QwtScaleDraw

Section: Qwt User's Guide (3) Updated: 16 Nov 2004 Local index Up

NAME

QwtScaleDraw -

SYNOPSIS

Inherits QwtDiMap.

Inherited by QwtDialScaleDraw.

Detailed Description

A class for drawing scales.

QwtScaleDraw can be used to draw linear or logarithmic scales. A scale has an origin, an orientation and a length, which all can be specified with QwtScaleDraw::setGeometry(). The labels can be rotated and aligned to the ticks using QwtScaleDraw::setLabelRotation(), QwtScaleDraw::setLabelAlignment().

After a scale division has been specified as a QwtScaleDiv object using QwtScaleDraw::setScale(const QwtScaleDiv &s), or determined internally using QwtScaleDraw::setScale(double vmin, double vmax, int maxMajIntv, int maxMinIntv, double step = 0.0, int logarithmic = 0), the scale can be drawn with the QwtScaleDraw::draw() member.

Definition at line 38 of file qwt_scldraw.h.

Public Types

enum Orientation { Bottom, Top, Left, Right, Round }

enum Option { None = 0, Backbone = 1 }

Public Member Functions

QwtScaleDraw ()

virtual ~QwtScaleDraw ()

void setScale (const QwtScaleDiv &s)

void setScale (double vmin, double vmax, int maxMajIntv, int maxMinIntv, double step=0.0, int logarithmic=0)

void setOptions (int opt)

int options () const

void setGeometry (int xorigin, int yorigin, int length, Orientation o)

int x () const

int y () const

int length () const

Orientation orientation () const

void setAngleRange (double angle1, double angle2)

void setLabelFormat (char f, int prec, int fieldwidth=0)

void setLabelAlignment (int align)

void setLabelRotation (double rotation)

void setTickLength (unsigned int minLen, unsigned int medLen, unsigned int majLen)

void setMargin (uint hMargin, uint vMargin)

const QwtScaleDiv & scaleDiv () const

int maxWidth (const QPen &pen, const QFontMetrics &fm) const

int maxHeight (const QPen &pen, const QFontMetrics &fm) const

void minBorderDist (const QFontMetrics &fm, int &start, int &end) const

int minLabelDist (const QFontMetrics &fm) const

int minHeight (const QPen &pen, const QFontMetrics &fm) const

int minWidth (const QPen &pen, const QFontMetrics &fm) const

void labelFormat (char &f, int &prec, int &fieldwidth) const

int labelAlignment () const

double labelRotation () const

void tickLength (unsigned int &minLen, unsigned int &medLen, unsigned int &majLen) const

unsigned int majTickLength () const

virtual void draw (QPainter *p) const

virtual QString label (double) const

Protected Member Functions

virtual void labelPlacement (const QFontMetrics &, double val, QPoint &pos, int &alignment, double &rotation) const

virtual int maxLabelHeight (const QFontMetrics &) const

virtual int maxLabelWidth (const QFontMetrics &) const

QRect labelBoundingRect (const QFontMetrics &, double val) const

void drawTick (QPainter *p, double val, int len) const

void drawBackbone (QPainter *p) const

void drawLabel (QPainter *p, double val) const

QWMatrix labelWorldMatrix (const QFontMetrics &, const QPoint &, int alignment, double rotation, const QString &) const

Member Enumeration Documentation

enum QwtScaleDraw::Orientation

Orientation/Position of the scale draw

See also:

: QwtScaleDraw::setGeometry

Definition at line 45 of file qwt_scldraw.h.

Referenced by orientation().

Constructor & Destructor Documentation

QwtScaleDraw::QwtScaleDraw ()

Constructor.

The range of the scale is initialized to [0, 100], the angle range is set to [-135, 135], the geometry is initialized such that the origin is at (0,0), the length is 100, and the orientation is QwtScaleDraw::Bottom. Definition at line 29 of file qwt_scldraw.cpp.

References setGeometry(), and setScale().

QwtScaleDraw::~QwtScaleDraw () [virtual]

Destructor.

Definition at line 52 of file qwt_scldraw.cpp.

Member Function Documentation

void QwtScaleDraw::draw (QPainter * p) const [virtual]

Draw the scale.

Parameters:

: p the painter

Definition at line 104 of file qwt_scldraw.cpp.

References drawBackbone(), drawLabel(), drawTick(), QwtScaleDiv::logScale(), QwtScaleDiv::majCnt(), QwtScaleDiv::majMark(), QwtScaleDiv::majStep(), QwtScaleDiv::minCnt(), QwtScaleDiv::minMark(), and options().

Referenced by QwtThermo::draw(), QwtSlider::draw(), QwtScale::draw(), QwtKnob::draw(), QwtDial::drawScale(), and QwtPlot::printScale().

void QwtScaleDraw::drawBackbone (QPainter * p) const [protected]

Draws the baseline of the scale.

Definition at line 374 of file qwt_scldraw.cpp.

References QwtPainter::drawLine(), QwtDiMap::i1(), and QwtDiMap::i2().

Referenced by draw().

void QwtScaleDraw::drawLabel (QPainter * p, double val) const [protected]

Draws the number label for a major scale tick.

Definition at line 204 of file qwt_scldraw.cpp.

References QwtPainter::drawText(), label(), labelPlacement(), and labelWorldMatrix().

Referenced by draw().

void QwtScaleDraw::drawTick (QPainter * p, double val, int len) const [protected]

Draws a single scale tick.

Definition at line 160 of file qwt_scldraw.cpp.

References QwtPainter::drawLine(), and QwtDiMap::transform().

Referenced by draw().

QString QwtScaleDraw::label (double value) const [virtual]

Convert a value into its representing label using the labelFormat.

Parameters:

: value Value

Returns:

: Label string.

See also:

: QwtScaleDraw::setLabelFormat()

Reimplemented in QwtDialScaleDraw.

Definition at line 1045 of file qwt_scldraw.cpp.

Referenced by drawLabel(), QwtDialScaleDraw::label(), labelBoundingRect(), and labelPlacement().

int QwtScaleDraw::labelAlignment () const

Returns:

: the label alignment

See also:

: setLabelAlignment(), labelRotation()

Definition at line 588 of file qwt_scldraw.cpp.

QRect QwtScaleDraw::labelBoundingRect (const QFontMetrics & fm, double val) const [protected]

Find the bounding rect for the label. The coordinates of the rect are relative to margin + ticklength from the backbone in direction of the tick. Definition at line 793 of file qwt_scldraw.cpp.

References label(), labelPlacement(), and labelWorldMatrix().

Referenced by maxLabelHeight(), maxLabelWidth(), minBorderDist(), and minLabelDist().

void QwtScaleDraw::labelFormat (char & f, int & prec, int & fieldwidth) const

Return the number format for the major scale labels.

Format character, precision and fieldwidth have the same meaning as for sprintf().

Parameters:

f format character 'e', 'f' or 'g'
prec

•: for 'e', 'f': the number of digits after the radix character (point)
•: for 'g': the maximum number of significant digits

fieldwidth fieldwidth

See also:

: setLabelFormat()

Definition at line 679 of file qwt_scldraw.cpp.

Referenced by QwtScale::labelFormat().

void QwtScaleDraw::labelPlacement (const QFontMetrics &, double val, QPoint & pos, int & alignment, double & rotation) const [protected, virtual]

Find position, alignment and rotation of the label.

Definition at line 232 of file qwt_scldraw.cpp.

References label(), QwtScaleDiv::logScale(), QwtScaleDiv::majStep(), QwtDiMap::transform(), x(), and y().

Referenced by drawLabel(), and labelBoundingRect().

double QwtScaleDraw::labelRotation () const

Returns:

: the label rotation

See also:

: setLabelRotation(), labelAlignment()

Definition at line 555 of file qwt_scldraw.cpp.

QWMatrix QwtScaleDraw::labelWorldMatrix (const QFontMetrics &, const QPoint &, int alignment, double rotation, const QString &) const [protected]

Return the world matrix for painting the label.

Definition at line 335 of file qwt_scldraw.cpp.

References x(), and y().

Referenced by drawLabel(), and labelBoundingRect().

int QwtScaleDraw::length () const

Return length.

Definition at line 1076 of file qwt_scldraw.cpp.

Referenced by QwtPlot::printScale().

unsigned int QwtScaleDraw::majTickLength () const

Return the length of the major ticks

See also:

: QwtScaleDraw::tickLength()

Definition at line 727 of file qwt_scldraw.cpp.

Referenced by QwtPlotLayout::minimumSizeHint().

int QwtScaleDraw::maxHeight (const QPen & pen, const QFontMetrics & fm) const

Parameters:

: pen pen
fm font metrics

Returns:

: the maximum height of the scale

Definition at line 513 of file qwt_scldraw.cpp.

References maxLabelHeight().

Referenced by QwtScale::layoutScale(), maxLabelHeight(), and QwtDial::scaleContentsRect().

int QwtScaleDraw::maxLabelHeight (const QFontMetrics & fm) const [protected, virtual]

Parameters:

: fm QFontMetrics

Returns:

: the maximum width of a label

Definition at line 764 of file qwt_scldraw.cpp.

References labelBoundingRect(), QwtScaleDiv::logScale(), QwtScaleDiv::majCnt(), QwtScaleDiv::majMark(), QwtScaleDiv::majStep(), and maxHeight().

Referenced by maxHeight(), and minHeight().

int QwtScaleDraw::maxLabelWidth (const QFontMetrics & fm) const [protected, virtual]

Parameters:

: fm QFontMetrics

Returns:

: the maximum width of a label

Definition at line 736 of file qwt_scldraw.cpp.

References labelBoundingRect(), QwtScaleDiv::logScale(), QwtScaleDiv::majCnt(), QwtScaleDiv::majMark(), QwtScaleDiv::majStep(), and maxWidth().

Referenced by maxWidth(), minHeight(), and minWidth().

int QwtScaleDraw::maxWidth (const QPen & pen, const QFontMetrics & fm) const

Parameters:

: pen pen
fm font metrics

Returns:

: the maximum width of the scale

Definition at line 487 of file qwt_scldraw.cpp.

References maxLabelWidth().

Referenced by QwtScale::layoutScale(), maxLabelWidth(), and QwtDial::scaleContentsRect().

void QwtScaleDraw::minBorderDist (const QFontMetrics & fm, int & start, int & end) const

Determine the minimum border distance.

This member function returns the minimum space needed to draw the mark labels at the scale's endpoints.

Parameters:

: fm QFontMetrics
start start border distance
end end border distance

Definition at line 839 of file qwt_scldraw.cpp.

References labelBoundingRect(), QwtScaleDiv::majCnt(), and QwtScaleDiv::majMark().

Referenced by QwtSlider::layoutSlider(), QwtThermo::layoutThermo(), QwtScale::minBorderDist(), minHeight(), QwtSlider::minimumSizeHint(), and minWidth().

int QwtScaleDraw::minHeight (const QPen & pen, const QFontMetrics & fm) const

Parameters:

: pen pen
fm font metrics

Returns:

: the minimum height required to draw the scale including the minimum border distance

Definition at line 960 of file qwt_scldraw.cpp.

References QwtScaleDiv::majCnt(), maxLabelHeight(), maxLabelWidth(), minBorderDist(), QwtScaleDiv::minCnt(), and minLabelDist().

Referenced by QwtScale::dimForLength(), QwtThermo::minimumSizeHint(), QwtSlider::minimumSizeHint(), QwtScale::minimumSizeHint(), QwtKnob::minimumSizeHint(), QwtDial::minimumSizeHint(), and QwtDial::sizeHint().

int QwtScaleDraw::minLabelDist (const QFontMetrics & fm) const

Determine the minimum distance between two labels, that is necessairy that the texts don't overlap.

Parameters:

: fm QFontMetrics

Returns:

: the maximum width of a label

Warning:

: Not implemented for round scales

Definition at line 880 of file qwt_scldraw.cpp.

References labelBoundingRect(), QwtScaleDiv::majCnt(), and QwtScaleDiv::majMark().

Referenced by minHeight(), and minWidth().

int QwtScaleDraw::minWidth (const QPen & pen, const QFontMetrics & fm) const

Parameters:

: pen pen
fm font metrics

Returns:

: the minimum width required to draw the scale including the minimum border distance

Definition at line 1000 of file qwt_scldraw.cpp.

References QwtScaleDiv::majCnt(), maxLabelWidth(), minBorderDist(), QwtScaleDiv::minCnt(), and minLabelDist().

Referenced by QwtScale::dimForLength(), QwtThermo::minimumSizeHint(), QwtSlider::minimumSizeHint(), and QwtScale::minimumSizeHint().

int QwtScaleDraw::options () const

Returns:

: scale draw options

Definition at line 65 of file qwt_scldraw.cpp.

Referenced by draw(), and QwtDial::setScaleOptions().

QwtScaleDraw::Orientation QwtScaleDraw::orientation () const

Return scale orientation.

Definition at line 1082 of file qwt_scldraw.cpp.

References Orientation.

Referenced by QwtScale::dimForLength(), QwtScale::draw(), QwtScale::layoutScale(), QwtScale::minimumSizeHint(), QwtScale::position(), QwtThermo::sizePolicy(), and QwtScale::sizePolicy().

const QwtScaleDiv& QwtScaleDraw::scaleDiv () const

Returns:

: scale division

Definition at line 74 of file qwt_scldraw.h.

Referenced by QwtThermo::setRange(), QwtScaleIf::setScale(), QwtScale::setScaleDiv(), QwtScaleIf::setScaleMaxMajor(), QwtScaleIf::setScaleMaxMinor(), and QwtPlot::sizeHint().

void QwtScaleDraw::setAngleRange (double angle1, double angle2)

Adjust the baseline circle segment for round scales.

The baseline will be drawn from min(angle1,angle2) to max(angle1, angle2). The settings have no effect if the scale orientation is not set to QwtScaleDraw::Round. The default setting is [ -135, 135 ]. An angle of 0 degrees corresponds to the 12 o'clock position, and positive angles count in a clockwise direction.

Parameters:

: angle1
angle2 boundaries of the angle interval in degrees.

Warning:

•: The angle range is limited to [-360, 360] degrees. Angles exceeding this range will be clipped.
•: For angles more than 359 degrees above or below min(angle1, angle2), scale marks will not be drawn.
•: If you need a counterclockwise scale, use QwtScaleDiv::setRange

Definition at line 611 of file qwt_scldraw.cpp.

References qwtLim(), and QwtDiMap::setIntRange().

Referenced by QwtDial::drawScale(), and QwtKnob::setTotalAngle().

void QwtScaleDraw::setGeometry (int xorigin, int yorigin, int length, Orientation o)

Specify the geometry of the scale.

The parameters xorigin, yorigin and length have different meanings, dependent on the orientation:

QwtScaleDraw::Left: The origin is the topmost point of the baseline. The baseline is a vertical line with the specified length. Scale marks and labels are drawn at the left of the baseline.
QwtScaleDraw::Right: The origin is the topmost point of the baseline. The baseline is a vertical line with the specified length. Scale marks and labels are drawn at the right of the baseline.
QwtScaleDraw::Top: The origin is the leftmost point of the baseline. The baseline is a horizontal line with the specified length. Scale marks and labels are drawn above the baseline.
QwtScaleDraw::Bottom: The origin is the leftmost point of the baseline. The baseline is a horizontal line with the specified length. Scale marks and labels are drawn below the baseline.
QwtScaleDraw::Round: The origin is the top left corner of the bounding rectangle of the baseline circle. The baseline is the segment of a circle with a diameter of the specified length. Scale marks and labels are drawn outside the baseline circle.

Parameters:

: xorigin x coordinate of the origin
yorigin y coordinate of the origin
length length or diameter of the scale, excluding border distance
o The orientation

Definition at line 448 of file qwt_scldraw.cpp.

References QwtDiMap::setIntRange().

Referenced by QwtDial::drawScale(), QwtScale::layoutScale(), QwtSlider::layoutSlider(), QwtThermo::layoutThermo(), QwtPlot::printScale(), QwtDial::QwtDial(), QwtKnob::QwtKnob(), QwtScaleDraw(), QwtSlider::QwtSlider(), and QwtScale::setPosition().

void QwtScaleDraw::setLabelAlignment (int alignment)

Labels are aligned to the point ticklength + margin away from the backbone. The alignment is relative to the orientation of the label text. In case of an alignment of 0 the label will be aligned depending on the orientation of the scale:

QwtScaleDraw::Top: Qt::AlignHCenter | Qt::AlignTop

QwtScaleDraw::Bottom: Qt::AlignHCenter | Qt::AlignBottom

QwtScaleDraw::Left: Qt::AlignLeft | Qt::AlignVCenter

QwtScaleDraw::Right: Qt::AlignRight | Qt::AlignVCenter

Changing the alignment is often necessary for rotated labels.

Parameters:

: alignment Or'd Qt::AlignmentFlags <see qnamespace.h>

Warning:

: Alignment of labels is not implemented for round scales.

See also:

: QwtScaleDraw::setLabelRotation(), QwtScaleDraw::labelRotation(), QwtScaleDraw::labelAlignment()

Definition at line 579 of file qwt_scldraw.cpp.

Referenced by QwtScale::setLabelAlignment().

void QwtScaleDraw::setLabelFormat (char f, int prec, int fieldwidth = 0)

Set the number format for the major scale labels.

Format character, precision and fieldwidth have the same meaning as for sprintf().

Parameters:

f format character 'e', 'f', 'g'
prec

•: for 'e', 'f': the number of digits after the radix character (point)
•: for 'g': the maximum number of significant digits

fieldwidth fieldwidth

Note:

: precision and fieldwidth must be in the range 0, 1, .., 99. Invalid input is discarded.

See also:

: labelFormat()

Definition at line 646 of file qwt_scldraw.cpp.

Referenced by QwtScale::setLabelFormat().

void QwtScaleDraw::setLabelRotation (double rotation)

Rotate all labels.

Parameters:

: rotation Angle in degrees. When changing the label rotation, the label alignment might be adjusted too.

See also:

: setLabelAlignment(), labelRotation(), labelAlignment().

Warning:

: Rotation of labels is not implemented for round scales.

Definition at line 546 of file qwt_scldraw.cpp.

Referenced by QwtScale::setLabelRotation().

void QwtScaleDraw::setMargin (uint hMargin, uint vMargin)

Set the margins of the ticks

Parameters:

: hMargin Horizontal margin
vMargin Vertical margin

Definition at line 692 of file qwt_scldraw.cpp.

void QwtScaleDraw::setOptions (int opt)

Change the scale draw options.

Definition at line 57 of file qwt_scldraw.cpp.

Referenced by QwtDial::setScaleOptions().

void QwtScaleDraw::setScale (double x1, double x2, int maxMajIntv, int maxMinIntv, double step = 0.0, int logscale = 0)

Adjust the range of the scale.

If step == 0.0, the step width is calculated automatically dependent on the maximal number of scale ticks.

Parameters:

: x1 Value at the left/low endpoint of the scale
x2 Value at the right/high endpoint of the scale
maxMajIntv Max. number of major step intervals
maxMinIntv Max. number of minor step intervals
step Step size (default : 0.0)
logscale Logarithmic scale (default : 0)

Definition at line 82 of file qwt_scldraw.cpp.

References QwtScaleDiv::hBound(), QwtScaleDiv::lBound(), QwtScaleDiv::logScale(), QwtScaleDiv::rebuild(), and QwtDiMap::setDblRange().

void QwtScaleDraw::setScale (const QwtScaleDiv & sd)

Change the scale division.

Parameters:

: sd new scale division

Definition at line 94 of file qwt_scldraw.cpp.

References QwtScaleDiv::hBound(), QwtScaleDiv::lBound(), QwtScaleDiv::logScale(), and QwtDiMap::setDblRange().

Referenced by QwtScaleDraw(), QwtScaleIf::QwtScaleIf(), QwtSlider::rangeChange(), QwtSlider::scaleChange(), QwtThermo::setRange(), QwtScaleIf::setScale(), QwtScale::setScaleDiv(), QwtScaleIf::setScaleMaxMajor(), QwtScaleIf::setScaleMaxMinor(), and QwtDial::updateScale().