# Copyright (C) 2006, Red Hat, Inc.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.

import gobject
import gtk

class MenuShell(gobject.GObject):
    __gsignals__ = {
        'activated':   (gobject.SIGNAL_RUN_FIRST,
                        gobject.TYPE_NONE, ([])),
        'deactivated': (gobject.SIGNAL_RUN_FIRST,
                        gobject.TYPE_NONE, ([])),
    }

    AUTO = 0
    LEFT = 1
    RIGHT = 2
    TOP = 3
    BOTTOM = 4

    def __init__(self, parent_canvas):
        gobject.GObject.__init__(self)

        self._parent_canvas = parent_canvas
        self._menu_controller = None
        self._position = MenuShell.AUTO

    def set_position(self, position):
        self._position = position

    def is_active(self):
        return (self._menu_controller != None)

    def set_active(self, controller):
        if controller == None:
            self.emit('deactivated')
        else:
            self.emit('activated')

        if self._menu_controller:
            self._menu_controller.popdown()
        self._menu_controller = controller

    def _get_item_rect(self, item):
        [x, y] = item.get_context().translate_to_widget(item)

        [origin_x, origin_y] = self._parent_canvas.window.get_origin()
        x += origin_x
        y += origin_y

        [w, h] = item.get_allocation()

        return [x, y, w, h]

    def get_position(self, menu, item):
        [item_x, item_y, item_w, item_h] = self._get_item_rect(item)
        [menu_w, menu_h] = menu.size_request()

        left_x = item_x - menu_w
        left_y = item_y
        right_x = item_x + item_w
        right_y = item_y
        top_x = item_x
        top_y = item_y - menu_h
        bottom_x = item_x
        bottom_y = item_y + item_h

        if self._position == MenuShell.LEFT:
            [x, y] = [left_x, left_y]
        elif self._position == MenuShell.RIGHT:
            [x, y] = [right_x, right_y]
        elif self._position == MenuShell.TOP:
            [x, y] = [top_x, top_y]
        elif self._position == MenuShell.BOTTOM:
            [x, y] = [bottom_x, bottom_y]
        elif self._position == MenuShell.AUTO:
            [x, y] = [right_x, right_y]
            if x + menu_w > gtk.gdk.screen_width():
                [x, y] = [left_x, left_y]

        x = min(x, gtk.gdk.screen_width() - menu_w)
        x = max(0, x)

        y = min(y, gtk.gdk.screen_height() - menu_h)
        y = max(0, y)

        return [x, y]