Thuban/Model/map.py

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

__version__ = "$Revision$"

from messages import LAYERS_CHANGED, MAP_PROJECTION_CHANGED, \
     CHANGED, LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
     LAYER_VISIBILITY_CHANGED

from base import TitledObject, Modifiable

from label import LabelLayer


class Map(TitledObject, Modifiable):

    """Represent a map. A map is simply a list of layers.

    Map objects send the following message types:

        TITLE_CHANGED -- The title has changed. Parameter: the map.

        LAYERS_CHANGED -- Layers were added, removed or rearranged.
                        Parameters: the map

        MAP_PROJECTION_CHANGED -- the map's projection has changed.
                        Parameter: the map
    """

    forwarded_channels = (CHANGED,
                          LAYER_PROJECTION_CHANGED,
                          LAYER_LEGEND_CHANGED,
                          LAYER_VISIBILITY_CHANGED)

    def __init__(self, title, projection = None):
        """Initialize the map."""
        TitledObject.__init__(self, title)
        Modifiable.__init__(self)
        self.layers = []
        self.label_layer = LabelLayer("Labels")
        self.label_layer.Subscribe(CHANGED, self.forward, LAYERS_CHANGED)
        self.projection = projection

    def Destroy(self):
        # call Modifiable.Destroy first since it will call
        # Publisher.Destroy which removes all subscriptions. Otherwise
        # clearing the layers results in messages to be sent which can
        # cause problems.
        Modifiable.Destroy(self)
        self.ClearLayers()
        self.label_layer.Unsubscribe(CHANGED, self.forward, LAYERS_CHANGED)
        self.label_layer.Destroy()

    def AddLayer(self, layer):
        """Append layer to the map on top opf all."""
        self.layers.append(layer)
        self.subscribe_layer_channels(layer)
        self.changed(LAYERS_CHANGED, self)

    def RemoveLayer(self, layer):
        """Remove layer from the map."""
        self.unsubscribe_layer_channels(layer)
        self.layers.remove(layer)
        self.changed(LAYERS_CHANGED, self)
        layer.Destroy()

    def CanRemoveLayer(self, layer):
        """Return true if the layer can be deleted.

        The default implementation always returns 1. Derived classes
        should override this method if they have e.g. special layers
        that the user should not be able to remove.
        """
        return 1

    def ClearLayers(self):
        """Delete all layers."""
        for layer in self.layers:
            self.unsubscribe_layer_channels(layer)
            layer.Destroy()
        del self.layers[:]
        self.label_layer.ClearLabels()
        self.changed(LAYERS_CHANGED, self)

    def subscribe_layer_channels(self, layer):
        """Subscribe to some of layer's channels."""
        for channel in self.forwarded_channels:
            layer.Subscribe(channel, self.forward, channel)

    def unsubscribe_layer_channels(self, layer):
        """Unsubscribe to some of layer's channels."""
        for channel in self.forwarded_channels:
            layer.Unsubscribe(channel, self.forward, channel)

    def LabelLayer(self):
        """Return the Map's label layer"""
        return self.label_layer

    def Layers(self):
        """Return the list of layers contained in the map.

        The list does not include the label layer"""
        return self.layers

    def HasLayers(self):
        """Return true if the map has at least one shape layer"""
        return len(self.layers) > 0

    def RaiseLayer(self, layer):
        """Swap the layer with the one above it.

        If the layer is already at the top do nothing. If the stacking
        order has been changed, issue a LAYERS_CHANGED message.
        """
        index = self.layers.index(layer)
        if index < len(self.layers) - 1:
            del self.layers[index]
            self.layers.insert(index + 1, layer)
            self.changed(LAYERS_CHANGED, self)

    def LowerLayer(self, layer):
        """Swap the layer with the one below it.

        If the layer is already at the bottom do nothing. If the
        stacking order has been changed, issue a LAYERS_CHANGED message.
        """
        index = self.layers.index(layer)
        if index > 0:
            del self.layers[index]
            self.layers.insert(index - 1, layer)
            self.changed(LAYERS_CHANGED, self)

    def BoundingBox(self):
        """Return the bounding box of the map in Lat/Lon coordinates.

        Return None if there are no layers or no layer contains any shapes.
        """
        if not self.layers:
            return None
        llx = []
        lly = []
        urx = []
        ury = []
        for layer in self.layers:
            if layer is self.label_layer:
                continue
            # the layer's bbox may be None if it doesn't have any layers
            bbox = layer.LatLongBoundingBox()
            if bbox is not None:
                left, bottom, right, top = bbox
                llx.append(left)
                lly.append(bottom)
                urx.append(right)
                ury.append(top)

        # check whether there were any empty layers.
        if llx:
            return (min(llx), min(lly), max(urx), max(ury))
        else:
            return None

    def ProjectedBoundingBox(self):
        """Return the bounding box of the map in projected coordinates.

        Return None if there are no layers or no layer contains any shapes.
        """
        # This simply returns the rectangle given by the projected
        # corners of the non-projected bbox.
        bbox = self.BoundingBox()
        if bbox is not None and self.projection is not None:
            bbox = self.projection.ForwardBBox(bbox)
        return bbox

    def SetProjection(self, projection):
        """Set the projection of the map.

        Issue a MAP_PROJECTION_CHANGED message."""
        self.projection = projection
        self.changed(MAP_PROJECTION_CHANGED, 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 map or one of the layers was modified"""
        if self.modified:
            return 1
        else:
            for layer in self.layers:
                if layer.WasModified():
                    return 1
            return self.label_layer.WasModified()

    def UnsetModified(self):
        """Unset the modified flag of the map and the layers"""
        Modifiable.UnsetModified(self)
        for layer in self.layers:
            layer.UnsetModified()
        self.label_layer.UnsetModified()

    def TreeInfo(self):
        items = []
        if self.BoundingBox() != None:
            items.append("Extent (lat-lon): (%g, %g, %g, %g)"
                         % self.BoundingBox())
            if self.projection and len(self.projection.params) > 0:
                items.append("Extent (projected): (%g, %g, %g, %g)"
                             % self.ProjectedBoundingBox())
                items.append(("Projection",
                              [str(param)
                               for param in self.projection.params]))

        layers = self.layers[:]
        layers.reverse()
        items.extend(layers)

        return ("Map: %s" % self.title, items)

1	# Copyright (c) 2001, 2002 by Intevation GmbH
2	# Authors:
3	# Bernhard Herzog <[email protected]>
4	#
5	# This program is free software under the GPL (>=v2)
6	# Read the file COPYING coming with Thuban for details.
7
8	__version__ = "$Revision$"
9
10	from messages import LAYERS_CHANGED, MAP_PROJECTION_CHANGED, \
11	CHANGED, LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
12	LAYER_VISIBILITY_CHANGED
13
14	from base import TitledObject, Modifiable
15
16	from label import LabelLayer
17
18
19
20	class Map(TitledObject, Modifiable):
21
22	"""Represent a map. A map is simply a list of layers.
23
24	Map objects send the following message types:
25
26	TITLE_CHANGED -- The title has changed. Parameter: the map.
27
28	LAYERS_CHANGED -- Layers were added, removed or rearranged.
29	Parameters: the map
30
31	MAP_PROJECTION_CHANGED -- the map's projection has changed.
32	Parameter: the map
33	"""
34
35	forwarded_channels = (CHANGED,
36	LAYER_PROJECTION_CHANGED,
37	LAYER_LEGEND_CHANGED,
38	LAYER_VISIBILITY_CHANGED)
39
40	def __init__(self, title, projection = None):
41	"""Initialize the map."""
42	TitledObject.__init__(self, title)
43	Modifiable.__init__(self)
44	self.layers = []
45	self.label_layer = LabelLayer("Labels")
46	self.label_layer.Subscribe(CHANGED, self.forward, LAYERS_CHANGED)
47	self.projection = projection
48
49	def Destroy(self):
50	# call Modifiable.Destroy first since it will call
51	# Publisher.Destroy which removes all subscriptions. Otherwise
52	# clearing the layers results in messages to be sent which can
53	# cause problems.
54	Modifiable.Destroy(self)
55	self.ClearLayers()
56	self.label_layer.Unsubscribe(CHANGED, self.forward, LAYERS_CHANGED)
57	self.label_layer.Destroy()
58
59	def AddLayer(self, layer):
60	"""Append layer to the map on top opf all."""
61	self.layers.append(layer)
62	self.subscribe_layer_channels(layer)
63	self.changed(LAYERS_CHANGED, self)
64
65	def RemoveLayer(self, layer):
66	"""Remove layer from the map."""
67	self.unsubscribe_layer_channels(layer)
68	self.layers.remove(layer)
69	self.changed(LAYERS_CHANGED, self)
70	layer.Destroy()
71
72	def CanRemoveLayer(self, layer):
73	"""Return true if the layer can be deleted.
74
75	The default implementation always returns 1. Derived classes
76	should override this method if they have e.g. special layers
77	that the user should not be able to remove.
78	"""
79	return 1
80
81	def ClearLayers(self):
82	"""Delete all layers."""
83	for layer in self.layers:
84	self.unsubscribe_layer_channels(layer)
85	layer.Destroy()
86	del self.layers[:]
87	self.label_layer.ClearLabels()
88	self.changed(LAYERS_CHANGED, self)
89
90	def subscribe_layer_channels(self, layer):
91	"""Subscribe to some of layer's channels."""
92	for channel in self.forwarded_channels:
93	layer.Subscribe(channel, self.forward, channel)
94
95	def unsubscribe_layer_channels(self, layer):
96	"""Unsubscribe to some of layer's channels."""
97	for channel in self.forwarded_channels:
98	layer.Unsubscribe(channel, self.forward, channel)
99
100	def LabelLayer(self):
101	"""Return the Map's label layer"""
102	return self.label_layer
103
104	def Layers(self):
105	"""Return the list of layers contained in the map.
106
107	The list does not include the label layer"""
108	return self.layers
109
110	def HasLayers(self):
111	"""Return true if the map has at least one shape layer"""
112	return len(self.layers) > 0
113
114	def RaiseLayer(self, layer):
115	"""Swap the layer with the one above it.
116
117	If the layer is already at the top do nothing. If the stacking
118	order has been changed, issue a LAYERS_CHANGED message.
119	"""
120	index = self.layers.index(layer)
121	if index < len(self.layers) - 1:
122	del self.layers[index]
123	self.layers.insert(index + 1, layer)
124	self.changed(LAYERS_CHANGED, self)
125
126	def LowerLayer(self, layer):
127	"""Swap the layer with the one below it.
128
129	If the layer is already at the bottom do nothing. If the
130	stacking order has been changed, issue a LAYERS_CHANGED message.
131	"""
132	index = self.layers.index(layer)
133	if index > 0:
134	del self.layers[index]
135	self.layers.insert(index - 1, layer)
136	self.changed(LAYERS_CHANGED, self)
137
138	def BoundingBox(self):
139	"""Return the bounding box of the map in Lat/Lon coordinates.
140
141	Return None if there are no layers or no layer contains any shapes.
142	"""
143	if not self.layers:
144	return None
145	llx = []
146	lly = []
147	urx = []
148	ury = []
149	for layer in self.layers:
150	if layer is self.label_layer:
151	continue
152	# the layer's bbox may be None if it doesn't have any layers
153	bbox = layer.LatLongBoundingBox()
154	if bbox is not None:
155	left, bottom, right, top = bbox
156	llx.append(left)
157	lly.append(bottom)
158	urx.append(right)
159	ury.append(top)
160
161	# check whether there were any empty layers.
162	if llx:
163	return (min(llx), min(lly), max(urx), max(ury))
164	else:
165	return None
166
167	def ProjectedBoundingBox(self):
168	"""Return the bounding box of the map in projected coordinates.
169
170	Return None if there are no layers or no layer contains any shapes.
171	"""
172	# This simply returns the rectangle given by the projected
173	# corners of the non-projected bbox.
174	bbox = self.BoundingBox()
175	if bbox is not None and self.projection is not None:
176	bbox = self.projection.ForwardBBox(bbox)
177	return bbox
178
179	def SetProjection(self, projection):
180	"""Set the projection of the map.
181
182	Issue a MAP_PROJECTION_CHANGED message."""
183	self.projection = projection
184	self.changed(MAP_PROJECTION_CHANGED, self)
185
186	def forward(self, *args):
187	"""Reissue events"""
188	if len(args) > 1:
189	args = (args[-1],) + args[:-1]
190	apply(self.issue, args)
191
192	def WasModified(self):
193	"""Return true if the map or one of the layers was modified"""
194	if self.modified:
195	return 1
196	else:
197	for layer in self.layers:
198	if layer.WasModified():
199	return 1
200	return self.label_layer.WasModified()
201
202	def UnsetModified(self):
203	"""Unset the modified flag of the map and the layers"""
204	Modifiable.UnsetModified(self)
205	for layer in self.layers:
206	layer.UnsetModified()
207	self.label_layer.UnsetModified()
208
209	def TreeInfo(self):
210	items = []
211	if self.BoundingBox() != None:
212	items.append("Extent (lat-lon): (%g, %g, %g, %g)"
213	% self.BoundingBox())
214	if self.projection and len(self.projection.params) > 0:
215	items.append("Extent (projected): (%g, %g, %g, %g)"
216	% self.ProjectedBoundingBox())
217	items.append(("Projection",
218	[str(param)
219	for param in self.projection.params]))
220
221	layers = self.layers[:]
222	layers.reverse()
223	items.extend(layers)
224
225	return ("Map: %s" % self.title, items)
226
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