Public Types¶

enum KnobStyle { Flat, Raised, Sunken, Styled }
Style of the knob surface. enum MarkerStyle { NoMarker = -1, Tick, Triangle, Dot, Nub, Notch }
Marker type.

Public Member Functions¶

QwtKnob (QWidget *parent=NULL)
Constructor. virtual ~QwtKnob ()
Destructor. void setAlignment (Qt::Alignment)
Set the alignment of the knob. Qt::Alignment alignment () const
void setKnobWidth (int)
Change the knob's width. int knobWidth () const
Return the width of the knob. void setNumTurns (int)
Set the number of turns. int numTurns () const
void setTotalAngle (double angle)
Set the total angle by which the knob can be turned. double totalAngle () const
void setKnobStyle (KnobStyle)
Set the knob type. KnobStyle knobStyle () const
void setBorderWidth (int)
Set the knob's border width. int borderWidth () const
Return the border width. void setMarkerStyle (MarkerStyle)
Set the marker type of the knob. MarkerStyle markerStyle () const
void setMarkerSize (int)
Set the size of the marker. int markerSize () const
virtual QSize sizeHint () const
virtual QSize minimumSizeHint () const
void setScaleDraw (QwtRoundScaleDraw *)
const QwtRoundScaleDraw * scaleDraw () const
QwtRoundScaleDraw * scaleDraw ()
QRect knobRect () const

Protected Member Functions¶

virtual void paintEvent (QPaintEvent *)
virtual void changeEvent (QEvent *)
virtual void drawKnob (QPainter *, const QRectF &) const
Draw the knob. virtual void drawFocusIndicator (QPainter *) const
virtual void drawMarker (QPainter *, const QRectF &, double angle) const
Draw the marker at the knob's front. virtual double scrolledTo (const QPoint &) const
Determine the value for a new position of the mouse. virtual bool isScrollPosition (const QPoint &) const
Determine what to do when the user presses a mouse button.

Additional Inherited Members¶

enum QwtKnob::KnobStyle¶

Style of the knob surface. Depending on the KnobStyle the surface of the knob is filled from the brushes of the widget palette().

See also:

Enumerator

Flat

Fill the knob with a brush from QPalette::Button.

Raised

Build a gradient from QPalette::Midlight and QPalette::Button.

Sunken

Build a gradient from QPalette::Midlight, QPalette::Button and QPalette::Midlight

Styled

Build a radial gradient from QPalette::Button like it is used for QDial in various Qt styles.

enum QwtKnob::MarkerStyle¶

Marker type. The marker indicates the current value on the knob The default setting is a Notch marker.

See also:

Enumerator

NoMarker

Don't paint any marker.

Tick

Paint a single tick in QPalette::ButtonText color.

Triangle

Paint a triangle in QPalette::ButtonText color.

Dot

Paint a circle in QPalette::ButtonText color.

Nub

Draw a raised ellipse with a gradient build from QPalette::Light and QPalette::Mid

Notch

Draw a sunken ellipse with a gradient build from QPalette::Light and QPalette::Mid

QwtKnob::QwtKnob (QWidget * parent = NULL) [explicit]¶

Constructor. Construct a knob with an angle of 270°. The style is QwtKnob::Raised and the marker style is QwtKnob::Notch. The width of the knob is set to 50 pixels.

Parameters:

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Qt::Alignment QwtKnob::alignment () const¶

Returns:

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void QwtKnob::changeEvent (QEvent * event) [protected], [virtual]¶

Handle QEvent::StyleChange and QEvent::FontChange;

Parameters:

void QwtKnob::drawFocusIndicator (QPainter * painter) const [protected], [virtual]¶

Draw the focus indicator

Parameters:

void QwtKnob::drawKnob (QPainter * painter, const QRectF & knobRect) const [protected], [virtual]¶

Draw the knob.

Parameters:

void QwtKnob::drawMarker (QPainter * painter, const QRectF & rect, double angle) const [protected], [virtual]¶

Draw the marker at the knob's front.

Parameters:

bool QwtKnob::isScrollPosition (const QPoint & pos) const [protected], [virtual]¶

Determine what to do when the user presses a mouse button.

Parameters:

Return values:

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Implements QwtAbstractSlider.

QRect QwtKnob::knobRect () const¶

Calculate the bounding rectangle of the knob without the scale

Returns:

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QwtKnob::KnobStyle QwtKnob::knobStyle () const¶

Returns:

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int QwtKnob::markerSize () const¶

Returns:

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QwtKnob::MarkerStyle QwtKnob::markerStyle () const¶

Returns:

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QSize QwtKnob::minimumSizeHint () const [virtual]¶

Returns:

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int QwtKnob::numTurns () const¶

Returns:

When the total angle is below 360° numTurns() is ceiled to 1.

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void QwtKnob::paintEvent (QPaintEvent * event) [protected], [virtual]¶

Repaint the knob

Parameters:

const QwtRoundScaleDraw * QwtKnob::scaleDraw () const¶

Returns:

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QwtRoundScaleDraw * QwtKnob::scaleDraw ()¶

Returns:

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double QwtKnob::scrolledTo (const QPoint & pos) const [protected], [virtual]¶

Determine the value for a new position of the mouse.

Parameters:

Returns:

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Implements QwtAbstractSlider.

void QwtKnob::setAlignment (Qt::Alignment alignment)¶

Set the alignment of the knob. Similar to a QLabel::alignment() the flags decide how to align the knob inside of contentsRect().

The default setting is Qt::AlignCenter

Parameters:

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void QwtKnob::setBorderWidth (int borderWidth)¶

Set the knob's border width.

Parameters:

void QwtKnob::setKnobStyle (KnobStyle knobStyle)¶

Set the knob type.

Parameters:

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void QwtKnob::setKnobWidth (int width)¶

Change the knob's width. Setting a fixed value for the diameter of the knob is helpful for aligning several knobs in a row.

Parameters:

See also:

Note:

void QwtKnob::setMarkerSize (int size)¶

Set the size of the marker. When setting a size <= 0 the marker will automatically scaled to 40% of the radius of the knob.

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void QwtKnob::setMarkerStyle (MarkerStyle markerStyle)¶

Set the marker type of the knob.

Parameters:

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void QwtKnob::setNumTurns (int numTurns)¶

Set the number of turns. When numTurns > 1 the knob can be turned several times around its axis

•

otherwise the total angle is floored to 360°.

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void QwtKnob::setScaleDraw (QwtRoundScaleDraw * scaleDraw)¶

Change the scale draw of the knob

For changing the labels of the scales, it is necessary to derive from QwtRoundScaleDraw and overload QwtRoundScaleDraw::label().

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void QwtKnob::setTotalAngle (double angle)¶

Set the total angle by which the knob can be turned.

Parameters:

The angle has to be between [10, 360] degrees. Angles above 360 ( so that the knob can be turned several times around its axis ) have to be set using setNumTurns().

The default angle is 270 degrees.

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QSize QwtKnob::sizeHint () const [virtual]¶

Returns:

double QwtKnob::totalAngle () const¶

Returns:

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