Thuban/Model/layer.py

# Copyright (c) 2001, 2002 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__ = "$Revision$"

import os
from math import log, ceil

from Thuban import _

import shapelib, shptree

from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
     LAYER_VISIBILITY_CHANGED, LAYER_CHANGED

from color import Color

import classification

from table import Table

from base import TitledObject, Modifiable

class Shape:

    """Represent one shape"""

    def __init__(self, points):
        self.points = points
        #self.compute_bbox()

    def compute_bbox(self):
        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)

    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 = 1):
        """Initialize the layer.

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

    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)


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.
        LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed

    """

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

        title -- the title
        filename -- the name of the shapefile
        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.None if the shapes are not filled
        stroke -- the stroke color or Color.None 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)

        # Make the filename absolute. The filename will be
        # interpreted relative to that anyway, but when saving a
        # session we need to compare absolute paths and it's usually
        # safer to always work with absolute paths.
        self.filename = os.path.abspath(filename)

        self.projection = projection
        self.shapefile = None
        self.shapetree = None
        self.open_shapefile()
        # shapetable is the table associated with the shapefile, while
        # table is the default table used to look up attributes for
        # display
        self.shapetable = Table(filename)
        self.table = self.shapetable

        #
        # 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.SetClassification(None)

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

        self.UnsetModified()

    def open_shapefile(self):
        if self.shapefile is None:
            self.shapefile = shapelib.ShapeFile(self.filename)
            numshapes, shapetype, mins, maxs = self.shapefile.info()
            self.numshapes = numshapes
            self.shapetype = shapelib_shapetypes[shapetype]

            # if there are shapes, set the bbox accordinly. 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)

    def Destroy(self):
        BaseLayer.Destroy(self)
        if self.shapefile is not None:
            self.shapefile.close()
            self.shapefile = None
            self.shapetree = None
        self.SetClassification(None)
        self.table.Destroy()

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

        If the layer has no shapes, return None.
        """
        # The bbox will be set by open_shapefile just as we need it
        # here.
        self.open_shapefile()
        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 GetFieldType(self, fieldName):
        self.open_shapefile()
        info = self.table.field_info_by_name(fieldName)
        if info is not None:
            return info[0]
        else:
            return None

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

    def Shape(self, index):
        """Return the shape with index index"""
        self.open_shapefile()
        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 the coordinate
        system used by the layer's shapefile.
        """
        left, bottom, right, top = box
        return self.shapetree.find_shapes((left, bottom), (right, top))

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

    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_LEGEND_CHANGED, self)
 
    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):"))
        items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])

        items.append(self.__classification)

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

1	bh	73	# Copyright (c) 2001, 2002 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	276	import os
12	bh	171	from math import log, ceil
13
14	jan	374	from Thuban import _
15
16	bh	143	import shapelib, shptree
17	bh	6
18			from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
19	jonathan	545	LAYER_VISIBILITY_CHANGED, LAYER_CHANGED
20	bh	6
21			from color import Color
22
23	jonathan	437	import classification
24	bh	6
25			from table import Table
26
27			from base import TitledObject, Modifiable
28
29			class Shape:
30
31			"""Represent one shape"""
32
33			def __init__(self, points):
34			self.points = points
35			#self.compute_bbox()
36
37			def compute_bbox(self):
38			xs = []
39			ys = []
40			for x, y in self.points:
41			xs.append(x)
42			ys.append(y)
43			self.llx = min(xs)
44			self.lly = min(ys)
45			self.urx = max(xs)
46			self.ury = max(ys)
47
48			def Points(self):
49			return self.points
50
51
52
53			# Shape type constants
54			SHAPETYPE_POLYGON = "polygon"
55			SHAPETYPE_ARC = "arc"
56			SHAPETYPE_POINT = "point"
57
58			# mapping from shapelib shapetype constants to our constants
59			shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
60			shapelib.SHPT_ARC: SHAPETYPE_ARC,
61			shapelib.SHPT_POINT: SHAPETYPE_POINT}
62
63			shapetype_names = {SHAPETYPE_POINT: "Point",
64			SHAPETYPE_ARC: "Arc",
65			SHAPETYPE_POLYGON: "Polygon"}
66
67			class BaseLayer(TitledObject, Modifiable):
68
69			"""Base class for the layers."""
70
71			def __init__(self, title, visible = 1):
72			"""Initialize the layer.
73
74			title -- the title
75			visible -- boolean. If true the layer is visible.
76			"""
77			TitledObject.__init__(self, title)
78			Modifiable.__init__(self)
79			self.visible = visible
80
81			def Visible(self):
82			"""Return true if layer is visible"""
83			return self.visible
84
85			def SetVisible(self, visible):
86			"""Set the layer's visibility."""
87			self.visible = visible
88			self.issue(LAYER_VISIBILITY_CHANGED, self)
89	bh	276
90
91	bh	6	class Layer(BaseLayer):
92
93			"""Represent the information of one geodata file (currently a shapefile)
94
95			All children of the layer have the same type.
96
97			A layer has fill and stroke colors. Colors should be instances of
98			Color. They can also be None, indicating no fill or no stroke.
99
100			The layer objects send the following events, all of which have the
101			layer object as parameter:
102
103			TITLE_CHANGED -- The title has changed.
104			LAYER_PROJECTION_CHANGED -- the projection has changed.
105			LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed
106
107			"""
108
109			def __init__(self, title, filename, projection = None,
110	jonathan	412	fill = Color.None,
111			stroke = Color.Black,
112	jonathan	464	lineWidth = 1,
113	jonathan	412	visible = 1):
114	bh	6	"""Initialize the layer.
115
116			title -- the title
117			filename -- the name of the shapefile
118			projection -- the projection object. Its Inverse method is
119			assumed to map the layer's coordinates to lat/long
120			coordinates
121	jonathan	464	fill -- the fill color or Color.None if the shapes are not filled
122			stroke -- the stroke color or Color.None if the shapes are not stroked
123	bh	6	visible -- boolean. If true the layer is visible.
124
125			colors are expected to be instances of Color class
126			"""
127			BaseLayer.__init__(self, title, visible = visible)
128	bh	276
129			# Make the filename absolute. The filename will be
130			# interpreted relative to that anyway, but when saving a
131			# session we need to compare absolute paths and it's usually
132			# safer to always work with absolute paths.
133			self.filename = os.path.abspath(filename)
134
135	bh	6	self.projection = projection
136			self.shapefile = None
137	bh	143	self.shapetree = None
138	bh	21	self.open_shapefile()
139	bh	6	# shapetable is the table associated with the shapefile, while
140			# table is the default table used to look up attributes for
141			# display
142			self.shapetable = Table(filename)
143			self.table = self.shapetable
144
145	jonathan	481	#
146			# this is really important so that when the classification class
147			# tries to set its parent layer the variable will exist
148			#
149			self.__classification = None
150	jonathan	529	self.__setClassLock = False
151	jonathan	481
152	jonathan	492
153			self.SetClassification(None)
154
155	jonathan	464	self.__classification.SetDefaultLineColor(stroke)
156			self.__classification.SetDefaultLineWidth(lineWidth)
157	jonathan	412	self.__classification.SetDefaultFill(fill)
158	jonathan	492	self.__classification.SetLayer(self)
159	jonathan	364
160	jonathan	389	self.UnsetModified()
161
162	bh	6	def open_shapefile(self):
163			if self.shapefile is None:
164			self.shapefile = shapelib.ShapeFile(self.filename)
165			numshapes, shapetype, mins, maxs = self.shapefile.info()
166			self.numshapes = numshapes
167			self.shapetype = shapelib_shapetypes[shapetype]
168
169	bh	179	# if there are shapes, set the bbox accordinly. Otherwise
170			# set it to None.
171			if self.numshapes:
172			self.bbox = mins[:2] + maxs[:2]
173			else:
174			self.bbox = None
175
176	bh	171	# estimate a good depth for the quad tree. Each depth
177			# multiplies the number of nodes by four, therefore we
178			# basically take the base 4 logarithm of the number of
179			# shapes.
180			if self.numshapes < 4:
181			maxdepth = 1
182			else:
183			maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
184
185			self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
186			maxdepth)
187
188	bh	258	def Destroy(self):
189	bh	260	BaseLayer.Destroy(self)
190	bh	258	if self.shapefile is not None:
191			self.shapefile.close()
192			self.shapefile = None
193			self.shapetree = None
194	jonathan	529	self.SetClassification(None)
195	bh	258	self.table.Destroy()
196
197	bh	6	def BoundingBox(self):
198	bh	179	"""Return the layer's bounding box in the intrinsic coordinate system.
199
200			If the layer has no shapes, return None.
201			"""
202			# The bbox will be set by open_shapefile just as we need it
203			# here.
204	bh	6	self.open_shapefile()
205			return self.bbox
206
207			def LatLongBoundingBox(self):
208	bh	179	"""Return the layer's bounding box in lat/long coordinates.
209	bh	6
210	bh	179	Return None, if the layer doesn't contain any shapes.
211			"""
212			bbox = self.BoundingBox()
213			if bbox is not None:
214			llx, lly, urx, ury = bbox
215			if self.projection is not None:
216			llx, lly = self.projection.Inverse(llx, lly)
217			urx, ury = self.projection.Inverse(urx, ury)
218			return llx, lly, urx, ury
219			else:
220			return None
221
222	jonathan	464	def GetFieldType(self, fieldName):
223			self.open_shapefile()
224			info = self.table.field_info_by_name(fieldName)
225			if info is not None:
226			return info[0]
227			else:
228			return None
229
230	bh	6	def NumShapes(self):
231			"""Return the number of shapes in the layer"""
232			self.open_shapefile()
233			return self.numshapes
234
235			def ShapeType(self):
236			"""Return the type of the shapes in the layer.
237			This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
238			"""
239			self.open_shapefile()
240			return self.shapetype
241
242			def Shape(self, index):
243			"""Return the shape with index index"""
244			self.open_shapefile()
245			shape = self.shapefile.read_object(index)
246	jonathan	364
247	bh	6	if self.shapetype == SHAPETYPE_POINT:
248			points = shape.vertices()
249			else:
250			#for poly in shape.vertices():
251			poly = shape.vertices()[0]
252			points = []
253			for x, y in poly:
254	bh	82	points.append((x, y))
255	jonathan	364
256	bh	6	return Shape(points)
257
258	bh	143	def ShapesInRegion(self, box):
259			"""Return the ids of the shapes that overlap the box.
260
261			Box is a tuple (left, bottom, right, top) in the coordinate
262			system used by the layer's shapefile.
263			"""
264			left, bottom, right, top = box
265	bh	147	return self.shapetree.find_shapes((left, bottom), (right, top))
266	bh	143
267	bh	6	def SetProjection(self, projection):
268			"""Set the layer's projection"""
269			self.projection = projection
270			self.changed(LAYER_PROJECTION_CHANGED, self)
271
272	jonathan	412	def GetClassification(self):
273			return self.__classification
274
275			def SetClassification(self, clazz):
276	jonathan	492	"""Set the classification to 'clazz'
277	jonathan	481
278	jonathan	492	If 'clazz' is None a default classification is created
279			"""
280	jonathan	481
281	jonathan	529	# prevent infinite recursion when calling SetLayer()
282			if self.__setClassLock: return
283
284			self.__setClassLock = True
285
286	jonathan	492	if clazz is None:
287	jonathan	529	if self.__classification is not None:
288			self.__classification.SetLayer(None)
289	jonathan	492	self.__classification = classification.Classification()
290			else:
291			self.__classification = clazz
292	jonathan	529	try:
293			self.__classification.SetLayer(self)
294			except ValueError:
295			self.__setClassLock = False
296			raise ValueError
297	jonathan	492
298	jonathan	545	self.changed(LAYER_CHANGED, self)
299	jonathan	412
300	jonathan	529	self.__setClassLock = False
301
302	jonathan	492	def ClassChanged(self):
303			"""Called from the classification object when it has changed."""
304			self.changed(LAYER_LEGEND_CHANGED, self)
305
306	bh	217	def TreeInfo(self):
307			items = []
308
309			if self.Visible():
310	jan	374	items.append(_("Shown"))
311	bh	217	else:
312	jan	374	items.append(_("Hidden"))
313			items.append(_("Shapes: %d") % self.NumShapes())
314	bh	217
315			bbox = self.LatLongBoundingBox()
316			if bbox is not None:
317	jan	374	items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
318	bh	217	else:
319	jan	374	items.append(_("Extent (lat-lon):"))
320			items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
321	bh	217
322	jonathan	412	items.append(self.__classification)
323	bh	217
324	jan	374	return (_("Layer '%s'") % self.Title(), items)
325	jonathan	382
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision