QwtAbstractScaleDraw(3) Qwt User's Guide QwtAbstractScaleDraw(3)NAMEQwtAbstractScaleDraw-
SYNOPSIS
#include <qwt_abstract_scale_draw.h>
Inherited by QwtRoundScaleDraw, and QwtScaleDraw.
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
[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,
doublevalue) 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,
doublevalue, intlen) 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 QwtScaleDraw, and QwtRoundScaleDraw.
void QwtAbstractScaleDraw::enableComponent (ScaleComponentcomponent,
boolenable = 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 (ScaleComponentcomponent) 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 (doublevalue) 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 (intminExtent)
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 (intspacing)
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::TickTypetickType,
intlength)
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,
doublevalue) 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::TickTypetickType) const
Return the length of the ticks
See also:
setTickLength(), majTickLength()Author
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Version 5.2.3 Tue Nov 20 2012 QwtAbstractScaleDraw(3)
