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NAME

       QwtDblRange -

SYNOPSIS

       Inherited by QwtCounter, and QwtSliderBase.

Detailed Description

       A class which controls a value within an interval.

       This class is useful as a base class or a member for sliders. It
       represents an interval of type double within which a value can be
       moved. The value can be either an arbitrary point inside the interval
       (see QwtDblRange::setValue), or it can be fitted into a step raster
       (see QwtDblRange::fitValue and QwtDblRange::incValue).

       As a special case, a QwtDblRange can be periodic, which means that a
       value outside the interval will be mapped to a value inside the
       interval when QwtDblRange::setValue(), QwtDblRange::fitValue(),
       QwtDblRange::incValue() or QwtDblRange::incPages() are called.

       Definition at line 31 of file qwt_drange.h.

   Public Member Functions
       QwtDblRange ()
       virtual ~QwtDblRange ()
       void setRange (double vmin, double vmax, double vstep=0.0, int
           pagesize=1)
       void setValid (bool)
       bool isValid () const
       virtual void setValue (double)
       double value () const
       void setPeriodic (bool tf)
       bool periodic () const
       void setStep (double)
       double step () const
       double maxValue () const
       double minValue () const
       int pageSize () const
       virtual void incValue (int)
       virtual void incPages (int)
       virtual void fitValue (double)

   Protected Member Functions
       double exactValue () const
       double exactPrevValue () const
       double prevValue () const
       virtual void valueChange ()
       virtual void stepChange ()
       virtual void rangeChange ()

Constructor & Destructor Documentation

   QwtDblRange::QwtDblRange ()
       The range is initialized to [0.0, 100.0], the step size to 1.0, and the
       value to 0.0. Definition at line 21 of file qwt_drange.cpp.

   QwtDblRange::~QwtDblRange () [virtual]
       Destroys the QwtDblRange.

       Definition at line 36 of file qwt_drange.cpp.

Member Function Documentation

   double QwtDblRange::exactPrevValue () const [protected]
       Returns the exact previous value.

       Definition at line 380 of file qwt_drange.cpp.

       Referenced by QwtSliderBase::mouseMoveEvent().

   double QwtDblRange::exactValue () const [protected]
       Returns the exact value.

       The exact value is the value which QwtDblRange::value would return if
       the value were not adjusted to the step raster. It differs from the
       current value only if QwtDblRange::fitValue or QwtDblRange::incValue
       have been used before. This function is intended for internal use in
       derived classes. Definition at line 374 of file qwt_drange.cpp.

       Referenced by QwtSliderBase::mouseMoveEvent(), and
       QwtSliderBase::timerEvent().

   void QwtDblRange::fitValue (double x) [virtual]
       Adjust the value to the closest point in the step raster.

       Parameters:
           x value

       Warning:
           The value is clipped when it lies outside the range. When the range
           is QwtDblRange::periodic, it will be mapped to a point in the
           interval such that

            new value := x + n * (max. value - min. value)

           with an integer number n.

       Reimplemented in QwtSliderBase.

       Definition at line 132 of file qwt_drange.cpp.

       Referenced by QwtSliderBase::fitValue(),
       QwtSliderBase::mouseReleaseEvent(), QwtSliderBase::setPosition(), and
       QwtSliderBase::timerEvent().

   void QwtDblRange::incPages (int nPages) [virtual]
       Increment the value by a specified number of pages.

       Parameters:
           nPages Number of pages to increment. A negative number decrements
           the value.

       Warning:
           The Page size is specified in the constructor.

       Definition at line 271 of file qwt_drange.cpp.

       References isValid().

       Referenced by QwtSliderBase::mouseReleaseEvent(),
       QwtSliderBase::timerEvent(), and QwtSliderBase::wheelEvent().

   void QwtDblRange::incValue (int nSteps) [virtual]
       Increment the value by a specified number of steps.

       Parameters:
           nSteps Number of steps to increment

       Warning:
           As a result of this operation, the new value will always be
           adjusted to the step raster.

       Reimplemented in QwtSliderBase.

       Definition at line 259 of file qwt_drange.cpp.

       References isValid().

       Referenced by QwtSliderBase::incValue(),
       QwtSliderBase::keyPressEvent(), and QwtDial::keyPressEvent().

   bool QwtDblRange::isValid () const
       Indicates if the value is valid.

       Reimplemented in QwtSliderBase.

       Definition at line 51 of file qwt_drange.cpp.

       Referenced by incPages(), incValue(), and QwtSliderBase::isValid().

   double QwtDblRange::maxValue () const
       Returns the value of the second border of the range.

       maxValue returns the value which has been specified as the second
       parameter in QwtDblRange::setRange.

       See also:
           QwtDblRange::setRange()

       Definition at line 326 of file qwt_drange.cpp.

       Referenced by QwtDial::drawContents(), QwtWheel::drawWheel(),
       QwtWheel::getValue(), QwtSlider::getValue(), QwtDial::getValue(),
       QwtDial::keyPressEvent(), QwtCounter::maxVal(),
       QwtSlider::rangeChange(), QwtSlider::scaleChange(),
       QwtCounter::setMinValue(), QwtDial::updateScale(), and
       QwtSlider::xyPosition().

   double QwtDblRange::minValue () const
       Returns the value at the first border of the range.

       minValue returns the value which has been specified as the first
       parameter in setRange().

       See also:
           QwtDblRange::setRange()

       Definition at line 339 of file qwt_drange.cpp.

       Referenced by QwtDial::drawContents(), QwtWheel::drawWheel(),
       QwtWheel::getValue(), QwtSlider::getValue(), QwtDial::getValue(),
       QwtDial::keyPressEvent(), QwtCounter::minVal(),
       QwtSlider::rangeChange(), QwtSlider::scaleChange(),
       QwtCounter::setMaxValue(), QwtDial::updateScale(), and
       QwtSlider::xyPosition().

   int QwtDblRange::pageSize () const
       Returns the page size in steps.

       Definition at line 354 of file qwt_drange.cpp.

       Referenced by QwtDial::keyPressEvent().

   bool QwtDblRange::periodic () const
       Returns TRUE if the range is periodic.

       See also:
           QwtDblRange::setPeriodic()

       Definition at line 348 of file qwt_drange.cpp.

       Referenced by QwtDial::wrapping().

   double QwtDblRange::prevValue () const [protected]
       Returns the previous value.

       Definition at line 386 of file qwt_drange.cpp.

       Referenced by QwtSliderBase::keyPressEvent(), QwtDial::keyPressEvent(),
       QwtSliderBase::mouseMoveEvent(), and QwtSliderBase::wheelEvent().

   void QwtDblRange::rangeChange () [protected, virtual]
       Notify a change of the range.

       This virtual function is called whenever the range changes. The default
       implementation does nothing.

       Reimplemented in QwtCounter, QwtDial, and QwtSlider.

       Definition at line 294 of file qwt_drange.cpp.

       Referenced by QwtSlider::rangeChange(), and setRange().

   void QwtDblRange::setPeriodic (bool tf)
       Make the range periodic.

       When the range is periodic, the value will be set to a point inside the
       interval such that

        point = value + n * width .fi

       if the user tries to set a new value which is outside the range. If the range is nonperiodic (the default), values outside the range will be clipped.

       Parameters:
           tf TRUE for a periodic range

       Definition at line 248 of file qwt_drange.cpp.

       Referenced by QwtDial::setWrapping().

   void QwtDblRange::setRange (double vmin, double vmax, double vstep = 0.0,
       int pageSize = 1)
       Specify range and step size.

       Parameters:
           vmin lower boundary of the interval
           vmax higher boundary of the interval
           vstep step width
           pageSize page size in steps

       Warning:
           · A change of the range changes the value if it lies outside the
             new range. The current value will *not* be adjusted to the new
             step raster.
           · vmax < vmin is allowed.
           · If the step size is left out or set to zero, it will be set to
             1/100 of the interval length.
           · If the step size has an absurd value, it will be corrected to a
             better one.
       Definition at line 169 of file qwt_drange.cpp.
       References qwtLim(), rangeChange(), and setStep().
       Referenced by QwtAnalogClock::QwtAnalogClock(),
       QwtCounter::QwtCounter(), QwtDial::QwtDial(),
       QwtSliderBase::QwtSliderBase(), QwtCounter::setMaxValue(), and
       QwtCounter::setMinValue().
   void QwtDblRange::setStep (double vstep)
       Change the step raster.
       Parameters:
           vstep new step width
       Warning:
           The value will not be adjusted to the new step raster.

       Reimplemented in QwtCounter.
       Definition at line 208 of file qwt_drange.cpp.
       References stepChange().
       Referenced by setRange(), and QwtCounter::setStep().
   void QwtDblRange::setValid (bool)
       Set the value to be valid/invalid.
       Reimplemented in QwtSliderBase.
       Definition at line 41 of file qwt_drange.cpp.
       References valueChange().
       Referenced by QwtSliderBase::setValid().
   void QwtDblRange::setValue (double x) [virtual]
       Set a new value without adjusting to the step raster.
       Parameters:
           x new value
       Warning:
           The value is clipped when it lies outside the range. When the range
           is QwtDblRange::periodic, it will be mapped to a point in the
           interval such that
            new value := x + n * (max. value - min. value)
           with an integer number n.

       Reimplemented in QwtCounter, and QwtSliderBase.
       Definition at line 147 of file qwt_drange.cpp.
       Referenced by QwtSliderBase::setValue(), and QwtCounter::setValue().
   double QwtDblRange::step () const
       Returns:
           the step size
       See also:
           QwtDblRange::setStep, QwtDblRange::setRange

       Reimplemented in QwtCounter.
       Definition at line 313 of file qwt_drange.cpp.
       Referenced by QwtSliderBase::mouseReleaseEvent(),
       QwtCounter::setMaxValue(), QwtCounter::setMinValue(),
       QwtCounter::step(), and QwtSliderBase::timerEvent().
   void QwtDblRange::stepChange () [protected, virtual]
       Notify a change of the step size.
       This virtual function is called whenever the step size changes. The
       default implementation does nothing. Definition at line 305 of file
       qwt_drange.cpp.
       Referenced by setStep().
   double QwtDblRange::value () const
       Returns the current value.
       Reimplemented in QwtCounter.
       Definition at line 360 of file qwt_drange.cpp.
       Referenced by QwtDial::drawContents(), QwtAnalogClock::drawNeedle(),
       QwtCompass::drawScaleContents(), QwtSlider::drawSlider(),
       QwtWheel::drawWheel(), QwtSlider::getScrollMode(), QwtDial::getValue(),
       QwtSliderBase::keyPressEvent(), QwtDial::keyPressEvent(),
       QwtCompass::keyPressEvent(), QwtSliderBase::mouseMoveEvent(),
       QwtSliderBase::mousePressEvent(), QwtSliderBase::mouseReleaseEvent(),
       QwtSliderBase::timerEvent(), QwtCounter::value(),
       QwtSliderBase::valueChange(), and QwtSliderBase::wheelEvent().
   void QwtDblRange::valueChange () [protected, virtual]
       Notify a change of value.
       This virtual function is called whenever the value changes. The default
       implementation does nothing.
       Reimplemented in QwtDial, QwtSliderBase, QwtSlider, and QwtWheel.
       Definition at line 283 of file qwt_drange.cpp.
       Referenced by setValid().

Author

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