NAME¶

QwtAbstractSlider - An abstract base class for slider widgets.

SYNOPSIS¶

#include <qwt_abstract_slider.h> Inherits QwtDoubleRange. Inherited by QwtDial, QwtKnob, QwtSlider, and QwtWheel.

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¶

QwtAbstractSlider (Qt::Orientation, QWidget *parent=NULL) virtual ~QwtAbstractSlider () void setUpdateTime (int t) void stopMoving () void setTracking (bool enable) virtual void setMass (double val) virtual double mass () const virtual void setOrientation (Qt::Orientation o) Qt::Orientation orientation () const bool isReadOnly () const bool isValid () const void setValid (bool valid)

Protected Member Functions¶

virtual void setPosition (const QPoint &) 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 &pos, ScrollMode &scrollMode, int &direction) const =0 void setMouseOffset (double) double mouseOffset () const int scrollMode () const

Detailed Description¶

An abstract base class for slider widgets. QwtAbstractSlider is a base class for slider widgets. It handles 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.

Member Enumeration Documentation¶

enum QwtAbstractSlider::ScrollMode Scroll mode¶

See also: Enumerator:

ScrNone

Scrolling switched off. Don't change the value.

ScrMouse

Change the value while the user keeps the button pressed and moves the mouse.

ScrTimer

Automatic scrolling. Increment the value in the specified direction as long as the user keeps the button pressed.

ScrPage

Automatic scrolling. Same as ScrTimer, but increment by page size.

Constructor & Destructor Documentation¶

QwtAbstractSlider::QwtAbstractSlider (Qt::Orientationorientation, QWidget *parent = NULL) [explicit]¶

Constructor. Parameters:

QwtAbstractSlider::~QwtAbstractSlider () [virtual]¶

Destructor.

Member Function Documentation¶

void QwtAbstractSlider::fitValue (doublevalue) [virtual, slot]¶

Set the slider's value to the nearest integer multiple of the step size. Parameters: See also: Reimplemented from QwtDoubleRange.

virtual void QwtAbstractSlider::getScrollMode (const QPoint &pos, ScrollMode &scrollMode, int &direction) const [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. Parameters: Return values: Implemented in QwtDial, QwtKnob, QwtSlider, and QwtWheel.

virtual double QwtAbstractSlider::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: Implemented in QwtDial, QwtKnob, QwtSlider, and QwtWheel.

void QwtAbstractSlider::incValue (intsteps) [virtual, slot]¶

Increment the value by a specified number of steps. Parameters: See also: Reimplemented from QwtDoubleRange.

bool QwtAbstractSlider::isReadOnly () const In read only mode the slider can't be controlled by mouse or keyboard.¶

Returns: See also:

bool QwtAbstractSlider::isValid () const [inline] See also:¶

Reimplemented from QwtDoubleRange.

void QwtAbstractSlider::keyPressEvent (QKeyEvent *e) [protected, virtual] Handles key events¶

•

Key_Down, KeyLeft

 

Decrement by 1

•

Key_Up, Key_Right

 

Increment by 1

Parameters: See also: Reimplemented in QwtCompass, and QwtDial.

double QwtAbstractSlider::mass () const [virtual] Returns:¶

See also: Reimplemented in QwtWheel.

void QwtAbstractSlider::mouseMoveEvent (QMouseEvent *e) [protected, virtual] Mouse Move Event handler¶

Parameters:

double QwtAbstractSlider::mouseOffset () const [protected] See also:¶

void QwtAbstractSlider::mousePressEvent (QMouseEvent *e) [protected, virtual] Mouse press event handler¶

Parameters:

void QwtAbstractSlider::mouseReleaseEvent (QMouseEvent *e) [protected, virtual] Mouse Release Event handler¶

Parameters:

Qt::Orientation QwtAbstractSlider::orientation () const Returns:¶

See also:

int QwtAbstractSlider::scrollMode () const [protected]¶

sa ScrollMode

void QwtAbstractSlider::setMass (doubleval) [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: See also: Reimplemented in QwtWheel.

void QwtAbstractSlider::setMouseOffset (doubleoffset) [protected] See also:¶

void QwtAbstractSlider::setOrientation (Qt::Orientationo) [virtual]¶

Set the orientation. Parameters: Reimplemented in QwtSlider, and QwtWheel.

void QwtAbstractSlider::setPosition (const QPoint &p) [protected, virtual] Move the slider to a specified point, adjust the value and emit signals if necessary.¶

void QwtAbstractSlider::setReadOnly (boolreadOnly) [virtual, slot] En/Disable read only mode¶

In read only mode the slider can't be controlled by mouse or keyboard. Parameters: See also:

void QwtAbstractSlider::setTracking (boolenable)¶

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:

void QwtAbstractSlider::setUpdateTime (intt)¶

Specify the update interval for automatic scrolling. Parameters: See also:

void QwtAbstractSlider::setValid (boolvalid) [inline] Parameters:¶

See also: Reimplemented from QwtDoubleRange.

void QwtAbstractSlider::setValue (doubleval) [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: See also: Reimplemented from QwtDoubleRange.

void QwtAbstractSlider::sliderMoved (doublevalue) [signal] This signal is emitted when the user moves the slider with the mouse.¶

Parameters:

void QwtAbstractSlider::sliderPressed () [signal] This signal is emitted when the user presses the movable part of the slider (start ScrMouse Mode).¶

void QwtAbstractSlider::sliderReleased () [signal] This signal is emitted when the user releases the movable part of the slider.¶

void QwtAbstractSlider::stopMoving ()¶

Stop updating if automatic scrolling is active.

void QwtAbstractSlider::timerEvent (QTimerEvent *e) [protected, virtual] Qt timer event¶

Parameters:

void QwtAbstractSlider::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 QwtDoubleRange. Reimplemented in QwtDial, QwtSlider, and QwtWheel.

void QwtAbstractSlider::valueChanged (doublevalue) [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:

void QwtAbstractSlider::wheelEvent (QWheelEvent *e) [protected, virtual] Wheel Event handler¶

Parameters:

Author¶

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