#include <qwt_abstract_scale_draw.h>

Inheritance diagram for QwtAbstractScaleDraw:

Public Types
enum	ScaleComponent { Backbone = 1, Ticks = 2, Labels = 4 }

Public Member Functions
	QwtAbstractScaleDraw ()
	QwtAbstractScaleDraw (const QwtAbstractScaleDraw &)
virtual	~QwtAbstractScaleDraw ()
virtual void	draw (QPainter *, const QPalette &) const
void	enableComponent (ScaleComponent, bool enable=true)
virtual int	extent (const QPen &, const QFont &) const =0
bool	hasComponent (ScaleComponent) const
virtual QwtText	label (double) const
int	majTickLength () const
const QwtScaleMap &	map () const
int	minimumExtent () const
QwtAbstractScaleDraw &	operator= (const QwtAbstractScaleDraw &)
const QwtScaleDiv &	scaleDiv () const
QwtScaleMap &	scaleMap ()
void	setMinimumExtent (int)
void	setScaleDiv (const QwtScaleDiv &s)
void	setSpacing (int margin)
void	setTickLength (QwtScaleDiv::TickType, int length)
void	setTransformation (QwtScaleTransformation *)
int	spacing () const
int	tickLength (QwtScaleDiv::TickType) const

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, int len) const =0
void	invalidateCache ()
const QwtText &	tickLabel (const QFont &, double value) const

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 QwtAbstractScaleDraw::setScaleDiv(const QwtScaleDiv &s), the scale can be drawn with the QwtAbstractScaleDraw::draw() member.

Member Enumeration Documentation

enum QwtAbstractScaleDraw::ScaleComponent

Components of a scale

Backbone
Ticks
Labels

See also:: enableComponent(), hasComponent

Constructor & Destructor Documentation

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

Member Function Documentation

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

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.

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.

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

protectedpure virtual

Draw a tick

Parameters:

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

See also:: drawBackbone(), drawLabel()

Implemented in QwtScaleDraw, and QwtRoundScaleDraw.

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()

virtual int QwtAbstractScaleDraw::extent	(	const QPen &	,
		const QFont &
	)		const

pure virtual

Calculate the extent

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

See also:: setMinimumExtent(), minimumExtent()

Implemented in QwtRoundScaleDraw, and QwtScaleDraw.

bool QwtAbstractScaleDraw::hasComponent ( ScaleComponent component ) const

Check if a component is enabled

See also:: enableComponent()

void QwtAbstractScaleDraw::invalidateCache ( )

protected

Invalidate the cache used by QwtAbstractScaleDraw::tickLabel

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

QwtText QwtAbstractScaleDraw::label ( double value ) const

virtual

Convert a value into its representing label.

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

Parameters:

value Value

Returns:: Label string.

Reimplemented in QwtDialScaleDraw.

int QwtAbstractScaleDraw::majTickLength ( ) const

The same as QwtAbstractScaleDraw::tickLength(QwtScaleDiv::MajorTick).

const QwtScaleMap & QwtAbstractScaleDraw::map ( ) const

Returns:: Map how to translate between scale and pixel values

int QwtAbstractScaleDraw::minimumExtent ( ) const

Get the minimum extent

See also:: extent(), setMinimumExtent()

const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv ( ) const

Returns:: scale division

QwtScaleMap & QwtAbstractScaleDraw::scaleMap ( )

Returns:: Map how to translate between scale and pixel values

void QwtAbstractScaleDraw::setMinimumExtent ( int minExtent )

Set a minimum for the extent.

The extent is calculated from the coomponents 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()

void QwtAbstractScaleDraw::setScaleDiv ( const QwtScaleDiv & sd )

Change the scale division

Parameters:

sd	New scale division

void QwtAbstractScaleDraw::setSpacing ( int 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()

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

Set the length of the ticks

Parameters:

tickType	Tick type
length	New length

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

void QwtAbstractScaleDraw::setTransformation ( QwtScaleTransformation * transformation )

Change the transformation of the scale

Parameters:

transformation New scale transformation

int QwtAbstractScaleDraw::spacing ( ) const

Get the spacing.

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

See also:: setSpacing()

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

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

Return the length of the ticks

See also:: setTickLength(), majTickLength()

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation