.. _qtservice:

=========
QtService
=========

.. currentmodule:: PyroMP

QtServices provide an event loop for Qt and Pyro4.
PySide and PyQt4 is supported, but the former is prefered.

.. warning::
    Due to problems of Qt with threads it is not possible to use :func:`~QtService.init_resources` to initialize Qt objects.
    The user interface has to be initialized in the :func:`~QtService.qt_main` function,
    which is called in the main thread after :func:`~QtService.init_resources` has finished.
  
.. warning::
    You have to connect to :class:`events <PyroMP.Event>` or other PyroMP stuff in
    the :func:`~QtService.init_resources` function or your program
    will deadlock

.. note::
    QtService makes it possible to use PySide and PyQt4 in parallel (see :ref:`pyside_pyqt_example`).


Calling convention
------------------

Qt objects are not thread-safe.
If a threaded server is used, normal function calls won't work (see :ref:`qtservice_example`).
Calling functions on QObject needs to use the Qt Signal/Slot mechanism.


Example
-------


.. code-block:: python

    import PyroMP
    from PyroMP.Qt import QtGui, QtCore

    class MyDialog(QtGui.QDialog):
    
        call_func = QtCore.Signal(object)

        def __init__(self):
            super(MyDialog, self).__init__()
            self.call_func.connect(self.my_function)

        def my_function(self, arg):
            # do some stuff here


    class MyService(PyroMP.QtService):

        def qt_main(self):
            self.dlg = MyDialog()
            self.dlg.show()

        def my_function(self, arg):
            self.dlg.call_func.emit(arg)


API Reference
-------------

.. autoclass:: QtService

    **Methods**
    
    .. automethod:: get_logger
    
    .. automethod:: init_resources
    
    .. automethod:: close_resources

    .. automethod:: qt_main

    **Class Methods**
    
    .. automethod:: get_connection
    
    .. automethod:: get_pyro_name

    .. automethod:: is_running
    
    .. automethod:: start
    
    .. automethod:: stop

    .. automethod:: wait_for