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

#include <qwt_abstract_scale_draw.h>

Inheritance diagram for QwtAbstractScaleDraw:

Collaboration diagram for QwtAbstractScaleDraw:

Classes
class	PrivateData
Public Types
enum	ScaleComponent { Backbone = 1, Ticks = 2, Labels = 4 }
Public Member Functions
	QwtAbstractScaleDraw ()
	Constructor.
	QwtAbstractScaleDraw (const QwtAbstractScaleDraw &)
	Copy constructor.
virtual	~QwtAbstractScaleDraw ()
	Destructor.
QwtAbstractScaleDraw &	operator= (const QwtAbstractScaleDraw &)
	Assignment operator.
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)
	Set the spacing between tick and labels.
int	spacing () const
	Get the spacing.
virtual void	draw (QPainter *, const QColorGroup &) const
	Draw the scale.
virtual QwtText	label (double) const
	Convert a value into its representing label.
virtual int	extent (const QPen &, const QFont &) const =0
void	setMinimumExtent (int)
	Set a minimum for the extent.
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
	Convert a value into its representing label and cache it.

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.

Member Enumeration Documentation

enum QwtAbstractScaleDraw::ScaleComponent

Components of a scale

Backbone
Ticks
Labels

See also:: enableComponent(), hasComponent

Enumerator:

Backbone
Ticks
Labels

Definition at line 51 of file qwt_abstract_scale_draw.h.

    { 
        Backbone = 1,
        Ticks = 2,
        Labels = 4
    };

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 55 of file qwt_abstract_scale_draw.cpp.

{
    d_data = new QwtAbstractScaleDraw::PrivateData;
}

QwtAbstractScaleDraw::QwtAbstractScaleDraw ( const QwtAbstractScaleDraw & other )

Copy constructor.

Definition at line 61 of file qwt_abstract_scale_draw.cpp.

{
    d_data = new QwtAbstractScaleDraw::PrivateData(*other.d_data);
}

QwtAbstractScaleDraw::~QwtAbstractScaleDraw ( ) [virtual]

Destructor.

Definition at line 67 of file qwt_abstract_scale_draw.cpp.

{
    delete d_data;
}

Member Function Documentation

void QwtAbstractScaleDraw::draw	(	QPainter *	painter,
		const QColorGroup &	colorGroup
	)		const `[virtual]`

Draw the scale.

Parameters:

painter	The painter
colorGroup	Color group, text color is used for the labels, foreground color for ticks and backbone

Definition at line 152 of file qwt_abstract_scale_draw.cpp.

References Backbone, int(), Labels, QwtScaleDiv::MajorTick, QwtScaleDiv::MinorTick, QwtScaleDiv::NTickTypes, and Ticks.

Referenced by QwtThermo::draw(), QwtSlider::draw(), QwtScaleWidget::draw(), QwtPlotScaleItem::draw(), QwtKnob::draw(), QwtDial::drawScale(), and QwtPlot::printScale().

{
    if ( hasComponent(QwtAbstractScaleDraw::Labels) )
    {
        painter->save();

#if QT_VERSION < 0x040000
        painter->setPen(colorGroup.text()); // ignore pen style
#else
        painter->setPen(palette.color(QPalette::Text)); // ignore pen style
#endif

        const QwtValueList &majorTicks = 
            d_data->scldiv.ticks(QwtScaleDiv::MajorTick);

        for (int i = 0; i < (int)majorTicks.count(); i++)
        {
            const double v = majorTicks[i];
            if ( d_data->scldiv.contains(v) )
                drawLabel(painter, majorTicks[i]);
        }

        painter->restore();
    }

    if ( hasComponent(QwtAbstractScaleDraw::Ticks) )
    {
        painter->save();

        QPen pen = painter->pen();
#if QT_VERSION < 0x040000
        pen.setColor(colorGroup.foreground());
#else
        pen.setColor(palette.color(QPalette::Foreground));
#endif
        painter->setPen(pen);

        for ( int tickType = QwtScaleDiv::MinorTick; 
            tickType < QwtScaleDiv::NTickTypes; tickType++ )
        {
            const QwtValueList &ticks = d_data->scldiv.ticks(tickType);
            for (int i = 0; i < (int)ticks.count(); i++)
            {
                const double v = ticks[i];
                if ( d_data->scldiv.contains(v) )
                    drawTick(painter, v, d_data->tickLength[tickType]);
            }
        }

        painter->restore();
    }

    if ( hasComponent(QwtAbstractScaleDraw::Backbone) )
    {
        painter->save();

        QPen pen = painter->pen();
#if QT_VERSION < 0x040000
        pen.setColor(colorGroup.foreground());
#else
        pen.setColor(palette.color(QPalette::Foreground));
#endif
        painter->setPen(pen);

        drawBackbone(painter);

        painter->restore();
    }
}

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:: hasComponent()

Definition at line 86 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::components.

Referenced by QwtDial::setScaleOptions().

{
    if ( enable )
        d_data->components |= component;
    else
        d_data->components &= ~component;
}

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()

Definition at line 99 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::components.

Referenced by QwtRoundScaleDraw::drawLabel(), QwtScaleDraw::extent(), QwtRoundScaleDraw::extent(), QwtScaleDraw::getBorderDistHint(), QwtPlotLayout::LayoutData::init(), QwtScaleDraw::labelPosition(), QwtPlotLayout::minimumSizeHint(), QwtScaleDraw::minLabelDist(), and QwtScaleDraw::minLength().

{
    return (d_data->components & component);
}

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 403 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::labelCache.

{
    d_data->labelCache.clear();
}

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.

Definition at line 360 of file qwt_abstract_scale_draw.cpp.

Referenced by QwtRoundScaleDraw::drawLabel(), QwtRoundScaleDraw::extent(), and tickLabel().

{
    return QLocale::system().toString(value);
}

int QwtAbstractScaleDraw::majTickLength ( ) const

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

Definition at line 344 of file qwt_abstract_scale_draw.cpp.

References QwtScaleDiv::MajorTick, and QwtAbstractScaleDraw::PrivateData::tickLength.

Referenced by QwtRoundScaleDraw::drawLabel(), QwtScaleDraw::extent(), QwtRoundScaleDraw::extent(), QwtPlotLayout::LayoutData::init(), QwtScaleDraw::labelPosition(), and QwtPlotLayout::minimumSizeHint().

{
    return d_data->tickLength[QwtScaleDiv::MajorTick];
}

const QwtScaleMap & QwtAbstractScaleDraw::map ( ) const

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

Definition at line 126 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::map.

Referenced by QwtRoundScaleDraw::drawBackbone(), QwtScaleWidget::drawColorBar(), QwtRoundScaleDraw::drawLabel(), QwtScaleDraw::drawTick(), QwtRoundScaleDraw::drawTick(), QwtRoundScaleDraw::extent(), QwtScaleDraw::getBorderDistHint(), QwtSlider::getScrollMode(), QwtScaleDraw::labelPosition(), and QwtScaleWidget::setScaleDiv().

{
    return d_data->map;
}

int QwtAbstractScaleDraw::minimumExtent ( ) const

Get the minimum extent

See also:: extent(), setMinimumExtent()

Definition at line 293 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::minExtent.

Referenced by QwtScaleDraw::extent(), and QwtRoundScaleDraw::extent().

{
    return d_data->minExtent;
}

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

Assignment operator.

Definition at line 72 of file qwt_abstract_scale_draw.cpp.

{
    *d_data = *other.d_data;
    return *this;
}

const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv ( ) const

Returns:: scale division

Definition at line 138 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::scldiv.

Referenced by QwtRoundScaleDraw::extent(), QwtScaleDraw::getBorderDistHint(), QwtScaleDraw::maxLabelHeight(), QwtScaleDraw::maxLabelWidth(), QwtScaleDraw::minLabelDist(), QwtScaleDraw::minLength(), QwtAbstractScale::rescale(), QwtPlotScaleItem::scaleDiv(), QwtAbstractScale::setAbstractScaleDraw(), QwtAbstractScale::setScale(), QwtScaleWidget::setScaleDiv(), and QwtPlot::sizeHint().

{ 
    return d_data->scldiv; 
}

QwtScaleMap & QwtAbstractScaleDraw::scaleMap ( )

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

Definition at line 132 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::map.

Referenced by QwtScaleDraw::drawTick(), QwtRoundScaleDraw::QwtRoundScaleDraw(), QwtAbstractScale::scaleMap(), and QwtRoundScaleDraw::setAngleRange().

{
    return d_data->map;
}

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 281 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::minExtent.

{
    if ( minExtent < 0 )
        minExtent = 0;

    d_data->minExtent = minExtent;
}

void QwtAbstractScaleDraw::setScaleDiv ( const QwtScaleDiv & sd )

Change the scale division

Parameters:

sd	New scale division

Definition at line 108 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::labelCache, QwtScaleDiv::lowerBound(), QwtAbstractScaleDraw::PrivateData::map, QwtAbstractScaleDraw::PrivateData::scldiv, QwtScaleMap::setScaleInterval(), and QwtScaleDiv::upperBound().

Referenced by QwtAbstractScale::rescale(), QwtAbstractScale::setAbstractScaleDraw(), QwtAbstractScale::setScale(), QwtScaleWidget::setScaleDiv(), QwtPlotScaleItem::setScaleDiv(), QwtDial::updateScale(), and QwtPlotScaleItem::updateScaleDiv().

{
    d_data->scldiv = sd;
    d_data->map.setScaleInterval(sd.lowerBound(), sd.upperBound());
    d_data->labelCache.clear();
}

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()

Definition at line 247 of file qwt_abstract_scale_draw.cpp.

References spacing(), and QwtAbstractScaleDraw::PrivateData::spacing.

{
    if ( spacing < 0 )
        spacing = 0;

    d_data->spacing = 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]

Definition at line 306 of file qwt_abstract_scale_draw.cpp.

References QwtScaleDiv::MajorTick, QwtScaleDiv::MinorTick, and QwtAbstractScaleDraw::PrivateData::tickLength.

Referenced by QwtDial::setScaleTicks().

{
    if ( tickType < QwtScaleDiv::MinorTick || 
        tickType > QwtScaleDiv::MajorTick )
    {
        return;
    }

    if ( length < 0 )
        length = 0;

    const int maxTickLen = 1000;
    if ( length > maxTickLen )
        length = 1000;

    d_data->tickLength[tickType] = length;
}

void QwtAbstractScaleDraw::setTransformation ( QwtScaleTransformation * transformation )

Change the transformation of the scale

Parameters:

transformation New scale transformation

Definition at line 119 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::map, and QwtScaleMap::setTransformation().

Referenced by QwtPlotScaleItem::draw(), QwtAbstractScale::rescale(), QwtScaleWidget::setScaleDiv(), and QwtDial::updateScale().

{
    d_data->map.setTransformation(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()

Definition at line 263 of file qwt_abstract_scale_draw.cpp.

References QwtAbstractScaleDraw::PrivateData::spacing.

Referenced by QwtRoundScaleDraw::drawLabel(), QwtScaleDraw::extent(), QwtRoundScaleDraw::extent(), QwtScaleDraw::labelPosition(), and setSpacing().

{
    return d_data->spacing;
}

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 378 of file qwt_abstract_scale_draw.cpp.

References label(), QwtAbstractScaleDraw::PrivateData::labelCache, QwtText::MinimumLayout, QwtText::setLayoutAttribute(), QwtText::setRenderFlags(), QwtText::textSize(), and void().

Referenced by QwtScaleDraw::boundingLabelRect(), QwtScaleDraw::drawLabel(), QwtRoundScaleDraw::drawLabel(), QwtRoundScaleDraw::extent(), and QwtScaleDraw::labelRect().

{
    QMap<double, QwtText>::const_iterator it = d_data->labelCache.find(value);
    if ( it == d_data->labelCache.end() )
    {
        QwtText lbl = label(value);
        lbl.setRenderFlags(0);
        lbl.setLayoutAttribute(QwtText::MinimumLayout);

        (void)lbl.textSize(font); // initialize the internal cache

        it = d_data->labelCache.insert(value, lbl);
    }

    return (*it);
}

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

Return the length of the ticks

See also:: setTickLength(), majTickLength()

Definition at line 330 of file qwt_abstract_scale_draw.cpp.

References QwtScaleDiv::MajorTick, QwtScaleDiv::MinorTick, and QwtAbstractScaleDraw::PrivateData::tickLength.

{
    if ( tickType < QwtScaleDiv::MinorTick || 
        tickType > QwtScaleDiv::MajorTick )
    {
        return 0;
    }

    return d_data->tickLength[tickType];
}

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

QwtAbstractScaleDraw Class Reference

Classes

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation