# Copyright (c) 2005-2018, Enthought, Inc.
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in enthought/LICENSE.txt and may be redistributed only
# under the conditions described in the aforementioned license.  The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
# Thanks for using Enthought open source!
#
# Author: Enthought, Inc.
# Description: <Enthought pyface package component>
""" Abstract base class for all application actions. """

import platform

# Enthought library imports.
from traits.api import Instance, Property, cached_property

# Local imports.
from pyface.action.listening_action import ListeningAction

IS_WINDOWS = platform.system() == 'Windows'


class GUIApplicationAction(ListeningAction):
    """ Abstract base class for GUI Application actions. """

    # 'ListeningAction' interface --------------------------------------------

    object = Property(depends_on='application')

    # 'WindowAction' interface -----------------------------------------------

    #: The application that the action is associated with.
    application = Instance('pyface.gui_application.GUIApplication')

    # ------------------------------------------------------------------------
    # Protected interface.
    # ------------------------------------------------------------------------

    def _get_object(self):
        return self.application

    def destroy(self):
        # Disconnect listeners to application and dependent properties.
        self.application = None
        super(GUIApplicationAction, self).destroy()


class ActiveWindowAction(GUIApplicationAction):
    """ Abstract base class for application active window actions. """

    # 'ListeningAction' interface --------------------------------------------

    object = Property(depends_on='application.active_window')

    # ------------------------------------------------------------------------
    # Protected interface.
    # ------------------------------------------------------------------------

    @cached_property
    def _get_object(self):
        if self.application is not None:
            return self.application.active_window


class CreateWindowAction(GUIApplicationAction):
    """ A standard 'New Window' menu action. """
    name = u'New Window'
    accelerator = 'Ctrl+N'

    def perform(self, event=None):
        window = self.application.create_window()
        self.application.add_window(window)


class ExitAction(GUIApplicationAction):
    """ A standard 'Quit' or 'Exit' menu action. """
    accelerator = 'Alt+F4' if IS_WINDOWS else 'Ctrl+Q'
    method = 'exit'

    def _name_default(self):
        return (u'Exit ' if IS_WINDOWS else u'Quit ') + self.application.name


class AboutAction(GUIApplicationAction):
    """ A standard 'About' dialog menu action. """
    method = 'do_about'

    def _name_default(self):
        return u"About " + self.application.name


class CloseActiveWindowAction(ActiveWindowAction):
    """ A standard 'Close window' menu action at the application level.

    This method closes the active window of the application.
    """
    name = u'Close Window'
    accelerator = 'Ctrl+W'
    method = 'close'