cpython/Doc/library/easydialogs.rst

:mod:`EasyDialogs` --- Basic Macintosh dialogs
==============================================

.. module:: EasyDialogs
   :platform: Mac
   :synopsis: Basic Macintosh dialogs.


The :mod:`EasyDialogs` module contains some simple dialogs for the Macintosh.
All routines take an optional resource ID parameter *id* with which one can
override the :const:`DLOG` resource used for the dialog, provided that the
dialog items correspond (both type and item number) to those in the default
:const:`DLOG` resource. See source code for details.

The :mod:`EasyDialogs` module defines the following functions:


.. function:: Message(str[, id[, ok]])

   Displays a modal dialog with the message text *str*, which should be at most 255
   characters long. The button text defaults to "OK", but is set to the string
   argument *ok* if the latter is supplied. Control is returned when the user
   clicks the "OK" button.


.. function:: AskString(prompt[, default[, id[, ok[, cancel]]]])

   Asks the user to input a string value via a modal dialog. *prompt* is the prompt
   message, and the optional *default* supplies the initial value for the string
   (otherwise ``""`` is used). The text of the "OK" and "Cancel" buttons can be
   changed with the *ok* and *cancel* arguments. All strings can be at most 255
   bytes long. :func:`AskString` returns the string entered or :const:`None` in
   case the user cancelled.


.. function:: AskPassword(prompt[, default[, id[, ok[, cancel]]]])

   Asks the user to input a string value via a modal dialog. Like
   :func:`AskString`, but with the text shown as bullets. The arguments have the
   same meaning as for :func:`AskString`.


.. function:: AskYesNoCancel(question[, default[, yes[, no[, cancel[, id]]]]])

   Presents a dialog with prompt *question* and three buttons labelled "Yes", "No",
   and "Cancel". Returns ``1`` for "Yes", ``0`` for "No" and ``-1`` for "Cancel".
   The value of *default* (or ``0`` if *default* is not supplied) is returned when
   the :kbd:`RETURN` key is pressed. The text of the buttons can be changed with
   the *yes*, *no*, and *cancel* arguments; to prevent a button from appearing,
   supply ``""`` for the corresponding argument.


.. function:: ProgressBar([title[, maxval[, label[, id]]]])

   Displays a modeless progress-bar dialog. This is the constructor for the
   :class:`ProgressBar` class described below. *title* is the text string displayed
   (default "Working..."), *maxval* is the value at which progress is complete
   (default ``0``, indicating that an indeterminate amount of work remains to be
   done), and *label* is the text that is displayed above the progress bar itself.


.. function:: GetArgv([optionlist[ commandlist[, addoldfile[, addnewfile[, addfolder[, id]]]]]])

   Displays a dialog which aids the user in constructing a command-line argument
   list.  Returns the list in ``sys.argv`` format, suitable for passing as an
   argument to :func:`getopt.getopt`.  *addoldfile*, *addnewfile*, and *addfolder*
   are boolean arguments.  When nonzero, they enable the user to insert into the
   command line paths to an existing file, a (possibly) not-yet-existent file, and
   a folder, respectively.  (Note: Option arguments must appear in the command line
   before file and folder arguments in order to be recognized by
   :func:`getopt.getopt`.)  Arguments containing spaces can be specified by
   enclosing them within single or double quotes.  A :exc:`SystemExit` exception is
   raised if the user presses the "Cancel" button.

   *optionlist* is a list that determines a popup menu from which the allowed
   options are selected.  Its items can take one of two forms: *optstr* or
   ``(optstr, descr)``.  When present, *descr* is a short descriptive string that
   is displayed in the dialog while this option is selected in the popup menu.  The
   correspondence between *optstr*\s and command-line arguments is:

   +----------------------+------------------------------------------+
   | *optstr* format      | Command-line format                      |
   +======================+==========================================+
   | ``x``                | :option:`-x` (short option)              |
   +----------------------+------------------------------------------+
   | ``x:`` or ``x=``     | :option:`-x` (short option with value)   |
   +----------------------+------------------------------------------+
   | ``xyz``              | :option:`--xyz` (long option)            |
   +----------------------+------------------------------------------+
   | ``xyz:`` or ``xyz=`` | :option:`--xyz` (long option with value) |
   +----------------------+------------------------------------------+

   *commandlist* is a list of items of the form *cmdstr* or ``(cmdstr, descr)``,
   where *descr* is as above.  The *cmdstr*s will appear in a popup menu.  When
   chosen, the text of *cmdstr* will be appended to the command line as is, except
   that a trailing ``':'`` or ``'='`` (if present) will be trimmed off.


.. function:: AskFileForOpen( [message] [, typeList] [, defaultLocation] [, defaultOptionFlags] [, location] [, clientName] [, windowTitle] [, actionButtonLabel] [, cancelButtonLabel] [, preferenceKey] [, popupExtension] [, eventProc] [, previewProc] [, filterProc] [, wanted] )

   Post a dialog asking the user for a file to open, and return the file selected
   or :const:`None` if the user cancelled. *message* is a text message to display,
   *typeList* is a list of 4-char filetypes allowable, *defaultLocation* is the
   pathname, :class:`FSSpec` or :class:`FSRef` of the folder to show initially,
   *location* is the ``(x, y)`` position on the screen where the dialog is shown,
   *actionButtonLabel* is a string to show instead of "Open" in the OK button,
   *cancelButtonLabel* is a string to show instead of "Cancel" in the cancel
   button, *wanted* is the type of value wanted as a return: :class:`str`,
   :class:`FSSpec`, :class:`FSRef` and subtypes thereof are
   acceptable.

   .. index:: single: Navigation Services

   For a description of the other arguments please see the Apple Navigation
   Services documentation and the :mod:`EasyDialogs` source code.


.. function:: AskFileForSave( [message] [, savedFileName] [, defaultLocation] [, defaultOptionFlags] [, location] [, clientName] [, windowTitle] [, actionButtonLabel] [, cancelButtonLabel] [, preferenceKey] [, popupExtension] [, fileType] [, fileCreator] [, eventProc] [, wanted] )

   Post a dialog asking the user for a file to save to, and return the file
   selected or :const:`None` if the user cancelled. *savedFileName* is the default
   for the file name to save to (the return value). See :func:`AskFileForOpen` for
   a description of the other arguments.


.. function:: AskFolder( [message] [, defaultLocation] [, defaultOptionFlags] [, location] [, clientName] [, windowTitle] [, actionButtonLabel] [, cancelButtonLabel] [, preferenceKey] [, popupExtension] [, eventProc] [, filterProc] [, wanted] )

   Post a dialog asking the user to select a folder, and return the folder selected
   or :const:`None` if the user cancelled. See :func:`AskFileForOpen` for a
   description of the arguments.


.. seealso::

   `Navigation Services Reference <http://developer.apple.com/documentation/Carbon/Reference/Navigation_Services_Ref/>`_
      Programmer's reference documentation for the Navigation Services, a part of the
      Carbon framework.


.. _progressbar-objects:

ProgressBar Objects
-------------------

:class:`ProgressBar` objects provide support for modeless progress-bar dialogs.
Both determinate (thermometer style) and indeterminate (barber-pole style)
progress bars are supported.  The bar will be determinate if its maximum value
is greater than zero; otherwise it will be indeterminate.

The dialog is displayed immediately after creation. If the dialog's "Cancel"
button is pressed, or if :kbd:`Cmd-.` or :kbd:`ESC` is typed, the dialog window
is hidden and :exc:`KeyboardInterrupt` is raised (but note that this response
does not occur until the progress bar is next updated, typically via a call to
:meth:`inc` or :meth:`set`).  Otherwise, the bar remains visible until the
:class:`ProgressBar` object is discarded.

:class:`ProgressBar` objects possess the following attributes and methods:


.. attribute:: ProgressBar.curval

   The current value (of type integer) of the progress bar.  The
   normal access methods coerce :attr:`curval` between ``0`` and :attr:`maxval`.
   This attribute should not be altered directly.


.. attribute:: ProgressBar.maxval

   The maximum value (of type integer) of the progress bar; the
   progress bar (thermometer style) is full when :attr:`curval` equals
   :attr:`maxval`.  If :attr:`maxval` is ``0``, the bar will be indeterminate
   (barber-pole).  This attribute should not be altered directly.


.. method:: ProgressBar.title([newstr])

   Sets the text in the title bar of the progress dialog to *newstr*.


.. method:: ProgressBar.label([newstr])

   Sets the text in the progress box of the progress dialog to *newstr*.


.. method:: ProgressBar.set(value[, max])

   Sets the progress bar's :attr:`curval` to *value*, and also :attr:`maxval` to
   *max* if the latter is provided.  *value* is first coerced between 0 and
   :attr:`maxval`.  The thermometer bar is updated to reflect the changes,
   including a change from indeterminate to determinate or vice versa.


.. method:: ProgressBar.inc([n])

   Increments the progress bar's :attr:`curval` by *n*, or by ``1`` if *n* is not
   provided.  (Note that *n* may be negative, in which case the effect is a
   decrement.)  The progress bar is updated to reflect the change.  If the bar is
   indeterminate, this causes one "spin" of the barber pole.  The resulting
   :attr:`curval` is coerced between 0 and :attr:`maxval` if incrementing causes it
   to fall outside this range.