rsc3/doc-schelp/HelpSource/Classes/Knob.scrbl

381 lines
7.8 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{Knob}
A rotary controller view@section{categories}
GUI>Views
@section{related}
Classes/Slider, Classes/Slider2D
@section{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 link::#-centered::.
To switch between the mouse interaction modes, use link::#-mode::.
The amount by which the value changes at interaction can be fine-tuned using link::#-step::, link::#-keystep::, link::#-shift_scale::, link::#-ctrl_scale::, and link::#-alt_scale::
@section{CLASSMETHODS}
@section{PRIVATE}
key
@section{METHOD}
defaultMode
The default link::#-mode:: for newly created Knobs.
@section{INSTANCEMETHODS}
@section{SUBSECTION}
Data
@section{METHOD}
value
The displayed value.
@section{argument}
A Number in the range of 0.0 to 1.0.
@section{METHOD}
valueAction
Sets the value and triggers link::#-action::.
@section{METHOD}
increment
Increments the value by link::#-keystep:: multiplied by the argument.
@section{argument}
A Number.
@section{METHOD}
decrement
Decrements the value by link::#-keystep:: multiplied by the argument.
@section{argument}
zoom
A Number.
@section{SUBSECTION}
Interaction
@section{METHOD}
mode
The way value is controlled with respect to mouse movement after clicking on the view:
@section{list}
##
@racketblock[\round:: - value follows circular movement
## ]
@racketblock[\horiz:: - value follows linear movement in horizontal direction
## ]
@racketblock[\vert:: - value follows linear movement in vertical direction
::
Defaults to ]
@racketblock[\round::.
]
@section{Argument}
One of the symbols listed above.
@section{METHOD}
keystep
The amount by which the value is incremented/decremented when pressing a relevant key.
Defaults to 0.01;
@section{Argument}
A Number.
@section{METHOD}
step
The amount by which the value is incremented/decremented using the mouse in 'horizontal' and 'vertical' link::#-mode#modes::.
@section{Argument}
A Number.
@section{METHOD}
shift_scale
The factor by which link::#-step:: or link::#-keystep:: is multiplied when used at mouse or keyboard interaction while the Shift key is pressed.
@section{argument}
A Float.
@section{METHOD}
ctrl_scale
The factor by which link::#-step:: or link::#-keystep:: is multiplied when used at mouse or keyboard interaction while the Ctrl key is pressed.
@section{argument}
A Float.
@section{METHOD}
alt_scale
The factor by which link::#-step:: or link::#-keystep:: is multiplied when used at mouse or keyboard interaction while the Alt key is pressed.
@section{argument}
A Float.
@section{SUBSECTION}
Appearance
@section{METHOD}
centered
Whether the deviation of value will be displayed in relation to 0.0 or 0.5 (e.g. as in a panning controller);
@section{Argument}
A Boolean.
@section{METHOD}
color
The colors used by the Knob to draw the following elements:
@section{list}
## the main Knob color
## the value indicator
## the deviation indicator
## the background of the deviation indicator
::
@section{Argument}
An Array of four Colors in the order listed above.
@section{SUBSECTION}
Actions
@section{METHOD}
action
The action object evaluated whenever the user interacts with the Knob using the mouse or the keyboard.
@section{METHOD}
defaultKeyDownAction
Implements the default effects of key presses as follows:
@section{table}
## strong::Key:: || strong::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
::
See also: link::#-keystep::, link::#-shift_scale::, link::#-ctrl_scale::, link::#-alt_scale::.
@section{SUBSECTION}
Drag and drop
@section{METHOD}
defaultGetDrag
@section{returns}
The link::#-value::.
@section{METHOD}
defaultCanReceiveDrag
@section{returns}
True if the current drag data is a Number.
@section{METHOD}
defaultReceiveDrag
Sets link::#-valueAction:: to the current drag data.
@section{EXAMPLES}
@section{subsection}
Basic Example
@racketblock[
(
var window, size = 32; // try different sizes - from 15 to 200 or more!
window = Window.new("Knob", Rect(640,630,270,70)).front;
k = Knob.new(window, Rect(20, 10, size, size));
k.action_({|v,x,y,m| postf("action func called: %\n", v.value); });
//k.color[1] = Color.gray(alpha:0);
)
k.value
k.value = 0.25
k.valueAction = 0.125
// modes
k.mode = \vert;
k.mode = \horiz;
k.mode = \round; // default
k.visible
k.visible = false
k.visible = true
k.enabled = false
k.enabled_(true)
k.canFocus = false
k.canFocus = true
::
]
@section{subsection}
Centered Mode
Center mode is useful for pan or eq gain control etc.
@racketblock[
(
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
::
]
@section{subsection}
step
link::#-step:: only affects the 'horiz' and 'vert' modes:
@racketblock[
(
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;
::
]
@section{subsection}
mouseOverAction
@racketblock[
(
var size = 28;
w = Window.new("Knobs", Rect(250,500,270,70));
w.acceptsMouseOver=true; // must be true in parent window!
w.view.decorator = FlowLayout(w.view.bounds);
h = StaticText(w, 150 @ 10);
w.view.decorator.nextLine;
k = Array(8);
8.do({|item, i|
var knob;
knob = Knob.new(w, size @ size)
.action_({|v,x,y,m| h.string = "val: " ++ v.value.asString; })
.mouseOverAction_({|v,x,y| h.string = "val: " ++ v.value.asString; });
k = k.add(knob);
});
w.front
)
k[4].value
::
]
@section{subsection}
Drag and Drop
@racketblock[
(
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; }
::
]