A abstract base class for drawing scales. More...

#include <qwt_abstract_scale_draw.h>

Inheritance diagram for QwtAbstractScaleDraw:

[legend]

Classes
class	PrivateData

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

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

void	enableComponent (ScaleComponent, bool enable=true)

virtual double	extent (const QFont &font) const =0

bool	hasComponent (ScaleComponent) const

void	invalidateCache ()

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

double	maxTickLength () const

double	minimumExtent () const

qreal	penWidthF () const

	QwtAbstractScaleDraw ()
	Constructor. More...

const QwtScaleDiv &	scaleDiv () const

QwtScaleMap &	scaleMap ()

const QwtScaleMap &	scaleMap () const

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

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

void	setScaleDiv (const QwtScaleDiv &)

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

void	setTickLength (QwtScaleDiv::TickType, double length)

void	setTransformation (QwtTransform *)

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

double	tickLength (QwtScaleDiv::TickType) const

virtual	~QwtAbstractScaleDraw ()
	Destructor. More...

Protected Member Functions
virtual void	drawBackbone (QPainter *painter) const =0

virtual void	drawLabel (QPainter *painter, double value) const =0

virtual void	drawTick (QPainter *painter, double value, double len) const =0

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

Private Attributes
PrivateData *	m_data

Detailed Description

A abstract base class for drawing scales.

QwtAbstractScaleDraw can be used to draw linear or logarithmic scales.

After a scale division has been specified as a QwtScaleDiv object using setScaleDiv(), the scale can be drawn with the draw() member.

Definition at line 31 of file qwt_abstract_scale_draw.h.

Member Enumeration Documentation

◆ ScaleComponent

enum QwtAbstractScaleDraw::ScaleComponent

Components of a scale

See also: enableComponent(), hasComponent

Enumerator
Backbone	Backbone = the line where the ticks are located.
Ticks	Ticks.
Labels	Labels.

Definition at line 39 of file qwt_abstract_scale_draw.h.

Constructor & Destructor Documentation

◆ QwtAbstractScaleDraw()

QwtAbstractScaleDraw::QwtAbstractScaleDraw ( )

Constructor.

The range of the scale is initialized to [0, 100], The spacing (distance between ticks and labels) is set to 4, the tick lengths are set to 4,6 and 8 pixels

Definition at line 60 of file qwt_abstract_scale_draw.cpp.

◆ ~QwtAbstractScaleDraw()

QwtAbstractScaleDraw::~QwtAbstractScaleDraw ( )

virtual

Destructor.

Definition at line 66 of file qwt_abstract_scale_draw.cpp.

Member Function Documentation

◆ draw()

void QwtAbstractScaleDraw::draw	(	QPainter *	painter,
		const QPalette &	palette
	)		const

virtual

Draw the scale.

Parameters

painter	The painter
palette	Palette, text color is used for the labels, foreground color for ticks and backbone

Definition at line 169 of file qwt_abstract_scale_draw.cpp.

◆ drawBackbone()

virtual void QwtAbstractScaleDraw::drawBackbone ( QPainter * painter ) const

protectedpure virtual

Draws the baseline of the scale

Parameters

painter Painter

See also: drawTick(), drawLabel()

Implemented in QwtScaleDraw, and QwtRoundScaleDraw.

◆ drawLabel()

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

protectedpure virtual

Draws the label for a major scale tick

Parameters

painter	Painter
value	Value

See also: drawTick(), drawBackbone()

Implemented in QwtScaleDraw, and QwtRoundScaleDraw.

◆ drawTick()

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

protectedpure virtual

Draw a tick

Parameters

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

See also: drawBackbone(), drawLabel()

Implemented in QwtScaleDraw, and QwtRoundScaleDraw.

◆ enableComponent()

void QwtAbstractScaleDraw::enableComponent	(	ScaleComponent	component,
		bool	enable = `true`
	)

En/Disable a component of the scale

Parameters

component	Scale component
enable	On/Off

See also: hasComponent()

Definition at line 79 of file qwt_abstract_scale_draw.cpp.

◆ extent()

virtual double QwtAbstractScaleDraw::extent ( const QFont & font ) const

pure virtual

Calculate the extent

The extent is the distance from the baseline to the outermost pixel of the scale draw in opposite to its orientation. It is at least minimumExtent() pixels.

Parameters

font	Font used for drawing the tick labels

Returns: Number of pixels

See also: setMinimumExtent(), minimumExtent()

Implemented in QwtScaleDraw, and QwtRoundScaleDraw.

◆ hasComponent()

bool QwtAbstractScaleDraw::hasComponent ( ScaleComponent component ) const

Check if a component is enabled

Parameters

component Component type

Returns: true, when component is enabled

See also: enableComponent()

Definition at line 95 of file qwt_abstract_scale_draw.cpp.

◆ invalidateCache()

void QwtAbstractScaleDraw::invalidateCache ( )

Invalidate the cache used by tickLabel()

The cache is invalidated, when a new QwtScaleDiv is set. If the labels need to be changed. while the same QwtScaleDiv is set, invalidateCache() needs to be called manually.

Definition at line 420 of file qwt_abstract_scale_draw.cpp.

◆ label()

QwtText QwtAbstractScaleDraw::label ( double value ) const

virtual

Convert a value into its representing label.

The value is converted to a plain text using QLocale().toString(value). This method is often overloaded by applications to have individual labels.

Parameters

value Value

Returns: Label string.

Reimplemented in QwtDateScaleDraw, QwtCompassScaleDraw, and TimeScaleDraw.

Definition at line 375 of file qwt_abstract_scale_draw.cpp.

◆ maxTickLength()

double QwtAbstractScaleDraw::maxTickLength ( ) const

Returns: Length of the longest tick

Useful for layout calculations

See also: tickLength(), setTickLength()

Definition at line 355 of file qwt_abstract_scale_draw.cpp.

◆ minimumExtent()

double QwtAbstractScaleDraw::minimumExtent ( ) const

Get the minimum extent

Returns: Minimum extent

See also: extent(), setMinimumExtent()

Definition at line 302 of file qwt_abstract_scale_draw.cpp.

◆ penWidthF()

qreal QwtAbstractScaleDraw::penWidthF ( ) const

Returns: Scale pen width

See also: setPenWidth()

Definition at line 156 of file qwt_abstract_scale_draw.cpp.

◆ scaleDiv()

const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv ( ) const

Returns: scale division

Definition at line 133 of file qwt_abstract_scale_draw.cpp.

◆ scaleMap() [1/2]

QwtScaleMap& QwtAbstractScaleDraw::scaleMap ( )

◆ scaleMap() [2/2]

QwtScaleMap & QwtAbstractScaleDraw::scaleMap ( ) const

Returns: Map how to translate between scale and pixel values

Definition at line 121 of file qwt_abstract_scale_draw.cpp.

◆ setMinimumExtent()

void QwtAbstractScaleDraw::setMinimumExtent ( double minExtent )

Set a minimum for the extent.

The extent is calculated from the components of the scale draw. In situations, where the labels are changing and the layout depends on the extent (f.e scrolling a scale), setting an upper limit as minimum extent will avoid jumps of the layout.

Parameters

minExtent Minimum extent

See also: extent(), minimumExtent()

Definition at line 289 of file qwt_abstract_scale_draw.cpp.

◆ setPenWidthF()

void QwtAbstractScaleDraw::setPenWidthF ( qreal width )

Specify the width of the scale pen.

Parameters

width Pen width

See also: penWidth()

Definition at line 144 of file qwt_abstract_scale_draw.cpp.

◆ setScaleDiv()

void QwtAbstractScaleDraw::setScaleDiv ( const QwtScaleDiv & scaleDiv )

Change the scale division

Parameters

scaleDiv New scale division

Definition at line 104 of file qwt_abstract_scale_draw.cpp.

◆ setSpacing()

void QwtAbstractScaleDraw::setSpacing ( double spacing )

Set the spacing between tick and labels.

The spacing is the distance between ticks and labels. The default spacing is 4 pixels.

Parameters

spacing Spacing

See also: spacing()

Definition at line 254 of file qwt_abstract_scale_draw.cpp.

◆ setTickLength()

void QwtAbstractScaleDraw::setTickLength	(	QwtScaleDiv::TickType	tickType,
		double	length
	)

Set the length of the ticks

Parameters

tickType	Tick type
length	New length

Warning: the length is limited to [0..1000]

Definition at line 315 of file qwt_abstract_scale_draw.cpp.

◆ setTransformation()

void QwtAbstractScaleDraw::setTransformation ( QwtTransform * transformation )

Change the transformation of the scale

Parameters

transformation New scale transformation

Definition at line 115 of file qwt_abstract_scale_draw.cpp.

◆ spacing()

double QwtAbstractScaleDraw::spacing ( ) const

Get the spacing.

The spacing is the distance between ticks and labels. The default spacing is 4 pixels.

Returns: Spacing

See also: setSpacing()

Definition at line 271 of file qwt_abstract_scale_draw.cpp.

◆ tickLabel()

const QwtText & QwtAbstractScaleDraw::tickLabel	(	const QFont &	font,
		double	value
	)		const

protected

Convert a value into its representing label and cache it.

The conversion between value and label is called very often in the layout and painting code. Unfortunately the calculation of the label sizes might be slow (really slow for rich text in Qt4), so it's necessary to cache the labels.

Parameters

font	Font
value	Value

Returns: Tick label

Definition at line 396 of file qwt_abstract_scale_draw.cpp.

◆ tickLength()

double QwtAbstractScaleDraw::tickLength ( QwtScaleDiv::TickType tickType ) const

Returns: Length of the ticks

See also: setTickLength(), maxTickLength()

Definition at line 338 of file qwt_abstract_scale_draw.cpp.

Member Data Documentation

◆ m_data

PrivateData* QwtAbstractScaleDraw::m_data

private

Definition at line 134 of file qwt_abstract_scale_draw.h.

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

Classes

Public Types

Public Member Functions

Protected Member Functions

Private Attributes

Detailed Description

Member Enumeration Documentation

◆ ScaleComponent

Constructor & Destructor Documentation

◆ QwtAbstractScaleDraw()

◆ ~QwtAbstractScaleDraw()

Member Function Documentation

◆ draw()

◆ drawBackbone()

◆ drawLabel()

◆ drawTick()

◆ enableComponent()

◆ extent()

◆ hasComponent()

◆ invalidateCache()

◆ label()

◆ maxTickLength()

◆ minimumExtent()

◆ penWidthF()

◆ scaleDiv()

◆ scaleMap() [1/2]

◆ scaleMap() [2/2]

◆ setMinimumExtent()

◆ setPenWidthF()

◆ setScaleDiv()

◆ setSpacing()

◆ setTickLength()

◆ setTransformation()

◆ spacing()

◆ tickLabel()

◆ tickLength()

Member Data Documentation

◆ m_data