Provided by: libqwt-doc_6.1.4-2build2_all 
NAME
QwtDial - QwtDial class provides a rounded range control.
SYNOPSIS
#include <qwt_dial.h>
Inherits QwtAbstractSlider.
Inherited by QwtAnalogClock, and QwtCompass.
Public Types
enum Shadow { Plain = QFrame::Plain, Raised = QFrame::Raised, Sunken = QFrame::Sunken }
Frame shadow.
enum Mode { RotateNeedle, RotateScale }
Mode controlling whether the needle or the scale is rotating.
Public Member Functions
QwtDial (QWidget *parent=NULL)
Constructor.
virtual ~QwtDial ()
Destructor.
void setFrameShadow (Shadow)
Shadow frameShadow () const
void setLineWidth (int)
int lineWidth () const
void setMode (Mode)
Change the mode of the dial.
Mode mode () const
void setScaleArc (double minArc, double maxArc)
void setMinScaleArc (double)
double minScaleArc () const
void setMaxScaleArc (double)
double maxScaleArc () const
virtual void setOrigin (double)
Change the origin.
double origin () const
void setNeedle (QwtDialNeedle *)
const QwtDialNeedle * needle () const
QwtDialNeedle * needle ()
QRect boundingRect () const
QRect innerRect () const
virtual QRect scaleInnerRect () const
virtual QSize sizeHint () const
virtual QSize minimumSizeHint () const
void setScaleDraw (QwtRoundScaleDraw *)
QwtRoundScaleDraw * scaleDraw ()
const QwtRoundScaleDraw * scaleDraw () const
Protected Member Functions
virtual void wheelEvent (QWheelEvent *)
virtual void paintEvent (QPaintEvent *)
virtual void changeEvent (QEvent *)
virtual void drawFrame (QPainter *)
virtual void drawContents (QPainter *) const
Draw the contents inside the frame.
virtual void drawFocusIndicator (QPainter *) const
void invalidateCache ()
virtual void drawScale (QPainter *, const QPointF ¢er, double radius) const
virtual void drawScaleContents (QPainter *painter, const QPointF ¢er, double radius) const
virtual void drawNeedle (QPainter *, const QPointF &, double radius, double direction,
QPalette::ColorGroup) const
virtual double scrolledTo (const QPoint &) const
Determine the value for a new position of the slider handle.
virtual bool isScrollPosition (const QPoint &) const
Determine what to do when the user presses a mouse button.
virtual void sliderChange ()
Calling update()
virtual void scaleChange ()
Additional Inherited Members
Detailed Description
QwtDial class provides a rounded range control.
QwtDial is intended as base class for dial widgets like speedometers, compass widgets, clocks ...
A dial contains a scale and a needle indicating the current value of the dial. Depending on Mode one of
them is fixed and the other is rotating. If not isReadOnly() the dial can be rotated by dragging the
mouse or using keyboard inputs (see QwtAbstractSlider::keyPressEvent()). A dial might be wrapping, what
means a rotation below/above one limit continues on the other limit (f.e compass). The scale might cover
any arc of the dial, its values are related to the origin() of the dial.
Often dials have to be updated very often according to values from external devices. For these high
refresh rates QwtDial caches as much as possible. For derived classes it might be necessary to clear
these caches manually according to attribute changes using invalidateCache().
See also:
QwtCompass, QwtAnalogClock, QwtDialNeedle
Note:
The controls and dials examples shows different types of dials.
QDial is more similar to QwtKnob than to QwtDial
Member Enumeration Documentation
enum QwtDial::Mode
Mode controlling whether the needle or the scale is rotating.
Enumerator
RotateNeedle
The needle is rotating.
RotateScale
The needle is fixed, the scales are rotating.
enum QwtDial::Shadow
Frame shadow. Unfortunately it is not possible to use QFrame::Shadow as a property of a widget that is
not derived from QFrame. The following enum is made for the designer only. It is safe to use
QFrame::Shadow instead.
Enumerator
Plain QFrame::Plain.
Raised QFrame::Raised.
Sunken QFrame::Sunken.
Constructor & Destructor Documentation
QwtDial::QwtDial (QWidget * parent = NULL) [explicit]
Constructor.
Parameters:
parent Parent widget
Create a dial widget with no needle. The scale is initialized to [ 0.0, 360.0 ] and 360 steps (
QwtAbstractSlider::setTotalSteps() ). The origin of the scale is at 90°,
The value is set to 0.0.
The default mode is QwtDial::RotateNeedle.
Member Function Documentation
QRect QwtDial::boundingRect () const
Returns:
bounding rectangle of the dial including the frame
See also:
setLineWidth(), scaleInnerRect(), innerRect()
void QwtDial::changeEvent (QEvent * event) [protected], [virtual]
Change Event handler
Parameters:
event Change event
Invalidates internal paint caches if necessary
void QwtDial::drawContents (QPainter * painter) const [protected], [virtual]
Draw the contents inside the frame. QPalette::Window is the background color outside of the frame.
QPalette::Base is the background color inside the frame. QPalette::WindowText is the background color
inside the scale.
Parameters:
painter Painter
See also:
boundingRect(), innerRect(), scaleInnerRect(), QWidget::setPalette()
void QwtDial::drawFocusIndicator (QPainter * painter) const [protected], [virtual]
Draw the focus indicator
Parameters:
painter Painter
void QwtDial::drawFrame (QPainter * painter) [protected], [virtual]
Draw the frame around the dial
Parameters:
painter Painter
See also:
lineWidth(), frameShadow()
void QwtDial::drawNeedle (QPainter * painter, const QPointF & center, double radius, double direction,
QPalette::ColorGroup colorGroup) const [protected], [virtual]
Draw the needle
Parameters:
painter Painter
center Center of the dial
radius Length for the needle
direction Direction of the needle in degrees, counter clockwise
colorGroup ColorGroup
Reimplemented in QwtAnalogClock.
void QwtDial::drawScale (QPainter * painter, const QPointF & center, double radius) const [protected],
[virtual]
Draw the scale
Parameters:
painter Painter
center Center of the dial
radius Radius of the scale
void QwtDial::drawScaleContents (QPainter * painter, const QPointF & center, double radius) const
[protected], [virtual]
Draw the contents inside the scale
Paints nothing.
Parameters:
painter Painter
center Center of the contents circle
radius Radius of the contents circle
Reimplemented in QwtCompass.
QwtDial::Shadow QwtDial::frameShadow () const
Returns:
Frame shadow /sa setFrameShadow(), lineWidth(), QFrame::frameShadow()
QRect QwtDial::innerRect () const
Returns:
bounding rectangle of the circle inside the frame
See also:
setLineWidth(), scaleInnerRect(), boundingRect()
void QwtDial::invalidateCache () [protected]
Invalidate the internal caches used to speed up repainting
bool QwtDial::isScrollPosition (const QPoint & pos) const [protected], [virtual]
Determine what to do when the user presses a mouse button.
Parameters:
pos Mouse position
Return values:
True,when the inner circle contains pos
See also:
scrolledTo()
Implements QwtAbstractSlider.
int QwtDial::lineWidth () const
Returns:
Line width of the frame
See also:
setLineWidth(), frameShadow(), lineWidth()
double QwtDial::maxScaleArc () const
Returns:
Upper limit of the scale arc
See also:
setScaleArc()
QSize QwtDial::minimumSizeHint () const [virtual]
Returns:
Minimum size hint
See also:
sizeHint()
double QwtDial::minScaleArc () const
Returns:
Lower limit of the scale arc
See also:
setScaleArc()
QwtDial::Mode QwtDial::mode () const
Returns:
Mode of the dial.
See also:
setMode(), origin(), setScaleArc(), value()
const QwtDialNeedle * QwtDial::needle () const
Returns:
needle
See also:
setNeedle()
QwtDialNeedle * QwtDial::needle ()
Returns:
needle
See also:
setNeedle()
double QwtDial::origin () const
The origin is the angle where scale and needle is relative to.
Returns:
Origin of the dial
See also:
setOrigin()
void QwtDial::paintEvent (QPaintEvent * event) [protected], [virtual]
Paint the dial
Parameters:
event Paint event
void QwtDial::scaleChange () [protected], [virtual]
Invalidate the internal caches and call QwtAbstractSlider::scaleChange()
Reimplemented from QwtAbstractSlider.
QwtRoundScaleDraw * QwtDial::scaleDraw ()
Returns:
the scale draw
const QwtRoundScaleDraw * QwtDial::scaleDraw () const
Returns:
the scale draw
QRect QwtDial::scaleInnerRect () const [virtual]
Returns:
rectangle inside the scale
See also:
setLineWidth(), boundingRect(), innerRect()
double QwtDial::scrolledTo (const QPoint & pos) const [protected], [virtual]
Determine the value for a new position of the slider handle.
Parameters:
pos Mouse position
Returns:
Value for the mouse position
See also:
isScrollPosition()
Implements QwtAbstractSlider.
void QwtDial::setFrameShadow (Shadow shadow)
Sets the frame shadow value from the frame style.
Parameters:
shadow Frame shadow
See also:
setLineWidth(), QFrame::setFrameShadow()
void QwtDial::setLineWidth (int lineWidth)
Sets the line width of the frame
Parameters:
lineWidth Line width
See also:
setFrameShadow()
void QwtDial::setMaxScaleArc (double max)
Set the upper limit for the scale arc
Parameters:
max Upper limit of the scale arc
See also:
setScaleArc(), setMinScaleArc()
void QwtDial::setMinScaleArc (double min)
Set the lower limit for the scale arc
Parameters:
min Lower limit of the scale arc
See also:
setScaleArc(), setMaxScaleArc()
void QwtDial::setMode (Mode mode)
Change the mode of the dial.
Parameters:
mode New mode
In case of QwtDial::RotateNeedle the needle is rotating, in case of QwtDial::RotateScale, the needle
points to origin() and the scale is rotating.
The default mode is QwtDial::RotateNeedle.
See also:
mode(), setValue(), setOrigin()
void QwtDial::setNeedle (QwtDialNeedle * needle)
Set a needle for the dial
Parameters:
needle Needle
Warning:
The needle will be deleted, when a different needle is set or in ~QwtDial()
void QwtDial::setOrigin (double origin) [virtual]
Change the origin. The origin is the angle where scale and needle is relative to.
Parameters:
origin New origin
See also:
origin()
void QwtDial::setScaleArc (double minArc, double maxArc)
Change the arc of the scale
Parameters:
minArc Lower limit
maxArc Upper limit
See also:
minScaleArc(), maxScaleArc()
void QwtDial::setScaleDraw (QwtRoundScaleDraw * scaleDraw)
Set an individual scale draw
The motivation for setting a scale draw is often to overload QwtRoundScaleDraw::label() to return
individual tick labels.
Parameters:
scaleDraw Scale draw
Warning:
The previous scale draw is deleted
QSize QwtDial::sizeHint () const [virtual]
Returns:
Size hint
See also:
minimumSizeHint()
void QwtDial::wheelEvent (QWheelEvent * event) [protected], [virtual]
Wheel Event handler
Parameters:
event Wheel event
Reimplemented from QwtAbstractSlider.
Author
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Version 6.1.4 Wed Jan 2 2019 QwtDial(3)