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

from Thuban import _

import shapelib, shptree

import gdal
from gdalconst import GA_ReadOnly

from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
     LAYER_CHANGED

from color import Color

import classification

from base import TitledObject, Modifiable


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 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 None, 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 = Color.Transparent, 
                 stroke = Color.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 Color.Transparent if the shapes are 
                not filled
        stroke -- the stroke color or Color.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.__setClassLock = False

        self.SetShapeStore(data)

        self.SetClassification(None)

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

        self.UnsetModified()


    def SetShapeStore(self, store):
        self.store = store
        self.shapefile = self.store.Shapefile()
        self.shapetable = self.store.Table()
        if hasattr(self.store, "FileName"):
            self.filename = self.store.FileName()
        self.table = self.shapetable

        numshapes, shapetype, mins, maxs = self.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(self.shapefile.cobject(), 2,
                                         maxdepth)
        if self.__classification is not None:
            fieldname = self.__classification.GetField()
            if fieldname is not None and \
               not self.store.Table().HasColumn(fieldname):
                self.SetClassification(None)
        self.changed(LAYER_CHANGED, self)

    def ShapeStore(self):
        return self.store

    def Destroy(self):
        BaseLayer.Destroy(self)
        self.SetClassification(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):
        if self.table.HasColumn(fieldName):
            return self.table.Column(fieldName).type
        return None

    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.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 to 'clazz'

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

        # prevent infinite recursion when calling SetLayer()
        if self.__setClassLock: return

        self.__setClassLock = True

        if clazz is None:
            if self.__classification is not None:
                self.__classification.SetLayer(None)
            self.__classification = classification.Classification()
        else:
            self.__classification = clazz
            try:
                self.__classification.SetLayer(self)
            except ValueError:
                self.__setClassLock = False
                raise ValueError

        self.changed(LAYER_CHANGED, self)

        self.__setClassLock = False

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

        if hasattr(self, 'filename'):
            items.append(_("Filename: %s") % self.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)


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

        #
        # 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 layer has no shapes, 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 = []

        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):"))

        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
13	jan	374	from Thuban import _
14
15	bh	143	import shapelib, shptree
16	bh	6
17	jonathan	929	import gdal
18			from gdalconst import GA_ReadOnly
19
20	bh	701	from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
21			LAYER_CHANGED
22	bh	6
23			from color import Color
24
25	jonathan	437	import classification
26	bh	6
27			from base import TitledObject, Modifiable
28
29	bh	723
30	bh	6	class Shape:
31
32			"""Represent one shape"""
33
34			def __init__(self, points):
35			self.points = points
36			#self.compute_bbox()
37	jonathan	828	self.bbox = None
38	bh	6
39			def compute_bbox(self):
40	jonathan	828	if self.bbox is not None:
41			return self.bbox
42
43	bh	6	xs = []
44			ys = []
45			for x, y in self.points:
46			xs.append(x)
47			ys.append(y)
48			self.llx = min(xs)
49			self.lly = min(ys)
50			self.urx = max(xs)
51			self.ury = max(ys)
52
53	jonathan	828	self.bbox = (self.llx, self.lly, self.urx, self.ury)
54
55			return self.bbox
56
57	bh	6	def Points(self):
58			return self.points
59
60
61
62			# Shape type constants
63			SHAPETYPE_POLYGON = "polygon"
64			SHAPETYPE_ARC = "arc"
65			SHAPETYPE_POINT = "point"
66
67			# mapping from shapelib shapetype constants to our constants
68			shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
69			shapelib.SHPT_ARC: SHAPETYPE_ARC,
70			shapelib.SHPT_POINT: SHAPETYPE_POINT}
71
72			shapetype_names = {SHAPETYPE_POINT: "Point",
73			SHAPETYPE_ARC: "Arc",
74			SHAPETYPE_POLYGON: "Polygon"}
75
76			class BaseLayer(TitledObject, Modifiable):
77
78			"""Base class for the layers."""
79
80	jonathan	929	def __init__(self, title, visible = True, projection = None):
81	bh	6	"""Initialize the layer.
82
83			title -- the title
84			visible -- boolean. If true the layer is visible.
85			"""
86			TitledObject.__init__(self, title)
87			Modifiable.__init__(self)
88			self.visible = visible
89	jonathan	929	self.projection = projection
90	bh	6
91			def Visible(self):
92			"""Return true if layer is visible"""
93			return self.visible
94
95			def SetVisible(self, visible):
96			"""Set the layer's visibility."""
97			self.visible = visible
98			self.issue(LAYER_VISIBILITY_CHANGED, self)
99	bh	276
100	jonathan	929	def HasClassification(self):
101			"""Determine if this layer support classifications."""
102			return False
103	bh	276
104	jonathan	929	def GetProjection(self):
105			"""Return the layer's projection."""
106			return self.projection
107
108			def SetProjection(self, projection):
109			"""Set the layer's projection"""
110			self.projection = projection
111			self.changed(LAYER_PROJECTION_CHANGED, self)
112
113	bh	6	class Layer(BaseLayer):
114
115			"""Represent the information of one geodata file (currently a shapefile)
116
117			All children of the layer have the same type.
118
119			A layer has fill and stroke colors. Colors should be instances of
120			Color. They can also be None, indicating no fill or no stroke.
121
122			The layer objects send the following events, all of which have the
123			layer object as parameter:
124
125			TITLE_CHANGED -- The title has changed.
126			LAYER_PROJECTION_CHANGED -- the projection has changed.
127			"""
128
129	bh	723	def __init__(self, title, data, projection = None,
130	jonathan	610	fill = Color.Transparent,
131	jonathan	412	stroke = Color.Black,
132	jonathan	464	lineWidth = 1,
133	jonathan	771	visible = True):
134	bh	6	"""Initialize the layer.
135
136			title -- the title
137	bh	723	data -- datastore object for the shape data shown by the layer
138	bh	6	projection -- the projection object. Its Inverse method is
139			assumed to map the layer's coordinates to lat/long
140			coordinates
141	jonathan	610	fill -- the fill color or Color.Transparent if the shapes are
142			not filled
143			stroke -- the stroke color or Color.Transparent if the shapes
144			are not stroked
145	bh	6	visible -- boolean. If true the layer is visible.
146
147			colors are expected to be instances of Color class
148			"""
149	jonathan	929	BaseLayer.__init__(self, title,
150			visible = visible,
151			projection = projection)
152	bh	276
153	jonathan	481	#
154			# this is really important so that when the classification class
155			# tries to set its parent layer the variable will exist
156			#
157	bh	723	self.__classification = None
158	jonathan	529	self.__setClassLock = False
159	jonathan	481
160	bh	723	self.SetShapeStore(data)
161	jonathan	492
162			self.SetClassification(None)
163
164	jonathan	464	self.__classification.SetDefaultLineColor(stroke)
165			self.__classification.SetDefaultLineWidth(lineWidth)
166	jonathan	412	self.__classification.SetDefaultFill(fill)
167	jonathan	492	self.__classification.SetLayer(self)
168	jonathan	364
169	jonathan	389	self.UnsetModified()
170
171	bh	6
172	bh	723	def SetShapeStore(self, store):
173			self.store = store
174			self.shapefile = self.store.Shapefile()
175			self.shapetable = self.store.Table()
176	bh	996	if hasattr(self.store, "FileName"):
177			self.filename = self.store.FileName()
178	bh	723	self.table = self.shapetable
179	bh	179
180	bh	723	numshapes, shapetype, mins, maxs = self.shapefile.info()
181			self.numshapes = numshapes
182			self.shapetype = shapelib_shapetypes[shapetype]
183	bh	171
184	bh	723	# if there are shapes, set the bbox accordingly. Otherwise
185			# set it to None.
186			if self.numshapes:
187			self.bbox = mins[:2] + maxs[:2]
188			else:
189			self.bbox = None
190	bh	171
191	bh	723	# estimate a good depth for the quad tree. Each depth
192			# multiplies the number of nodes by four, therefore we
193			# basically take the base 4 logarithm of the number of
194			# shapes.
195			if self.numshapes < 4:
196			maxdepth = 1
197			else:
198			maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
199
200			self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
201			maxdepth)
202			if self.__classification is not None:
203			fieldname = self.__classification.GetField()
204	jan	791	if fieldname is not None and \
205	bh	839	not self.store.Table().HasColumn(fieldname):
206	bh	723	self.SetClassification(None)
207			self.changed(LAYER_CHANGED, self)
208
209			def ShapeStore(self):
210			return self.store
211
212	bh	258	def Destroy(self):
213	bh	260	BaseLayer.Destroy(self)
214	jonathan	529	self.SetClassification(None)
215	bh	258
216	bh	6	def BoundingBox(self):
217	bh	179	"""Return the layer's bounding box in the intrinsic coordinate system.
218
219			If the layer has no shapes, return None.
220			"""
221	bh	6	return self.bbox
222
223			def LatLongBoundingBox(self):
224	bh	179	"""Return the layer's bounding box in lat/long coordinates.
225	bh	6
226	bh	179	Return None, if the layer doesn't contain any shapes.
227			"""
228			bbox = self.BoundingBox()
229			if bbox is not None:
230			llx, lly, urx, ury = bbox
231			if self.projection is not None:
232			llx, lly = self.projection.Inverse(llx, lly)
233			urx, ury = self.projection.Inverse(urx, ury)
234			return llx, lly, urx, ury
235			else:
236			return None
237
238	jonathan	828	def ShapesBoundingBox(self, shapes):
239			"""Return a bounding box in lat/long coordinates for the given
240			list of shape ids.
241
242			If shapes is None or empty, return None.
243			"""
244
245			if shapes is None or len(shapes) == 0: return None
246
247			llx = []
248			lly = []
249			urx = []
250			ury = []
251
252			if self.projection is not None:
253			inverse = lambda x, y: self.projection.Inverse(x, y)
254			else:
255			inverse = lambda x, y: (x, y)
256
257			for id in shapes:
258			left, bottom, right, top = self.Shape(id).compute_bbox()
259
260			left, bottom = inverse(left, bottom)
261			right, top = inverse(right, top)
262
263			llx.append(left)
264			lly.append(bottom)
265			urx.append(right)
266			ury.append(top)
267
268			return (min(llx), min(lly), max(urx), max(ury))
269
270	jonathan	464	def GetFieldType(self, fieldName):
271	bh	839	if self.table.HasColumn(fieldName):
272			return self.table.Column(fieldName).type
273			return None
274	jonathan	464
275	bh	6	def NumShapes(self):
276			"""Return the number of shapes in the layer"""
277			return self.numshapes
278
279			def ShapeType(self):
280			"""Return the type of the shapes in the layer.
281			This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
282			"""
283			return self.shapetype
284
285			def Shape(self, index):
286			"""Return the shape with index index"""
287			shape = self.shapefile.read_object(index)
288	jonathan	364
289	bh	6	if self.shapetype == SHAPETYPE_POINT:
290			points = shape.vertices()
291			else:
292			#for poly in shape.vertices():
293			poly = shape.vertices()[0]
294			points = []
295			for x, y in poly:
296	bh	82	points.append((x, y))
297	jonathan	364
298	bh	6	return Shape(points)
299
300	bh	143	def ShapesInRegion(self, box):
301			"""Return the ids of the shapes that overlap the box.
302
303	jonathan	794	Box is a tuple (left, bottom, right, top) in unprojected coordinates.
304	bh	143	"""
305			left, bottom, right, top = box
306	jonathan	794
307			if self.projection is not None:
308			left, bottom = self.projection.Forward(left, bottom)
309			right, top = self.projection.Forward(right, top)
310
311	bh	147	return self.shapetree.find_shapes((left, bottom), (right, top))
312	bh	143
313	jonathan	929	def HasClassification(self):
314			return True
315	jonathan	725
316	jonathan	412	def GetClassification(self):
317			return self.__classification
318
319			def SetClassification(self, clazz):
320	jonathan	492	"""Set the classification to 'clazz'
321	jonathan	481
322	jonathan	492	If 'clazz' is None a default classification is created
323			"""
324	jonathan	481
325	jonathan	529	# prevent infinite recursion when calling SetLayer()
326			if self.__setClassLock: return
327
328			self.__setClassLock = True
329
330	jonathan	492	if clazz is None:
331	jonathan	529	if self.__classification is not None:
332			self.__classification.SetLayer(None)
333	jonathan	492	self.__classification = classification.Classification()
334			else:
335			self.__classification = clazz
336	jonathan	529	try:
337			self.__classification.SetLayer(self)
338			except ValueError:
339			self.__setClassLock = False
340			raise ValueError
341	jonathan	492
342	jonathan	545	self.changed(LAYER_CHANGED, self)
343	jonathan	412
344	jonathan	529	self.__setClassLock = False
345
346	jonathan	492	def ClassChanged(self):
347			"""Called from the classification object when it has changed."""
348	jonathan	558	self.changed(LAYER_CHANGED, self)
349	jonathan	492
350	bh	217	def TreeInfo(self):
351			items = []
352
353	jan	1086	if hasattr(self, 'filename'):
354			items.append(_("Filename: %s") % self.filename)
355	jan	1012
356	bh	217	if self.Visible():
357	jan	374	items.append(_("Shown"))
358	bh	217	else:
359	jan	374	items.append(_("Hidden"))
360			items.append(_("Shapes: %d") % self.NumShapes())
361	bh	217
362			bbox = self.LatLongBoundingBox()
363			if bbox is not None:
364	jan	374	items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
365	bh	217	else:
366	jan	374	items.append(_("Extent (lat-lon):"))
367			items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
368	bh	217
369	jonathan	736	if self.projection and len(self.projection.params) > 0:
370			items.append((_("Projection"),
371			[str(param) for param in self.projection.params]))
372
373	jonathan	412	items.append(self.__classification)
374	bh	217
375	jan	374	return (_("Layer '%s'") % self.Title(), items)
376	jonathan	382
377	jonathan	736
378	jonathan	929	class RasterLayer(BaseLayer):
379
380			def __init__(self, title, filename, projection = None, visible = True):
381			"""Initialize the Raster Layer.
382
383			title -- title for the layer.
384
385			filename -- file name of the source image.
386
387			projection -- Projection object describing the projection which
388			the source image is in.
389
390			visible -- True is the layer should initially be visible.
391	jonathan	961
392			Throws IOError if the filename is invalid or points to a file that
393			is not in a format GDAL can use.
394	jonathan	929	"""
395
396			BaseLayer.__init__(self, title, visible = visible)
397
398			self.projection = projection
399			self.filename = filename
400
401			self.bbox = -1
402
403	jonathan	961	#
404			# temporarily open the file so that GDAL can test if it's valid.
405			#
406			dataset = gdal.Open(self.filename, GA_ReadOnly)
407
408			if dataset is None:
409			raise IOError()
410
411	jonathan	929	self.UnsetModified()
412
413			def BoundingBox(self):
414			"""Return the layer's bounding box in the intrinsic coordinate system.
415
416			If the layer has no shapes, return None.
417			"""
418			if self.bbox == -1:
419			dataset = gdal.Open(self.filename, GA_ReadOnly)
420			if dataset is None:
421			self.bbox = None
422			else:
423	jonathan	961	geotransform = dataset.GetGeoTransform()
424			if geotransform is None:
425			return None
426
427			x = 0
428			y = dataset.RasterYSize
429			left = geotransform[0] + \
430			geotransform[1] * x + \
431			geotransform[2] * y
432
433			bottom = geotransform[3] + \
434			geotransform[4] * x + \
435			geotransform[5] * y
436
437			x = dataset.RasterXSize
438			y = 0
439			right = geotransform[0] + \
440			geotransform[1] * x + \
441			geotransform[2] * y
442
443			top = geotransform[3] + \
444			geotransform[4] * x + \
445			geotransform[5] * y
446
447	jonathan	929	self.bbox = (left, bottom, right, top)
448
449			return self.bbox
450
451			def LatLongBoundingBox(self):
452			bbox = self.BoundingBox()
453	jonathan	961	if bbox is None:
454	jonathan	929	return None
455
456	jonathan	961	llx, lly, urx, ury = bbox
457			if self.projection is not None:
458			llx, lly = self.projection.Inverse(llx, lly)
459			urx, ury = self.projection.Inverse(urx, ury)
460
461			return llx, lly, urx, ury
462
463	jonathan	929	def GetImageFilename(self):
464			return self.filename
465
466			def TreeInfo(self):
467			items = []
468
469			if self.Visible():
470			items.append(_("Shown"))
471			else:
472			items.append(_("Hidden"))
473			items.append(_("Shapes: %d") % self.NumShapes())
474
475			bbox = self.LatLongBoundingBox()
476			if bbox is not None:
477			items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
478			else:
479			items.append(_("Extent (lat-lon):"))
480
481			if self.projection and len(self.projection.params) > 0:
482			items.append((_("Projection"),
483			[str(param) for param in self.projection.params]))
484
485			return (_("Layer '%s'") % self.Title(), items)
486
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