NAME¶

QwtRoundScaleDraw - A class for drawing round scales.

SYNOPSIS¶

#include <qwt_round_scale_draw.h> Inherits QwtAbstractScaleDraw. Inherited by QwtDialScaleDraw.

Public Types¶

enum ScaleComponent { Backbone = 1, Ticks = 2, Labels = 4 }

Public Member Functions¶

QPoint center () const virtual void draw (QPainter *, const QPalette &) const void enableComponent (ScaleComponent, bool enable=true) virtual int extent (const QPen &, const QFont &) const bool hasComponent (ScaleComponent) const virtual QwtText label (double) const int majTickLength () const const QwtScaleMap & map () const int minimumExtent () const void moveCenter (const QPoint &) void moveCenter (int x, int y) QwtRoundScaleDraw & operator= (const QwtRoundScaleDraw &other) QwtRoundScaleDraw (const QwtRoundScaleDraw &) QwtRoundScaleDraw () int radius () const const QwtScaleDiv & scaleDiv () const QwtScaleMap & scaleMap () void setAngleRange (double angle1, double angle2) void setMinimumExtent (int) void setRadius (int radius) 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 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, int len) const void invalidateCache () const QwtText & tickLabel (const QFont &, double value) const

Detailed Description¶

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.

Member Enumeration Documentation¶

enum QwtAbstractScaleDraw::ScaleComponent [inherited] Components of a scale¶

•

Backbone

•

Ticks

•

Labels

See also:

Constructor & Destructor Documentation¶

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 (const QwtRoundScaleDraw &other)¶

Copy constructor.

QwtRoundScaleDraw::~QwtRoundScaleDraw () [virtual]¶

Destructor.

Member Function Documentation¶

QPoint QwtRoundScaleDraw::center () const¶

Get the center of the scale.

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

Draw the scale. Parameters:

void QwtRoundScaleDraw::drawBackbone (QPainter *painter) const [protected, virtual] Draws the baseline of the scale¶

Parameters: See also: Implements QwtAbstractScaleDraw.

void QwtRoundScaleDraw::drawLabel (QPainter *painter, doublevalue) const [protected, virtual] Draws the label for a major scale tick¶

Parameters: See also: Implements QwtAbstractScaleDraw.

void QwtRoundScaleDraw::drawTick (QPainter *painter, doublevalue, intlen) const [protected, virtual] Draw a tick¶

Parameters: See also: Implements QwtAbstractScaleDraw.

void QwtAbstractScaleDraw::enableComponent (ScaleComponentcomponent, boolenable = true) [inherited] En/Disable a component of the scale¶

Parameters: See also:

int QwtRoundScaleDraw::extent (const QPen &pen, const QFont &font) const [virtual] Calculate the extent of the scale¶

The extent is the distcance between the baseline to the outermost pixel of the scale draw. radius() + extent() is an upper limit for the radius of the bounding circle. Parameters: See also: Warning: Implements QwtAbstractScaleDraw.

bool QwtAbstractScaleDraw::hasComponent (ScaleComponentcomponent) const [inherited] Check if a component is enabled¶

See also:

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, QwtAbstractScaleDraw::invalidateCache needs to be called manually.

QwtText QwtAbstractScaleDraw::label (doublevalue) 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. Parameters: Returns: Reimplemented in QwtDialScaleDraw.

int QwtAbstractScaleDraw::majTickLength () const [inherited] The same as QwtAbstractScaleDraw::tickLength(QwtScaleDiv::MajorTick).¶

const QwtScaleMap & QwtAbstractScaleDraw::map () const [inherited] Returns:¶

int QwtAbstractScaleDraw::minimumExtent () const [inherited] Get the minimum extent¶

See also:

void QwtRoundScaleDraw::moveCenter (const QPoint &center) Move the center of the scale draw, leaving the radius unchanged¶

Parameters: See also:

void QwtRoundScaleDraw::moveCenter (intx, inty) [inline]¶

Move the center of the scale draw, leaving the radius unchanged.

QwtRoundScaleDraw & QwtRoundScaleDraw::operator= (const QwtRoundScaleDraw &other)¶

Assignment operator.

int QwtRoundScaleDraw::radius () const Get the radius¶

Radius is the radius of the backbone without ticks and labels. See also:

const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv () const [inherited] Returns:¶

QwtScaleMap & QwtAbstractScaleDraw::scaleMap () [inherited] Returns:¶

void QwtRoundScaleDraw::setAngleRange (doubleangle1, doubleangle2)¶

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. Parameters: Warning:

void QwtAbstractScaleDraw::setMinimumExtent (intminExtent) [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. Parameters: See also:

void QwtRoundScaleDraw::setRadius (intradius) Change of radius the scale¶

Radius is the radius of the backbone without ticks and labels. Parameters: See also:

void QwtAbstractScaleDraw::setScaleDiv (const QwtScaleDiv &sd) [inherited] Change the scale division¶

Parameters:

void QwtAbstractScaleDraw::setSpacing (intspacing) [inherited]¶

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::TickTypetickType, intlength) [inherited] Set the length of the ticks¶

Parameters: Warning:

void QwtAbstractScaleDraw::setTransformation (QwtScaleTransformation *transformation) [inherited] Change the transformation of the scale¶

Parameters:

int QwtAbstractScaleDraw::spacing () const [inherited]¶

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

const QwtText & QwtAbstractScaleDraw::tickLabel (const QFont &font, doublevalue) 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. Parameters: Returns:

int QwtAbstractScaleDraw::tickLength (QwtScaleDiv::TickTypetickType) const [inherited] Return the length of the ticks¶

See also:

Author¶

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