5.3.6
36.1 Notify-boxes
This library is unstable;
compatibility will not be maintained.
See Unstable: May Change Without Warning for more information.
| (require unstable/gui/notify) |
|
superclass: object% |
A notify-box contains a mutable cell. The notify-box notifies its
listeners when the contents of the cell is changed.
Examples: | |||||||||||||||
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constructor
(new notify-box% [value value]) → (is-a?/c notify-box%)
value : any/c Creates a notify-box initially containing value.Gets the value currently stored in the notify-box.Updates the value stored in the notify-box and notifies the listeners.Adds a callback to be invoked on the new value when the notify-box’s contents change.Removes a previously-added callback.
method
(send a-notify-box remove-all-listeners) → void?
Removes all previously registered callbacks.
procedure
(notify-box/pref proc [ #:readonly? readonly?]) → (is-a?/c notify-box%) proc : (case-> (-> any/c) (-> any/c void?)) readonly? : boolean? = #f
Creates a notify-box with an initial value of (proc). Unless
readonly? is true, proc is invoked on the new value
when the notify-box is updated.
Useful for tying a notify-box to a preference or parameter. Of course, changes made directly to the underlying parameter or state are not reflected in the notify-box.
Examples: | ||||||||||||||||||||||||
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syntax
(define-notify name value-expr)
value-expr : (is-a?/c notify-box%)
Class-body form. Declares name as a field and
get-name, set-name,
and listen-name as methods that delegate to
the get, set, and
listen methods of value.
The value-expr argument must evaluate to a notify-box, not just the initial contents for a notify box.
Useful for aggregating many notify-boxes together into one “configuration” object.
Examples: | |||||||||||||||||||||||
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procedure
(menu-option/notify-box parent label notify-box) → (is-a?/c checkable-menu-item%) parent : (or/c (is-a?/c menu%) (is-a?/c popup-menu%)) label : label-string? notify-box : (is-a?/c notify-box%)
Creates a checkable-menu-item% tied to notify-box. The menu item is
checked whenever (send notify-box get) is true. Clicking the
menu item toggles the value of notify-box and invokes its listeners.
procedure
(check-box/notify-box parent label notify-box) → (is-a?/c check-box%)
parent :
(or/c (is-a?/c frame%) (is-a?/c dialog%) (is-a?/c panel%) (is-a?/c pane%)) label : label-string? notify-box : (is-a?/c notify-box%)
Creates a check-box% tied to notify-box. The
check-box is checked whenever (send notify-box get) is
true. Clicking the check box toggles the value of notify-box
and invokes its listeners.
procedure
(choice/notify-box parent label choices notify-box) → (is-a?/c choice%)
parent :
(or/c (is-a?/c frame%) (is-a?/c dialog%) (is-a?/c panel%) (is-a?/c pane%)) label : label-string? choices : (listof label-string?) notify-box : (is-a?/c notify-box%)
Creates a choice% tied to notify-box. The choice
control has the value (send notify-box get) selected, and
selecting a different choice updates notify-box and invokes
its listeners.
If the value of notify-box is not in choices, either initially or upon an update, an error is raised.
procedure
(menu-group/notify-box parent labels notify-box) → (listof (is-a?/c checkable-menu-item%)) parent : (or/c (is-a?/c menu%) (is-a?/c popup-menu%)) labels : (listof label-string?) notify-box : (is-a?/c notify-box%)
Returns a list of checkable-menu-item% controls tied to
notify-box. A menu item is checked when its label is
(send notify-box get). Clicking a menu item updates
notify-box to its label and invokes notify-box’s
listeners.