QwtScaleDraw(3) Qwt User's Guide QwtScaleDraw(3)NAMEQwtScaleDraw-
SYNOPSIS
#include <qwt_scale_draw.h>
Inherits QwtAbstractScaleDraw.
Public Types
enum Alignment { BottomScale, TopScale, LeftScale, RightScale }
Public Member Functions
QwtScaleDraw ()
QwtScaleDraw (const QwtScaleDraw &)
virtual ~QwtScaleDraw ()
Alignment alignment () const
QRect boundingLabelRect (const QFont &, double val) const
virtual int extent (const QPen &, const QFont &) const
void getBorderDistHint (const QFont &, int &start, int &end) const
Qt::Alignment labelAlignment () const
QPoint labelPosition (double val) const
QRect labelRect (const QFont &, double val) const
double labelRotation () const
QSize labelSize (const QFont &, double val) const
int length () const
int maxLabelHeight (const QFont &) const
int maxLabelWidth (const QFont &) const
int minLabelDist (const QFont &) const
int minLength (const QPen &, const QFont &) const
void move (int x, int y)
void move (const QPoint &)
QwtScaleDraw & operator= (const QwtScaleDraw &other)
Qt::Orientation orientation () const
QPoint pos () const
void setAlignment (Alignment)
void setLabelAlignment (Qt::Alignment)
void setLabelRotation (double rotation)
void setLength (int length)
Protected Member Functions
virtual void drawBackbone (QPainter *p) const
virtual void drawLabel (QPainter *p, double val) const
virtual void drawTick (QPainter *p, double val, int len) const
QMatrix labelMatrix (const QPoint &, const QSize &) const
Detailed Description
A class for drawing scales.
QwtScaleDraw can be used to draw linear or logarithmic scales. A scale
has a position, an alignment and a length, which can be specified . The
labels can be rotated and aligned to the ticks using setLabelRotation()
and setLabelAlignment().
After a scale division has been specified as a QwtScaleDiv object using
QwtAbstractScaleDraw::setScaleDiv(const QwtScaleDiv &s), the scale can
be drawn with the QwtAbstractScaleDraw::draw() member.
Member Enumeration Documentation
enum QwtScaleDraw::Alignment
Alignment of the scale draw
See also:
setAlignment(), alignment()Constructor & Destructor Documentation
QwtScaleDraw::QwtScaleDraw ()
Constructor. The range of the scale is initialized to [0, 100], The
position is at (0, 0) with a length of 100. The orientation is
QwtAbstractScaleDraw::Bottom.
Member Function Documentation
QwtScaleDraw::Alignment QwtScaleDraw::alignment () const
Return alignment of the scale
See also:
setAlignment()
QRect QwtScaleDraw::boundingLabelRect (const QFont &font, doublevalue)
const
Find the bounding rect for the label. The coordinates of the rect are
absolute coordinates ( calculated from pos() ). in direction of the
tick.
Parameters:
font Font used for painting
value Value
See also:
labelRect()
void QwtScaleDraw::drawBackbone (QPainter *painter) const [protected],
[virtual]
Draws the baseline of the scale
Parameters:
painter Painter
See also:
drawTick(), drawLabel()
Implements QwtAbstractScaleDraw.
void QwtScaleDraw::drawLabel (QPainter *painter, doublevalue) const
[protected], [virtual]
Draws the label for a major scale tick
Parameters:
painter Painter
value Value
See also:
drawTick(), drawBackbone(), boundingLabelRect()
Implements QwtAbstractScaleDraw.
void QwtScaleDraw::drawTick (QPainter *painter, doublevalue, intlen) const
[protected], [virtual]
Draw a tick
Parameters:
painter Painter
value Value of the tick
len Lenght of the tick
See also:
drawBackbone(), drawLabel()
Implements QwtAbstractScaleDraw.
int QwtScaleDraw::extent (const QPen &pen, const QFont &font) const
[virtual]
Calculate the width/height that is needed for a vertical/horizontal
scale.
The extent is calculated from the pen width of the backbone, the major
tick length, the spacing and the maximum width/height of the labels.
Parameters:
pen Pen that is used for painting backbone and ticks
font Font used for painting the labels
See also:
minLength()
Implements QwtAbstractScaleDraw.
void QwtScaleDraw::getBorderDistHint (const QFont &font, 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:
font Font
start Start border distance
end End border distance
Qt::Alignment QwtScaleDraw::labelAlignment () const
Returns:
the label flags
See also:
setLabelAlignment(), labelRotation()
QMatrix QwtScaleDraw::labelMatrix (const QPoint &pos, const QSize &size)
const [protected]
Calculate the matrix that is needed to paint a label depending on its
alignment and rotation.
Parameters:
pos Position where to paint the label
size Size of the label
See also:
setLabelAlignment(), setLabelRotation()
QPoint QwtScaleDraw::labelPosition (doublevalue) const
Find the position, where to paint a label
The position has a distance of majTickLength() + spacing() + 1 from the
backbone. The direction depends on the alignment()
Parameters:
value Value
QRect QwtScaleDraw::labelRect (const QFont &font, doublevalue) const
Find the bounding rect for the label. The coordinates of the rect are
relative to spacing + ticklength from the backbone in direction of the
tick.
Parameters:
font Font used for painting
value Value
double QwtScaleDraw::labelRotation () const
Returns:
the label rotation
See also:
setLabelRotation(), labelAlignment()
QSize QwtScaleDraw::labelSize (const QFont &font, doublevalue) const
Calculate the size that is needed to draw a label
Parameters:
font Label font
value Value
int QwtScaleDraw::length () const
Returns:
the length of the backbone
See also:
setLength(), pos()
int QwtScaleDraw::maxLabelHeight (const QFont &font) const
Parameters:
font Font
Returns:
the maximum height of a label
int QwtScaleDraw::maxLabelWidth (const QFont &font) const
Parameters:
font Font
Returns:
the maximum width of a label
int QwtScaleDraw::minLabelDist (const QFont &font) const
Determine the minimum distance between two labels, that is necessary
that the texts don't overlap.
Parameters:
font Font
Returns:
The maximum width of a label
See also:
getBorderDistHint()
int QwtScaleDraw::minLength (const QPen &pen, const QFont &font) const
Calculate the minimum length that is needed to draw the scale
Parameters:
pen Pen that is used for painting backbone and ticks
font Font used for painting the labels
See also:
extent()
void QwtScaleDraw::move (intx, inty) [inline]
Move the position of the scale
See also:
move(const QPoint &)
void QwtScaleDraw::move (const QPoint &pos)
Move the position of the scale. The meaning of the parameter pos
depends on the alignment:
QwtScaleDraw::LeftScale
The origin is the topmost point of the backbone. The backbone is a
vertical line. Scale marks and labels are drawn at the left of the
backbone.
QwtScaleDraw::RightScale
The origin is the topmost point of the backbone. The backbone is a
vertical line. Scale marks and labels are drawn at the right of the
backbone.
QwtScaleDraw::TopScale
The origin is the leftmost point of the backbone. The backbone is a
horizontal line. Scale marks and labels are drawn above the
backbone.
QwtScaleDraw::BottomScale
The origin is the leftmost point of the backbone. The backbone is a
horizontal line Scale marks and labels are drawn below the
backbone.
Parameters:
pos Origin of the scale
See also:
pos(), setLength()
Qt::Orientation QwtScaleDraw::orientation () const
Return the orientation
TopScale, BottomScale are horizontal (Qt::Horizontal) scales,
LeftScale, RightScale are vertical (Qt::Vertical) scales.
See also:
alignment()
QPoint QwtScaleDraw::pos () const
Returns:
Origin of the scale
See also:
move(), length()
void QwtScaleDraw::setAlignment (Alignmentalign)
Set the alignment of the scale
The default alignment is QwtScaleDraw::BottomScale
See also:
alignment()
void QwtScaleDraw::setLabelAlignment (Qt::Alignmentalignment)
Change the label flags. Labels are aligned to the point ticklength +
spacing away from the backbone.
The alignment is relative to the orientation of the label text. In case
of an flags of 0 the label will be aligned depending on the orientation
of the scale:
QwtScaleDraw::TopScale: Qt::AlignHCenter | Qt::AlignTop
QwtScaleDraw::BottomScale: Qt::AlignHCenter | Qt::AlignBottom
QwtScaleDraw::LeftScale: Qt::AlignLeft | Qt::AlignVCenter
QwtScaleDraw::RightScale: Qt::AlignRight | Qt::AlignVCenter
Changing the alignment is often necessary for rotated labels.
Parameters:
alignment Or'd Qt::AlignmentFlags <see qnamespace.h>
See also:
setLabelRotation(), labelRotation(), labelAlignment()
Warning:
The various alignments might be confusing. The alignment of the
label is not the alignment of the scale and is not the alignment of
the flags (QwtText::flags()) returned from
QwtAbstractScaleDraw::label().
void QwtScaleDraw::setLabelRotation (doublerotation)
Rotate all labels.
When changing the rotation, it might be necessary to adjust the label
flags too. Finding a useful combination is often the result of try and
error.
Parameters:
rotation Angle in degrees. When changing the label rotation, the
label flags often needs to be adjusted too.
See also:
setLabelAlignment(), labelRotation(), labelAlignment().
void QwtScaleDraw::setLength (intlength)
Set the length of the backbone.
The length doesn't include the space needed for overlapping labels.
See also:
move(), minLabelDist()Author
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Version 5.2.3 Tue Nov 20 2012 QwtScaleDraw(3)
