QwtPlotRescaler(3)

NAME
QwtPlotRescaler -

QwtPlotRescaler takes care of fixed aspect ratios for plot scales.

SYNOPSIS

#include <qwt_plot_rescaler.h>

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

  Public Member Functions
QwtPlotRescaler (QwtPlotCanvas *, int referenceAxis=QwtPlot::xBottom, RescalePolicy=Expanding)
virtual ~QwtPlotRescaler ()
void setEnabled (bool)
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 QwtDoubleInterval &)
QwtDoubleInterval intervalHint (int axis) const
QwtPlotCanvas * canvas ()
const QwtPlotCanvas * canvas () const
QwtPlot * plot ()
const QwtPlot * plot () const
virtual bool eventFilter (QObject *, QEvent *)
void rescale () const

  Protected Member Functions
virtual void canvasResizeEvent (QResizeEvent *)
virtual void rescale (const QSize &oldSize, const QSize &newSize) const
virtual QwtDoubleInterval expandScale (int axis, 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
Qt::Orientation orientation (int axis) const
QwtDoubleInterval interval (int axis) const
QwtDoubleInterval expandInterval (const QwtDoubleInterval &, double width, ExpandingDirection) 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()

  QwtPlotRescaler::~QwtPlotRescaler () [virtual]

Destructor.

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()

  const QwtPlotCanvas * QwtPlotRescaler::canvas () const Returns:
    plot canvas

  QwtPlotCanvas * QwtPlotRescaler::canvas () Returns:
    plot canvas

  bool QwtPlotRescaler::eventFilter (QObject * o, QEvent * e) [virtual]

Event filter for the 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 [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

  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 )

  const QwtPlot * QwtPlotRescaler::plot () const Returns:
    plot widget

  QwtPlot * QwtPlotRescaler::plot () 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

  void QwtPlotRescaler::rescale () const

Adjust the plot axes scales.

  QwtPlotRescaler::RescalePolicy QwtPlotRescaler::rescalePolicy () const Returns:
    Rescale policy

See also:
    setRescalePolicy()

  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::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::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 (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::setExpandingDirection (ExpandingDirection direction) Set the direction in which all axis should be expanded

Parameters:
    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 [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

  void QwtPlotRescaler::updateScales (QwtDoubleInterval intervals[QwtPlot::axisCnt]) const [protected, virtual] Update the axes scales

Parameters:
    intervals Scale intervals

Author

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