Public Types¶

enum ScaleComponent { Backbone = 0x01, Ticks = 0x02, Labels = 0x04 }
typedef QFlags< ScaleComponent > ScaleComponents
Scale components.

Public Member Functions¶

QwtAbstractScaleDraw ()
Constructor. virtual ~QwtAbstractScaleDraw ()
Destructor. void setScaleDiv (const QwtScaleDiv &)
const QwtScaleDiv & scaleDiv () const
void setTransformation (QwtTransform *)
const QwtScaleMap & scaleMap () const
QwtScaleMap & scaleMap ()
void enableComponent (ScaleComponent, bool enable=true)
bool hasComponent (ScaleComponent) const
void setTickLength (QwtScaleDiv::TickType, double length)
double tickLength (QwtScaleDiv::TickType) const
double maxTickLength () const
void setSpacing (double)
Set the spacing between tick and labels. double spacing () const
Get the spacing. void setPenWidth (int width)
Specify the width of the scale pen. int penWidth () const
virtual void draw (QPainter *, const QPalette &) const
Draw the scale. virtual QwtText label (double) const
Convert a value into its representing label. virtual double extent (const QFont &font) const =0
void setMinimumExtent (double)
Set a minimum for the extent. double minimumExtent () const

Protected Member Functions¶

virtual void drawTick (QPainter *painter, double value, double 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.

enum QwtAbstractScaleDraw::ScaleComponent¶

Components of a scale

See also:

Enumerator

Backbone

Backbone = the line where the ticks are located.

Ticks

Ticks.

Labels

Labels.

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

void QwtAbstractScaleDraw::draw (QPainter * painter, const QPalette & palette) const [virtual]¶

Draw the scale.

Parameters:

virtual void QwtAbstractScaleDraw::drawBackbone (QPainter * painter) const [protected], [pure virtual]¶

Draws the baseline of the scale

Parameters:

See also:

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:

See also:

Implemented in QwtScaleDraw, and QwtRoundScaleDraw.

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

Draw a tick

Parameters:

See also:

Implemented in QwtScaleDraw, and QwtRoundScaleDraw.

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

En/Disable a component of the scale

Parameters:

See also:

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:

Returns:

See also:

Implemented in QwtScaleDraw, and QwtRoundScaleDraw.

bool QwtAbstractScaleDraw::hasComponent (ScaleComponent component) const¶

Check if a component is enabled

Parameters:

Returns:

See also:

void QwtAbstractScaleDraw::invalidateCache () [protected]¶

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.

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:

Returns:

Reimplemented in QwtDateScaleDraw, and QwtCompassScaleDraw.

double QwtAbstractScaleDraw::maxTickLength () const¶

Returns:

Useful for layout calculations

See also:

double QwtAbstractScaleDraw::minimumExtent () const¶

Get the minimum extent

Returns:

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int QwtAbstractScaleDraw::penWidth () const¶

Returns:

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const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv () const¶

Returns:

const QwtScaleMap & QwtAbstractScaleDraw::scaleMap () const¶

Returns:

QwtScaleMap & QwtAbstractScaleDraw::scaleMap ()¶

Returns:

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:

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void QwtAbstractScaleDraw::setPenWidth (int width)¶

Specify the width of the scale pen.

Parameters:

See also:

void QwtAbstractScaleDraw::setScaleDiv (const QwtScaleDiv & scaleDiv)¶

Change the scale division

Parameters:

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:

See also:

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

Set the length of the ticks

Parameters:

Warning:

void QwtAbstractScaleDraw::setTransformation (QwtTransform * transformation)¶

Change the transformation of the scale

Parameters:

double QwtAbstractScaleDraw::spacing () const¶

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

Returns:

See also:

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:

Returns:

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

Returns:

See also: