Source code for vdat.libvdat.callback

"""Enqueue commands coming from users pushing buttons on the gui"""

from __future__ import (absolute_import, division, print_function,
                        unicode_literals)

from logging import getLogger

from PyQt4.QtCore import QObject

import vdat.libvdat


# TODO: move it to vdat/gui
class Worker(QObject):
    """Generic worker that runs the given function"""
    def __init__(self, parent=None):
        super(Worker, self).__init__(parent)

    def run(func):
        """Run the given function: it doesn't have any argument"""
        func()


class Callback(object):
    """Class to deal with the user pushing buttons in the GUI. Causes the
    buttons to add commands to a queue, specified by the set_queue command.

    Attributes
    ----------
    queue : :class:`vdat.gui.queue.Queue` object
        the queue the callback interacts with
    """
    queue = None

    @classmethod
    def set_queue(cls, queue):
        """Set the queue that the callbacks post jobs too.

        Parameters
        ----------
        queue : vdat.gui.queue Queue object
            the queue the callback interacts with
        """
        cls.queue = queue

    @staticmethod
    def make_callback_function(name, alias):
        """Factory function, used to generate functions
        to attach to objects.

        Parameters
        ----------
        name : String
            name of function to run on button click. Has to  be in libvdat.
            Syntax is::

                package_name:function_name
        alias : String
            a label for the job on the queue GUI.
        immediate : bool (optional)
            bypass the usual queue and run immediately
        """
        log = getLogger('logger')

        def _notImplemented():
            """Deal with a button click from the GUI
            """
            log.error("<b> %s </b> not yet implemented!", name)

        try:
            split_name = name.split(':')
            log.debug(split_name)
            package = getattr(vdat.libvdat, split_name[0])

            cmd = getattr(package, split_name[1])

            def func():
                Callback.queue.queue_command(cmd, alias)
        except AttributeError:
            func = _notImplemented

        return func