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

362 lines
7.1 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{Slider}
A view consisting of a sliding handle.@section{categories}
GUI>Views
@section{description}
A view that allows setting a numerical value by means of moving a sliding handle. It can have horizontal or vertical orientation, meaning the direction in which the handle moves.
@section{CLASSMETHODS}
@section{PRIVATE}
key
@section{METHOD}
new
When a new Slider is created, its link::#-orientation:: is determined by the initial size: if it is wider than high, the orientation will be horizontal, otherwise it will be vertical.
@section{INSTANCEMETHODS}
@section{SUBSECTION}
Data
@section{METHOD}
value
Numerical value between 0 and 1, represented by the handle position within the groove.
@section{argument}
A Float.
@section{METHOD}
valueAction
Sets link::#-value:: and triggers link::#-action::.
@section{METHOD}
increment
Increments the value by link::#-step:: multiplied by 'factor'.
@section{argument}
factor
Any number.
@section{METHOD}
decrement
Decrements the value by link::#-step:: multiplied by 'factor'.
@section{argument}
factor
Any number.
@section{SUBSECTION}
Appearance
@section{METHOD}
orientation
The orientation of the Slider - the direction in which the handle moves. The default value depends on the size of the view when created.
@section{argument}
One of the two Symbols: \horizontal or \vertical.
@section{METHOD}
thumbSize
The size of the handle - its width or height, depending on link::#-orientation::.
@section{argument}
An Integer amount of pixels.
@section{METHOD}
knobColor
The color of the handle.
@section{argument}
A Color.
@section{SUBSECTION}
Interaction
@section{METHOD}
step
The amount by which the value will changed when link::#-increment:: or link::#-decrement:: is called, or when related keys are pressed.
@section{argument}
A Float.
@section{METHOD}
pixelStep
The absolute amount by which the value would change if the handle moved by one pixel.
@section{returns}
A Float.
@section{METHOD}
shift_scale
The factor by which link::#-step:: is multiplied when incrementing or decrementing the value by keyboard while the Shift key is pressed.
@section{argument}
A Float.
@section{METHOD}
ctrl_scale
The factor by which link::#-step:: is multiplied when incrementing or decrementing the value by keyboard while the Ctrl key is pressed.
@section{argument}
A Float.
@section{METHOD}
alt_scale
The factor by which link::#-step:: is multiplied when incrementing or decrementing the value by keyboard while the Alt key is pressed.
@section{argument}
A Float.
@section{SUBSECTION}
Actions
@section{METHOD}
action
The action object evaluated whenever the user moves the handle.
@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
::
@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}
Show the slider value in a NumberBox
@racketblock[
(
w = Window.new.front;
c = NumberBox(w, Rect(20, 20, 150, 20));
a = Slider(w, Rect(20, 60, 150, 20))
.action_({
c.value_(a.value)
});
a.action.value;
)
( // change the bounds to become vertical
w = Window.new.front;
c = NumberBox(w, Rect(20, 20, 150, 20));
a = Slider(w, Rect(200, 60, 20, 150))
.action_({
c.value_(a.value)
});
a.action.value;
)
::
]
@section{subsection}
Use a Spec to round and map the output range
@racketblock[
(
w = Window.new.front;
b = ControlSpec(-50, 50, \linear, 0.01); // min, max, mapping, step
c = StaticText(w, Rect(20, 20, 150, 20)).align_(\center).background_(Color.rand);
a = Slider(w, Rect(20, 50, 150, 20))
.focusColor_(Color.red(alpha:0.2))
.background_(Color.rand)
.value_(0.5)
.action_({
c.string_(b.map(a.value).asString)
// round the float so it will fit in the NumberBox
});
a.action.value;
)
::
]
@section{subsection}
Change the stepsize of the slider, selected via a PopUpMenu
@racketblock[
(
w = Window.new.front;
a = ["0", "0.0625", "0.125", "0.25", "0.5", "1"];
b = Slider(w, Rect(20, 100, 100, 20))
.action_({
c.value_(b.value)
}).background_(Color.rand);
d = PopUpMenu(w, Rect(20, 60, 100, 20))
.items_(a)
.action_({
b.step_((a.at(d.value)).asFloat);
});
StaticText(w, Rect(130, 60, 100, 20)).string_("change step");
c = NumberBox(w, Rect(20, 20, 100, 20));
)
::
]
@section{subsection}
Use the slider view to accept key actions
@racketblock[
( // select the slider, type something and watch the post window
w = Window.new;
c = Slider(w,Rect(0,0,100,30));
c.keyDownAction = { arg view,char,modifiers,unicode,keycode;
[char,modifiers,unicode,keycode].postln;
};
w.front;
)
::
]
@section{subsection}
Adding functionality to a view by the method addAction
This is useful for adding things to existing frameworks that have action functions already.
@racketblock[
(
w = Window.new("A Slider");
a = Slider.new(w, Rect(40, 10, 300, 30));
w.front
);
// now incrementally add some action to the slider
a.addAction({ |sl| sl.value.postln });
a.addAction({ |sl| w.view.background = Color.green(sl.value) });
a.addAction({ |sl| sl.background = Color.red(1 - sl.value) });
// adding and removing an action:
f = { |sl| "--------*******-------".postln; };
a.addAction(f);
a.removeAction(f);
// or remove all, of course
a.action = nil;
::
]
@section{subsection}
Use Slider for triggering sounds
@racketblock[
(
s.waitForBoot({
SynthDef(\pluck,{arg freq=55;
Out.ar(0,
Pluck.ar(WhiteNoise.ar(0.06),
EnvGen.kr(Env.perc(0,4), 1.0, doneAction: Done.freeSelf),
freq.reciprocal,
freq.reciprocal,
10,
coef:0.1)
);
}).add;
w = Window.new("Hold arrow keys to trigger sound",Rect(300,Window.screenBounds.height-300,400,100)).front;
a = Slider(w, Rect(50, 20, 300, 40))
.value_(0.5)
.step_(0.05)
.focus
.action_({
// trigger a synth with varying frequencies
Synth(\pluck, [\freq,55+(1100*a.value)]);
w.view.background_(Gradient(Color.rand,Color.rand));
})
});
)
::
]
@section{subsection}
Change background color of Window
@racketblock[
(
w = Window("RGB fader", Rect(100, 500, 400, 400))
.front;
f = { w.view.background_(Color.new(r.value, g.value, b.value, 1)) };
r = Slider(w, Rect(100, 140, 200, 20))
.value_(0.5)
.action_({ f.value });
g = Slider(w, Rect(100, 170, 200, 20))
.value_(0.5)
.action_({ f.value });
b = Slider(w, Rect(100, 200, 200, 20))
.value_(0.5)
.action_({ f.value });
f.value;
);
::
]