Public Types¶

enum Attribute { NoAttribute = 0x00, IncludeReference = 0x01, Symmetric = 0x02, Floating = 0x04, Inverted = 0x08 }
typedef QFlags< Attribute > Attributes
Layout attributes.

Public Member Functions¶

QwtScaleEngine (uint base=10)
virtual ~QwtScaleEngine ()
Destructor. void setBase (uint base)
uint base () const
void setAttribute (Attribute, bool on=true)
bool testAttribute (Attribute) const
void setAttributes (Attributes)
Attributes attributes () const
void setReference (double)
Specify a reference point. double reference () const
void setMargins (double lower, double upper)
Specify margins at the scale's endpoints. double lowerMargin () const
double upperMargin () const
virtual void autoScale (int maxNumSteps, double &x1, double &x2, double &stepSize) const =0
virtual QwtScaleDiv divideScale (double x1, double x2, int maxMajorSteps, int maxMinorSteps, double stepSize=0.0) const =0
Calculate a scale division. void setTransformation (QwtTransform *)
QwtTransform * transformation () const

Protected Member Functions¶

bool contains (const QwtInterval &, double value) const
QList< double > strip (const QList< double > &, const QwtInterval &) const
double divideInterval (double intervalSize, int numSteps) const
QwtInterval buildInterval (double value) const
Build an interval around a value.

enum QwtScaleEngine::Attribute¶

Layout attributes

See also:

Enumerator

NoAttribute

No attributes.

IncludeReference

Build a scale which includes the reference() value.

Symmetric

Build a scale which is symmetric to the reference() value.

Floating

The endpoints of the scale are supposed to be equal the outmost included values plus the specified margins (see setMargins()). If this attribute is not set, the endpoints of the scale will be integer multiples of the step size.

Inverted

Turn the scale upside down.

QwtScaleEngine::QwtScaleEngine (uint base = 10) [explicit]¶

Constructor

Parameters:

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QwtScaleEngine::Attributes QwtScaleEngine::attributes () const¶

Returns:

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virtual void QwtScaleEngine::autoScale (int maxNumSteps, double & x1, double & x2, double & stepSize) const [pure virtual]¶

Align and divide an interval

Parameters:

Implemented in QwtLogScaleEngine, QwtLinearScaleEngine, and QwtDateScaleEngine.

uint QwtScaleEngine::base () const¶

Returns:

See also:

QwtInterval QwtScaleEngine::buildInterval (double value) const [protected]¶

Build an interval around a value. In case of v == 0.0 the interval is [-0.5, 0.5], otherwide it is [0.5 * v, 1.5 * v]

Parameters:

Returns:

bool QwtScaleEngine::contains (const QwtInterval & interval, double value) const [protected]¶

Check if an interval 'contains' a value

Parameters:

Returns:

double QwtScaleEngine::divideInterval (double intervalSize, int numSteps) const [protected]¶

Calculate a step size for an interval size

Parameters:

Returns:

virtual QwtScaleDiv QwtScaleEngine::divideScale (double x1, double x2, int maxMajorSteps, int maxMinorSteps, double stepSize = 0.0) const [pure virtual]¶

Calculate a scale division.

Parameters:

Returns:

Implemented in QwtLogScaleEngine, QwtLinearScaleEngine, and QwtDateScaleEngine.

double QwtScaleEngine::lowerMargin () const¶

Returns:

See also:

double QwtScaleEngine::reference () const¶

Returns:

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void QwtScaleEngine::setAttribute (Attribute attribute, bool on = true)¶

Change a scale attribute

Parameters:

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void QwtScaleEngine::setAttributes (Attributes attributes)¶

Change the scale attribute

Parameters:

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void QwtScaleEngine::setBase (uint base)¶

Set the base of the scale engine

While a base of 10 is what 99.9% of all applications need certain scales might need a different base: f.e 2

The default setting is 10

Parameters:

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void QwtScaleEngine::setMargins (double lower, double upper)¶

Specify margins at the scale's endpoints.

Parameters:

Margins can be used to leave a minimum amount of space between the enclosed intervals and the boundaries of the scale.

Warning:

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void QwtScaleEngine::setReference (double reference)¶

Specify a reference point.

Parameters:

The reference point is needed if options IncludeReference or Symmetric are active. Its default value is 0.0.

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void QwtScaleEngine::setTransformation (QwtTransform * transform)¶

Assign a transformation

Parameters:

The transformation object is used as factory for clones that are returned by transformation()

The scale engine takes ownership of the transformation.

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QList< double > QwtScaleEngine::strip (const QList< double > & ticks, const QwtInterval & interval) const [protected]¶

Remove ticks from a list, that are not inside an interval

Parameters:

Returns:

bool QwtScaleEngine::testAttribute (Attribute attribute) const¶

Returns:

Parameters:

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QwtTransform * QwtScaleEngine::transformation () const¶

Create and return a clone of the transformation of the engine. When the engine has no special transformation NULL is returned, indicating no transformation.

Returns:

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double QwtScaleEngine::upperMargin () const¶

Returns:

See also: