65 lines
2.6 KiB
Racket
65 lines
2.6 KiB
Racket
#lang scribble/doc
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@(require "common.rkt")
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@defclass/title[choice% object% (list-control<%>)]{
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A choice item allows the user to select one string item from a pop-up
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list of items. Unlike a list box, only the currently selection is
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visible until the user pops-up the menu of choices.
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Whenever the selection of a choice item is changed by the user, the
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choice item's callback procedure is invoked. A callback procedure is
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provided as an initialization argument when each choice item is
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created.
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See also @racket[list-box%].
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@defconstructor[([label (or/c label-string? #f)]
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[choices (listof label-string?)]
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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 choice%) (is-a?/c control-event%) . -> . any)
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(lambda (c e) (void))]
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[style (listof (or/c 'horizontal-label 'vertical-label
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'deleted))
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null]
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[selection exact-nonnegative-integer? 0]
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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 #f]
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[stretchable-height any/c #f])]{
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Creates a choice item. If @racket[label] is a string, it is used as the
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label for the choice item.
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@labelstripped[@racket[label]
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@elem{} @elem{move the keyboard focus to the choice item}]
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The @racket[choices] list specifies the initial list of user-selectable
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items for the control. The initial set of choices determines the
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control's minimum graphical width (see @|geomdiscuss| for more
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information).
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The @racket[callback] procedure is called (with the event type
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@indexed-racket['choice]) when the user selects a choice item (or
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re-selects the currently selected item).
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@HVLabelNote[@racket[style]]{choice item}
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@DeletedStyleNote[@racket[style] @racket[parent]]{choice item}
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By default, the first choice (if any) is initially selected. If
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@racket[selection] is positive, it is passed to
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@method[list-control<%> set-selection] to set the initial choice selection. Although @racket[selection] normally
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must be less than the length of @racket[choices], it can be @racket[0]
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when @racket[choices] is empty.
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@FontKWs[@racket[font]] @WindowKWs[@racket[enabled]] @SubareaKWs[] @AreaKWs[]
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}}
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