Modal Dialogs

Modal dialogs are designed to ask specific questions and wait until they receive a response. All other interaction is disabled until the dialog is dismissed -- they place the system in dialog mode . Six functions are available for producing some standard modal dialogs:

• (message-dialog < string > ) -- presents a message with an OK button; returns nil when the button is pressed.
• (ok-or-cancel-dialog < string > ) -- presents a message with an OK and a Cancel button; returns t or NIL according to the button pressed.
• (choose-item-dialog < string > < string-list > ) -- presents a heading and a set of radio buttons for choosing one of the strings. Returns the index of the selected string on OK or nil on Cancel . Example:

  > (choose-item-dialog "Dependent variable:" '("X" "Y" "Z"))
  1
  
  

• (choose-subset-dialog < string > < string-list > ) -- presents a heading and a set of check boxes for indicating which items to select. Returns a list of the list of selected indices on OK or nil on Cancel . Example:

  > (choose-subset-dialog "Independent variables:" '("X" "Y" "Z"))
  ((0 2))
  
  

• (get-string-dialog < prompt > [:initial < expr > ]) -- presents a dialog with a prompt, an editable text field, an OK and a Cancel button. The initial contents of the editable field is empty or the princ formated version of < expr > . The result is a string or nil . Example:

  > (get-string-dialog "New variable label:" :initial "X")
  "Tensile Strength"
  
  

• (get-value-dialog < prompt > [:initial < expr > ]) -- like get-string-dialog , except
  • the initial value expression is converted to a string with print formatting
  • the result is interpreted as a lisp expression and is evaluated
  • the result is a list of the value, or nil

On the Macintosh there are two additional dialogs for dealing with files:

• (open-file-dialog) -- presents a standard Open File dialog and returns a file name string or nil . Resets the working folder on OK .
• (set-file-dialog prompt ) -- presents a standard Save File dialog. Returns a file name string or nil . Resets the working folder on OK .