Knob | SuperCollider 3.14.0-dev Help

Subclasses: QKnob

Description

Knob displays a value from 0.0 to 1.0 in rotary fashion, and allows to control it with either circular or linear mouse motion.

It also displays the deviation of the value from either 0.0 or 0.5, which you can choose using -centered.

To switch between the mouse interaction modes, use -mode.

The amount by which the value changes at interaction can be fine-tuned using -step, -keystep, -shift_scale, -ctrl_scale, and -alt_scale

Class Methods

Knob.defaultMode = value

The default -mode for newly created Knobs.

Knob.new(parent, bounds)

Instance Methods

.value = val

The displayed value.

Arguments:

val	A Number in the range of 0.0 to 1.0.

.increment(zoom: 1)

Increments the value by -keystep multiplied by the argument.

Arguments:

zoom

A Number.

.decrement(zoom: 1)

Decrements the value by -keystep multiplied by the argument.

Arguments:

zoom

A Number.

.mode = inputMode

The way value is controlled with respect to mouse movement after clicking on the view:

\round - value follows circular movement
\horiz - value follows linear movement in horizontal direction
\vert - value follows linear movement in vertical direction

Defaults to \round.

Arguments:

inputMode

One of the symbols listed above.

.keystep = value

The amount by which the value is incremented/decremented when pressing a relevant key.

Defaults to 0.01;

Arguments:

(arg1)

A Number.

.step = aFloat

From superclass: AbstractStepValue

The amount by which the value is incremented/decremented using the mouse in 'horizontal' and 'vertical' modes.

Arguments:

aFloat

A Number.

.shift_scale = aFloat

From superclass: AbstractStepValue

The factor by which -step or -keystep is multiplied when used at mouse or keyboard interaction while the Shift key is pressed.

Arguments:

aFloat

A Float.

.ctrl_scale = aFloat

From superclass: AbstractStepValue

The factor by which -step or -keystep is multiplied when used at mouse or keyboard interaction while the Ctrl key is pressed.

Arguments:

aFloat

A Float.

.alt_scale = aFloat

From superclass: AbstractStepValue

The factor by which -step or -keystep is multiplied when used at mouse or keyboard interaction while the Alt key is pressed.

Arguments:

aFloat

A Float.

.centered = bool

Whether the deviation of value will be displayed in relation to 0.0 or 0.5 (e.g. as in a panning controller);

Arguments:

bool	A Boolean.

.color = colors

The colors used by the Knob to draw the following elements:

the main Knob color
the value indicator
the deviation indicator
the background of the deviation indicator

Arguments:

colors

An Array of four Colors in the order listed above.

.action = func

From superclass: View

The action object evaluated whenever the user interacts with the Knob using the mouse or the keyboard.

.defaultKeyDownAction(char, modifiers, unicode, keycode, key)

Implements the default effects of key presses as follows:

Key	Effect
r	valueAction_(1.0.rand)
n	valueAction_(0)
x	valueAction_(1)
c	valueAction_(0.5)
]	increment
[	decrement
up arrow	increment
down arrow	decrement
right arrow	increment
left arrow	decrement

.defaultCanReceiveDrag

Returns:

True if the current drag data is a Number.

.defaultReceiveDrag

Sets -valueAction to the current drag data.

.getScale(modifiers)

Center mode is useful for pan or eq gain control etc.( var window; window = Window.new("Pan Knob", Rect(640,630,270,70)).front; k = Knob.new(window, Rect(20,10,36,36)); k.action_({|v,x,y,m| \pan.asSpec.map(v.value).postln; }) // .mode_(\horiz) .centered_(false) .value_(\pan.asSpec.unmap(0)); // 0.5 //k.color[1] = Color.gray(alpha:0); ) k.centered k.centered = true k.centered = false

step

-step only affects the 'horiz' and 'vert' modes:( var window, midispec; midispec = [0,127,'linear',1].asSpec; window = Window.new("step Knob", Rect(640,630,270,70)).front; k = Knob.new(window, Rect(20,10,32,32)); k.action_({|v,x,y,m| midispec.map(v.value).postln; }) .value_(midispec.unmap(0)); k.mode = \vert; ) k.step k.step = 10/127 // step by 10 k.mode = \horiz; k.mode = \round;

mouseOverAction

Drag and Drop

(
var w, txt, size = 36;
w = Window.new("Knobs", Rect(400,400,250,100)).front;
w.acceptsMouseOver=true;
w.view.decorator = FlowLayout(w.view.bounds).gap_(10 @ 10).margin_(10 @10);
txt = StaticText(w, 200 @ 14);
w.view.decorator.nextLine;

k = Knob(w, size @ size);
k.action = {arg v,x,y;  v.value.postln; txt.string_("value: " ++ v.value); };
k.mouseOverAction = {|v| txt.string_("value: " ++ v.value); };

j = Knob(w, size @ size);
j.action = {arg v,x,y;  j.value.postln; txt.string_("value: " ++ v.value); };
j.mouseOverAction = { txt.string_("value: " ++ j.value); };

n = NumberBox(w, 100 @ 20);
//n.setProperty(\boxColor,Color.grey(alpha:0.0));
n.value = 0.0;
)

// customize drag and drop methods
k.canReceiveDragHandler
k.canReceiveDragHandler = false; // don't accept drops

k.canReceiveDragHandler = { View.currentDrag.isFloat }; // accept only if drag is float

k.receiveDragHandler = { ("value dropped in: " ++ View.currentDrag).postln }

k.receiveDragHandler = { k.valueAction = View.currentDrag.clip(0.0, 1.0); }

k.beginDragAction = { ("drag out -> " ++ k.value).postln; }

k.beginDragAction = { k.value.asFloat; }

helpfile source: /usr/local/share/SuperCollider/HelpSource/Classes/Knob.schelp
link::Classes/Knob::

Knob : QAbstractStepValue : AbstractStepValue : View : QObject : Object

Knob.defaultMode

Knob.defaultMode = value

Knob.new(parent, bounds)

Knob.qtClass

.value

.value = val

Arguments:

.valueAction = val

.increment(zoom: 1)

Arguments:

.decrement(zoom: 1)

Arguments:

.mode

.mode = inputMode

Arguments:

.keystep

.keystep = value

Arguments:

.step

.step = aFloat

Arguments:

.shift_scale

.shift_scale = aFloat

Arguments:

.ctrl_scale

.ctrl_scale = aFloat

Arguments:

.alt_scale

.alt_scale = aFloat

Arguments:

.centered

.centered = bool

Arguments:

.color

.color = colors

Arguments:

.action

.action = func

.defaultKeyDownAction(char, modifiers, unicode, keycode, key)

.defaultGetDrag

Returns:

.defaultCanReceiveDrag

Returns:

.defaultReceiveDrag

.background

.background = color

.getScale(modifiers)