A class for drawing scales. More...

#include <qwt_scale_draw.h>

Inheritance diagram for QwtScaleDraw:

Public Types
enum	Alignment { BottomScale, TopScale, LeftScale, RightScale }

Public Types inherited from QwtAbstractScaleDraw
enum	ScaleComponent { Backbone = 0x01, Ticks = 0x02, Labels = 0x04 }

typedef QFlags< ScaleComponent >	ScaleComponents
	Scale components.

Public Member Functions
	QwtScaleDraw ()
	Constructor. More...

virtual	~QwtScaleDraw ()
	Destructor.

void	getBorderDistHint (const QFont &, int &start, int &end) const
	Determine the minimum border distance. More...

int	minLabelDist (const QFont &) const

int	minLength (const QFont &) const

virtual double	extent (const QFont &) const

void	move (double x, double y)

void	move (const QPointF &)
	Move the position of the scale. More...

void	setLength (double length)

Alignment	alignment () const

void	setAlignment (Alignment)

Qt::Orientation	orientation () const

QPointF	pos () const

double	length () const

void	setLabelAlignment (Qt::Alignment)
	Change the label flags. More...

Qt::Alignment	labelAlignment () const

void	setLabelRotation (double rotation)

double	labelRotation () const

int	maxLabelHeight (const QFont &) const

int	maxLabelWidth (const QFont &) const

QPointF	labelPosition (double value) const

QRectF	labelRect (const QFont &, double value) const

QSizeF	labelSize (const QFont &, double value) const

QRect	boundingLabelRect (const QFont &, double value) const
	Find the bounding rectangle for the label. More...

Public Member Functions inherited from QwtAbstractScaleDraw
	QwtAbstractScaleDraw ()
	Constructor. More...

virtual	~QwtAbstractScaleDraw ()
	Destructor.

void	setScaleDiv (const QwtScaleDiv &)

const QwtScaleDiv &	scaleDiv () const

void	setTransformation (QwtTransform *)

const QwtScaleMap &	scaleMap () const

QwtScaleMap &	scaleMap ()

void	enableComponent (ScaleComponent, bool enable=true)

bool	hasComponent (ScaleComponent) const

void	setTickLength (QwtScaleDiv::TickType, double length)

double	tickLength (QwtScaleDiv::TickType) const

double	maxTickLength () const

void	setSpacing (double)
	Set the spacing between tick and labels. More...

double	spacing () const
	Get the spacing. More...

void	setPenWidth (int width)
	Specify the width of the scale pen. More...

int	penWidth () const

virtual void	draw (QPainter *, const QPalette &) const
	Draw the scale. More...

virtual QwtText	label (double) const
	Convert a value into its representing label. More...

void	setMinimumExtent (double)
	Set a minimum for the extent. More...

double	minimumExtent () const

Protected Member Functions
QTransform	labelTransformation (const QPointF &, const QSizeF &) const

virtual void	drawTick (QPainter *, double value, double len) const

virtual void	drawBackbone (QPainter *) const

virtual void	drawLabel (QPainter *, double value) const

Protected Member Functions inherited from QwtAbstractScaleDraw
void	invalidateCache ()

const QwtText &	tickLabel (const QFont &, double value) const
	Convert a value into its representing label and cache it. More...

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

◆ Alignment

enum QwtScaleDraw::Alignment

Alignment of the scale draw

See also: setAlignment(), alignment()

Enumerator
BottomScale	The scale is below.
TopScale	The scale is above.
LeftScale	The scale is left.
RightScale	The scale is right.

Constructor & Destructor Documentation

◆ QwtScaleDraw()

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

◆ alignment()

QwtScaleDraw::Alignment QwtScaleDraw::alignment ( ) const

Return alignment of the scale

See also: setAlignment()

Returns: Alignment of the scale

◆ boundingLabelRect()

QRect QwtScaleDraw::boundingLabelRect	(	const QFont &	font,
		double	value
	)		const

Find the bounding rectangle for the label.

The coordinates of the rectangle are absolute ( calculated from pos() ). in direction of the tick.

Parameters

font	Font used for painting
value	Value

Returns: Bounding rectangle

See also: labelRect()

◆ drawBackbone()

void QwtScaleDraw::drawBackbone ( QPainter * painter ) const

protectedvirtual

Draws the baseline of the scale

Parameters

painter Painter

See also: drawTick(), drawLabel()

Implements QwtAbstractScaleDraw.

◆ drawLabel()

void QwtScaleDraw::drawLabel	(	QPainter *	painter,
		double	value
	)		const

protectedvirtual

Draws the label for a major scale tick

Parameters

painter	Painter
value	Value

See also: drawTick(), drawBackbone(), boundingLabelRect()

Implements QwtAbstractScaleDraw.

◆ drawTick()

void QwtScaleDraw::drawTick	(	QPainter *	painter,
		double	value,
		double	len
	)		const

protectedvirtual

Draw a tick

Parameters

painter	Painter
value	Value of the tick
len	Length of the tick

See also: drawBackbone(), drawLabel()

Implements QwtAbstractScaleDraw.

◆ extent()

double QwtScaleDraw::extent ( 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

font	Font used for painting the labels

Returns: Extent

See also: minLength()

Implements QwtAbstractScaleDraw.

◆ getBorderDistHint()

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

◆ labelAlignment()

Qt::Alignment QwtScaleDraw::labelAlignment ( ) const

Returns: the label flags

See also: setLabelAlignment(), labelRotation()

◆ labelPosition()

QPointF QwtScaleDraw::labelPosition ( double value ) const

Find the position, where to paint a label

The position has a distance that depends on the length of the ticks in direction of the alignment().

Parameters

value Value

Returns: Position, where to paint a label

◆ labelRect()

QRectF QwtScaleDraw::labelRect	(	const QFont &	font,
		double	value
	)		const

Find the bounding rectangle for the label. The coordinates of the rectangle are relative to spacing + tick length from the backbone in direction of the tick.

Parameters

font	Font used for painting
value	Value

Returns: Bounding rectangle that is needed to draw a label

◆ labelRotation()

double QwtScaleDraw::labelRotation ( ) const

Returns: the label rotation

See also: setLabelRotation(), labelAlignment()

◆ labelSize()

QSizeF QwtScaleDraw::labelSize	(	const QFont &	font,
		double	value
	)		const

Calculate the size that is needed to draw a label

Parameters

font	Label font
value	Value

Returns: Size that is needed to draw a label

◆ labelTransformation()

QTransform QwtScaleDraw::labelTransformation	(	const QPointF &	pos,
		const QSizeF &	size
	)		const

protected

Calculate the transformation 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

Returns: Transformation matrix

See also: setLabelAlignment(), setLabelRotation()

◆ length()

double QwtScaleDraw::length ( ) const

Returns: the length of the backbone

See also: setLength(), pos()

◆ maxLabelHeight()

int QwtScaleDraw::maxLabelHeight ( const QFont & font ) const

Parameters

font Font

Returns: the maximum height of a label

◆ maxLabelWidth()

int QwtScaleDraw::maxLabelWidth ( const QFont & font ) const

Parameters

font Font

Returns: the maximum width of a label

◆ minLabelDist()

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()

◆ minLength()

int QwtScaleDraw::minLength ( const QFont & font ) const

Calculate the minimum length that is needed to draw the scale

Parameters

font	Font used for painting the labels

Returns: Minimum length that is needed to draw the scale

See also: extent()

◆ move() [1/2]

void QwtScaleDraw::move ( const QPointF & 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()

◆ move() [2/2]

void QwtScaleDraw::move	(	double	x,
		double	y
	)

inline

Move the position of the scale

Parameters

x	X coordinate
y	Y coordinate

See also: move(const QPointF &)

◆ orientation()

Qt::Orientation QwtScaleDraw::orientation ( ) const

Return the orientation

TopScale, BottomScale are horizontal (Qt::Horizontal) scales, LeftScale, RightScale are vertical (Qt::Vertical) scales.

Returns: Orientation of the scale

See also: alignment()

◆ pos()

QPointF QwtScaleDraw::pos ( ) const

Returns: Origin of the scale

See also: move(), length()

◆ setAlignment()

void QwtScaleDraw::setAlignment ( Alignment align )

Set the alignment of the scale

Parameters

align Alignment of the scale

The default alignment is QwtScaleDraw::BottomScale

See also: alignment()

◆ setLabelAlignment()

void QwtScaleDraw::setLabelAlignment ( Qt::Alignment alignment )

Change the label flags.

Labels are aligned to the point tick length + 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\n
QwtScaleDraw::BottomScale: Qt::AlignHCenter | Qt::AlignBottom\n
QwtScaleDraw::LeftScale: Qt::AlignLeft | Qt::AlignVCenter\n
QwtScaleDraw::RightScale: Qt::AlignRight | Qt::AlignVCenter\n

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().

◆ setLabelRotation()

void QwtScaleDraw::setLabelRotation ( double rotation )

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().

◆ setLength()

void QwtScaleDraw::setLength ( double length )

Set the length of the backbone.

The length doesn't include the space needed for overlapping labels.

Parameters

length Length of the backbone

See also: move(), minLabelDist()

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ Alignment

Constructor & Destructor Documentation

◆ QwtScaleDraw()

Member Function Documentation

◆ alignment()

◆ boundingLabelRect()

◆ drawBackbone()

◆ drawLabel()

◆ drawTick()

◆ extent()

◆ getBorderDistHint()

◆ labelAlignment()

◆ labelPosition()

◆ labelRect()

◆ labelRotation()

◆ labelSize()

◆ labelTransformation()

◆ length()

◆ maxLabelHeight()

◆ maxLabelWidth()

◆ minLabelDist()

◆ minLength()

◆ move() [1/2]

◆ move() [2/2]

◆ orientation()

◆ pos()

◆ setAlignment()

◆ setLabelAlignment()

◆ setLabelRotation()

◆ setLength()