Thuban/Model/session.py

# Copyright (c) 2001, 2002 by Intevation GmbH
# Authors:
# Bernhard Herzog <[email protected]>
# Jan-Oliver Wagner <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

__version__ = "$Revision$"

from Thuban.Lib.connector import Publisher

from messages import MAPS_CHANGED, EXTENSIONS_CHANGED, FILENAME_CHANGED, \
     LAYERS_CHANGED, MAP_PROJECTION_CHANGED, \
     LAYER_LEGEND_CHANGED, LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
     EXTENSION_CHANGED, EXTENSION_OBJECTS_CHANGED

from base import TitledObject, Modifiable

from map import Map


class Session(TitledObject, Modifiable):

    """A complete session.

    A Session consists of arbitrary numbers of maps, tables and extensions

    Session objects send the following events:

        TITLE_CHANGED -- The title has changed. Parameters: the session.

        FILENAME_CHANGED -- The filename has changed. No parameters.

        MAPS_CHANGED -- Maps were added, removed.

        EXTENSIONS_CHANGED -- Extensions were added, removed.

        LAYERS_CHANGED -- Same as the map's event of the same name.
                          It's simply resent from the session to make
                          subscriptions easier.
    """

    # message channels that have to be forwarded from maps contained in
    # the session.
    forwarded_channels = (
        # map specific channels
        MAP_PROJECTION_CHANGED,
        LAYERS_CHANGED,

        # layer channels forwarded by the map
        LAYER_PROJECTION_CHANGED,
        LAYER_LEGEND_CHANGED,
        LAYER_VISIBILITY_CHANGED,

        # channels forwarded by an extension
        EXTENSION_CHANGED,
        EXTENSION_OBJECTS_CHANGED)

    def __init__(self, title):
        TitledObject.__init__(self, title)
        Modifiable.__init__(self)
        self.filename = None
        self.maps = []
        self.tables = []
        self.extensions = []

    def SetFilename(self, filename):
        self.filename = filename
        self.changed(FILENAME_CHANGED)

    def Maps(self):
        return self.maps

    def HasMaps(self):
        return len(self.maps) > 0

    def AddMap(self, map):
        self.maps.append(map)
        for channel in self.forwarded_channels:
            map.Subscribe(channel, self.forward, channel)
        self.changed(MAPS_CHANGED)

    def Extensions(self):
        return self.extensions

    def HasExtensions(self):
        return len(self.extensions) > 0

    def AddExtension(self, extension):
        self.extensions.append(extension)
        for channel in self.forwarded_channels:
            extension.Subscribe(channel, self.forward, channel)
        self.changed(EXTENSIONS_CHANGED)

    def Destroy(self):
        for map in self.maps:
            map.Destroy()
        self.maps = []
        self.tables = []
        Publisher.Destroy(self)

    def forward(self, *args):
        """Reissue events"""
        if len(args) > 1:
            args = (args[-1],) + args[:-1]
        apply(self.issue, args)

    def WasModified(self):
        """Return true if the session or one of the maps was modified"""
        if self.modified:
            return 1
        else:
            for map in self.maps:
                if map.WasModified():
                    return 1
        return 0

    def UnsetModified(self):
        """Unset the modified flag of the session and the maps"""
        Modifiable.UnsetModified(self)
        for map in self.maps:
            map.UnsetModified()


def create_empty_session():
    """Return an empty session useful as a starting point"""
    import os
    session = Session('unnamed session')
    session.SetFilename(None)
    session.AddMap(Map('unnamed map'))
    session.UnsetModified()
    return session
1	# Copyright (c) 2001, 2002 by Intevation GmbH
2	# Authors:
3	# Bernhard Herzog <[email protected]>
4	# Jan-Oliver Wagner <[email protected]>
5	#
6	# This program is free software under the GPL (>=v2)
7	# Read the file COPYING coming with Thuban for details.
8
9	__version__ = "$Revision$"
10
11	from Thuban.Lib.connector import Publisher
12
13	from messages import MAPS_CHANGED, EXTENSIONS_CHANGED, FILENAME_CHANGED, \
14	LAYERS_CHANGED, MAP_PROJECTION_CHANGED, \
15	LAYER_LEGEND_CHANGED, LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
16	EXTENSION_CHANGED, EXTENSION_OBJECTS_CHANGED
17
18	from base import TitledObject, Modifiable
19
20	from map import Map
21
22
23	class Session(TitledObject, Modifiable):
24
25	"""A complete session.
26
27	A Session consists of arbitrary numbers of maps, tables and extensions
28
29	Session objects send the following events:
30
31	TITLE_CHANGED -- The title has changed. Parameters: the session.
32
33	FILENAME_CHANGED -- The filename has changed. No parameters.
34
35	MAPS_CHANGED -- Maps were added, removed.
36
37	EXTENSIONS_CHANGED -- Extensions were added, removed.
38
39	LAYERS_CHANGED -- Same as the map's event of the same name.
40	It's simply resent from the session to make
41	subscriptions easier.
42	"""
43
44	# message channels that have to be forwarded from maps contained in
45	# the session.
46	forwarded_channels = (
47	# map specific channels
48	MAP_PROJECTION_CHANGED,
49	LAYERS_CHANGED,
50
51	# layer channels forwarded by the map
52	LAYER_PROJECTION_CHANGED,
53	LAYER_LEGEND_CHANGED,
54	LAYER_VISIBILITY_CHANGED,
55
56	# channels forwarded by an extension
57	EXTENSION_CHANGED,
58	EXTENSION_OBJECTS_CHANGED)
59
60	def __init__(self, title):
61	TitledObject.__init__(self, title)
62	Modifiable.__init__(self)
63	self.filename = None
64	self.maps = []
65	self.tables = []
66	self.extensions = []
67
68	def SetFilename(self, filename):
69	self.filename = filename
70	self.changed(FILENAME_CHANGED)
71
72	def Maps(self):
73	return self.maps
74
75	def HasMaps(self):
76	return len(self.maps) > 0
77
78	def AddMap(self, map):
79	self.maps.append(map)
80	for channel in self.forwarded_channels:
81	map.Subscribe(channel, self.forward, channel)
82	self.changed(MAPS_CHANGED)
83
84	def Extensions(self):
85	return self.extensions
86
87	def HasExtensions(self):
88	return len(self.extensions) > 0
89
90	def AddExtension(self, extension):
91	self.extensions.append(extension)
92	for channel in self.forwarded_channels:
93	extension.Subscribe(channel, self.forward, channel)
94	self.changed(EXTENSIONS_CHANGED)
95
96	def Destroy(self):
97	for map in self.maps:
98	map.Destroy()
99	self.maps = []
100	self.tables = []
101	Publisher.Destroy(self)
102
103	def forward(self, *args):
104	"""Reissue events"""
105	if len(args) > 1:
106	args = (args[-1],) + args[:-1]
107	apply(self.issue, args)
108
109	def WasModified(self):
110	"""Return true if the session or one of the maps was modified"""
111	if self.modified:
112	return 1
113	else:
114	for map in self.maps:
115	if map.WasModified():
116	return 1
117	return 0
118
119	def UnsetModified(self):
120	"""Unset the modified flag of the session and the maps"""
121	Modifiable.UnsetModified(self)
122	for map in self.maps:
123	map.UnsetModified()
124
125
126
127	def create_empty_session():
128	"""Return an empty session useful as a starting point"""
129	import os
130	session = Session('unnamed session')
131	session.SetFilename(None)
132	session.AddMap(Map('unnamed map'))
133	session.UnsetModified()
134	return session
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision