QwtKnob

Section: Qwt User's Guide (3) Updated: 16 Nov 2004 Local index Up

NAME

QwtKnob -

SYNOPSIS

Inherits QwtSliderBase, and QwtScaleIf.

Detailed Description

The Knob Widget.

The QwtKnob widget imitates look and behaviour of a volume knob on a radio. It contains a scale around the knob which is set up automatically or can be configured manually (see QwtScaleIf). Automatic scrolling is enabled when the user presses a mouse button on the scale. For a description of signals, slots and other members, see QwtSliderBase.

See also:

: QwtSliderBase and QwtScaleIf for the descriptions of the inherited members.

Definition at line 32 of file qwt_knob.h.

Public Types

enum Symbol { Line, Dot }

Public Member Functions

QwtKnob (QWidget *parent=0, const char *name=0)

virtual ~QwtKnob ()

void setKnobWidth (int w)

void setTotalAngle (double angle)

void setBorderWidth (int bw)

int knobWidth () const

double totalAngle () const

int borderWidth () const

void setSymbol (Symbol)

Symbol symbol () const

virtual QSize sizeHint () const

virtual QSize minimumSizeHint () const

Protected Member Functions

virtual void paintEvent (QPaintEvent *e)

virtual void resizeEvent (QResizeEvent *e)

void draw (QPainter *p, const QRect &ur)

void drawKnob (QPainter *p, const QRect &r)

void drawMarker (QPainter *p, double arc, const QColor &c)

Member Enumeration Documentation

enum QwtKnob::Symbol

Symbol

See also:

: QwtKnob::QwtKnob()

Definition at line 47 of file qwt_knob.h.

Referenced by symbol().

Constructor & Destructor Documentation

QwtKnob::QwtKnob (QWidget * parent = 0, const char * name = 0)

Constructor.

Parameters:

: parent Parent widget
name Name

Definition at line 23 of file qwt_knob.cpp.

References QwtScaleIf::scaleDraw(), QwtScaleDraw::setGeometry(), setTotalAngle(), and QwtSliderBase::setUpdateTime().

QwtKnob::~QwtKnob () [virtual]

Destructor.

Definition at line 49 of file qwt_knob.cpp.

Member Function Documentation

int QwtKnob::borderWidth () const

Return the border width.

Definition at line 61 of file qwt_knob.h.

void QwtKnob::draw (QPainter * painter, const QRect & ur) [protected]

Repaint the knob.

Definition at line 275 of file qwt_knob.cpp.

References QwtScaleDraw::draw(), drawKnob(), and QwtScaleIf::scaleDraw().

Referenced by paintEvent().

void QwtKnob::drawKnob (QPainter * p, const QRect & r) [protected]

Draw the knob.

Parameters:

: p painter
r borders of the knob

Definition at line 99 of file qwt_knob.cpp.

References drawMarker(), and QwtSliderBase::isValid().

Referenced by draw().

void QwtKnob::drawMarker (QPainter * p, double arc, const QColor & c) [protected]

Draw the marker at the knob's front.

Parameters:

: p Painter
arc Angle of the marker
c Marker color

Definition at line 301 of file qwt_knob.cpp.

Referenced by drawKnob().

int QwtKnob::knobWidth () const

Return the width of the knob.

Definition at line 57 of file qwt_knob.h.

QSize QwtKnob::minimumSizeHint () const [virtual]

Return a minimum size hint.

Warning:

: The return value of QwtKnob::minimumSizeHint() depends on the font and the scale.

Definition at line 424 of file qwt_knob.cpp.

References QwtScaleDraw::minHeight(), and QwtScaleIf::scaleDraw().

Referenced by sizeHint().

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

Repaint the knob.

Definition at line 262 of file qwt_knob.cpp.

References draw(), and QwtPaintBuffer::painter().

void QwtKnob::resizeEvent (QResizeEvent * e) [protected, virtual]

Qt Resize Event.

Definition at line 228 of file qwt_knob.cpp.

void QwtKnob::setBorderWidth (int bw)

Set the knob's border width.

Parameters:

: bw new border width

Definition at line 360 of file qwt_knob.cpp.

void QwtKnob::setKnobWidth (int w)

Change the knob's width.

The specified width must be >= 5, or it will be clipped.

Parameters:

: w New width

Definition at line 350 of file qwt_knob.cpp.

void QwtKnob::setSymbol (QwtKnob::Symbol s)

Set the symbol of the knob.

See also:

: QwtKnob::symbol()

Definition at line 57 of file qwt_knob.cpp.

void QwtKnob::setTotalAngle (double angle)

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

Parameters:

: angle Angle in degrees.

The default angle is 270 degrees. It is possible to specify an angle of more than 360 degrees so that the knob can be turned several times around its axis. Definition at line 83 of file qwt_knob.cpp.

References QwtScaleIf::scaleDraw(), and QwtScaleDraw::setAngleRange().

Referenced by QwtKnob().