QwtAbstractSlider(3) Qwt User's Guide QwtAbstractSlider(3) NAME QwtAbstractSlider - An abstract base class for slider widgets with a scale. SYNOPSIS #include Inherits QwtAbstractScale. Inherited by QwtDial, QwtKnob, and QwtSlider. Public Slots void setValue (double value) Signals void valueChanged (double value) Notify a change of value. void sliderPressed () void sliderReleased () void sliderMoved (double value) Public Member Functions QwtAbstractSlider (QWidget *parent=NULL) Constructor. virtual ~QwtAbstractSlider () Destructor. void setValid (bool) bool isValid () const double value () const Returns the current value. void setWrapping (bool) bool wrapping () const void setTotalSteps (uint) Set the number of steps. uint totalSteps () const void setSingleSteps (uint) Set the number of steps for a single increment. uint singleSteps () const void setPageSteps (uint) Set the number of steps for a page increment. uint pageSteps () const void setStepAlignment (bool) Enable step alignment. bool stepAlignment () const void setTracking (bool) Enables or disables tracking. bool isTracking () const void setReadOnly (bool) bool isReadOnly () const void setInvertedControls (bool) bool invertedControls () const Protected Member Functions virtual void mousePressEvent (QMouseEvent *) override virtual void mouseReleaseEvent (QMouseEvent *) override virtual void mouseMoveEvent (QMouseEvent *) override virtual void keyPressEvent (QKeyEvent *) override virtual void wheelEvent (QWheelEvent *) override virtual bool isScrollPosition (const QPoint &pos) const =0 Determine what to do when the user presses a mouse button. virtual double scrolledTo (const QPoint &pos) const =0 Determine the value for a new position of the movable part of the slider. void incrementValue (int stepCount) virtual void scaleChange () override virtual void sliderChange () Calling update() double incrementedValue (double value, int stepCount) const Detailed Description An abstract base class for slider widgets with a scale. A slider widget displays a value according to a scale. The class is designed as a common super class for widgets like QwtKnob, QwtDial and QwtSlider. When the slider is nor readOnly() its value can be modified by keyboard, mouse and wheel inputs. The range of the slider is divided into a number of steps from which the value increments according to user inputs depend. Only for linear scales the number of steps correspond with a fixed step size. Definition at line 32 of file qwt_abstract_slider.h. Constructor & Destructor Documentation QwtAbstractSlider::QwtAbstractSlider (QWidget * parent = NULL) [explicit] Constructor. The scale is initialized to [0.0, 100.0], the number of steps is set to 100 with 1 and 10 and single an page step sizes. Step alignment is enabled. The initial value is invalid. Parameters parent Parent widget Definition at line 91 of file qwt_abstract_slider.cpp. Member Function Documentation double QwtAbstractSlider::incrementedValue (double value, int stepCount) const [protected] Increment a value Parameters value Value stepCount Number of steps Returns Incremented value Definition at line 670 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::incrementValue (int stepCount) [protected] Increment the slider The step size depends on the number of totalSteps() Parameters stepCount Number of steps See also setTotalSteps(), incrementedValue() Definition at line 650 of file qwt_abstract_slider.cpp. bool QwtAbstractSlider::invertedControls () const Returns True, when the controls are inverted See also setInvertedControls() Definition at line 637 of file qwt_abstract_slider.cpp. bool QwtAbstractSlider::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 159 of file qwt_abstract_slider.cpp. virtual bool QwtAbstractSlider::isScrollPosition (const QPoint & pos) const [protected], [pure virtual] Determine what to do when the user presses a mouse button. Parameters pos Mouse position Return values True,when pos is a valid scroll position See also scrolledTo() Implemented in QwtSlider, QwtKnob, and QwtDial. bool QwtAbstractSlider::isTracking () const Returns True, when tracking has been enabled See also setTracking() Definition at line 186 of file qwt_abstract_slider.cpp. bool QwtAbstractSlider::isValid () const Returns True, when the value is invalid Definition at line 125 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::keyPressEvent (QKeyEvent * event) [override], [protected], [virtual] Handles key events QwtAbstractSlider handles the following keys: o Qt::Key_Left Add/Subtract singleSteps() in direction to lowerBound(); o Qt::Key_Right Add/Subtract singleSteps() in direction to upperBound(); o Qt::Key_Down Subtract singleSteps(), when invertedControls() is false o Qt::Key_Up Add singleSteps(), when invertedControls() is false o Qt::Key_PageDown Subtract pageSteps(), when invertedControls() is false o Qt::Key_PageUp Add pageSteps(), when invertedControls() is false o Qt::Key_Home Set the value to the minimum() o Qt::Key_End Set the value to the maximum() Parameters event Key event See also isReadOnly() Reimplemented in QwtCompass. Definition at line 370 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::mouseMoveEvent (QMouseEvent * event) [override], [protected], [virtual] Mouse Move Event handler Parameters event Mouse event Definition at line 220 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::mousePressEvent (QMouseEvent * event) [override], [protected], [virtual] Mouse press event handler Parameters event Mouse event Reimplemented in QwtSlider. Definition at line 195 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::mouseReleaseEvent (QMouseEvent * event) [override], [protected], [virtual] Mouse Release Event handler Parameters event Mouse event Reimplemented in QwtSlider. Definition at line 265 of file qwt_abstract_slider.cpp. uint QwtAbstractSlider::pageSteps () const Returns Number of steps See also setPageSteps(), totalSteps(), singleSteps() Definition at line 533 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::scaleChange () [override], [protected], [virtual] Update the slider according to modifications of the scale Reimplemented from QwtAbstractScale. Reimplemented in QwtSlider, and QwtDial. Definition at line 811 of file qwt_abstract_slider.cpp. virtual double QwtAbstractSlider::scrolledTo (const QPoint & pos) const [protected], [pure virtual] Determine the value for a new position of the movable part of the slider. Parameters pos Mouse position Returns Value for the mouse position See also isScrollPosition() Implemented in QwtSlider, QwtKnob, and QwtDial. void QwtAbstractSlider::setInvertedControls (bool on) Invert wheel and key events Usually scrolling the mouse wheel 'up' and using keys like page up will increase the slider's value towards its maximum. When invertedControls() is enabled the value is scrolled towards its minimum. Inverting the controls might be f.e. useful for a vertical slider with an inverted scale ( decreasing from top to bottom ). Parameters on Invert controls, when true See also invertedControls(), keyEvent(), wheelEvent() Definition at line 628 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::setPageSteps (uint stepCount) Set the number of steps for a page increment. The range of the slider is divided into a number of steps from which the value increments according to user inputs depend. Parameters stepCount Number of steps See also pageSteps(), setTotalSteps(), setSingleSteps() Definition at line 524 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::setReadOnly (bool on) En/Disable read only mode In read only mode the slider can't be controlled by mouse or keyboard. Parameters on Enables in case of true See also isReadOnly() Warning The focus policy is set to Qt::StrongFocus or Qt::NoFocus Definition at line 141 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::setSingleSteps (uint stepCount) Set the number of steps for a single increment. The range of the slider is divided into a number of steps from which the value increments according to user inputs depend. Parameters stepCount Number of steps See also singleSteps(), setTotalSteps(), setPageSteps() Definition at line 499 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::setStepAlignment (bool on) Enable step alignment. When step alignment is enabled values resulting from slider movements are aligned to the step size. Parameters on Enable step alignment when true See also stepAlignment() Definition at line 547 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::setTotalSteps (uint stepCount) Set the number of steps. The range of the slider is divided into a number of steps from which the value increments according to user inputs depend. The default setting is 100. Parameters stepCount Number of steps See also totalSteps(), setSingleSteps(), setPageSteps() Definition at line 474 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::setTracking (bool on) Enables or disables tracking. If tracking is enabled, the slider emits the valueChanged() signal while the movable part of the slider is being dragged. If tracking is disabled, the slider emits the valueChanged() signal only when the user releases the slider. Tracking is enabled by default. Parameters on true (enable) or false (disable) tracking. See also isTracking(), sliderMoved() Definition at line 177 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::setValid (bool on) Set the value to be valid/invalid Parameters on When true, the value is invalidated See also setValue() Definition at line 113 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::setValue (double value) [slot] Set the slider to the specified value Parameters value New value See also setValid(), sliderChange(), valueChanged() Definition at line 570 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::setWrapping (bool on) If wrapping is true stepping up from upperBound() value will take you to the minimum() value and vice versa. Parameters on En/Disable wrapping See also wrapping() Definition at line 599 of file qwt_abstract_slider.cpp. uint QwtAbstractSlider::singleSteps () const Returns Number of steps See also setSingleSteps(), totalSteps(), pageSteps() Definition at line 508 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::sliderMoved (double value) [signal] This signal is emitted when the user moves the slider with the mouse. Parameters value New value See also valueChanged() void QwtAbstractSlider::sliderPressed () [signal] This signal is emitted when the user presses the movable part of the slider. void QwtAbstractSlider::sliderReleased () [signal] This signal is emitted when the user releases the movable part of the slider. bool QwtAbstractSlider::stepAlignment () const Returns True, when step alignment is enabled See also setStepAlignment() Definition at line 559 of file qwt_abstract_slider.cpp. uint QwtAbstractSlider::totalSteps () const Returns Number of steps See also setTotalSteps(), singleSteps(), pageSteps() Definition at line 483 of file qwt_abstract_slider.cpp. void QwtAbstractSlider::valueChanged (double value) [signal] Notify a change of value. When tracking is enabled (default setting), this signal will be emitted every time the value changes. Parameters value New value See also setTracking(), sliderMoved() void QwtAbstractSlider::wheelEvent (QWheelEvent * event) [override], [protected], [virtual] Wheel Event handler In/decreases the value by s number of steps. The direction depends on the invertedControls() property. When the control or shift modifier is pressed the wheel delta ( divided by 120 ) is mapped to an increment according to pageSteps(). Otherwise it is mapped to singleSteps(). Parameters event Wheel event Reimplemented in QwtDial. Definition at line 296 of file qwt_abstract_slider.cpp. bool QwtAbstractSlider::wrapping () const Returns True, when wrapping is set See also setWrapping() Definition at line 608 of file qwt_abstract_slider.cpp. Author Generated automatically by Doxygen for Qwt User's Guide from the source code. Version 6.2.0 Sun Jul 18 2021 QwtAbstractSlider(3)