81 lines
3.1 KiB
Racket
81 lines
3.1 KiB
Racket
#lang scribble/doc
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@(require "common.rkt")
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@defclass/title[slider% object% (control<%>)]{
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A @racket[slider] object is a panel item with a handle that the user can
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drag to change the control's value. Each slider has a fixed minimum
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and maximum value.
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Whenever the user changes the value of a slider, its callback
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procedure is invoked. A callback procedure is provided as an
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initialization argument when each slider is created.
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@defconstructor[([label (or/c label-string? #f)]
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[min-value (integer-in -10000 10000)]
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[max-value (integer-in -10000 10000)]
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[parent (or/c (is-a?/c frame%) (is-a?/c dialog%)
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(is-a?/c panel%) (is-a?/c pane%))]
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[callback ((is-a?/c slider%) (is-a?/c control-event%) . -> . any) (lambda (b e) (void))]
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[init-value (integer-in -10000 10000) min-value]
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[style (listof (or/c 'horizontal 'vertical 'plain
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'vertical-label 'horizontal-label
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'deleted))
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'(horizontal)]
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[font (is-a?/c font%) normal-control-font]
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[enabled any/c #t]
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[vert-margin (integer-in 0 1000) 2]
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[horiz-margin (integer-in 0 1000) 2]
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[min-width (integer-in 0 10000) _graphical-minimum-width]
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[min-height (integer-in 0 10000) _graphical-minimum-height]
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[stretchable-width any/c (memq 'horizontal style)]
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[stretchable-height any/c (memq 'vertical style)])]{
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If @racket[label] is a string, it is used as the label for the slider.
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Otherwise, the slider does not display its label.
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@labelstripped[@racket[label]
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@elem{} @elem{move the keyboard focus to the slider}]
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The @racket[min-value] and @racket[max-value] arguments specify the
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range of the slider, inclusive. The @racket[init-value] argument
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optionally specifies the slider's initial value. If the sequence
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[@racket[min-value], @racket[initial-value], @racket[maximum-value]]
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is not increasing, @|MismatchExn|.
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The @racket[callback] procedure is called (with the event type
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@indexed-racket['slider]) when the user changes the slider's value.
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The @racket[style] argument must include either @racket['vertical] for
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a vertical slider, or @racket['horizontal] for a horizontal
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slider. If @racket[style] includes @racket['plain], the slider does
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not display numbers for its range and current value to the user.
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@HVLabelNote[@racket[style]]{slider} @DeletedStyleNote[@racket[style] @racket[parent]]{slider}
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@FontKWs[@racket[font]] @WindowKWs[@racket[enabled]] @SubareaKWs[] @AreaKWs[]
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}
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@defmethod[(get-value)
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(integer-in -10000 10000)]{
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Gets the current slider value.
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}
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@defmethod[(set-value [value (integer-in -10000 10000)])
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void?]{
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Sets the value (and displayed position) of the slider. (The control's
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callback procedure is @italic{not} invoked.) If @racket[value] is
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outside the slider's minimum and maximum range, @|MismatchExn|.
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@MonitorCallback[@elem{A slider's value} @elem{the user clicking the control} @elem{value}]
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}}
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