()

QwtPlotCanvas * QwtPlotRescaler::canvas

(

)

Returns:

plot canvas

const QwtPlotCanvas * QwtPlotRescaler::canvas

(

)

const

Returns:

plot canvas

QwtPlotRescaler::ExpandingDirection QwtPlotRescaler::expandingDirection

(

int

axis

)

const

Return direction in which an axis should be expanded

Parameters:

axis	Axis index ( see QwtPlot::AxisId )

See also:

setExpandingDirection()

QwtDoubleInterval QwtPlotRescaler::expandInterval ( const QwtDoubleInterval &  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

QwtDoubleInterval 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

QwtDoubleInterval QwtPlotRescaler::interval ( int  axis ) const

protected

Return interval of an axis

Parameters:

axis	Axis index ( see QwtPlot::AxisId )

bool QwtPlotRescaler::isEnabled

(

)

const

Returns:

true when enabled, false otherwise

See also:

setEnabled, eventFilter()

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

protected

Return 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::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()

QwtDoubleInterval QwtPlotRescaler::syncScale ( int  axis, const QwtDoubleInterval &  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

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

protectedvirtual

Update the axes scales

Parameters:

intervals

Scale intervals