view man/lispref/dialog.texi @ 4502:8748a3f7ceb4

Handle varalias chains, custom variables in #'user-variable-p. src/ChangeLog addition: 2008-08-23 Aidan Kehoe <kehoea@parhasard.net> * eval.c (Fuser_variable_p): Moved to symbols.c * symbols.c (Fcustom_variable_p): Moved here from custom.el. (user_variable_alias_check_fun): Mapper function used in `user-variable-p'. (Fuser_variable_p): Moved here from eval.c, to allow it to examine the variable alias chain. Expanded to check each entry in the variable alias chain for signs of being a user variable; documentation updated, noting the differences between GNU's behaviour and ours (ours is a little more sensible) (map_varalias_chain): New. Given a C function, call it at least once for each symbol in a symbol's varalias chain, signalling an error if there's a cycle, and returning immediately if the function returns something other than Qzero. (Fdefvaralias): Correct the use of the word "alias" in the docstring and in the argument name. Motivate this in a comment. Add support for a DOCSTRING argument, something GNU has too, and document this * gc.c (vars_of_gc): Start the docstring of `garbage-collection-messages' with an asterisk, to indicate that it's a user variable. lisp/ChangeLog addition: 2008-08-23 Aidan Kehoe <kehoea@parhasard.net> * custom.el: Move #'custom-variable-p to C, since it's now called from #'user-variable-p.
author Aidan Kehoe <kehoea@parhasard.net>
date Sat, 23 Aug 2008 16:38:51 +0200
parents 576fb035e263
children 9fae6227ede5
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@c -*-texinfo-*-
@c This is part of the XEmacs Lisp Reference Manual.
@c Copyright (C) 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
@c See the file lispref.texi for copying conditions.
@setfilename ../../info/dialog.info
@node Dialog Boxes, Toolbar, Menus, Top
@chapter Dialog Boxes
@cindex dialog box

@menu
* Dialog Box Format::
* Dialog Box Functions::
@end menu

@node Dialog Box Format
@section Dialog Box Format

A dialog box description is a list.

@itemize @bullet
@item
The first element of the list is a string to display in the dialog box.
@item
The rest of the elements are descriptions of the dialog box's buttons.
Each one is a vector of three elements:
@itemize @minus
@item
The first element is the text of the button.
@item
The second element is the @dfn{callback}.
@item
The third element is @code{t} or @code{nil}, whether this button is
selectable.
@end itemize
@end itemize

If the callback of a button is a symbol, then it must name a command.
It will be invoked with @code{call-interactively}.  If it is a list,
then it is evaluated with @code{eval}.

One (and only one) of the buttons may be @code{nil}.  This marker means
that all following buttons should be flushright instead of flushleft.

The syntax, more precisely:

@example
   form         :=  <something to pass to `eval'>
   command      :=  <a symbol or string, to pass to `call-interactively'>
   callback     :=  command | form
   active-p     :=  <t, nil, or a form to evaluate to decide whether this
                    button should be selectable>
   name         :=  <string>
   partition    :=  'nil'
   button       :=  '['  name callback active-p ']'
   dialog       :=  '(' name [ button ]+ [ partition [ button ]+ ] ')'
@end example

@node Dialog Box Functions
@section Dialog Box Functions

@defun popup-dialog-box dbox-desc
This function pops up a dialog box.  @var{dbox-desc} describes how the
dialog box will appear (@pxref{Dialog Box Format}).
@end defun

@xref{Yes-or-No Queries}, for functions to ask a yes/no question using
a dialog box.