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

#include <qwt_plot_rescaler.h>

Inheritance diagram for QwtPlotRescaler:

Classes
class	AxisData

class	PrivateData

Public Types
enum	RescalePolicy { Fixed , Expanding , Fitting }
	Rescale policies. More...

enum	ExpandingDirection { ExpandUp , ExpandDown , ExpandBoth }
	Expanding directions. More...

Public Member Functions
	QwtPlotRescaler (QWidget *canvas, QwtAxisId referenceAxis=QwtAxis::XBottom, RescalePolicy=Expanding)
	Constructs a rescaler for the given canvas.

void	setEnabled (bool)
	Enables or disables the rescaler.

bool	isEnabled () const
	Checks if the rescaler is enabled.

void	setRescalePolicy (RescalePolicy)
	Sets the rescale policy.

RescalePolicy	rescalePolicy () const
	Gets the rescale policy.

void	setExpandingDirection (ExpandingDirection)
	Sets the expanding direction for all axes.

void	setExpandingDirection (QwtAxisId, ExpandingDirection)
	Sets the expanding direction for a specific axis.

ExpandingDirection	expandingDirection (QwtAxisId) const
	Gets the expanding direction for a specific axis.

void	setReferenceAxis (QwtAxisId)
	Sets the reference axis.

QwtAxisId	referenceAxis () const
	Gets the reference axis.

void	setAspectRatio (double ratio)
	Sets the aspect ratio for all axes.

void	setAspectRatio (QwtAxisId, double ratio)
	Sets the aspect ratio for a specific axis.

double	aspectRatio (QwtAxisId) const
	Gets the aspect ratio for a specific axis.

void	setIntervalHint (QwtAxisId, const QwtInterval &)
	Sets an interval hint for an axis.

QwtInterval	intervalHint (QwtAxisId) const
	Gets the interval hint for an axis.

QWidget *	canvas ()
	Gets the canvas widget.

const QWidget *	canvas () const
	Gets the canvas widget (const version)

QwtPlot *	plot ()
	Gets the plot widget.

const QwtPlot *	plot () const
	Gets the plot widget (const version)

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

void	rescale () const
	Rescales the plot axes.

Protected Member Functions
virtual void	canvasResizeEvent (QResizeEvent *)
	Event handler for resize events of the plot canvas.

virtual void	rescale (const QSize &oldSize, const QSize &newSize) const
	Adjust the plot axes scales.

virtual QwtInterval	expandScale (QwtAxisId, const QSize &oldSize, const QSize &newSize) const
	Calculate the new scale interval of a plot axis.

virtual QwtInterval	syncScale (QwtAxisId, const QwtInterval &reference, const QSize &size) const
	Synchronize an axis scale according to the scale of the reference axis.

virtual void	updateScales (QwtInterval intervals[QwtAxis::AxisPositions]) const
	Update the axes scales.

Qt::Orientation	orientation (QwtAxisId) const

QwtInterval	interval (QwtAxisId) const

QwtInterval	expandInterval (const QwtInterval &, double width, ExpandingDirection) const
	Expand the interval.

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

◆ ExpandingDirection

enum QwtPlotRescaler::ExpandingDirection

Expanding directions.

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.

◆ RescalePolicy

enum QwtPlotRescaler::RescalePolicy

Rescale policies.

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::QwtPlotRescaler	(	QWidget *	canvas,
		QwtAxisId	referenceAxis = `QwtAxis::XBottom`,
		RescalePolicy	policy = `Expanding`
	)

explicit

Constructs a rescaler for the given canvas.

Parameters

[in]	canvas	Canvas widget
[in]	referenceAxis	Reference axis, see RescalePolicy
[in]	policy	Rescale policy

See also: setRescalePolicy(), setReferenceAxis()

Destructs the rescaler

Member Function Documentation

◆ aspectRatio()

double QwtPlotRescaler::aspectRatio ( QwtAxisId axisId ) const

Gets the aspect ratio for a specific axis.

Parameters

[in] axisId Axis identifier

Returns: Aspect ratio between the specified axis and the reference axis

See also: setAspectRatio()

◆ canvas() [1/2]

QWidget * QwtPlotRescaler::canvas ( )

Gets the canvas widget.

Returns: Canvas widget

◆ canvas() [2/2]

const QWidget * QwtPlotRescaler::canvas ( ) const

Gets the canvas widget (const version)

Returns: Canvas widget (const)

◆ canvasResizeEvent()

void QwtPlotRescaler::canvasResizeEvent ( QResizeEvent * event )

protectedvirtual

Event handler for resize events of the plot canvas.

Parameters

event Resize event

See also: rescale()

◆ eventFilter()

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

overridevirtual

Event filter for the plot canvas.

Handles resize and polish request events for the canvas.

Parameters

[in]	object	Object that received the event
[in]	event	Event that was received

Returns: false to allow further processing of the event

◆ expandingDirection()

QwtPlotRescaler::ExpandingDirection QwtPlotRescaler::expandingDirection ( QwtAxisId axisId ) const

Gets the expanding direction for a specific axis.

Parameters

[in] axisId Axis identifier

Returns: Expanding direction for the specified axis

See also: setExpandingDirection()

◆ expandInterval()

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

◆ expandScale()

QwtInterval QwtPlotRescaler::expandScale	(	QwtAxisId	axisId,
		const QSize &	oldSize,
		const QSize &	newSize
	)		const

protectedvirtual

Calculate the new scale interval of a plot axis.

Parameters

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

Returns: Calculated new interval for the axis

◆ interval()

QwtInterval QwtPlotRescaler::interval ( QwtAxisId axisId ) const

protected

Parameters

axisId Axis

Returns: Normalized interval of an axis

◆ intervalHint()

QwtInterval QwtPlotRescaler::intervalHint ( QwtAxisId axisId ) const

Gets the interval hint for an axis.

Parameters

[in] axisId Axis identifier

Returns: Interval hint

See also: setIntervalHint(), RescalePolicy

◆ isEnabled()

bool QwtPlotRescaler::isEnabled ( ) const

Checks if the rescaler is enabled.

Returns: true if enabled, false otherwise

See also: setEnabled(), eventFilter()

◆ orientation()

Qt::Orientation QwtPlotRescaler::orientation ( QwtAxisId axisId ) const

protected

Returns: Orientation of an axis

Parameters

axisId Axis

◆ plot() [1/2]

QwtPlot * QwtPlotRescaler::plot ( )

Gets the plot widget.

Returns: Plot widget

◆ plot() [2/2]

const QwtPlot * QwtPlotRescaler::plot ( ) const

Gets the plot widget (const version)

Returns: Plot widget (const)

◆ referenceAxis()

QwtAxisId QwtPlotRescaler::referenceAxis ( ) const

Gets the reference axis.

Returns: Reference axis identifier

See also: setReferenceAxis()

◆ rescale() [1/2]

void QwtPlotRescaler::rescale ( ) const

Rescales the plot axes.

Adjusts the plot axes scales based on the current canvas size.

◆ rescale() [2/2]

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

◆ rescalePolicy()

QwtPlotRescaler::RescalePolicy QwtPlotRescaler::rescalePolicy ( ) const

Gets the rescale policy.

Returns: Rescale policy

See also: setRescalePolicy()

◆ setAspectRatio() [1/2]

void QwtPlotRescaler::setAspectRatio ( double ratio )

Sets the aspect ratio for all axes.

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

Parameters

[in] ratio Aspect ratio

See also: aspectRatio()

◆ setAspectRatio() [2/2]

void QwtPlotRescaler::setAspectRatio	(	QwtAxisId	axisId,
		double	ratio
	)

Sets the aspect ratio for a specific axis.

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

Parameters

[in]	axisId	Axis identifier
[in]	ratio	Aspect ratio

See also: aspectRatio()

◆ setEnabled()

void QwtPlotRescaler::setEnabled ( bool on )

Enables or disables the rescaler.

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

Parameters

[in] on true to enable, false to disable

See also: isEnabled(), eventFilter()

◆ setExpandingDirection() [1/2]

void QwtPlotRescaler::setExpandingDirection ( ExpandingDirection direction )

Sets the expanding direction for all axes.

Parameters

[in] direction Expanding direction

See also: expandingDirection()

◆ setExpandingDirection() [2/2]

void QwtPlotRescaler::setExpandingDirection	(	QwtAxisId	axisId,
		ExpandingDirection	direction
	)

Sets the expanding direction for a specific axis.

Parameters

[in]	axisId	Axis identifier
[in]	direction	Expanding direction

See also: expandingDirection()

◆ setIntervalHint()

void QwtPlotRescaler::setIntervalHint	(	QwtAxisId	axisId,
		const QwtInterval &	interval
	)

Sets an interval hint for an axis.

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

Parameters

[in]	axisId	Axis identifier
[in]	interval	Interval hint

See also: intervalHint(), RescalePolicy

◆ setReferenceAxis()

void QwtPlotRescaler::setReferenceAxis ( QwtAxisId axisId )

Sets the reference axis.

The reference axis is used as the basis for rescale calculations.

Parameters

[in] axisId Axis identifier

See also: referenceAxis()

◆ setRescalePolicy()

void QwtPlotRescaler::setRescalePolicy ( RescalePolicy policy )

Sets the rescale policy.

Parameters

[in] policy Rescale policy

See also: rescalePolicy()

◆ syncScale()

QwtInterval QwtPlotRescaler::syncScale	(	QwtAxisId	axisId,
		const QwtInterval &	reference,
		const QSize &	size
	)		const

protectedvirtual

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

Parameters

axisId	Axis
reference	Interval of the reference axis
size	Size of the canvas

Returns: New interval for axis

◆ updateScales()

void QwtPlotRescaler::updateScales ( QwtInterval intervals[QwtAxis::AxisPositions] ) const

protectedvirtual

Update the axes scales.

Parameters

intervals Scale intervals

The documentation for this class was generated from the following files:

/home/runner/work/QWT/QWT/src/plot/qwt_plot_rescaler.h
/home/runner/work/QWT/QWT/src/plot/qwt_plot_rescaler.cpp

Classes

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ ExpandingDirection

◆ RescalePolicy

Constructor & Destructor Documentation

◆ QwtPlotRescaler()

Member Function Documentation

◆ aspectRatio()

◆ canvas() [1/2]

◆ canvas() [2/2]

◆ canvasResizeEvent()

◆ eventFilter()

◆ expandingDirection()

◆ expandInterval()

◆ expandScale()

◆ interval()

◆ intervalHint()

◆ isEnabled()

◆ orientation()

◆ plot() [1/2]

◆ plot() [2/2]

◆ referenceAxis()

◆ rescale() [1/2]

◆ rescale() [2/2]

◆ rescalePolicy()

◆ setAspectRatio() [1/2]

◆ setAspectRatio() [2/2]

◆ setEnabled()

◆ setExpandingDirection() [1/2]

◆ setExpandingDirection() [2/2]

◆ setIntervalHint()

◆ setReferenceAxis()

◆ setRescalePolicy()

◆ syncScale()

◆ updateScales()