Qwt User's Guide
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#include <qwt_round_scale_draw.h>
Inherits QwtAbstractScaleDraw.
Inherited by QwtDialScaleDraw.
Public Types | |
enum | ScaleComponent { Backbone = 0x01, Ticks = 0x02, Labels = 0x04 } |
typedef QFlags< ScaleComponent > | ScaleComponents |
Public Member Functions | |
QPointF | center () const |
virtual void | draw (QPainter *, const QPalette &) const |
void | enableComponent (ScaleComponent, bool enable=true) |
virtual double | extent (const QFont &) const |
bool | hasComponent (ScaleComponent) const |
virtual QwtText | label (double) const |
double | maxTickLength () const |
double | minimumExtent () const |
void | moveCenter (double x, double y) |
void | moveCenter (const QPointF &) |
int | penWidth () const |
QwtRoundScaleDraw () | |
int | radius () const |
const QwtScaleDiv & | scaleDiv () const |
const QwtScaleMap & | scaleMap () const |
QwtScaleMap & | scaleMap () |
void | setAngleRange (double angle1, double angle2) |
void | setMinimumExtent (double) |
void | setPenWidth (int width) |
void | setRadius (int radius) |
void | setScaleDiv (const QwtScaleDiv &s) |
void | setSpacing (double margin) |
void | setTickLength (QwtScaleDiv::TickType, double length) |
void | setTransformation (QwtScaleTransformation *) |
double | spacing () const |
double | tickLength (QwtScaleDiv::TickType) const |
virtual | ~QwtRoundScaleDraw () |
Protected Member Functions | |
virtual void | drawBackbone (QPainter *p) const |
virtual void | drawLabel (QPainter *p, double val) const |
virtual void | drawTick (QPainter *p, double val, double len) const |
void | invalidateCache () |
const QwtText & | tickLabel (const QFont &, double value) const |
A class for drawing round scales.
QwtRoundScaleDraw can be used to draw round scales. The circle segment can be adjusted by QwtRoundScaleDraw::setAngleRange(). The geometry of the scale can be specified with QwtRoundScaleDraw::moveCenter() and QwtRoundScaleDraw::setRadius().
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.
typedef QFlags<ScaleComponent> QwtAbstractScaleDraw::ScaleComponents [inherited] |
Scale components.
enum QwtAbstractScaleDraw::ScaleComponent [inherited] |
Components of a scale
QwtRoundScaleDraw::QwtRoundScaleDraw | ( | ) |
Constructor.
The range of the scale is initialized to [0, 100], The center is set to (50, 50) with a radius of 50. The angle range is set to [-135, 135].
QwtRoundScaleDraw::~QwtRoundScaleDraw | ( | ) | [virtual] |
Destructor.
QPointF QwtRoundScaleDraw::center | ( | ) | const |
Get the center of the scale.
void QwtAbstractScaleDraw::draw | ( | QPainter * | painter, |
const QPalette & | palette | ||
) | const [virtual, inherited] |
Draw the scale.
painter | The painter |
palette | Palette, text color is used for the labels, foreground color for ticks and backbone |
void QwtRoundScaleDraw::drawBackbone | ( | QPainter * | painter | ) | const [protected, virtual] |
Draws the baseline of the scale
painter | Painter |
Implements QwtAbstractScaleDraw.
void QwtRoundScaleDraw::drawLabel | ( | QPainter * | painter, |
double | value | ||
) | const [protected, virtual] |
Draws the label for a major scale tick
painter | Painter |
value | Value |
Implements QwtAbstractScaleDraw.
void QwtRoundScaleDraw::drawTick | ( | QPainter * | painter, |
double | value, | ||
double | len | ||
) | const [protected, virtual] |
Draw a tick
painter | Painter |
value | Value of the tick |
len | Lenght of the tick |
Implements QwtAbstractScaleDraw.
void QwtAbstractScaleDraw::enableComponent | ( | ScaleComponent | component, |
bool | enable = true |
||
) | [inherited] |
En/Disable a component of the scale
component | Scale component |
enable | On/Off |
double QwtRoundScaleDraw::extent | ( | const QFont & | font | ) | const [virtual] |
Calculate the extent of the scale
The extent is the distance between the baseline to the outermost pixel of the scale draw. radius() + extent() is an upper limit for the radius of the bounding circle.
font | Font used for painting the labels |
Implements QwtAbstractScaleDraw.
bool QwtAbstractScaleDraw::hasComponent | ( | ScaleComponent | component | ) | const [inherited] |
Check if a component is enabled
void QwtAbstractScaleDraw::invalidateCache | ( | ) | [protected, inherited] |
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, invalidateCache() needs to be called manually.
QwtText QwtAbstractScaleDraw::label | ( | double | value | ) | const [virtual, inherited] |
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.
value | Value |
Reimplemented in QwtDialScaleDraw.
double QwtAbstractScaleDraw::maxTickLength | ( | ) | const [inherited] |
Useful for layout calculations
double QwtAbstractScaleDraw::minimumExtent | ( | ) | const [inherited] |
Get the minimum extent
void QwtRoundScaleDraw::moveCenter | ( | double | x, |
double | y | ||
) | [inline] |
Move the center of the scale draw, leaving the radius unchanged.
void QwtRoundScaleDraw::moveCenter | ( | const QPointF & | center | ) |
Move the center of the scale draw, leaving the radius unchanged
center | New center |
int QwtAbstractScaleDraw::penWidth | ( | ) | const [inherited] |
int QwtRoundScaleDraw::radius | ( | ) | const |
Get the radius
Radius is the radius of the backbone without ticks and labels.
const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv | ( | ) | const [inherited] |
const QwtScaleMap & QwtAbstractScaleDraw::scaleMap | ( | ) | const [inherited] |
QwtScaleMap & QwtAbstractScaleDraw::scaleMap | ( | ) | [inherited] |
void QwtRoundScaleDraw::setAngleRange | ( | double | angle1, |
double | angle2 | ||
) |
Adjust the baseline circle segment for round scales.
The baseline will be drawn from min(angle1,angle2) to max(angle1, angle2). The default setting is [ -135, 135 ]. An angle of 0 degrees corresponds to the 12 o'clock position, and positive angles count in a clockwise direction.
angle1 | |
angle2 | boundaries of the angle interval in degrees. |
void QwtAbstractScaleDraw::setMinimumExtent | ( | double | minExtent | ) | [inherited] |
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.
minExtent | Minimum extent |
void QwtAbstractScaleDraw::setPenWidth | ( | int | width | ) | [inherited] |
void QwtRoundScaleDraw::setRadius | ( | int | radius | ) |
Change of radius the scale
Radius is the radius of the backbone without ticks and labels.
radius | New Radius |
void QwtAbstractScaleDraw::setScaleDiv | ( | const QwtScaleDiv & | sd | ) | [inherited] |
Change the scale division
sd | New scale division |
void QwtAbstractScaleDraw::setSpacing | ( | double | spacing | ) | [inherited] |
Set the spacing between tick and labels.
The spacing is the distance between ticks and labels. The default spacing is 4 pixels.
spacing | Spacing |
void QwtAbstractScaleDraw::setTickLength | ( | QwtScaleDiv::TickType | tickType, |
double | length | ||
) | [inherited] |
Set the length of the ticks
tickType | Tick type |
length | New length |
void QwtAbstractScaleDraw::setTransformation | ( | QwtScaleTransformation * | transformation | ) | [inherited] |
Change the transformation of the scale
transformation | New scale transformation |
double QwtAbstractScaleDraw::spacing | ( | ) | const [inherited] |
Get the spacing.
The spacing is the distance between ticks and labels. The default spacing is 4 pixels.
const QwtText & QwtAbstractScaleDraw::tickLabel | ( | const QFont & | font, |
double | value | ||
) | const [protected, inherited] |
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.
font | Font |
value | Value |
double QwtAbstractScaleDraw::tickLength | ( | QwtScaleDiv::TickType | tickType | ) | const [inherited] |
Return the length of the ticks