QwtPlotRescaler Class Reference

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

#include <qwt_plot_rescaler.h>

List of all members.

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 QwtInterval &)
QwtInterval intervalHint (int axis) const
QwtPlotCanvascanvas ()
const QwtPlotCanvascanvas () const
QwtPlotplot ()
const QwtPlotplot () 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 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 autoadjusts the axes of a QwtPlot according to fixed aspect ratios.


Member Enumeration Documentation

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

  • 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

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 interval hint.
See also:
ExpandingDirection, setIntervalHint()

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
void QwtPlotRescaler::canvasResizeEvent ( QResizeEvent *  event  )  [protected, virtual]

Event handler for resize events of the plot canvas

Parameters:
event Resize event
See also:
rescale()
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()
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 [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 ( int  axis  )  const [protected]

Return interval of an axis

Parameters:
axis Axis index ( see QwtPlot::AxisId )
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]

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::setIntervalHint ( int  axis,
const QwtInterval interval 
)

Set an interval hint for an axis

In Fitting mode, the hint is used as minimal interval taht 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 [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 ( QwtInterval  intervals[QwtPlot::axisCnt]  )  const [protected, virtual]

Update the axes scales

Parameters:
intervals Scale intervals
Generated on Sun Nov 21 12:01:45 2010 for Qwt User's Guide by  doxygen 1.6.3