QDial(3qt)QDial(3qt)NAME
QDial - Rounded rangecontrol (like a speedometer or
potentiometer)
#include <qdial.h>
Inherits QRangeControl and QWidget.
Public Members
QDial ( QWidget * parent=0, const char * name=0 )
QDial ( int minValue, int maxValue, int pageStep, int
value, QWidget * parent=0, const char * name=0 )
~QDial ()
bool tracking () const
bool wrapping () const
int notchSize () const
virtual void setNotchTarget ( double )
double notchTarget () const
bool notchesVisible () const
void setMinValue ( int )
void setMaxValue ( int )
void setLineStep ( int )
void setPageStep ( int )
Public Slots
virtual void setValue ( int )
void addLine ()
void subtractLine ()
void addPage ()
void subtractPage ()
virtual void setNotchesVisible ( bool b )
virtual void setWrapping ( bool on )
virtual void setTracking ( bool enable )
Signals
void valueChanged ( int value )
void dialPressed ()
void dialMoved ( int value )
void dialReleased ()
Protected Members
virtual void valueChange ()
virtual void rangeChange ()
virtual void repaintScreen ( const QRect * cr = 0 )
Properties
Type Name READ WRITE Options
-----------------------------------------------------------------------
bool tracking tracking setTracking
bool wrapping wrapping setWrapping
int notchSize notchSize
double notchTarget notchTarget setNotchTarget
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QDial(3qt)QDial(3qt)
bool notchesVisible notchesVisible setNotchesVisible
int minValue minValue setMinValue
int maxValue maxValue setMaxValue
int lineStep lineStep setLineStep
int pageStep pageStep setPageStep
int value value setValue
DESCRIPTION
The QDial class provides a rounded rangecontrol (like a
speedometer or potentiometer).
Q dial is used when the user needs to control a value
within a program-definable range, and the range either
wraps around (typically, 0-359 degrees) or the dialog
layout needs a square widget.
Both API- and UI-wise, the dial is very like a slider.
Indeed, when wrapping() is FALSE (the default) there is no
hard difference between a slider and a dial. They have the
same signals, slots and member functions, all of which do
the same things. Which one to use depends only on your
taste and on the application.
The dial initially emits valueChanged() signals
continuously while the slider is being moved; you can make
it emit the signal less often by calling setTracking(
FALSE ). dialMoved() is emitted continuously even when
tracking() is FALSE.
The slider also emits dialPressed() and dialReleased()
signals when the mouse button is pressed and released. But
note that the dial's value can change without these
signals being emitted; the keyboard and wheel can be used
to change the value.
Unlike the slider, QDial attempts to draw a "nice" number
of notches rather than one per lineStep(). If possible,
that number is lineStep(), but if there aren't enough
pixels to draw every, QDial will draw every second, third
or something. notchSize() returns the number of units per
notch, hopefully a multiple of lineStep();
setNotchTarget() sets the target distance between
neighbouring notches in pixels. The default is 3.75
pixels.
Like the slider, the dial makes the QRangeControl
functions setValue(), addLine(), substractLine(),
addPage() and subtractPage() available as slots.
The dial's keyboard interface is fairly simple: The
left/up and right/down arrow keys move by lineStep(), page
up and page down by pageStep() and Home and End to
minValue() and maxValue().
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QDial(3qt)QDial(3qt)
[Image Omitted]
[Image Omitted]
See also QScrollBar, QSpinBox and GUI Design Handbook:
Slider
MEMBER FUNCTION DOCUMENTATIONQDial::QDial ( QWidget * parent=0, const char * name=0 )
Constructs a dial with the default range of QRangeControl.
QDial::QDial ( int minValue, int maxValue, int pageStep, int
value, QWidget * parent=0, const char * name=0 )
Constructs a dial whose value can never be smaller than
minValue or greater than maxValue, whose line step size is
lineStep and page step size is pageStep, and whose value
is initially value.
value is forced to be within the legal range.
QDial::~QDial ()
Destructs the dial.
void QDial::addLine () [slot]
Moves the dial one lineStep() upwards.
void QDial::addPage () [slot]
Moves the dial one pageStep() upwards.
void QDial::dialMoved ( int value ) [signal]
This signal is emitted whenever the dial value changes.
The frequency of this signal is not influenced by
setTracking().
See also valueChanged(int).
void QDial::dialPressed () [signal]
This signal is emitted when the use begins mouse
interaction with the dial.
See also dialReleased().
void QDial::dialReleased () [signal]
This signal is emitted when the use ends mouse interaction
with the dial.
See also dialPressed().
void QDial::focusInEvent ( QFocusEvent * ) [virtual protected]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
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QDial(3qt)QDial(3qt)void QDial::focusOutEvent ( QFocusEvent * ) [virtual protected]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
void QDial::keyPressEvent ( QKeyEvent * e ) [virtual protected]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
int QDial::lineStep () const
Reimplemented for internal reasons; the API is not
affected.
int QDial::maxValue () const
Reimplemented for internal reasons; the API is not
affected.
int QDial::minValue () const
Reimplemented for internal reasons; the API is not
affected.
QSize QDial::minimumSizeHint () const [virtual]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
void QDial::mouseMoveEvent ( QMouseEvent * e ) [virtual
protected]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
void QDial::mousePressEvent ( QMouseEvent * e ) [virtual
protected]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
void QDial::mouseReleaseEvent ( QMouseEvent * e ) [virtual
protected]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
int QDial::notchSize () const
Returns the current notch size. This is in range control
units, not pixels, and if possible it is a multiple of
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QDial(3qt)QDial(3qt)lineStep() that results in an on-screen notch size near
notchTarget().
See also notchTarget() and lineStep().
double QDial::notchTarget () const
Returns the target size of the notch; this is the number
of pixels QDial attempts to put between each little line.
The actual size differs a bit from the target.
bool QDial::notchesVisible () const
Retuns TRUE if notches are shown, else FALSE.
See also setNotchesVisible().
int QDial::pageStep () const
Reimplemented for internal reasons; the API is not
affected.
void QDial::paintEvent ( QPaintEvent * e ) [virtual protected]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
void QDial::rangeChange () [virtual protected]
Reimplemented to ensure tick-marks are consistent with the
new range.
Reimplemented from QRangeControl.
void QDial::repaintScreen ( const QRect * cr = 0 ) [virtual
protected]
Paints the dial.
void QDial::resizeEvent ( QResizeEvent * e ) [virtual protected]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
void QDial::setLineStep ( int i )
Sets the line step to i.
Calls the virtual stepChange() function if the new line
step is different from the previous setting.
See also lineStep(), QRangeControl::setSteps(),
setPageStep() and setRange().
void QDial::setMaxValue ( int i )
A convenience function which just calls setRange(
minValue(), i )
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QDial(3qt)QDial(3qt)
See also setRange().
void QDial::setMinValue ( int i )
A convenience function which just calls setRange( i,
maxValue() )
See also setRange().
void QDial::setNotchTarget ( double target ) [virtual]
Sets the dial to use a notch size as close to target
pixels as possible. QDial will find a suitable number
close to this, based on the dial's on-screen size, range
and lineStep().
See also notchTarget() and notchSize().
void QDial::setNotchesVisible ( bool b ) [virtual slot]
Enables or disables showing of notches. If b is TRUE, the
notches are shown, else not.
void QDial::setPageStep ( int i )
Sets the page step to i.
Calls the virtual stepChange() function if the new page
step is different from the previous setting.
See also pageStep(), QRangeControl::setSteps(),
setLineStep() and setRange().
void QDial::setTracking ( bool enable ) [virtual slot]
If enable is TRUE, tracking is enabled. This means that
the arrow can be moved using the mouse. Else this is not
possible.
void QDial::setValue ( int newValue ) [virtual slot]
Makes QRangeControl::setValue() available as a slot.
void QDial::setWrapping ( bool enable ) [virtual slot]
If enable is TRUE, wrapping is enabled. This means that
the arrow can be turned around 360. Else there is some
space at the bottom which is skipped by the arrow.
QSize QDial::sizeHint () const [virtual]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
void QDial::subtractLine () [slot]
Moves the dial one lineStep() downwards.
void QDial::subtractPage () [slot]
Moves the dial one pageStep() downwards.
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QDial(3qt)QDial(3qt)bool QDial::tracking () const
Returns TRUE if tracking is enabled, or FALSE if tracking
is disabled.
Tracking is initially enabled.
See also setTracking().
int QDial::value () const
Reimplemented for internal reasons; the API is not
affected.
void QDial::valueChange () [virtual protected]
Reimplemented to ensure the display is correct and to emit
the valueChanged(int) signal when appropriate.
Reimplemented from QRangeControl.
void QDial::valueChanged ( int value ) [signal]
This signal is emitted whenever the dial value changes.
The frequency of this signal is influenced by
setTracking().
void QDial::wheelEvent ( QWheelEvent * e ) [virtual protected]
Reimplemented for internal reasons; the API is not
affected.
Reimplemented from QWidget.
bool QDial::wrapping () const
Returns TRUE if wrapping is enabled, else FALSE.
See also QDial::setWrapping().
SEE ALSO
http://doc.trolltech.com/qdial.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2001 Trolltech AS,
http://www.trolltech.com. See the license file included
in the distribution for a complete license statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports
make our job much simpler. Thank you.
In case of content or formattting problems with this
manual page, please report them to qt-bugs@trolltech.com.
Please include the name of the manual page (qdial.3qt) and
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QDial(3qt)QDial(3qt)
the Qt version (2.3.1).
Trolltech AS 13 June 2001 8
