message-box in Dialogs

See also message-box/custom.

• (message-box title message parent style) -> symbol in '(ok cancel yes no)
   title : string (up to 200 characters)
     message : string
     parent = #f : frame% or dialog% object or #f
   style = '(ok) : list of symbols in '(ok ok-cancel yes-no caution stop)

  Displays a message to the user in a (modal) dialog, using parent as the parent window if it is specified. The dialog's title is title. The message string can be arbitrarily long, and can contain explicit linefeeds or carriage returns for breaking lines.

  The style must include exactly one of the following:

  • 'ok -- the dialog only has an ``OK'' button and always returns 'ok.

  • 'ok-cancel -- the message dialog has ``Cancel'' and ``OK'' buttons. If the user clicks ``Cancel'', the result is 'cancel, otherwise the result is 'ok.

  • 'yes-no -- the message dialog has ``Yes'' and ``No'' buttons. If the user clicks ``Yes'', the result is 'yes, otherwise the result is 'no. Note: instead of a ``Yes''/``No'' dialog, best-practice GUI design is to use message-box/custom and give the buttons meaningful labels, so that the user does not have to read the message text carefully to make a selection.

  In addition, style can contain 'caution to make the dialog use a caution icon instead of the application (or generic ``info'') icon. Alternately, it can contain 'stop to make the dialog use a stop icon. If style contains both 'caution and 'stop, then 'caution is ignored.

  The class that implements the dialog provides a get-message method that takes no arguments and returns the text of the message as a string. (The dialog is accessible through the get-top-level-windows function.)