Thuban/Model/layer.py

# Copyright (c) 2001, 2002, 2003 by Intevation GmbH
# Authors:
# Bernhard Herzog <[email protected]>
# Jonathan Coles <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

__version__ = "$Revision$"

from math import log, ceil
import warnings

from Thuban import _
import shapelib, shptree

from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
     LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED

import classification

from color import Transparent, Black
from base import TitledObject, Modifiable

import resource


class Shape:

    """Represent one shape"""

    def __init__(self, points):
        self.points = points
        #self.compute_bbox()
        self.bbox = None

    def compute_bbox(self):
        if self.bbox is not None:
            return self.bbox

        xs = []
        ys = []
        for x, y in self.points:
            xs.append(x)
            ys.append(y)
        self.llx = min(xs)
        self.lly = min(ys)
        self.urx = max(xs)
        self.ury = max(ys)

        self.bbox = (self.llx, self.lly, self.urx, self.ury)

        return self.bbox

    def Points(self):
        return self.points


# Shape type constants
SHAPETYPE_POLYGON = "polygon"
SHAPETYPE_ARC = "arc"
SHAPETYPE_POINT = "point"

# mapping from shapelib shapetype constants to our constants
shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
                       shapelib.SHPT_ARC: SHAPETYPE_ARC,
                       shapelib.SHPT_POINT: SHAPETYPE_POINT}

shapetype_names = {SHAPETYPE_POINT: "Point",
                   SHAPETYPE_ARC: "Arc",
                   SHAPETYPE_POLYGON: "Polygon"}

class BaseLayer(TitledObject, Modifiable):

    """Base class for the layers."""

    def __init__(self, title, visible = True, projection = None):
        """Initialize the layer.

        title -- the title
        visible -- boolean. If true the layer is visible.
        """
        TitledObject.__init__(self, title)
        Modifiable.__init__(self)
        self.visible = visible
        self.projection = projection

    def Visible(self):
        """Return true if layer is visible"""
        return self.visible

    def SetVisible(self, visible):
        """Set the layer's visibility."""
        self.visible = visible
        self.issue(LAYER_VISIBILITY_CHANGED, self)

    def HasClassification(self):
        """Determine if this layer support classifications."""
        return False

    def HasShapes(self):
        """Determine if this layer supports shapes."""
        return False

    def GetProjection(self):
        """Return the layer's projection."""
        return self.projection

    def SetProjection(self, projection):
        """Set the layer's projection"""
        self.projection = projection
        self.changed(LAYER_PROJECTION_CHANGED, self)

class Layer(BaseLayer):

    """Represent the information of one geodata file (currently a shapefile)

    All children of the layer have the same type.

    A layer has fill and stroke colors. Colors should be instances of
    Color. They can also be Transparent, indicating no fill or no stroke.

    The layer objects send the following events, all of which have the
    layer object as parameter:

        TITLE_CHANGED -- The title has changed.
        LAYER_PROJECTION_CHANGED -- the projection has changed.
    """

    def __init__(self, title, data, projection = None,
                 fill = Transparent, 
                 stroke = Black, 
                 lineWidth = 1, 
                 visible = True):
        """Initialize the layer.

        title -- the title
        data -- datastore object for the shape data shown by the layer
        projection -- the projection object. Its Inverse method is
               assumed to map the layer's coordinates to lat/long
               coordinates
        fill -- the fill color or Transparent if the shapes are 
                not filled
        stroke -- the stroke color or Transparent if the shapes 
                are not stroked
        visible -- boolean. If true the layer is visible.

        colors are expected to be instances of Color class
        """
        BaseLayer.__init__(self, title, 
                                 visible = visible,
                                 projection = projection)

        #
        # this is really important so that when the classification class
        # tries to set its parent layer the variable will exist
        #
        self.__classification = None

        self.SetShapeStore(data)

        self.SetClassification(None)

        self.__classification.SetDefaultLineColor(stroke)
        self.__classification.SetDefaultLineWidth(lineWidth)
        self.__classification.SetDefaultFill(fill)

        self.UnsetModified()

    def __getattr__(self, attr):
        """Access to some attributes for backwards compatibility

        The attributes implemented here are now held by the shapestore
        if at all. For backwards compatibility pretend that they are
        still there but issue a DeprecationWarning when they are
        accessed.
        """
        if attr in ("table", "shapetable"):
            value = self.store.Table()
        elif attr == "shapefile":
            value = self.store.Shapefile()
        elif attr == "filename":
            value = self.store.FileName()
        else:
            raise AttributeError, attr
        warnings.warn("The Layer attribute %r is deprecated."
                      " It's value can be accessed through the shapestore"
                      % attr, DeprecationWarning, stacklevel = 2)
        return value

    def SetShapeStore(self, store):
        self.store = store
        shapefile = self.store.Shapefile()

        numshapes, shapetype, mins, maxs = shapefile.info()
        self.numshapes = numshapes
        self.shapetype = shapelib_shapetypes[shapetype]

        # if there are shapes, set the bbox accordingly. Otherwise
        # set it to None.
        if self.numshapes:
            self.bbox = mins[:2] + maxs[:2]
        else:
            self.bbox = None

        # estimate a good depth for the quad tree. Each depth
        # multiplies the number of nodes by four, therefore we
        # basically take the base 4 logarithm of the number of
        # shapes.
        if self.numshapes < 4:
            maxdepth = 1
        else:
            maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))

        self.shapetree = shptree.SHPTree(shapefile.cobject(), 2,
                                         maxdepth)
        # Set the classification to None if there is a classification
        # and the new shapestore doesn't have a table with a suitable
        # column, i.e one with the same name and type as before
        # FIXME: Maybe we should keep it the same if the type is
        # compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
        if self.__classification is not None:
            fieldname = self.__classification.GetField()
            fieldtype = self.__classification.GetFieldType()
            table = self.store.Table()
            if (fieldname is not None
                and (not table.HasColumn(fieldname)
                     or table.Column(fieldname).type != fieldtype)):
                self.SetClassification(None)
        self.changed(LAYER_SHAPESTORE_REPLACED, self)

    def ShapeStore(self):
        return self.store

    def Destroy(self):
        BaseLayer.Destroy(self)
        self.GetClassification()._set_layer(None)

    def BoundingBox(self):
        """Return the layer's bounding box in the intrinsic coordinate system.

        If the layer has no shapes, return None.
        """
        return self.bbox

    def LatLongBoundingBox(self):
        """Return the layer's bounding box in lat/long coordinates.

        Return None, if the layer doesn't contain any shapes.
        """
        bbox = self.BoundingBox()
        if bbox is not None:
            llx, lly, urx, ury = bbox
            if self.projection is not None:
                llx, lly = self.projection.Inverse(llx, lly)
                urx, ury = self.projection.Inverse(urx, ury)
            return llx, lly, urx, ury
        else:
            return None

    def ShapesBoundingBox(self, shapes):
        """Return a bounding box in lat/long coordinates for the given
        list of shape ids.

        If shapes is None or empty, return None.
        """

        if shapes is None or len(shapes) == 0: return None

        llx = []
        lly = []
        urx = []
        ury = []

        if self.projection is not None:
            inverse = lambda x, y: self.projection.Inverse(x, y)
        else:
            inverse = lambda x, y: (x, y)

        for id in shapes:
            left, bottom, right, top = self.Shape(id).compute_bbox()

            left, bottom = inverse(left, bottom)
            right, top   = inverse(right, top)

            llx.append(left)
            lly.append(bottom)
            urx.append(right)
            ury.append(top)

        return (min(llx), min(lly), max(urx), max(ury))

    def GetFieldType(self, fieldName):
        table = self.store.Table()
        if table.HasColumn(fieldName):
            return table.Column(fieldName).type
        return None

    def HasShapes(self):
        return True

    def NumShapes(self):
        """Return the number of shapes in the layer"""
        return self.numshapes

    def ShapeType(self):
        """Return the type of the shapes in the layer.
        This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
        """
        return self.shapetype

    def Shape(self, index):
        """Return the shape with index index"""
        shape = self.store.Shapefile().read_object(index)

        if self.shapetype == SHAPETYPE_POINT:
            points = shape.vertices()
        else:
            #for poly in shape.vertices():
            poly = shape.vertices()[0]
            points = []
            for x, y in poly:
                points.append((x, y))

        return Shape(points)

    def ShapesInRegion(self, box):
        """Return the ids of the shapes that overlap the box.

        Box is a tuple (left, bottom, right, top) in unprojected coordinates.
        """
        left, bottom, right, top = box

        if self.projection is not None:
            left,  bottom = self.projection.Forward(left, bottom)
            right, top    = self.projection.Forward(right, top)

        return self.shapetree.find_shapes((left, bottom), (right, top))

    def HasClassification(self):
        return True

    def GetClassification(self):
        return self.__classification

    def SetClassification(self, clazz):
        """Set the classification used by this layer to 'clazz'

        If 'clazz' is None a default classification is created.

        ValueError is raised if the classification's field name
        and type are different (if they aren't None) than what
        is in the shapestore. The Layer will not be changed in
        this case.
        """

        old_class = self.__classification

        if clazz is None:
            clazz = classification.Classification()

        try:
            self.__classification = clazz
            clazz._set_layer(self)

            # only change things after a successful call
            if old_class is not None:
                old_class._set_layer(None)
        except ValueError:
            self.__classification = old_class
            raise ValueError

        # we don't need this since a message will be sent 
        # after calling _set_layer()
        #self.changed(LAYER_CHANGED, self)

    def ClassChanged(self):
        """Called from the classification object when it has changed."""
        self.changed(LAYER_CHANGED, self)
 
    def TreeInfo(self):
        items = []

        items.append(_("Filename: %s") % self.ShapeStore().FileName())

        if self.Visible():
            items.append(_("Shown"))
        else:
            items.append(_("Hidden"))
        items.append(_("Shapes: %d") % self.NumShapes())

        bbox = self.LatLongBoundingBox()
        if bbox is not None:
            items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
        else:
            items.append(_("Extent (lat-lon):"))
        items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])

        if self.projection and len(self.projection.params) > 0:
            items.append((_("Projection"),
                        [str(param) for param in self.projection.params]))

        items.append(self.__classification)

        return (_("Layer '%s'") % self.Title(), items)


if resource.has_gdal_support():
    import gdal
    from gdalconst import GA_ReadOnly

class RasterLayer(BaseLayer):

    def __init__(self, title, filename, projection = None, visible = True):
        """Initialize the Raster Layer.

        title -- title for the layer.

        filename -- file name of the source image.

        projection -- Projection object describing the projection which
                      the source image is in.

        visible -- True is the layer should initially be visible.

        Throws IOError if the filename is invalid or points to a file that
        is not in a format GDAL can use.
        """

        BaseLayer.__init__(self, title, visible = visible)

        self.projection = projection
        self.filename = filename

        self.bbox = -1

        if resource.has_gdal_support():
            #
            # temporarily open the file so that GDAL can test if it's valid.
            #
            dataset = gdal.Open(self.filename, GA_ReadOnly)

            if dataset is None:
                raise IOError()

        self.UnsetModified()

    def BoundingBox(self):
        """Return the layer's bounding box in the intrinsic coordinate system.

        If the there is no support for images, or the file cannot
        be read, or there is no geographics information available, return None.
        """
        if not resource.has_gdal_support():
            return None

        if self.bbox == -1:
            dataset = gdal.Open(self.filename, GA_ReadOnly)
            if dataset is None:
                self.bbox = None
            else:
                geotransform = dataset.GetGeoTransform()
                if geotransform is None:
                    return None

                x = 0
                y = dataset.RasterYSize
                left = geotransform[0] +        \
                       geotransform[1] * x +    \
                       geotransform[2] * y

                bottom = geotransform[3] +      \
                         geotransform[4] * x +  \
                         geotransform[5] * y

                x = dataset.RasterXSize
                y = 0
                right = geotransform[0] +       \
                        geotransform[1] * x +   \
                        geotransform[2] * y

                top = geotransform[3] +         \
                      geotransform[4] * x +     \
                      geotransform[5] * y

                self.bbox = (left, bottom, right, top)

        return self.bbox

    def LatLongBoundingBox(self):
        bbox = self.BoundingBox()
        if bbox is None:
            return None

        llx, lly, urx, ury = bbox
        if self.projection is not None:
            llx, lly = self.projection.Inverse(llx, lly)
            urx, ury = self.projection.Inverse(urx, ury)

        return llx, lly, urx, ury

    def GetImageFilename(self):
        return self.filename

    def TreeInfo(self):
        items = []

        items.append(_("Filename: %s") % self.GetImageFilename())

        if self.Visible():
            items.append(_("Shown"))
        else:
            items.append(_("Hidden"))

        bbox = self.LatLongBoundingBox()
        if bbox is not None:
            items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
        else:
            items.append(_("Extent (lat-lon):"))

        if self.projection and len(self.projection.params) > 0:
            items.append((_("Projection"),
                        [str(param) for param in self.projection.params]))

        return (_("Layer '%s'") % self.Title(), items)

1	bh	701	# Copyright (c) 2001, 2002, 2003 by Intevation GmbH
2	bh	6	# Authors:
3			# Bernhard Herzog <[email protected]>
4	jonathan	412	# Jonathan Coles <[email protected]>
5	bh	6	#
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	bh	171	from math import log, ceil
12	bh	1219	import warnings
13	bh	171
14	jan	374	from Thuban import _
15	bh	143	import shapelib, shptree
16	bh	6
17	bh	701	from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
18	bh	1142	LAYER_CHANGED, LAYER_SHAPESTORE_REPLACED
19	bh	6
20	jonathan	437	import classification
21	bh	6
22	jonathan	1338	from color import Transparent, Black
23	bh	6	from base import TitledObject, Modifiable
24
25	jonathan	1158	import resource
26	bh	723
27	jonathan	1158
28	bh	6	class Shape:
29
30			"""Represent one shape"""
31
32			def __init__(self, points):
33			self.points = points
34			#self.compute_bbox()
35	jonathan	828	self.bbox = None
36	bh	6
37			def compute_bbox(self):
38	jonathan	828	if self.bbox is not None:
39			return self.bbox
40
41	bh	6	xs = []
42			ys = []
43			for x, y in self.points:
44			xs.append(x)
45			ys.append(y)
46			self.llx = min(xs)
47			self.lly = min(ys)
48			self.urx = max(xs)
49			self.ury = max(ys)
50
51	jonathan	828	self.bbox = (self.llx, self.lly, self.urx, self.ury)
52
53			return self.bbox
54
55	bh	6	def Points(self):
56			return self.points
57
58
59
60			# Shape type constants
61			SHAPETYPE_POLYGON = "polygon"
62			SHAPETYPE_ARC = "arc"
63			SHAPETYPE_POINT = "point"
64
65			# mapping from shapelib shapetype constants to our constants
66			shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
67			shapelib.SHPT_ARC: SHAPETYPE_ARC,
68			shapelib.SHPT_POINT: SHAPETYPE_POINT}
69
70			shapetype_names = {SHAPETYPE_POINT: "Point",
71			SHAPETYPE_ARC: "Arc",
72			SHAPETYPE_POLYGON: "Polygon"}
73
74			class BaseLayer(TitledObject, Modifiable):
75
76			"""Base class for the layers."""
77
78	jonathan	929	def __init__(self, title, visible = True, projection = None):
79	bh	6	"""Initialize the layer.
80
81			title -- the title
82			visible -- boolean. If true the layer is visible.
83			"""
84			TitledObject.__init__(self, title)
85			Modifiable.__init__(self)
86			self.visible = visible
87	jonathan	929	self.projection = projection
88	bh	6
89			def Visible(self):
90			"""Return true if layer is visible"""
91			return self.visible
92
93			def SetVisible(self, visible):
94			"""Set the layer's visibility."""
95			self.visible = visible
96			self.issue(LAYER_VISIBILITY_CHANGED, self)
97	bh	276
98	jonathan	929	def HasClassification(self):
99			"""Determine if this layer support classifications."""
100			return False
101	bh	276
102	jonathan	1273	def HasShapes(self):
103			"""Determine if this layer supports shapes."""
104			return False
105
106	jonathan	929	def GetProjection(self):
107			"""Return the layer's projection."""
108			return self.projection
109
110			def SetProjection(self, projection):
111			"""Set the layer's projection"""
112			self.projection = projection
113			self.changed(LAYER_PROJECTION_CHANGED, self)
114
115	bh	6	class Layer(BaseLayer):
116
117			"""Represent the information of one geodata file (currently a shapefile)
118
119			All children of the layer have the same type.
120
121			A layer has fill and stroke colors. Colors should be instances of
122	jonathan	1338	Color. They can also be Transparent, indicating no fill or no stroke.
123	bh	6
124			The layer objects send the following events, all of which have the
125			layer object as parameter:
126
127			TITLE_CHANGED -- The title has changed.
128			LAYER_PROJECTION_CHANGED -- the projection has changed.
129			"""
130
131	bh	723	def __init__(self, title, data, projection = None,
132	jonathan	1338	fill = Transparent,
133			stroke = Black,
134	jonathan	464	lineWidth = 1,
135	jonathan	771	visible = True):
136	bh	6	"""Initialize the layer.
137
138			title -- the title
139	bh	723	data -- datastore object for the shape data shown by the layer
140	bh	6	projection -- the projection object. Its Inverse method is
141			assumed to map the layer's coordinates to lat/long
142			coordinates
143	jonathan	1338	fill -- the fill color or Transparent if the shapes are
144	jonathan	610	not filled
145	jonathan	1338	stroke -- the stroke color or Transparent if the shapes
146	jonathan	610	are not stroked
147	bh	6	visible -- boolean. If true the layer is visible.
148
149			colors are expected to be instances of Color class
150			"""
151	jonathan	929	BaseLayer.__init__(self, title,
152			visible = visible,
153			projection = projection)
154	bh	276
155	jonathan	481	#
156			# this is really important so that when the classification class
157			# tries to set its parent layer the variable will exist
158			#
159	bh	723	self.__classification = None
160	jonathan	481
161	bh	723	self.SetShapeStore(data)
162	jonathan	492
163			self.SetClassification(None)
164
165	jonathan	464	self.__classification.SetDefaultLineColor(stroke)
166			self.__classification.SetDefaultLineWidth(lineWidth)
167	jonathan	412	self.__classification.SetDefaultFill(fill)
168	jonathan	364
169	jonathan	389	self.UnsetModified()
170
171	bh	1219	def __getattr__(self, attr):
172			"""Access to some attributes for backwards compatibility
173	bh	6
174	bh	1219	The attributes implemented here are now held by the shapestore
175			if at all. For backwards compatibility pretend that they are
176			still there but issue a DeprecationWarning when they are
177			accessed.
178			"""
179			if attr in ("table", "shapetable"):
180			value = self.store.Table()
181			elif attr == "shapefile":
182			value = self.store.Shapefile()
183			elif attr == "filename":
184			value = self.store.FileName()
185			else:
186			raise AttributeError, attr
187			warnings.warn("The Layer attribute %r is deprecated."
188			" It's value can be accessed through the shapestore"
189			% attr, DeprecationWarning, stacklevel = 2)
190			return value
191
192	bh	723	def SetShapeStore(self, store):
193			self.store = store
194	bh	1219	shapefile = self.store.Shapefile()
195	bh	179
196	bh	1219	numshapes, shapetype, mins, maxs = shapefile.info()
197	bh	723	self.numshapes = numshapes
198			self.shapetype = shapelib_shapetypes[shapetype]
199	bh	171
200	bh	723	# if there are shapes, set the bbox accordingly. Otherwise
201			# set it to None.
202			if self.numshapes:
203			self.bbox = mins[:2] + maxs[:2]
204			else:
205			self.bbox = None
206	bh	171
207	bh	723	# estimate a good depth for the quad tree. Each depth
208			# multiplies the number of nodes by four, therefore we
209			# basically take the base 4 logarithm of the number of
210			# shapes.
211			if self.numshapes < 4:
212			maxdepth = 1
213			else:
214			maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
215
216	bh	1219	self.shapetree = shptree.SHPTree(shapefile.cobject(), 2,
217	bh	723	maxdepth)
218	bh	1088	# Set the classification to None if there is a classification
219			# and the new shapestore doesn't have a table with a suitable
220			# column, i.e one with the same name and type as before
221			# FIXME: Maybe we should keep it the same if the type is
222			# compatible enough such as FIELDTYPE_DOUBLE and FIELDTYPE_INT
223	bh	723	if self.__classification is not None:
224			fieldname = self.__classification.GetField()
225	bh	1088	fieldtype = self.__classification.GetFieldType()
226			table = self.store.Table()
227			if (fieldname is not None
228			and (not table.HasColumn(fieldname)
229			or table.Column(fieldname).type != fieldtype)):
230	bh	723	self.SetClassification(None)
231	bh	1142	self.changed(LAYER_SHAPESTORE_REPLACED, self)
232	bh	723
233			def ShapeStore(self):
234			return self.store
235
236	bh	258	def Destroy(self):
237	bh	260	BaseLayer.Destroy(self)
238	jonathan	1338	self.GetClassification()._set_layer(None)
239	bh	258
240	bh	6	def BoundingBox(self):
241	bh	179	"""Return the layer's bounding box in the intrinsic coordinate system.
242
243			If the layer has no shapes, return None.
244			"""
245	bh	6	return self.bbox
246
247			def LatLongBoundingBox(self):
248	bh	179	"""Return the layer's bounding box in lat/long coordinates.
249	bh	6
250	bh	179	Return None, if the layer doesn't contain any shapes.
251			"""
252			bbox = self.BoundingBox()
253			if bbox is not None:
254			llx, lly, urx, ury = bbox
255			if self.projection is not None:
256			llx, lly = self.projection.Inverse(llx, lly)
257			urx, ury = self.projection.Inverse(urx, ury)
258			return llx, lly, urx, ury
259			else:
260			return None
261
262	jonathan	828	def ShapesBoundingBox(self, shapes):
263			"""Return a bounding box in lat/long coordinates for the given
264			list of shape ids.
265
266			If shapes is None or empty, return None.
267			"""
268
269			if shapes is None or len(shapes) == 0: return None
270
271			llx = []
272			lly = []
273			urx = []
274			ury = []
275
276			if self.projection is not None:
277			inverse = lambda x, y: self.projection.Inverse(x, y)
278			else:
279			inverse = lambda x, y: (x, y)
280
281			for id in shapes:
282			left, bottom, right, top = self.Shape(id).compute_bbox()
283
284			left, bottom = inverse(left, bottom)
285			right, top = inverse(right, top)
286
287			llx.append(left)
288			lly.append(bottom)
289			urx.append(right)
290			ury.append(top)
291
292			return (min(llx), min(lly), max(urx), max(ury))
293
294	jonathan	464	def GetFieldType(self, fieldName):
295	bh	1219	table = self.store.Table()
296			if table.HasColumn(fieldName):
297			return table.Column(fieldName).type
298	bh	839	return None
299	jonathan	464
300	jonathan	1273	def HasShapes(self):
301			return True
302
303	bh	6	def NumShapes(self):
304			"""Return the number of shapes in the layer"""
305			return self.numshapes
306
307			def ShapeType(self):
308			"""Return the type of the shapes in the layer.
309			This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
310			"""
311			return self.shapetype
312
313			def Shape(self, index):
314			"""Return the shape with index index"""
315	bh	1219	shape = self.store.Shapefile().read_object(index)
316	jonathan	364
317	bh	6	if self.shapetype == SHAPETYPE_POINT:
318			points = shape.vertices()
319			else:
320			#for poly in shape.vertices():
321			poly = shape.vertices()[0]
322			points = []
323			for x, y in poly:
324	bh	82	points.append((x, y))
325	jonathan	364
326	bh	6	return Shape(points)
327
328	bh	143	def ShapesInRegion(self, box):
329			"""Return the ids of the shapes that overlap the box.
330
331	jonathan	794	Box is a tuple (left, bottom, right, top) in unprojected coordinates.
332	bh	143	"""
333			left, bottom, right, top = box
334	jonathan	794
335			if self.projection is not None:
336			left, bottom = self.projection.Forward(left, bottom)
337			right, top = self.projection.Forward(right, top)
338
339	bh	147	return self.shapetree.find_shapes((left, bottom), (right, top))
340	bh	143
341	jonathan	929	def HasClassification(self):
342			return True
343	jonathan	725
344	jonathan	412	def GetClassification(self):
345			return self.__classification
346
347			def SetClassification(self, clazz):
348	jonathan	1338	"""Set the classification used by this layer to 'clazz'
349	jonathan	481
350	jonathan	1338	If 'clazz' is None a default classification is created.
351
352			ValueError is raised if the classification's field name
353			and type are different (if they aren't None) than what
354			is in the shapestore. The Layer will not be changed in
355			this case.
356	jonathan	492	"""
357	jonathan	481
358	jonathan	1338	old_class = self.__classification
359	jonathan	529
360	jonathan	1338	if clazz is None:
361			clazz = classification.Classification()
362	jonathan	529
363	jonathan	1338	try:
364	jonathan	1355	self.__classification = clazz
365	jonathan	1338	clazz._set_layer(self)
366
367			# only change things after a successful call
368			if old_class is not None:
369			old_class._set_layer(None)
370			except ValueError:
371	jonathan	1355	self.__classification = old_class
372	jonathan	1338	raise ValueError
373	jonathan	492
374	jonathan	1338	# we don't need this since a message will be sent
375			# after calling _set_layer()
376			#self.changed(LAYER_CHANGED, self)
377	jonathan	412
378	jonathan	492	def ClassChanged(self):
379			"""Called from the classification object when it has changed."""
380	jonathan	558	self.changed(LAYER_CHANGED, self)
381	jonathan	492
382	bh	217	def TreeInfo(self):
383			items = []
384
385	jonathan	1338	items.append(_("Filename: %s") % self.ShapeStore().FileName())
386	jan	1012
387	bh	217	if self.Visible():
388	jan	374	items.append(_("Shown"))
389	bh	217	else:
390	jan	374	items.append(_("Hidden"))
391			items.append(_("Shapes: %d") % self.NumShapes())
392	bh	217
393			bbox = self.LatLongBoundingBox()
394			if bbox is not None:
395	jan	374	items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
396	bh	217	else:
397	jan	374	items.append(_("Extent (lat-lon):"))
398			items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
399	bh	217
400	jonathan	736	if self.projection and len(self.projection.params) > 0:
401			items.append((_("Projection"),
402			[str(param) for param in self.projection.params]))
403
404	jonathan	412	items.append(self.__classification)
405	bh	217
406	jan	374	return (_("Layer '%s'") % self.Title(), items)
407	jonathan	382
408	jonathan	736
409	jonathan	1158	if resource.has_gdal_support():
410			import gdal
411			from gdalconst import GA_ReadOnly
412
413	jonathan	929	class RasterLayer(BaseLayer):
414
415			def __init__(self, title, filename, projection = None, visible = True):
416			"""Initialize the Raster Layer.
417
418			title -- title for the layer.
419
420			filename -- file name of the source image.
421
422			projection -- Projection object describing the projection which
423			the source image is in.
424
425			visible -- True is the layer should initially be visible.
426	jonathan	961
427			Throws IOError if the filename is invalid or points to a file that
428			is not in a format GDAL can use.
429	jonathan	929	"""
430
431			BaseLayer.__init__(self, title, visible = visible)
432
433			self.projection = projection
434			self.filename = filename
435
436			self.bbox = -1
437
438	jonathan	1158	if resource.has_gdal_support():
439			#
440			# temporarily open the file so that GDAL can test if it's valid.
441			#
442			dataset = gdal.Open(self.filename, GA_ReadOnly)
443	jonathan	961
444	jonathan	1158	if dataset is None:
445			raise IOError()
446	jonathan	961
447	jonathan	929	self.UnsetModified()
448
449			def BoundingBox(self):
450			"""Return the layer's bounding box in the intrinsic coordinate system.
451
452	jonathan	1338	If the there is no support for images, or the file cannot
453			be read, or there is no geographics information available, return None.
454	jonathan	929	"""
455	jonathan	1158	if not resource.has_gdal_support():
456			return None
457
458	jonathan	929	if self.bbox == -1:
459			dataset = gdal.Open(self.filename, GA_ReadOnly)
460			if dataset is None:
461			self.bbox = None
462			else:
463	jonathan	961	geotransform = dataset.GetGeoTransform()
464			if geotransform is None:
465			return None
466
467			x = 0
468			y = dataset.RasterYSize
469			left = geotransform[0] + \
470			geotransform[1] * x + \
471			geotransform[2] * y
472
473			bottom = geotransform[3] + \
474			geotransform[4] * x + \
475			geotransform[5] * y
476
477			x = dataset.RasterXSize
478			y = 0
479			right = geotransform[0] + \
480			geotransform[1] * x + \
481			geotransform[2] * y
482
483			top = geotransform[3] + \
484			geotransform[4] * x + \
485			geotransform[5] * y
486
487	jonathan	929	self.bbox = (left, bottom, right, top)
488
489			return self.bbox
490
491			def LatLongBoundingBox(self):
492			bbox = self.BoundingBox()
493	jonathan	961	if bbox is None:
494	jonathan	929	return None
495
496	jonathan	961	llx, lly, urx, ury = bbox
497			if self.projection is not None:
498			llx, lly = self.projection.Inverse(llx, lly)
499			urx, ury = self.projection.Inverse(urx, ury)
500
501			return llx, lly, urx, ury
502
503	jonathan	929	def GetImageFilename(self):
504			return self.filename
505
506			def TreeInfo(self):
507			items = []
508
509	jonathan	1338	items.append(_("Filename: %s") % self.GetImageFilename())
510
511	jonathan	929	if self.Visible():
512			items.append(_("Shown"))
513			else:
514			items.append(_("Hidden"))
515
516			bbox = self.LatLongBoundingBox()
517			if bbox is not None:
518			items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
519			else:
520			items.append(_("Extent (lat-lon):"))
521
522			if self.projection and len(self.projection.params) > 0:
523			items.append((_("Projection"),
524			[str(param) for param in self.projection.params]))
525
526			return (_("Layer '%s'") % self.Title(), items)
527
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