A class for drawing scales. More...

#include <qwt_scale_draw.h>

Inheritance diagram for QwtScaleDraw:

Classes
class	PrivateData

Public Types
enum	Alignment { BottomScale , TopScale , LeftScale , RightScale }
	Alignment of the scale draw. More...

Public Types inherited from QwtAbstractScaleDraw
enum	ScaleComponent { Backbone = 0x01 , Ticks = 0x02 , Labels = 0x04 }
	Components of a scale. More...

Public Member Functions
	QwtScaleDraw ()
	Constructor.

virtual	~QwtScaleDraw ()
	Destructor.

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

int	minLabelDist (const QFont &) const
	Determine the minimum distance between two labels, that is necessary that the texts don't overlap.

int	minLength (const QFont &) const
	Calculate the minimum length that is needed to draw the scale.

virtual double	extent (const QFont &) const QWT_OVERRIDE
	Calculate the width/height that is needed for a vertical/horizontal scale.

void	move (double x, double y)
	Move the position of the scale.

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

void	setLength (double length)
	Set the length of the backbone.

Alignment	alignment () const
	Return alignment of the scale.

void	setAlignment (Alignment)
	Set the alignment of the scale.

Qt::Orientation	orientation () const
	Return the orientation.

QPointF	pos () const

double	length () const

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

Qt::Alignment	labelAlignment () const

void	setLabelRotation (double rotation)
	Rotate all labels.

double	labelRotation () const

int	maxLabelHeight (const QFont &) const

int	maxLabelWidth (const QFont &) const

QPointF	labelPosition (double value) const
	Find the position, where to paint a label.

QRectF	labelRect (const QFont &, double value) const
	Find the bounding rectangle for the label.

QSizeF	labelSize (const QFont &, double value) const
	Calculate the size that is needed to draw a label.

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

Public Member Functions inherited from QwtAbstractScaleDraw
	QwtAbstractScaleDraw ()
	Constructor.

virtual	~QwtAbstractScaleDraw ()
	Destructor.

void	setScaleDiv (const QwtScaleDiv &)
	Change the scale division.

const QwtScaleDiv &	scaleDiv () const

void	setTransformation (QwtTransform *)
	Change the transformation of the scale.

const QwtScaleMap &	scaleMap () const

QwtScaleMap &	scaleMap ()

void	enableComponent (ScaleComponent, bool enable=true)
	En/Disable a component of the scale.

bool	hasComponent (ScaleComponent) const
	Check if a component is enabled.

void	setTickLength (QwtScaleDiv::TickType, double length)
	Set the length of the ticks.

double	tickLength (QwtScaleDiv::TickType) const

double	maxTickLength () const

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

double	spacing () const
	Get the spacing.

void	setPenWidthF (qreal width)
	Specify the width of the scale pen.

qreal	penWidthF () const

void	setSelected (bool on)
	设置是否选中

bool	isSelected () const
	是否选中

void	setSelectedPenWidthOffset (qreal offset=1)
	设置坐标轴在选中状态下的画笔宽度附加值

qreal	selectedPenWidthOffset () const
	获取当前坐标轴在选中状态下的画笔宽度附加值

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

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

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

double	minimumExtent () const
	Get the minimum extent.

void	invalidateCache ()
	Invalidate the cache used by tickLabel()

Protected Member Functions
QTransform	labelTransformation (const QPointF &, const QSizeF &) const
	Calculate the transformation that is needed to paint a label depending on its alignment and rotation.

virtual void	drawTick (QPainter *, double value, double len) const QWT_OVERRIDE
	Draw a tick.

virtual void	drawBackbone (QPainter *) const QWT_OVERRIDE
	Draws the baseline of the scale.

virtual void	drawLabel (QPainter *, double value) const QWT_OVERRIDE
	Draws the label for a major scale tick.

Protected Member Functions inherited from QwtAbstractScaleDraw
const QwtText &	tickLabel (const QFont &, double value) const
	Convert a value into its representing label and cache it.

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
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().

◆ 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()

The documentation for this class was generated from the following files:

/home/runner/work/QWT/QWT/src/qwt_scale_draw.h
/home/runner/work/QWT/QWT/src/qwt_scale_draw.cpp

Classes

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()