--- name: "QwtSliderBase" section: "3" platform: "linux" package: "libqwt-doc" version: "4.2.0-6" release: "Debian 6.0 (Squeeze)" platforms: ["linux"] url: "https://new.carta.tech/QwtSliderBase" --- # QwtSliderBase(3) ## NAME QwtSliderBase - ## SYNOPSIS Inherits **QwtDblRange**. Inherited by **QwtDial**, **QwtKnob**, **QwtSlider**, and **QwtWheel**. ## 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. ### 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, Qt::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\ bool **isValid** () const\ void **setValid** (bool valid)\ ### 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**\ ## Constructor & Destructor Documentation ### QwtSliderBase::QwtSliderBase (Qt::Orientation orientation, QWidget \* parent = `0`, const char \* name = `0`, Qt::WFlags flags = `0`) Constructor. Definition at line 19 of file qwt\_sldbase.cpp. References QwtDblRange::setRange(), and setValue(). ### QwtSliderBase::~QwtSliderBase ()` [virtual]` Destructor. Definition at line 38 of file qwt\_sldbase.cpp. ## Member Function Documentation ### 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 519 of file qwt\_sldbase.cpp. References QwtDblRange::fitValue(), 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**, **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**, **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 531 of file qwt\_sldbase.cpp. References QwtDblRange::incValue(), and stopMoving(). ### bool QwtSliderBase::isReadOnly () const In read only mode the slider can´t be controlled by mouse or keyboard. **Returns:** TRUE if read only **See also:** **setReadOnly** Definition at line 66 of file qwt\_sldbase.cpp. Referenced by QwtDial::drawFocusIndicator(), keyPressEvent(), QwtDial::keyPressEvent(), QwtCompass::keyPressEvent(), mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), and wheelEvent(). ### bool QwtSliderBase::isValid () const **See also:** **QwtDblRange::isValid** Reimplemented from **QwtDblRange**. Definition at line 66 of file qwt\_sldbase.h. References QwtDblRange::isValid(). Referenced by QwtDial::drawContents(), QwtKnob::drawKnob(), QwtAnalogClock::drawNeedle(), QwtCompass::drawScaleContents(), QwtSlider::drawSlider(), keyPressEvent(), QwtDial::keyPressEvent(), mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), and wheelEvent(). ### void QwtSliderBase::keyPressEvent (QKeyEvent \* e)` [protected, virtual]` Handles key events - • Key\_Down, KeyLeft\ \ Decrement by 1 - • Key\_Up, Key\_Right\ \ Increment by 1 **See also:** **isReadOnly()** Reimplemented in **QwtCompass**, and **QwtDial**. Definition at line 341 of file qwt\_sldbase.cpp. References QwtDblRange::incValue(), isReadOnly(), isValid(), orientation(), QwtDblRange::prevValue(), sliderMoved(), and QwtDblRange::value(). ### double QwtSliderBase::mass () const` [virtual]` **Returns:** mass **See also:** **QwtSliderBase::setMass** Reimplemented in **QwtWheel**. Definition at line 492 of file qwt\_sldbase.cpp. Referenced by QwtWheel::mass(). ### void QwtSliderBase::mouseMoveEvent (QMouseEvent \* e)` [protected, virtual]` Mouse Move Event handler. Definition at line 274 of file qwt\_sldbase.cpp. References QwtDblRange::exactPrevValue(), QwtDblRange::exactValue(), isReadOnly(), isValid(), QwtDblRange::prevValue(), setPosition(), sliderMoved(), and QwtDblRange::value(). ### void QwtSliderBase::mousePressEvent (QMouseEvent \* e)` [protected, virtual]` Mouse press event handler. Definition at line 115 of file qwt\_sldbase.cpp. References getScrollMode(), getValue(), isReadOnly(), isValid(), sliderPressed(), stopMoving(), and QwtDblRange::value(). ### void QwtSliderBase::mouseReleaseEvent (QMouseEvent \* e)` [protected, virtual]` Mouse Release Event handler. Definition at line 166 of file qwt\_sldbase.cpp. References QwtDblRange::fitValue(), QwtDblRange::incPages(), isReadOnly(), isValid(), setPosition(), sliderReleased(), QwtDblRange::step(), stopMoving(), and QwtDblRange::value(). ### Qt::Orientation QwtSliderBase::orientation () const **Returns:** Orientation **See also:** **QwtSliderBase::setOrientation** Definition at line 85 of file qwt\_sldbase.cpp. 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 **See also:** **QwtSliderBase::mass** Reimplemented in **QwtWheel**. Definition at line 478 of file qwt\_sldbase.cpp. 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 76 of file qwt\_sldbase.cpp. 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 248 of file qwt\_sldbase.cpp. References QwtDblRange::fitValue(), and getValue(). Referenced by mouseMoveEvent(), and mouseReleaseEvent(). ### void QwtSliderBase::setReadOnly (bool readOnly)` [virtual, slot]` En/Disable read only mode In read only mode the slider can´t be controlled by mouse or keyboard. **Parameters:** *readOnly* Enables in case of TRUE **See also:** **isReadOnly** Definition at line 53 of file qwt\_sldbase.cpp. Referenced by QwtAnalogClock::QwtAnalogClock(). ### 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:.PD 0 - • 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 268 of file qwt\_sldbase.cpp. ### 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 106 of file qwt\_sldbase.cpp. Referenced by QwtKnob::QwtKnob(), and QwtWheel::QwtWheel(). ### void QwtSliderBase::setValid (bool valid) **See also:** **QwtDblRange::isValid** Reimplemented from **QwtDblRange**. Definition at line 71 of file qwt\_sldbase.h. References QwtDblRange::setValid(). Referenced by QwtAnalogClock::setTime(). ### 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 506 of file qwt\_sldbase.cpp. References QwtDblRange::setValue(), and stopMoving(). Referenced by QwtDial::keyPressEvent(), QwtCompass::keyPressEvent(), QwtSliderBase(), and QwtAnalogClock::setTime(). ### 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(), QwtDial::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 92 of file qwt\_sldbase.cpp. Referenced by fitValue(), incValue(), mousePressEvent(), mouseReleaseEvent(), setValue(), and timerEvent(). ### void QwtSliderBase::timerEvent (QTimerEvent \* e)` [protected, virtual]` Qt timer event. Definition at line 388 of file qwt\_sldbase.cpp. References QwtDblRange::exactValue(), QwtDblRange::fitValue(), QwtDblRange::incPages(), 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**, **QwtSlider**, and **QwtWheel**. Definition at line 455 of file qwt\_sldbase.cpp. References QwtDblRange::value(), and valueChanged(). Referenced by QwtWheel::valueChange(), QwtSlider::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 valueChange(). ### void QwtSliderBase::wheelEvent (QWheelEvent \* e)` [protected, virtual]` Qt wheel event. Definition at line 304 of file qwt\_sldbase.cpp. References getScrollMode(), QwtDblRange::incPages(), isReadOnly(), isValid(), QwtDblRange::prevValue(), sliderMoved(), and QwtDblRange::value(). ## Author Generated automatically by Doxygen for Qwt User's Guide from the source code.