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 MAP_LAYERS_CHANGED, MAP_PROJECTION_CHANGED, \
     CHANGED, LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
     LAYER_VISIBILITY_CHANGED, LAYER_CHANGED, MAP_STACKING_CHANGED, \
     MAP_LAYERS_ADDED, MAP_LAYERS_REMOVED

from Thuban import _

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.

        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_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, MAP_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, MAP_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(MAP_LAYERS_CHANGED, self)
        self.changed(MAP_LAYERS_ADDED, self)

    def RemoveLayer(self, layer):
        """Remove layer from the map."""
        self.unsubscribe_layer_channels(layer)
        self.layers.remove(layer)
        self.changed(MAP_LAYERS_CHANGED, self)
        self.changed(MAP_LAYERS_REMOVED, 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(MAP_LAYERS_CHANGED, self)
        self.changed(MAP_LAYERS_REMOVED, 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 MAP_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(MAP_LAYERS_CHANGED, self)
            self.changed(MAP_STACKING_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 MAP_LAYERS_CHANGED message.
        """
        index = self.layers.index(layer)
        if index > 0:
            del self.layers[index]
            self.layers.insert(index - 1, layer)
            self.changed(MAP_LAYERS_CHANGED, self)
            self.changed(MAP_STACKING_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 GetProjection(self):
        return self.projection

    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 MAP_LAYERS_CHANGED, MAP_PROJECTION_CHANGED, \
11	CHANGED, LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
12	LAYER_VISIBILITY_CHANGED, LAYER_CHANGED, MAP_STACKING_CHANGED, \
13	MAP_LAYERS_ADDED, MAP_LAYERS_REMOVED
14
15	from Thuban import _
16
17	from base import TitledObject, Modifiable
18
19	from label import LabelLayer
20
21
22	class Map(TitledObject, Modifiable):
23
24	"""Represent a map. A map is simply a list of layers.
25
26	Map objects send the following message types:
27
28	TITLE_CHANGED -- The title has changed. Parameter: the map.
29
30	MAP_LAYERS_CHANGED -- Layers were added, removed or rearranged.
31	Parameters: the map
32
33	MAP_PROJECTION_CHANGED -- the map's projection has changed.
34	Parameter: the map
35	"""
36
37	forwarded_channels = (CHANGED,
38	LAYER_PROJECTION_CHANGED,
39	LAYER_LEGEND_CHANGED,
40	LAYER_CHANGED,
41	LAYER_VISIBILITY_CHANGED)
42
43	def __init__(self, title, projection = None):
44	"""Initialize the map."""
45	TitledObject.__init__(self, title)
46	Modifiable.__init__(self)
47	self.layers = []
48	self.label_layer = LabelLayer(_("Labels"))
49	self.label_layer.Subscribe(CHANGED, self.forward, MAP_LAYERS_CHANGED)
50	self.projection = projection
51
52	def Destroy(self):
53	# call Modifiable.Destroy first since it will call
54	# Publisher.Destroy which removes all subscriptions. Otherwise
55	# clearing the layers results in messages to be sent which can
56	# cause problems.
57	Modifiable.Destroy(self)
58	self.ClearLayers()
59	self.label_layer.Unsubscribe(CHANGED, self.forward, MAP_LAYERS_CHANGED)
60	self.label_layer.Destroy()
61
62	def AddLayer(self, layer):
63	"""Append layer to the map on top opf all."""
64	self.layers.append(layer)
65	self.subscribe_layer_channels(layer)
66	self.changed(MAP_LAYERS_CHANGED, self)
67	self.changed(MAP_LAYERS_ADDED, self)
68
69	def RemoveLayer(self, layer):
70	"""Remove layer from the map."""
71	self.unsubscribe_layer_channels(layer)
72	self.layers.remove(layer)
73	self.changed(MAP_LAYERS_CHANGED, self)
74	self.changed(MAP_LAYERS_REMOVED, self)
75	layer.Destroy()
76
77	def CanRemoveLayer(self, layer):
78	"""Return true if the layer can be deleted.
79
80	The default implementation always returns 1. Derived classes
81	should override this method if they have e.g. special layers
82	that the user should not be able to remove.
83	"""
84	return 1
85
86	def ClearLayers(self):
87	"""Delete all layers."""
88	for layer in self.layers:
89	self.unsubscribe_layer_channels(layer)
90	layer.Destroy()
91	del self.layers[:]
92	self.label_layer.ClearLabels()
93	self.changed(MAP_LAYERS_CHANGED, self)
94	self.changed(MAP_LAYERS_REMOVED, self)
95
96	def subscribe_layer_channels(self, layer):
97	"""Subscribe to some of layer's channels."""
98	for channel in self.forwarded_channels:
99	layer.Subscribe(channel, self.forward, channel)
100
101	def unsubscribe_layer_channels(self, layer):
102	"""Unsubscribe to some of layer's channels."""
103	for channel in self.forwarded_channels:
104	layer.Unsubscribe(channel, self.forward, channel)
105
106	def LabelLayer(self):
107	"""Return the Map's label layer"""
108	return self.label_layer
109
110	def Layers(self):
111	"""Return the list of layers contained in the map.
112
113	The list does not include the label layer"""
114	return self.layers
115
116	def HasLayers(self):
117	"""Return true if the map has at least one shape layer"""
118	return len(self.layers) > 0
119
120	def RaiseLayer(self, layer):
121	"""Swap the layer with the one above it.
122
123	If the layer is already at the top do nothing. If the stacking
124	order has been changed, issue a MAP_LAYERS_CHANGED message.
125	"""
126	index = self.layers.index(layer)
127	if index < len(self.layers) - 1:
128	del self.layers[index]
129	self.layers.insert(index + 1, layer)
130	self.changed(MAP_LAYERS_CHANGED, self)
131	self.changed(MAP_STACKING_CHANGED, self)
132
133	def LowerLayer(self, layer):
134	"""Swap the layer with the one below it.
135
136	If the layer is already at the bottom do nothing. If the
137	stacking order has been changed, issue a MAP_LAYERS_CHANGED message.
138	"""
139	index = self.layers.index(layer)
140	if index > 0:
141	del self.layers[index]
142	self.layers.insert(index - 1, layer)
143	self.changed(MAP_LAYERS_CHANGED, self)
144	self.changed(MAP_STACKING_CHANGED, self)
145
146	def BoundingBox(self):
147	"""Return the bounding box of the map in Lat/Lon coordinates.
148
149	Return None if there are no layers or no layer contains any shapes.
150	"""
151	if not self.layers:
152	return None
153	llx = []
154	lly = []
155	urx = []
156	ury = []
157	for layer in self.layers:
158	if layer is self.label_layer:
159	continue
160	# the layer's bbox may be None if it doesn't have any layers
161	bbox = layer.LatLongBoundingBox()
162	if bbox is not None:
163	left, bottom, right, top = bbox
164	llx.append(left)
165	lly.append(bottom)
166	urx.append(right)
167	ury.append(top)
168
169	# check whether there were any empty layers.
170	if llx:
171	return (min(llx), min(lly), max(urx), max(ury))
172	else:
173	return None
174
175	def ProjectedBoundingBox(self):
176	"""Return the bounding box of the map in projected coordinates.
177
178	Return None if there are no layers or no layer contains any shapes.
179	"""
180	# This simply returns the rectangle given by the projected
181	# corners of the non-projected bbox.
182	bbox = self.BoundingBox()
183	if bbox is not None and self.projection is not None:
184	bbox = self.projection.ForwardBBox(bbox)
185	return bbox
186
187	def GetProjection(self):
188	return self.projection
189
190	def SetProjection(self, projection):
191	"""Set the projection of the map.
192
193	Issue a MAP_PROJECTION_CHANGED message."""
194	self.projection = projection
195	self.changed(MAP_PROJECTION_CHANGED, self)
196
197	def forward(self, *args):
198	"""Reissue events"""
199	if len(args) > 1:
200	args = (args[-1],) + args[:-1]
201	apply(self.issue, args)
202
203	def WasModified(self):
204	"""Return true if the map or one of the layers was modified"""
205	if self.modified:
206	return 1
207	else:
208	for layer in self.layers:
209	if layer.WasModified():
210	return 1
211	return self.label_layer.WasModified()
212
213	def UnsetModified(self):
214	"""Unset the modified flag of the map and the layers"""
215	Modifiable.UnsetModified(self)
216	for layer in self.layers:
217	layer.UnsetModified()
218	self.label_layer.UnsetModified()
219
220	def TreeInfo(self):
221	items = []
222	if self.BoundingBox() != None:
223	items.append(_("Extent (lat-lon): (%g, %g, %g, %g)")
224	% self.BoundingBox())
225	if self.projection and len(self.projection.params) > 0:
226	items.append(_("Extent (projected): (%g, %g, %g, %g)")
227	% self.ProjectedBoundingBox())
228	items.append((_("Projection"),
229	[str(param)
230	for param in self.projection.params]))
231
232	layers = self.layers[:]
233	layers.reverse()
234	items.extend(layers)
235
236	return (_("Map: %s") % self.title, items)
237
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