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QwtSliderBase Class Reference

A Base class for sliders. More...

#include <qwt_sldbase.h>

Inheritance diagram for QwtSliderBase:

QwtDblRange QwtDial QwtKnob QwtSlider QwtWheel QwtCompass List of all members.

Public Types

enum  ScrollMode {
  ScrNone, ScrMouse, ScrTimer, ScrDirect,
  ScrPage
}

Public Slots

virtual void setValue (double val)
virtual void fitValue (double val)
virtual void incValue (int steps)
virtual void setReadOnly (bool)

Signals

void valueChanged (double value)
void sliderPressed ()
void sliderReleased ()
void sliderMoved (double value)

Public Member Functions

 QwtSliderBase (Qt::Orientation orientation, QWidget *parent=0, const char *name=0, WFlags flags=0)
virtual ~QwtSliderBase ()
void setUpdateTime (int t)
void stopMoving ()
void setTracking (bool enable)
virtual void setMass (double val)
virtual double mass () const
virtual void setOrientation (Orientation o)
Orientation orientation () const
bool isReadOnly () const

Protected Member Functions

void setPosition (const QPoint &p)
virtual void valueChange ()
virtual void timerEvent (QTimerEvent *e)
virtual void mousePressEvent (QMouseEvent *e)
virtual void mouseReleaseEvent (QMouseEvent *e)
virtual void mouseMoveEvent (QMouseEvent *e)
virtual void keyPressEvent (QKeyEvent *e)
virtual void wheelEvent (QWheelEvent *e)
virtual double getValue (const QPoint &p)=0
virtual void getScrollMode (const QPoint &p, int &scrollMode, int &direction)=0

Protected Attributes

int d_scrollMode
double d_mouseOffset
int d_direction
int d_tracking

Private Member Functions

void buttonReleased ()

Private Attributes

int d_tmrID
int d_updTime
int d_timerTick
QTime d_time
double d_speed
double d_mass
Orientation d_orientation
bool d_readOnly

Detailed Description

A Base class for sliders.

QwtSliderBase is a base class for slider widgets. QwtSliderBase handles the mouse events and updates the slider's value accordingly. Derived classes only have to implement the getValue() and getScrollMode() members, and should react to a valueChange(), which normally requires repainting.

Definition at line 30 of file qwt_sldbase.h.


Member Enumeration Documentation

enum QwtSliderBase::ScrollMode
 

Enumeration values:
ScrNone 
ScrMouse 
ScrTimer 
ScrDirect 
ScrPage 

Definition at line 38 of file qwt_sldbase.h.


Constructor & Destructor Documentation

QwtSliderBase::QwtSliderBase Qt::Orientation  orientation,
QWidget *  parent = 0,
const char *  name = 0,
WFlags  flags = 0
 

Constructor.

Definition at line 18 of file qwt_sldbase.cpp.

References d_mass, d_mouseOffset, d_tmrID, d_tracking, d_updTime, QwtDblRange::setRange(), and setValue().

QwtSliderBase::~QwtSliderBase  )  [virtual]
 

Destructor.

Definition at line 37 of file qwt_sldbase.cpp.

References d_tmrID.


Member Function Documentation

void QwtSliderBase::buttonReleased  )  [private]
 

Emits a valueChanged() signal if necessary.

Definition at line 141 of file qwt_sldbase.cpp.

References d_tracking, QwtDblRange::prevValue(), QwtDblRange::value(), and valueChanged().

Referenced by mouseReleaseEvent(), and timerEvent().

void QwtSliderBase::fitValue double  val  )  [virtual, slot]
 

Set the slider's value to the nearest integer multiple of the step size.

See also:
QwtSliderBase::setValue()

Reimplemented from QwtDblRange.

Definition at line 491 of file qwt_sldbase.cpp.

References d_scrollMode, QwtDblRange::fitValue(), ScrMouse, and stopMoving().

virtual void QwtSliderBase::getScrollMode const QPoint &  p,
int &  scrollMode,
int &  direction
[protected, pure virtual]
 

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

This function is abstract and has to be implemented by derived classes. It is called on a mousePress event. The derived class can determine what should happen next in dependence of the position where the mouse was pressed by returning scrolling mode and direction. QwtSliderBase knows the following modes:

QwtSliderBase::ScrNone
Scrolling switched off. Don't change the value.
QwtSliderBase::ScrMouse
Change the value while the user keeps the button pressed and moves the mouse.
QwtSliderBase::ScrTimer
Automatic scrolling. Increment the value in the specified direction as long as the user keeps the button pressed.
QwtSliderBase::ScrPage
Automatic scrolling. Same as ScrTimer, but increment by page size.

Parameters:
p point where the mouse was pressed
Return values:
scrollMode The scrolling mode
direction direction: 1, 0, or -1.

Implemented in QwtDial, QwtKnob, QwtSlider, and QwtWheel.

Referenced by mousePressEvent(), and wheelEvent().

virtual double QwtSliderBase::getValue const QPoint &  p  )  [protected, pure virtual]
 

Determine the value corresponding to a specified poind.

This is an abstract virtual function which is called when the user presses or releases a mouse button or moves the mouse. It has to be implemented by the derived class.

Parameters:
p point

Implemented in QwtDial, QwtKnob, QwtSlider, and QwtWheel.

Referenced by mousePressEvent(), and setPosition().

void QwtSliderBase::incValue int  steps  )  [virtual, slot]
 

Increment the value by a specified number of steps.

Parameters:
steps number of steps

Reimplemented from QwtDblRange.

Definition at line 503 of file qwt_sldbase.cpp.

References d_scrollMode, QwtDblRange::incValue(), ScrMouse, and stopMoving().

bool QwtSliderBase::isReadOnly  )  const
 

Definition at line 49 of file qwt_sldbase.cpp.

References d_readOnly.

Referenced by keyPressEvent(), QwtCompass::keyPressEvent(), mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), and wheelEvent().

void QwtSliderBase::keyPressEvent QKeyEvent *  e  )  [protected, virtual]
 

Reimplemented in QwtCompass.

Definition at line 313 of file qwt_sldbase.cpp.

References QwtDblRange::incValue(), isReadOnly(), QwtDblRange::isValid(), orientation(), QwtDblRange::prevValue(), sliderMoved(), and QwtDblRange::value().

Referenced by QwtCompass::keyPressEvent().

double QwtSliderBase::mass  )  const [virtual]
 

Returns:
mass
See also:
QwtSliderBase::setMass

Reimplemented in QwtWheel.

Definition at line 464 of file qwt_sldbase.cpp.

References d_mass.

Referenced by QwtWheel::mass().

void QwtSliderBase::mouseMoveEvent QMouseEvent *  e  )  [protected, virtual]
 

Mouse Move Event handler.

Definition at line 257 of file qwt_sldbase.cpp.

References d_mass, d_scrollMode, d_speed, d_time, QwtDblRange::exactPrevValue(), QwtDblRange::exactValue(), isReadOnly(), QwtDblRange::isValid(), QwtDblRange::prevValue(), ScrMouse, setPosition(), sliderMoved(), and QwtDblRange::value().

void QwtSliderBase::mousePressEvent QMouseEvent *  e  )  [protected, virtual]
 

Mouse press event handler.

Definition at line 98 of file qwt_sldbase.cpp.

References d_direction, d_mouseOffset, d_scrollMode, d_speed, d_time, d_timerTick, d_tmrID, d_updTime, getScrollMode(), getValue(), isReadOnly(), QwtDblRange::isValid(), qwtMax, ScrMouse, ScrPage, ScrTimer, sliderPressed(), stopMoving(), and QwtDblRange::value().

void QwtSliderBase::mouseReleaseEvent QMouseEvent *  e  )  [protected, virtual]
 

Mouse Release Event handler.

Definition at line 149 of file qwt_sldbase.cpp.

References buttonReleased(), d_direction, d_mass, d_mouseOffset, d_scrollMode, d_speed, d_time, d_timerTick, d_tmrID, d_updTime, QwtDblRange::fitValue(), QwtDblRange::incPages(), isReadOnly(), QwtDblRange::isValid(), ScrDirect, ScrMouse, ScrNone, ScrPage, ScrTimer, setPosition(), sliderReleased(), QwtDblRange::step(), stopMoving(), and QwtDblRange::value().

Qt::Orientation QwtSliderBase::orientation  )  const
 

Definition at line 68 of file qwt_sldbase.cpp.

References d_orientation.

Referenced by QwtSlider::drawSlider(), QwtSlider::drawThumb(), QwtWheel::drawWheel(), QwtWheel::drawWheelBackground(), QwtSlider::getScrollMode(), QwtWheel::getValue(), QwtSlider::getValue(), keyPressEvent(), QwtSlider::layoutSlider(), QwtWheel::minimumSizeHint(), QwtSlider::minimumSizeHint(), QwtSlider::QwtSlider(), QwtWheel::setOrientation(), QwtWheel::sizePolicy(), QwtSlider::sizePolicy(), and QwtSlider::xyPosition().

void QwtSliderBase::setMass double  val  )  [virtual]
 

Set the slider's mass for flywheel effect.

If the slider's mass is greater then 0, it will continue to move after the mouse button has been released. Its speed decreases with time at a rate depending on the slider's mass. A large mass means that it will continue to move for a long time.

Derived widgets may overload this function to make it public.

Parameters:
val new mass in kg

Bug:
If the mass is smaller than 1g, it is set to zero. The maximal mass is limited to 100kg.
See also:
QwtSliderBase::mass

Reimplemented in QwtWheel.

Definition at line 450 of file qwt_sldbase.cpp.

References d_mass.

Referenced by QwtWheel::setMass().

void QwtSliderBase::setOrientation Orientation  o  )  [virtual]
 

Set the orientation.

Parameters:
o Orientation. Allowed values are Qt::Horizontal and Qt::Vertical.

Definition at line 59 of file qwt_sldbase.cpp.

References d_orientation.

Referenced by QwtWheel::setOrientation(), and QwtSlider::setOrientation().

void QwtSliderBase::setPosition const QPoint &  p  )  [protected]
 

Move the slider to a specified point, adjust the value and emit signals if necessary.

Definition at line 231 of file qwt_sldbase.cpp.

References d_mouseOffset, QwtDblRange::fitValue(), and getValue().

Referenced by mouseMoveEvent(), and mouseReleaseEvent().

void QwtSliderBase::setReadOnly bool   )  [virtual, slot]
 

Definition at line 43 of file qwt_sldbase.cpp.

References d_readOnly.

void QwtSliderBase::setTracking bool  enable  ) 
 

Enables or disables tracking.

If tracking is enabled, the slider emits a valueChanged() signal whenever its value changes (the default behaviour). If tracking is disabled, the value changed() signal will only be emitted if:

  • the user releases the mouse button and the value has changed or
  • at the end of automatic scrolling.
Tracking is enabled by default.
Parameters:
enable TRUE (enable) or FALSE (disable) tracking.

Definition at line 251 of file qwt_sldbase.cpp.

References d_tracking.

void QwtSliderBase::setUpdateTime int  t  ) 
 

Specify the update interval for automatic scrolling.

Parameters:
t update interval in milliseconds
See also:
QwtSliderBase::getScrollMode()

Definition at line 89 of file qwt_sldbase.cpp.

References d_updTime.

Referenced by QwtKnob::QwtKnob(), and QwtWheel::QwtWheel().

void QwtSliderBase::setValue double  val  )  [virtual, slot]
 

Move the slider to a specified value.

This function can be used to move the slider to a value which is not an integer multiple of the step size.

Parameters:
val new value
See also:
QwtSliderBase::fitValue

Reimplemented from QwtDblRange.

Definition at line 478 of file qwt_sldbase.cpp.

References d_scrollMode, ScrMouse, QwtDblRange::setValue(), and stopMoving().

Referenced by QwtCompass::keyPressEvent(), and QwtSliderBase().

void QwtSliderBase::sliderMoved double  value  )  [signal]
 

This signal is emitted when the user moves the slider with the mouse.

Parameters:
value new value

Referenced by keyPressEvent(), mouseMoveEvent(), and wheelEvent().

void QwtSliderBase::sliderPressed  )  [signal]
 

This signal is emitted when the user presses the movable part of the slider (start ScrMouse Mode).

Referenced by mousePressEvent().

void QwtSliderBase::sliderReleased  )  [signal]
 

This signal is emitted when the user releases the movable part of the slider.

Referenced by mouseReleaseEvent().

void QwtSliderBase::stopMoving  ) 
 

Stop updating if automatic scrolling is active.

Definition at line 75 of file qwt_sldbase.cpp.

References d_tmrID.

Referenced by fitValue(), incValue(), mousePressEvent(), mouseReleaseEvent(), setValue(), and timerEvent().

void QwtSliderBase::timerEvent QTimerEvent *  e  )  [protected, virtual]
 

Qt timer event.

Definition at line 360 of file qwt_sldbase.cpp.

References buttonReleased(), d_direction, d_mass, d_scrollMode, d_speed, d_timerTick, d_tmrID, d_updTime, QwtDblRange::exactValue(), QwtDblRange::fitValue(), QwtDblRange::incPages(), ScrMouse, ScrPage, ScrTimer, QwtDblRange::step(), stopMoving(), and QwtDblRange::value().

void QwtSliderBase::valueChange  )  [protected, virtual]
 

Notify change of value

This function can be reimplemented by derived classes in order to keep track of changes, i.e. repaint the widget. The default implementation emits a valueChanged() signal if tracking is enabled.

Reimplemented from QwtDblRange.

Reimplemented in QwtDial, QwtKnob, QwtSlider, and QwtWheel.

Definition at line 427 of file qwt_sldbase.cpp.

References d_tracking, QwtDblRange::value(), and valueChanged().

Referenced by QwtWheel::valueChange(), QwtSlider::valueChange(), QwtKnob::valueChange(), and QwtDial::valueChange().

void QwtSliderBase::valueChanged double  value  )  [signal]
 

Notify a change of value.

In the default setting (tracking enabled), this signal will be emitted every time the value changes ( see setTracking() ).

Parameters:
value new value

Referenced by buttonReleased(), and valueChange().

void QwtSliderBase::wheelEvent QWheelEvent *  e  )  [protected, virtual]
 

Qt wheel event.

Definition at line 287 of file qwt_sldbase.cpp.

References getScrollMode(), QwtDblRange::incPages(), isReadOnly(), QwtDblRange::isValid(), QwtDblRange::prevValue(), ScrNone, sliderMoved(), QwtDblRange::value(), and WHEEL_DELTA.


Member Data Documentation

int QwtSliderBase::d_direction [protected]
 

Definition at line 145 of file qwt_sldbase.h.

Referenced by mousePressEvent(), mouseReleaseEvent(), and timerEvent().

double QwtSliderBase::d_mass [private]
 

Definition at line 156 of file qwt_sldbase.h.

Referenced by mass(), mouseMoveEvent(), mouseReleaseEvent(), QwtSliderBase(), setMass(), and timerEvent().

double QwtSliderBase::d_mouseOffset [protected]
 

Definition at line 144 of file qwt_sldbase.h.

Referenced by QwtKnob::getValue(), QwtDial::getValue(), mousePressEvent(), mouseReleaseEvent(), QwtSliderBase(), and setPosition().

Orientation QwtSliderBase::d_orientation [private]
 

Definition at line 157 of file qwt_sldbase.h.

Referenced by orientation(), and setOrientation().

bool QwtSliderBase::d_readOnly [private]
 

Definition at line 158 of file qwt_sldbase.h.

Referenced by isReadOnly(), and setReadOnly().

int QwtSliderBase::d_scrollMode [protected]
 

Definition at line 143 of file qwt_sldbase.h.

Referenced by fitValue(), QwtDial::getValue(), incValue(), mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), setValue(), and timerEvent().

double QwtSliderBase::d_speed [private]
 

Definition at line 155 of file qwt_sldbase.h.

Referenced by mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), and timerEvent().

QTime QwtSliderBase::d_time [private]
 

Definition at line 154 of file qwt_sldbase.h.

Referenced by mouseMoveEvent(), mousePressEvent(), and mouseReleaseEvent().

int QwtSliderBase::d_timerTick [private]
 

Definition at line 153 of file qwt_sldbase.h.

Referenced by mousePressEvent(), mouseReleaseEvent(), and timerEvent().

int QwtSliderBase::d_tmrID [private]
 

Definition at line 151 of file qwt_sldbase.h.

Referenced by mousePressEvent(), mouseReleaseEvent(), QwtSliderBase(), stopMoving(), timerEvent(), and ~QwtSliderBase().

int QwtSliderBase::d_tracking [protected]
 

Definition at line 146 of file qwt_sldbase.h.

Referenced by buttonReleased(), QwtSliderBase(), setTracking(), and valueChange().

int QwtSliderBase::d_updTime [private]
 

Definition at line 152 of file qwt_sldbase.h.

Referenced by mousePressEvent(), mouseReleaseEvent(), QwtSliderBase(), setUpdateTime(), and timerEvent().


The documentation for this class was generated from the following files:
Generated on Fri Nov 7 14:11:49 2003 for Qwt Developer's Guide by doxygen 1.3.2