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

#include <qwt_abstract_scale_draw.h>

Inheritance diagram for QwtAbstractScaleDraw:

Classes
class	PrivateData
Public Types
enum	ScaleComponent { Backbone = 0x01, Ticks = 0x02, Labels = 0x04 }
typedef QFlags< ScaleComponent >	ScaleComponents
	Scale components.
Public Member Functions
virtual void	draw (QPainter *, const QPalette &) const
	Draw the scale.
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.
double	maxTickLength () const
double	minimumExtent () const
int	penWidth () const
	QwtAbstractScaleDraw ()
	Constructor.
const QwtScaleDiv &	scaleDiv () const
const QwtScaleMap &	scaleMap () const
QwtScaleMap &	scaleMap ()
void	setMinimumExtent (double)
	Set a minimum for the extent.
void	setPenWidth (int width)
	Specify the width of the scale pen.
void	setScaleDiv (const QwtScaleDiv &s)
void	setSpacing (double margin)
	Set the spacing between tick and labels.
void	setTickLength (QwtScaleDiv::TickType, double length)
void	setTransformation (QwtTransform *)
double	spacing () const
	Get the spacing.
double	tickLength (QwtScaleDiv::TickType) const
virtual	~QwtAbstractScaleDraw ()
	Destructor.
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.
Private Attributes
PrivateData *	d_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 Typedef Documentation

typedef QFlags<ScaleComponent> QwtAbstractScaleDraw::ScaleComponents

Scale components.

Definition at line 52 of file qwt_abstract_scale_draw.h.

Member Enumeration Documentation

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 ( )

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 58 of file qwt_abstract_scale_draw.cpp.

QwtAbstractScaleDraw::~QwtAbstractScaleDraw ( ) [virtual]

Destructor.

Definition at line 64 of file qwt_abstract_scale_draw.cpp.

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

Definition at line 168 of file qwt_abstract_scale_draw.cpp.

virtual void QwtAbstractScaleDraw::drawBackbone ( QPainter * painter ) const [protected, pure 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 `[protected, pure 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,
		double	len
	)		const `[protected, pure 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.

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 77 of file qwt_abstract_scale_draw.cpp.

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.

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 93 of file qwt_abstract_scale_draw.cpp.

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 417 of file qwt_abstract_scale_draw.cpp.

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 QwtAnalogClockScaleDraw.

Definition at line 374 of file qwt_abstract_scale_draw.cpp.

double QwtAbstractScaleDraw::maxTickLength ( ) const

Returns:: Length of the longest tick

Useful for layout calculations

See also:: tickLength(), setTickLength()

Definition at line 354 of file qwt_abstract_scale_draw.cpp.

double QwtAbstractScaleDraw::minimumExtent ( ) const

Get the minimum extent

Returns:: Minimum extent

See also:: extent(), setMinimumExtent()

Definition at line 301 of file qwt_abstract_scale_draw.cpp.

int QwtAbstractScaleDraw::penWidth ( ) const

Returns:: Scale pen width

See also:: setPenWidth()

Definition at line 155 of file qwt_abstract_scale_draw.cpp.

const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv ( ) const

Returns:: scale division

Definition at line 132 of file qwt_abstract_scale_draw.cpp.

const QwtScaleMap & QwtAbstractScaleDraw::scaleMap ( ) const

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

Definition at line 120 of file qwt_abstract_scale_draw.cpp.

QwtScaleMap & QwtAbstractScaleDraw::scaleMap ( )

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

Definition at line 126 of file qwt_abstract_scale_draw.cpp.

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 288 of file qwt_abstract_scale_draw.cpp.

void QwtAbstractScaleDraw::setPenWidth ( int width )

Specify the width of the scale pen.

Parameters:

width Pen width

See also:: penWidth()

Definition at line 142 of file qwt_abstract_scale_draw.cpp.

void QwtAbstractScaleDraw::setScaleDiv ( const QwtScaleDiv & scaleDiv )

Change the scale division

Parameters:

scaleDiv New scale division

Definition at line 102 of file qwt_abstract_scale_draw.cpp.

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 253 of file qwt_abstract_scale_draw.cpp.

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 314 of file qwt_abstract_scale_draw.cpp.

void QwtAbstractScaleDraw::setTransformation ( QwtTransform * transformation )

Change the transformation of the scale

Parameters:

transformation New scale transformation

Definition at line 113 of file qwt_abstract_scale_draw.cpp.

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 270 of file qwt_abstract_scale_draw.cpp.

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: