16 GUI Utilities

16 GUI Utilities🔗ℹ

package: gui-lib

procedure
(gui-utils:trim-string str size)
→
(and/c string?
       (λ (str)
         ((string-length str) . <= . size)))
  str : string?
  size : (and/c number? positive?)

Constructs a string whose size is less than size by trimming the str and inserting an ellispses into it.

procedure
(gui-utils:quote-literal-label string
[ #:quote-amp? quote-amp?])
→
(and/c string?
       (λ (str) ((string-length str) . <= . 200)))
  string : string?
  quote-amp? : any/c = #t

Constructs a string whose length is less than 200 and, if quote-amp? is not #f, then it also quotes the ampersand in the result (making the string suitable for use in menu-item% label, for example).

procedure
(gui-utils:format-literal-label str
rest ...)
→
(and/c string?
       (lambda (str)
         ((string-length str) . <= . 200)))
  str : string?
  rest : (listof any/c)

Formats a string whose ampersand characters are mk-escaped; the label is also trimmed to <= 200 mk-characters.

procedure
(gui-utils:cancel-on-right?) → boolean?

Returns #t if cancel should be on the right-hand side (or below) in a dialog and #f otherwise.

Just returns what system-position-ok-before-cancel? does.

See also gui-utils:cancel-on-right?.

procedure
(gui-utils:next-untitled-name) → string?

Returns a name for the next opened untitled frame. The first name is “Untitled”, the second is “Untitled 2”, the third is “Untitled 3”, and so forth.

procedure
(gui-utils:cursor-delay) → real?
(gui-utils:cursor-delay new-delay) → void?
new-delay : real?

This function is not a parameter. Instead, the state is just stored in the closure.

The first case in the case lambda returns the current delay in seconds before a watch cursor is shown, when either gui-utils:local-busy-cursor or gui-utils:show-busy-cursor is called.

The second case in the case lambda Sets the delay, in seconds, before a watch cursor is shown, when either gui-utils:local-busy-cursor or gui-utils:show-busy-cursor is called.

procedure
(gui-utils:show-busy-cursor thunk [delay]) → any/c
thunk : (-> any/c)
delay : integer? = (gui-utils:cursor-delay)

Evaluates (thunk) with a watch cursor. The argument delay specifies the amount of time before the watch cursor is opened. Use gui-utils:cursor-delay to set this value to all calls.

This function returns the result of thunk.

procedure
(gui-utils:delay-action delay-time
open
close) → (-> void?)
  delay-time : real?
  open : (-> void?)
  close : (-> void?)

Use this function to delay an action for some period of time. It also supports canceling the action before the time period elapses. For example, if you want to display a watch cursor, but you only want it to appear after 2 seconds and the action may or may not take more than two seconds, use this pattern:

(let ([close-down
       (gui-utils:delay-action
        2
        (λ () .. init watch cursor ...)
        (λ () .. close watch cursor ...))])

  (close-down))

Creates a thread that waits delay-time. After delay-time has elapsed, if the result thunk has not been called, call open. Then, when the result thunk is called, call close. The function close will only be called if open has been called.

procedure
(gui-utils:local-busy-cursor window
thunk
[ delay]) → any/c
  window : (is-a?/c window<%>)
  thunk : (-> any/c)
  delay : integer? = (gui-utils:cursor-delay)

Evaluates (thunk) with a watch cursor in window. If window is #f, the watch cursor is turned on globally. The argument delay specifies the amount of time before the watch cursor is opened. Use gui-utils:cursor-delay to set this value for all uses of this function.

The result of this function is the result of thunk.

procedure
(gui-utils:unsaved-warning filename
action
[ can-save-now?
parent
cancel?
#:dialog-mixin dialog-mixin])
→ (symbols 'continue 'save 'cancel)
  filename : string?
  action : string?
  can-save-now? : boolean? = #f
   parent :
(or/c false/c
      (is-a?/c frame%)
      (is-a?/c dialog%))
= #f
  cancel? : boolean? = #t
  dialog-mixin : (make-mixin-contract dialog%) = values

This displays a dialog that warns the user of a unsaved file.

The string, action, indicates what action is about to take place, without saving. For example, if the application is about to close a file, a good action is "Close Anyway". The result symbol indicates the user’s choice. If can-save-now? is #f, this function does not give the user the “Save” option and thus will not return 'save.

If cancel? is #t there is a cancel button in the dialog and the result may be 'cancel. If it is #f, then there is no cancel button, and 'cancel will not be the result of the function.

The dialog-mixin argument is passed to message-box/custom.

Changed in version 1.29 of package gui-lib: Added the dialog-mixin argument.

procedure
(gui-utils:get-choice message
true-choice
false-choice
[ title
default-result
parent
style
checkbox-proc
checkbox-label
#:dialog-mixin dialog-mixin]) → any/c
  message : string?
  true-choice : string?
  false-choice : string?
  title : string? = (string-constant warning)
  default-result : any/c = 'disallow-close
   parent : (or/c false/c (is-a?/c frame%) (is-a?/c dialog%))
= #f
  style : (symbols 'app 'caution 'stop) = 'app
   checkbox-proc :
(or/c false/c (case-> (boolean? . -> . void?)
                      (-> boolean?)))
= #f
  checkbox-label : string? = (string-constant dont-ask-again)
  dialog-mixin : (make-mixin-contract dialog%) = values

Opens a dialog that presents a binary choice to the user. The user is forced to choose between these two options, ie cancelling or closing the dialog opens a message box asking the user to actually choose one of the two options.

The dialog will contain the string message and two buttons, labeled with the true-choice and the false-choice. If the user clicks on true-choice #t is returned. If the user clicks on false-choice, #f is returned.

The argument default-result determines how closing the window is treated. If the argument is 'disallow-close, closing the window is not allowed. If it is anything else, that value is returned when the user closes the window.

If gui-utils:cancel-on-right? returns #t, the false choice is on the right. Otherwise, the true choice is on the right.

The style parameter is (eventually) passed to message as an icon in the dialog.

If checkbox-proc is given, it should be a procedure that behaves like a parameter for getting/setting a boolean value. The intention for this value is that it can be used to disable the dialog. When it is given, a checkbox will appear with a checkbox-label label (defaults to the dont-ask-again string constant), and that checkbox value will be sent to the checkbox-proc when the dialog is closed. Note that the dialog will always pop-up — it is the caller’s responsibility to avoid the dialog if not needed.

The dialog-mixin argument is passed to message-box/custom or message+check-box/custom.

Changed in version 1.29 of package gui-lib: Added the dialog-mixin argument.

procedure
(gui-utils:get-clicked-clickback-delta [white-on-black?])
→ (is-a?/c style-delta%)
white-on-black? : boolean? = #f

This delta is designed for use with set-clickback. Use it as one of the style-delta% argument to set-clickback.

If white-on-black? is true, the function returns a delta suitable for use on a black background.

1	Framework Libraries Overview
2	Application
3	Autosave
4	Canvas
5	Color Model
6	Color Prefs
7	Color
8	Comment Box
9	Decorated Editor Snip
10	Editor Snip
11	Editor
12	Exit
13	Finder
14	Frame
15	Group
16	GUI Utilities
17	Handler
18	Icon
19	Keymap
20	Menu
21	Mode
22	Notify-boxes
23	Number Snip
24	Panel
25	Pasteboard
26	Path Utils
27	Preferences
28	Preferences, Textual
29	Racket
30	Srcloc Snips
31	Text
32	Splash
33	Test
34	Version
35	Backwards Compatibility
36	Signatures
37	Unit
	Index