qwtdblrange.3

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.TH "QwtDblRange" 3 "4 Nov 2003" "Qwt User's Guide" \" -*- nroff -*-
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.SH NAME
QwtDblRange \- 
.SH SYNOPSIS
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.PP
Inherited by \fBQwtCounter\fP, and \fBQwtSliderBase\fP.
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.SH "Detailed Description"
.PP 
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 \fBQwtDblRange::setValue\fP), or it can be fitted into a step raster (see \fBQwtDblRange::fitValue\fP and \fBQwtDblRange::incValue\fP).
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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 \fBQwtDblRange::setValue()\fP, \fBQwtDblRange::fitValue()\fP, \fBQwtDblRange::incValue()\fP or \fBQwtDblRange::incPages()\fP are called. 
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.SS "Public Member Functions"

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.RI "\fBQwtDblRange\fP ()"
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.RI "virtual \fB~QwtDblRange\fP ()"
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.RI "void \fBsetRange\fP (double vmin, double vmax, double vstep=0.0, int pagesize=1)"
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.RI "void \fBsetValid\fP (bool)"
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.RI "bool \fBisValid\fP () const "
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.RI "virtual void \fBsetValue\fP (double)"
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.RI "double \fBvalue\fP () const "
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.RI "void \fBsetPeriodic\fP (bool tf)"
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.RI "bool \fBperiodic\fP () const "
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.RI "void \fBsetStep\fP (double)"
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.RI "double \fBstep\fP () const "
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.RI "double \fBmaxValue\fP () const "
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.RI "double \fBminValue\fP () const "
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.RI "int \fBpageSize\fP () const "
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.RI "virtual void \fBincValue\fP (int)"
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.RI "virtual void \fBincPages\fP (int)"
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.RI "virtual void \fBfitValue\fP (double)"
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.SS "Protected Member Functions"

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.RI "double \fBexactValue\fP () const "
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.RI "double \fBexactPrevValue\fP () const "
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.RI "double \fBprevValue\fP () const "
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.RI "virtual void \fBvalueChange\fP ()"
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.RI "virtual void \fBstepChange\fP ()"
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.RI "virtual void \fBrangeChange\fP ()"
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.SH "Constructor & Destructor Documentation"
.PP 
.SS "QwtDblRange::QwtDblRange ()"
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The range is initialized to [0.0, 100.0], the step size to 1.0, and the value to 0.0. 
.SS "QwtDblRange::~\fBQwtDblRange\fP ()\fC [virtual]\fP"
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Destroys the QwtDblRange. 
.SH "Member Function Documentation"
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.SS "double QwtDblRange::exactPrevValue () const\fC [protected]\fP"
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Returns the exact previous value. 
.SS "double QwtDblRange::exactValue () const\fC [protected]\fP"
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Returns the exact value. The exact value is the value which \fBQwtDblRange::value\fP would return if the value were not adjusted to the step raster. It differs from the current value only if \fBQwtDblRange::fitValue\fP or \fBQwtDblRange::incValue\fP have been used before. This function is intended for internal use in derived classes. 
.SS "void QwtDblRange::fitValue (double x)\fC [virtual]\fP"
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Adjust the value to the closest point in the step raster. \fBParameters:\fP
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\fIx\fP value 
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\fBWarning:\fP
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The value is clipped when it lies outside the range. When the range is \fBQwtDblRange::periodic\fP, it will be mapped to a point in the interval such that 
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 new value := x + n * (max. value - min. value)
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with an integer number n. 
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Reimplemented in \fBQwtSliderBase\fP.
.SS "void QwtDblRange::incPages (int nPages)\fC [virtual]\fP"
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Increment the value by a specified number of pages. \fBParameters:\fP
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\fInPages\fP Number of pages to increment. A negative number decrements the value. 
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\fBWarning:\fP
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The Page size is specified in the constructor. 
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.SS "void QwtDblRange::incValue (int nSteps)\fC [virtual]\fP"
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Increment the value by a specified number of steps. \fBParameters:\fP
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\fInSteps\fP Number of steps to increment 
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\fBWarning:\fP
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As a result of this operation, the new value will always be adjusted to the step raster. 
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Reimplemented in \fBQwtSliderBase\fP.
.SS "bool QwtDblRange::isValid () const"
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Indicates if the value is valid. Reimplemented in \fBQwtSliderBase\fP.
.SS "double QwtDblRange::maxValue () const"
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Returns the value of the second border of the range. maxValue returns the value which has been specified as the second parameter in \fBQwtDblRange::setRange\fP.
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\fBSee also:\fP
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\fBQwtDblRange::setRange()\fP 
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.SS "double QwtDblRange::minValue () const"
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Returns the value at the first border of the range. minValue returns the value which has been specified as the first parameter in \fBsetRange()\fP.
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\fBSee also:\fP
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\fBQwtDblRange::setRange()\fP 
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.SS "int QwtDblRange::pageSize () const"
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Returns the page size in steps. 
.SS "bool QwtDblRange::periodic () const"
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Returns TRUE if the range is periodic. \fBSee also:\fP
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\fBQwtDblRange::setPeriodic()\fP 
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.SS "double QwtDblRange::prevValue () const\fC [protected]\fP"
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Returns the previous value. 
.SS "void QwtDblRange::rangeChange ()\fC [protected, virtual]\fP"
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Notify a change of the range. This virtual function is called whenever the range changes. The default implementation does nothing. Reimplemented in \fBQwtCounter\fP, \fBQwtDial\fP, and \fBQwtSlider\fP.
.SS "void QwtDblRange::setPeriodic (bool tf)"
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Make the range periodic. When the range is periodic, the value will be set to a point inside the interval such that
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 point = value + n * width .PP
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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.
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\fBParameters:\fP
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\fItf\fP TRUE for a periodic range 
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.SS "void QwtDblRange::setRange (double vmin, double vmax, double vstep = 0.0, int pageSize = 1)"
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Specify range and step size. \fBParameters:\fP
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\fIvmin\fP lower boundary of the interval 
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\fIvmax\fP higher boundary of the interval 
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\fIvstep\fP step width 
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\fIpageSize\fP page size in steps 
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\fBWarning:\fP
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.IP "\(bu" 2
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. 
.IP "\(bu" 2
vmax < vmin is allowed. 
.IP "\(bu" 2
If the step size is left out or set to zero, it will be set to 1/100 of the interval length. 
.IP "\(bu" 2
If the step size has an absurd value, it will be corrected to a better one. 
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.SS "void QwtDblRange::setStep (double vstep)"
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Change the step raster. \fBParameters:\fP
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\fIvstep\fP new step width 
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\fBWarning:\fP
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The value will \fInot\fP be adjusted to the new step raster. 
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Reimplemented in \fBQwtCounter\fP.
.SS "void QwtDblRange::setValid (bool)"
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Set the value to be valid/invalid. Reimplemented in \fBQwtSliderBase\fP.
.SS "void QwtDblRange::setValue (double x)\fC [virtual]\fP"
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Set a new value without adjusting to the step raster. \fBParameters:\fP
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\fIx\fP new value 
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\fBWarning:\fP
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The value is clipped when it lies outside the range. When the range is \fBQwtDblRange::periodic\fP, it will be mapped to a point in the interval such that 
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 new value := x + n * (max. value - min. value)
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with an integer number n. 
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Reimplemented in \fBQwtCounter\fP, and \fBQwtSliderBase\fP.
.SS "double QwtDblRange::step () const"
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\fBReturns:\fP
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the step size 
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\fBSee also:\fP
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\fBQwtDblRange::setStep\fP, \fBQwtDblRange::setRange\fP 
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Reimplemented in \fBQwtCounter\fP.
.SS "void QwtDblRange::stepChange ()\fC [protected, virtual]\fP"
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Notify a change of the step size. This virtual function is called whenever the step size changes. The default implementation does nothing. 
.SS "double QwtDblRange::value () const"
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Returns the current value. Reimplemented in \fBQwtCounter\fP.
.SS "void QwtDblRange::valueChange ()\fC [protected, virtual]\fP"
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Notify a change of value. This virtual function is called whenever the value changes. The default implementation does nothing. Reimplemented in \fBQwtDial\fP, \fBQwtSliderBase\fP, \fBQwtSlider\fP, and \fBQwtWheel\fP.

.SH "Author"
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