QwtAbstractScaleDraw Class Reference

Inheritance diagram for QwtAbstractScaleDraw:

[legend]List of all members.

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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.

Definition at line 37 of file qwt_abstract_scale_draw.h.

Public Types
enum	ScaleComponent {   Backbone = 1,   Ticks = 2,   Labels = 4 }
Public Member Functions
	QwtAbstractScaleDraw ()
	QwtAbstractScaleDraw (const QwtAbstractScaleDraw &)
virtual	~QwtAbstractScaleDraw ()
QwtAbstractScaleDraw &	operator= (const QwtAbstractScaleDraw &)
void	setScaleDiv (const QwtScaleDiv &s)
const QwtScaleDiv &	scaleDiv () const
void	setTransformation (QwtScaleTransformation *)
const QwtScaleMap &	map () const
void	enableComponent (ScaleComponent, bool enable=true)
bool	hasComponent (ScaleComponent) const
void	setTickLength (QwtScaleDiv::TickType, int length)
int	tickLength (QwtScaleDiv::TickType) const
int	majTickLength () const
void	setSpacing (int margin)
int	spacing () const
virtual void	draw (QPainter *, const QPalette &) const
virtual QwtText	label (double) const
virtual int	extent (const QPen &, const QFont &) const =0
void	setMinimumExtent (int)
int	minimumExtent () const
QwtScaleMap &	scaleMap ()
Protected Member Functions
virtual void	drawTick (QPainter *painter, double value, int len) const =0
virtual void	drawBackbone (QPainter *painter) const =0
virtual void	drawLabel (QPainter *painter, double value) const =0
void	invalidateCache ()
const QwtText &	tickLabel (const QFont &, double value) const

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Member Enumeration Documentation

enum QwtAbstractScaleDraw::ScaleComponent

Components of a scale Backbone Ticks Label See also: QwtAbstractScaleDraw::enableComponent, QwtAbstractScaleDraw::hasComponent Definition at line 52 of file qwt_abstract_scale_draw.h.

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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 54 of file qwt_abstract_scale_draw.cpp.

QwtAbstractScaleDraw::QwtAbstractScaleDraw (  const QwtAbstractScaleDraw &   )

Copy constructor. Definition at line 60 of file qwt_abstract_scale_draw.cpp. References d_data.

QwtAbstractScaleDraw::~QwtAbstractScaleDraw (   )  [virtual]

Destructor. Definition at line 66 of file qwt_abstract_scale_draw.cpp.

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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 164 of file qwt_abstract_scale_draw.cpp. Referenced by QwtThermo::draw(), QwtSlider::draw(), and QwtKnob::draw().

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 QwtRoundScaleDraw, and QwtScaleDraw.

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 QwtRoundScaleDraw, and QwtScaleDraw.

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

Draw a tick Parameters: painter  Painter value  Value of the tick len  Lenght of the tick See also: drawBackbone(), drawLabel() Implemented in QwtRoundScaleDraw, and QwtScaleDraw.

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

En/Disable a component of the scale Parameters: component  Scale component enable  On/Off See also: QwtAbstractScaleDraw::hasComponent Definition at line 85 of file qwt_abstract_scale_draw.cpp. Referenced by QwtDial::setScaleOptions().

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: QwtAbstractScaleDraw::enableComponent Definition at line 98 of file qwt_abstract_scale_draw.cpp. Referenced by QwtRoundScaleDraw::drawLabel(), QwtScaleDraw::extent(), QwtRoundScaleDraw::extent(), QwtScaleDraw::getBorderDistHint(), QwtScaleDraw::labelPosition(), QwtScaleDraw::minLabelDist(), and QwtScaleDraw::minLength().

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. Definition at line 402 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 QString::number(value). This method is often overloaded by applications to have individual labels. Parameters: value  Value Returns: Label string. Reimplemented in QwtDialScaleDraw. Definition at line 359 of file qwt_abstract_scale_draw.cpp. Referenced by QwtRoundScaleDraw::drawLabel(), QwtRoundScaleDraw::extent(), QwtDialScaleDraw::label(), and tickLabel().

int QwtAbstractScaleDraw::majTickLength (   )  const

The same as QwtAbstractScaleDraw::tickLength(QwtScaleDiv::MajorTick). Definition at line 344 of file qwt_abstract_scale_draw.cpp. Referenced by QwtRoundScaleDraw::drawLabel(), QwtScaleDraw::extent(), and QwtScaleDraw::labelPosition().

const QwtScaleMap & QwtAbstractScaleDraw::map (   )  const

Returns: Map how to translate between scale and pixel values Definition at line 125 of file qwt_abstract_scale_draw.cpp. Referenced by QwtRoundScaleDraw::drawBackbone(), QwtScaleWidget::drawColorBar(), QwtRoundScaleDraw::drawLabel(), QwtScaleDraw::drawTick(), QwtRoundScaleDraw::drawTick(), QwtRoundScaleDraw::extent(), QwtScaleDraw::getBorderDistHint(), QwtScaleDraw::labelPosition(), and QwtScaleWidget::setScaleDiv().

int QwtAbstractScaleDraw::minimumExtent (   )  const

Get the minimum extent See also: extent(), setMinimumExtent() Definition at line 292 of file qwt_abstract_scale_draw.cpp. Referenced by QwtScaleDraw::extent().

QwtAbstractScaleDraw & QwtAbstractScaleDraw::operator= (  const QwtAbstractScaleDraw &   )

Assignment operator. Definition at line 71 of file qwt_abstract_scale_draw.cpp. References d_data.

const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv (   )  const

Returns: scale division Definition at line 137 of file qwt_abstract_scale_draw.cpp. Referenced by QwtRoundScaleDraw::extent(), QwtScaleDraw::getBorderDistHint(), QwtScaleDraw::maxLabelHeight(), QwtScaleDraw::maxLabelWidth(), QwtScaleDraw::minLabelDist(), QwtScaleDraw::minLength(), QwtScaleWidget::setScaleDiv(), and QwtPlot::sizeHint().

QwtScaleMap & QwtAbstractScaleDraw::scaleMap (   )

Returns: Map how to translate between scale and pixel values Definition at line 131 of file qwt_abstract_scale_draw.cpp. Referenced by QwtScaleDraw::drawTick(), QwtRoundScaleDraw::QwtRoundScaleDraw(), and QwtRoundScaleDraw::setAngleRange().

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() Definition at line 280 of file qwt_abstract_scale_draw.cpp.

void QwtAbstractScaleDraw::setScaleDiv (  const QwtScaleDiv &  sd  )

Change the scale division Parameters: sd  New scale division Definition at line 107 of file qwt_abstract_scale_draw.cpp. References QwtScaleDiv::hBound(), and QwtScaleDiv::lBound(). Referenced by QwtScaleWidget::setScaleDiv().

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: QwtAbstractScaleDraw::spacing Definition at line 246 of file qwt_abstract_scale_draw.cpp.

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] Definition at line 305 of file qwt_abstract_scale_draw.cpp. Referenced by QwtDial::setScaleTicks().

void QwtAbstractScaleDraw::setTransformation (  QwtScaleTransformation *  transformation  )

Change the transformation of the scale Parameters: transformation  New scale transformation Definition at line 118 of file qwt_abstract_scale_draw.cpp. Referenced by QwtScaleWidget::setScaleDiv().

int QwtAbstractScaleDraw::spacing (   )  const

Get the spacing. The spacing is the distance between ticks and labels. The default spacing is 4 pixels. See also: QwtAbstractScaleDraw::setSpacing Definition at line 262 of file qwt_abstract_scale_draw.cpp. Referenced by QwtRoundScaleDraw::drawLabel(), QwtScaleDraw::extent(), and QwtScaleDraw::labelPosition().

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 377 of file qwt_abstract_scale_draw.cpp. References label(), and QwtText::setRenderFlags(). Referenced by QwtScaleDraw::drawLabel(), QwtRoundScaleDraw::drawLabel(), QwtRoundScaleDraw::extent(), and QwtScaleDraw::labelRect().

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

Return the length of the ticks See also: QwtAbstractScaleDraw::setTickLength, QwtAbstractScaleDraw::majTickLength Definition at line 330 of file qwt_abstract_scale_draw.cpp.

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