QwtWheel(3)

📦
version 6.3.0 · 6 versions
, in alpine 3.24

🎡 QwtWheel(3) — Library Functions Manual ✨

okay bestie, meet QwtWheel: The Wheel Widget. It’s giving very “spin the wheel, change the value” energy, and it lives in the Library Functions Manual. Periodt.

✨ NAME ✨

QwtWheel — The Wheel Widget. Literally the wheel widget, no cap.

🦋 SYNOPSIS 🦋

#include <qwt_wheel.h>

Inherits QWidget.

💖 Public Slots 💖

  • void setValue (double) — Set a new value without adjusting to the step raster.
  • void setTotalAngle (double) — Set the total angle which the wheel can be turned.
  • void setViewAngle (double) — Specify the visible portion of the wheel.
  • void setMass (double) — Set the slider’s mass for flywheel effect.

📣 Signals 📣

  • void valueChanged (double value) — Notify a change of value.
  • void wheelPressed ()
  • void wheelReleased ()
  • void wheelMoved (double value)

🫶 Public Member Functions 🫶

  • QwtWheel (QWidget *parent=NULL) — Constructor.
  • virtual ~QwtWheel () — Destructor.
  • double value () const
  • void setOrientation (Qt::Orientation) — Set the wheel’s orientation.
  • Qt::Orientation orientation () const
  • double totalAngle () const
  • double viewAngle () const
  • void setTickCount (int) — Adjust the number of grooves in the wheel’s surface.
  • int tickCount () const
  • void setWheelWidth (int) — Set the width of the wheel.
  • int wheelWidth () const
  • void setWheelBorderWidth (int) — Set the wheel border width of the wheel.
  • int wheelBorderWidth () const
  • void setBorderWidth (int) — Set the border width.
  • int borderWidth () const
  • void setInverted (bool) — En/Disable inverted appearance.
  • bool isInverted () const
  • void setWrapping (bool) — En/Disable wrapping.
  • bool wrapping () const
  • void setSingleStep (double) — Set the step size of the counter.
  • double singleStep () const
  • void setPageStepCount (int) — Set the page step count.
  • int pageStepCount () const
  • void setStepAlignment (bool on) — En/Disable step alignment.
  • bool stepAlignment () const
  • void setRange (double min, double max) — Set the minimum and maximum values.
  • void setMinimum (double)
  • double minimum () const
  • void setMaximum (double)
  • double maximum () const
  • void setUpdateInterval (int) — Specify the update interval when the wheel is flying.
  • int updateInterval () const
  • void setTracking (bool) — En/Disable tracking.
  • bool isTracking () const
  • double mass () const

🛡️ Protected Member Functions 🛡️

  • virtual void paintEvent (QPaintEvent *) override — Qt Paint Event.
  • virtual void mousePressEvent (QMouseEvent *) override — Mouse press event handler.
  • virtual void mouseReleaseEvent (QMouseEvent *) override — Mouse Release Event handler.
  • virtual void mouseMoveEvent (QMouseEvent *) override — Mouse Move Event handler.
  • virtual void keyPressEvent (QKeyEvent *) override
  • virtual void wheelEvent (QWheelEvent *) override — Handle wheel events.
  • virtual void timerEvent (QTimerEvent *) override — Qt timer event.
  • void stopFlying () — Stop the flying movement of the wheel.
  • QRect wheelRect () const
  • virtual QSize sizeHint () const override
  • virtual QSize minimumSizeHint () const override
  • virtual void drawTicks (QPainter *, const QRectF &)
  • virtual void drawWheelBackground (QPainter *, const QRectF &)
  • virtual double valueAt (const QPoint &) const

🌸 Detailed Description 🌸

The Wheel Widget. Iconic.

The wheel widget can be used to change values over a very large range in very small steps. Using the setMass() member, it can be configured as a flying wheel. That’s the flywheel vibe, bestie.

The default range of the wheel is [0.0, 100.0].

See also: The radio example.

Definition at line 27 of file qwt_wheel.h.

🎀 Constructor & Destructor Documentation 🎀

QwtWheel::QwtWheel (QWidget * parent = NULL) [explicit]

Constructor.

Definition at line 92 of file qwt_wheel.cpp.

QwtWheel::~QwtWheel () [virtual]

Destructor.

Definition at line 103 of file qwt_wheel.cpp.

💜 Member Function Documentation 💜

int QwtWheel::borderWidth () const

Returns: Border width.

See also: setBorderWidth()

Definition at line 586 of file qwt_wheel.cpp.

void QwtWheel::drawTicks (QPainter * painter, const QRectF & rect) [protected], [virtual]

Draw the Wheel’s ticks.

Parameters:

  • painter — Painter
  • rect — Geometry for the wheel

Definition at line 817 of file qwt_wheel.cpp.

void QwtWheel::drawWheelBackground (QPainter * painter, const QRectF & rect) [protected], [virtual]

Draw the Wheel’s background gradient.

Parameters:

  • painter — Painter
  • rect — Geometry for the wheel

Definition at line 761 of file qwt_wheel.cpp.

bool QwtWheel::isInverted () const

Returns: True, when the wheel is inverted.

See also: setInverted()

Definition at line 1176 of file qwt_wheel.cpp.

bool QwtWheel::isTracking () const

Returns: True, when tracking is enabled.

See also: setTracking(), valueChanged(), wheelMoved()

Definition at line 129 of file qwt_wheel.cpp.

void QwtWheel::keyPressEvent (QKeyEvent * event) [override], [protected], [virtual]

Handle key events. Keyboard queen behavior, incoming:

  • Qt::Key_Home — Step to minimum()
  • Qt::Key_End — Step to maximum()
  • Qt::Key_Up — In case of a horizontal or not inverted vertical wheel the value will be incremented by the step size. For an inverted vertical wheel the value will be decremented by the step size.
  • Qt::Key_Down — In case of a horizontal or not inverted vertical wheel the value will be decremented by the step size. For an inverted vertical wheel the value will be incremented by the step size.
  • Qt::Key_PageUp — The value will be incremented by pageStepSize() * singleStepSize().
  • Qt::Key_PageDown — The value will be decremented by pageStepSize() * singleStepSize().

Parameters:

  • event — Key event

Definition at line 409 of file qwt_wheel.cpp.

double QwtWheel::mass () const

Returns: mass.

See also: setMass()

Definition at line 1240 of file qwt_wheel.cpp.

double QwtWheel::maximum () const

Returns: The maximum of the range.

See also: setRange(), setMaximum(), minimum()

Definition at line 1114 of file qwt_wheel.cpp.

double QwtWheel::minimum () const

Returns: The minimum of the range.

See also: setRange(), setMinimum(), maximum()

Definition at line 1094 of file qwt_wheel.cpp.

QSize QwtWheel::minimumSizeHint () const [override], [protected], [virtual]

Returns: Minimum size hint.

⚠️ Warning: The return value is based on the wheel width.

Definition at line 962 of file qwt_wheel.cpp.

void QwtWheel::mouseMoveEvent (QMouseEvent * event) [override], [protected], [virtual]

Mouse Move Event handler. Turn the wheel according to the mouse position.

Parameters:

  • event — Mouse event

Definition at line 188 of file qwt_wheel.cpp.

void QwtWheel::mousePressEvent (QMouseEvent * event) [override], [protected], [virtual]

Mouse press event handler. Start movement of the wheel.

Parameters:

  • event — Mouse event

Definition at line 163 of file qwt_wheel.cpp.

void QwtWheel::mouseReleaseEvent (QMouseEvent * event) [override], [protected], [virtual]

Mouse Release Event handler. When the wheel has no mass the movement of the wheel stops, otherwise it starts flying.

Parameters:

  • event — Mouse event

Definition at line 237 of file qwt_wheel.cpp.

Qt::Orientation QwtWheel::orientation () const

Returns: Orientation.

See also: setOrientation()

Definition at line 661 of file qwt_wheel.cpp.

int QwtWheel::pageStepCount () const

Returns: Page step count.

See also: setPageStepCount(), singleStep()

Definition at line 1043 of file qwt_wheel.cpp.

void QwtWheel::paintEvent (QPaintEvent * event) [override], [protected], [virtual]

Qt Paint Event.

Parameters:

  • event — Paint event

Definition at line 736 of file qwt_wheel.cpp.

void QwtWheel::setBorderWidth (int width)

Set the border width. The border defaults to 2.

Parameters:

  • width — Border width

See also: borderWidth()

Definition at line 576 of file qwt_wheel.cpp.

void QwtWheel::setInverted (bool on)

En/Disable inverted appearance. An inverted wheel increases its values in the opposite direction. The direction of an inverted horizontal wheel will be from right to left; an inverted vertical wheel will increase from bottom to top.

Parameters:

  • on — En/Disable inverted appearance

See also: isInverted()

Definition at line 1163 of file qwt_wheel.cpp.

void QwtWheel::setMass (double mass) [slot]

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:

  • mass — New mass in kg

See also: mass()

Definition at line 1221 of file qwt_wheel.cpp.

void QwtWheel::setMaximum (double value)

Set the maximum value of the range.

Parameters:

  • value — Maximum value

See also: setRange(), setMinimum(), maximum()

Definition at line 1105 of file qwt_wheel.cpp.

void QwtWheel::setMinimum (double value)

Set the minimum value of the range.

Parameters:

  • value — Minimum value

See also: setRange(), setMaximum(), minimum()

Note: The maximum is adjusted if necessary to ensure that the range remains valid.

Definition at line 1085 of file qwt_wheel.cpp.

void QwtWheel::setOrientation (Qt::Orientation orientation)

Set the wheel’s orientation. The default orientation is Qt::Horizontal.

Parameters:

  • orientation — Qt::Horizontal or Qt::Vertical.

See also: orientation()

Definition at line 639 of file qwt_wheel.cpp.

void QwtWheel::setPageStepCount (int count)

Set the page step count. pageStepCount is a multiplicator for the single step size that typically corresponds to the user pressing PageUp or PageDown.

A value of 0 disables page stepping.

The default value is 1.

Parameters:

  • count — Multiplicator for the single step size

See also: pageStepCount(), setSingleStep()

Definition at line 1034 of file qwt_wheel.cpp.

void QwtWheel::setRange (double min, double max)

Set the minimum and maximum values. The maximum is adjusted if necessary to ensure that the range remains valid. The value might be modified to be inside of the range.

Parameters:

  • min — Minimum value
  • max — Maximum value

See also: minimum(), maximum()

Definition at line 1059 of file qwt_wheel.cpp.

void QwtWheel::setSingleStep(double stepSize)

Bestie, this is your "how much does one lil nudge move the value" dial 🎀. It sets the step size of the counter.

Lowkey important: a value <= 0.0 disables stepping entirely. Not "steps really tiny" — fully off. Periodt.

Parameters

  • stepSize — Single step size

See also singleStep(), setPageStepCount()

Defined at line 980 of file qwt_wheel.cpp.

void QwtWheel::setStepAlignment(bool on)

En/Disable step alignment ✨. When step alignment is enabled, value changes initiated by user input (mouse, keyboard, wheel) are aligned to the multiples of the single step. It's giving "snap to the grid, bestie" — so you never land on some cursed in-between number 🦋.

Parameters

  • on — On/Off

See also stepAlignment(), setSingleStep()

Defined at line 1004 of file qwt_wheel.cpp.

void QwtWheel::setTickCount(int count)

Adjusts the number of grooves in the wheel's surface 🎚️. The number of grooves is limited to 6 <= count <= 50. Values outside this range will be clipped (so don't try to be extra, it literally won't let you 💀). The default value is 10.

Parameters

  • count — Number of grooves per 360 degrees

See also tickCount()

Defined at line 519 of file qwt_wheel.cpp.

void QwtWheel::setTotalAngle(double angle) [slot]

Sets the total angle the wheel can be turned 🌈. One full turn of the wheel corresponds to an angle of 360 degrees. A total angle of n*360 degrees means the wheel has to be turned n times around its axis to get from the minimum value to the maximum value.

The default setting of the total angle is 360 degrees.

Parameters

  • angle — total angle in degrees

See also totalAngle()

Defined at line 613 of file qwt_wheel.cpp.

void QwtWheel::setTracking(bool enable)

En/Disable tracking 👀. If tracking is enabled (the default), the wheel emits the valueChanged() signal while the wheel is moving. If tracking is disabled, the wheel emits the valueChanged() signal only when the wheel movement is terminated.

Big note: the wheelMoved() signal is emitted regardless id tracking is enabled or not. (That's exactly what the page says, no cap — it's not a typo on my end 🙈.)

Parameters

  • enable — On/Off

See also isTracking()

Defined at line 120 of file qwt_wheel.cpp.

void QwtWheel::setUpdateInterval(int interval)

Specify the update interval when the wheel is flying 🕊️. Default and minimum value is 50 ms. Don't go lower, it said minimum, girlie 😭.

Parameters

  • interval — Interval in milliseconds

See also updateInterval(), setMass(), setTracking()

Defined at line 142 of file qwt_wheel.cpp.

void QwtWheel::setValue(double value) [slot]

Set a new value without adjusting to the step raster. So yes, she can land off-grid if you want her to 💅.

Parameters

  • value — New value

See also value(), valueChanged()

⚠️ Warning: the value is clipped when it lies outside the range. So if you're out here passing wild numbers, bestie, they're getting squished back in range, not saved 🫶.

Defined at line 1127 of file qwt_wheel.cpp.

void QwtWheel::setViewAngle(double angle) [slot]

Specify the visible portion of the wheel 👁️✨. You may use this function for fine-tuning the appearance of the wheel. The default value is 175 degrees. The value is limited from 10 to 175 degrees.

Parameters

  • angle — Visible angle in degrees

See also viewAngle(), setTotalAngle()

Defined at line 676 of file qwt_wheel.cpp.

void QwtWheel::setWheelBorderWidth(int borderWidth)

Set the wheel border width of the wheel 🎀. The wheel border must not be smaller than 1 and is limited in dependence on the wheel's size. Values outside the allowed range will be clipped.

The wheel border defaults to 2.

Parameters

  • borderWidth — Border width

See also internalBorder()

Defined at line 551 of file qwt_wheel.cpp.

void QwtWheel::setWheelWidth(int width)

Set the width of the wheel 📏. Corresponds to the wheel height for horizontal orientation, and the wheel width for vertical orientation. (Yes, orientation flips which dimension it means — she's flexible like that 🌸.)

Parameters

  • width — the wheel's width

See also wheelWidth()

Defined at line 934 of file qwt_wheel.cpp.

void QwtWheel::setWrapping(bool on)

En/Disable wrapping 🔁. If wrapping is true, stepping up from the maximum() value will take you to the minimum() value and vice versa. It's the "wrap around like a playlist on repeat" behaviour, iconic honestly 🎧.

Parameters

  • on — En/Disable wrapping

See also wrapping()

Defined at line 1190 of file qwt_wheel.cpp.

double QwtWheel::singleStep() const

Returns — Single step size

See also setSingleStep()

Defined at line 989 of file qwt_wheel.cpp.

QSize QwtWheel::sizeHint() const [override], [protected], [virtual]

Returns — a size hint

Defined at line 952 of file qwt_wheel.cpp.

bool QwtWheel::stepAlignment() const

Returns — True, when the step alignment is enabled

See also setStepAlignment(), singleStep()

Defined at line 1016 of file qwt_wheel.cpp.

void QwtWheel::stopFlying() [protected]

Stop the flying movement of the wheel 🛬. Put her down gently, she's done spinning.

Defined at line 1246 of file qwt_wheel.cpp.

int QwtWheel::tickCount() const

Returns — Number of grooves in the wheel's surface.

See also setTickCnt() (that's exactly how it's written on the page, iykyk 🫶)

Defined at line 534 of file qwt_wheel.cpp.

void QwtWheel::timerEvent(QTimerEvent *event) [override], [protected], [virtual]

Qt timer event ⏰. The flying wheel effect is implemented using a timer — that's the whole secret sauce, bestie, it's just a timer being dramatic.

Parameters

  • event — Timer event

See also updateInterval()

Defined at line 283 of file qwt_wheel.cpp.

double QwtWheel::totalAngle() const

Returns — Total angle which the wheel can be turned.

See also setTotalAngle()

Defined at line 626 of file qwt_wheel.cpp.

int QwtWheel::updateInterval() const

Returns — Update interval when the wheel is flying

See also setUpdateInterval(), mass(), isTracking()

Defined at line 151 of file qwt_wheel.cpp.

double QwtWheel::value() const

Returns — Current value of the wheel

See also setValue(), valueChanged()

Defined at line 1147 of file qwt_wheel.cpp.

double QwtWheel::valueAt(const QPoint &pos) const [protected], [virtual]

Determine the value corresponding to a specified point 📍 — like, "you clicked here, so the value is this."

Parameters

  • pos — Position

Returns — Value corresponding to pos

Defined at line 697 of file qwt_wheel.cpp.

void QwtWheel::valueChanged(double value) [signal]

Notify a change of value 🔔. When tracking is enabled this signal will be emitted every time the value changes.

Parameters

  • value — new value

See also setTracking()

double QwtWheel::viewAngle() const

Returns — Visible portion of the wheel

See also setViewAngle(), totalAngle()

Defined at line 686 of file qwt_wheel.cpp.

int QwtWheel::wheelBorderWidth() const

Returns — Wheel border width

See also setWheelBorderWidth()

Defined at line 563 of file qwt_wheel.cpp.

void QwtWheel::wheelEvent(QWheelEvent *event) [override], [protected], [virtual]

Handle wheel events 🖱️. In/Decrement the value.

Parameters

  • event — Wheel event

Defined at line 324 of file qwt_wheel.cpp.

void QwtWheel::wheelMoved(double value) [signal]

This signal is emitted when the user moves the wheel with the mouse 🖱️✨.

Parameters

  • value — new value

void QwtWheel::wheelPressed() [signal]

This signal is emitted when the user presses the the wheel with the mouse. (Two "the"s, bestie — that's the page's words, not mine 🙈💅)

QRect QwtWheel::wheelRect() const [protected]

Returns — Rectangle of the wheel without the outer border

Defined at line 594 of file qwt_wheel.cpp.

void QwtWheel::wheelReleased() [signal]

This signal is emitted when the user releases the mouse 🫶.

int QwtWheel::wheelWidth() const

Returns — Width of the wheel

See also setWheelWidth()

Defined at line 944 of file qwt_wheel.cpp.

bool QwtWheel::wrapping() const

Returns — True, when wrapping is set

See also setWrapping()

Defined at line 1199 of file qwt_wheel.cpp.

🫶 AUTHOR 🫶

Generated automatically by Doxygen for Qwt User's Guide from the source code. She wasn't hand-written by a human, she was birthed by a doc generator, and honestly? Still ate 💅✨.

And that's the whole page, bestie — no cap, every flag, every line number, every signal accounted for 🌈👑. This lil masterpiece is from the Qwt User's Guide, filed under QwtWheel(3), auto-generated by Doxygen straight from the source code. Go forth and spin that wheel, you gorgeous Unix gremlin 🎀🦋💖.

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