QwtPlotRescaler (3) - Linux Manuals

NAME

QwtPlotRescaler -

QwtPlotRescaler takes care of fixed aspect ratios for plot scales.

SYNOPSIS

#include <qwt_plot_rescaler.h>

Inherits QObject.

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.
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, intreferenceAxis = QwtPlot::xBottom, RescalePolicypolicy = Expanding) [explicit]

Constructor

Parameters:

canvas Canvas
referenceAxis Reference axis, see RescalePolicy
policy Rescale policy

See Also:

setRescalePolicy(), setReferenceAxis()

Member Function Documentation

double QwtPlotRescaler::aspectRatio (intaxis) 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) [protected], [virtual]

Event handler for resize events of the plot canvas

Parameters:

event Resize event

See Also:

rescale()

QwtPlotRescaler::ExpandingDirection QwtPlotRescaler::expandingDirection (intaxis) 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, doublewidth, ExpandingDirectiondirection) 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 (intaxis, const QSize &oldSize, const QSize &newSize) const [protected], [virtual]

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 (intaxis) const [protected]

Parameters:

axis Axis index ( see QwtPlot::AxisId )

Returns:

Normalized interval of an axis

QwtInterval QwtPlotRescaler::intervalHint (intaxis) 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 (intaxis) 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 [protected], [virtual]

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 (doubleratio)

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 (intaxis, doubleratio)

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 (boolon)

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 (ExpandingDirectiondirection)

Set the direction in which all axis should be expanded

Parameters:

direction Direction

See Also:

expandingDirection()

void QwtPlotRescaler::setExpandingDirection (intaxis, ExpandingDirectiondirection)

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 (intaxis, 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 (intaxis)

Set the reference axis ( see RescalePolicy )

Parameters:

axis Axis index ( QwtPlot::Axis )

See Also:

referenceAxis()

void QwtPlotRescaler::setRescalePolicy (RescalePolicypolicy)

Change the rescale policy

Parameters:

policy Rescale policy

See Also:

rescalePolicy()

QwtInterval QwtPlotRescaler::syncScale (intaxis, const QwtInterval &reference, const QSize &size) const [protected], [virtual]

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 (QwtIntervalintervals[QwtPlot::axisCnt]) const [protected], [virtual]

Update the axes scales

Parameters:

intervals Scale intervals

Author

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