
:mod:`aetools` --- OSA client support
=====================================

.. module:: aetools
   :platform: Mac
   :synopsis: Basic support for sending Apple Events
.. sectionauthor:: Jack Jansen <Jack.Jansen@cwi.nl>
.. moduleauthor:: Jack Jansen

The :mod:`aetools` module contains the basic functionality on which Python
AppleScript client support is built. It also imports and re-exports the core
functionality of the :mod:`aetypes` and :mod:`aepack` modules. The stub packages
generated by :mod:`gensuitemodule` import the relevant portions of
:mod:`aetools`, so usually you do not need to import it yourself. The exception
to this is when you cannot use a generated suite package and need lower-level
access to scripting.

The :mod:`aetools` module itself uses the AppleEvent support provided by the
:mod:`Carbon.AE` module. This has one drawback: you need access to the window
manager, see section :ref:`osx-gui-scripts` for details. This restriction may be
lifted in future releases.

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


.. function:: packevent(ae, parameters, attributes)

   Stores parameters and attributes in a pre-created ``Carbon.AE.AEDesc`` object.
   ``parameters`` and ``attributes`` are  dictionaries mapping 4-character OSA
   parameter keys to Python objects. The objects are packed using
   ``aepack.pack()``.


.. function:: unpackevent(ae[, formodulename])

   Recursively unpacks a ``Carbon.AE.AEDesc`` event to Python objects. The function
   returns the parameter dictionary and the attribute dictionary. The
   ``formodulename`` argument is used by generated stub packages to control where
   AppleScript classes are looked up.


.. function:: keysubst(arguments, keydict)

   Converts a Python keyword argument dictionary ``arguments`` to the format
   required by ``packevent`` by replacing the keys, which are Python identifiers,
   by the four-character OSA keys according to the mapping specified in
   ``keydict``. Used by the generated suite packages.


.. function:: enumsubst(arguments, key, edict)

   If the ``arguments`` dictionary contains an entry for ``key`` convert the value
   for that entry according to dictionary ``edict``. This converts human-readable
   Python enumeration names to the OSA 4-character codes. Used by the generated
   suite packages.

The :mod:`aetools` module defines the following class:


.. class:: TalkTo([signature=None, start=0, timeout=0])

   Base class for the proxy used to talk to an application. ``signature`` overrides
   the class attribute ``_signature`` (which is usually set by subclasses) and is
   the 4-char creator code defining the application to talk to. ``start`` can be
   set to true to enable running the application on class instantiation.
   ``timeout`` can be specified to change the default timeout used while waiting
   for an AppleEvent reply.


.. method:: TalkTo._start()

   Test whether the application is running, and attempt to start it if not.


.. method:: TalkTo.send(code, subcode[, parameters, attributes])

   Create the AppleEvent ``Carbon.AE.AEDesc`` for the verb with the OSA designation
   ``code, subcode`` (which are the usual 4-character strings), pack the
   ``parameters`` and ``attributes`` into it, send it to the target application,
   wait for the reply, unpack the reply with ``unpackevent`` and return the reply
   appleevent, the unpacked return values as a dictionary and the return
   attributes.

