#!/usr/bin/python2.5

#

# Copyright 2008 the Melange authors.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#   http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"""Representations and manipulation of arbitrarily nested menus.

"""

__authors__ = [

  '"Todd Larsen" <tlarsen@google.com>',

  ]

from django.utils import datastructures

class Menu:

  """Ordered collection of MenuItem objects.

  MenuItems are retrievable as an ordered list or individually by their

  MenuItem.text key.

  """

  def __init__(self, items=None):

    """Initializes ordered list of MenuItems.

    Args:

      items: list of MenuItem objects in display order

    """

    if not items:

      items = []

    items = [(i.name, i) for i in items]

    self._items = datastructures.SortedDict(data=items)

  def getItem(self, name):

    """Returns a MenuItem retrieved by its MenuItem.text."""

    return self._items.get(name)

  def setItem(self, item):

    """Overwrites an existing MenuItem, or appends a new one."""

    self._items[item.name] = item

  def delItem(self, name):

    """Removes an existing MenuItem."""

    del self._items[name]

  def _getItems(self):

    """Returns an ordered list of the MenuItems."""

    return self._items.values()

  items = property(_getItems, doc=

    """Read-only list of MenuItems, for use in templates.""")

class MenuItem:

  """Provides menu item properties as easily-accessible attributes.

  """

  def __init__(self, name, value=None, selected=False, annotation=None,

                sub_menu=None):

    """Initializes the menu item attributes from supplied arguments.

    Args:

      name: name of the menu item

      value: optional value associated with the menu item;

        default is None

      selected: Boolean indicating if this menu item is selected;

        default is False

      annotation: optional annotation associated with the menu item;

        default is None

      sub_menu: a Menu of sub-items to display below this menu item;

        default is None, indicating no sub-menu

    """

    self.name = name

    self.value = value

    self.selected = selected

    self.annotation = annotation

    self.sub_menu = sub_menu