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

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):
        """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.
    """

    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)

        self.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()
        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 GetProjection(self):
        return self.projection

    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_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()])

        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)


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	bh	701	from messages import LAYER_PROJECTION_CHANGED, LAYER_VISIBILITY_CHANGED, \
18			LAYER_CHANGED
19	bh	6
20			from color import Color
21
22	jonathan	437	import classification
23	bh	6
24			from base import TitledObject, Modifiable
25
26	bh	723
27	bh	6	class Shape:
28
29			"""Represent one shape"""
30
31			def __init__(self, points):
32			self.points = points
33			#self.compute_bbox()
34	jonathan	828	self.bbox = None
35	bh	6
36			def compute_bbox(self):
37	jonathan	828	if self.bbox is not None:
38			return self.bbox
39
40	bh	6	xs = []
41			ys = []
42			for x, y in self.points:
43			xs.append(x)
44			ys.append(y)
45			self.llx = min(xs)
46			self.lly = min(ys)
47			self.urx = max(xs)
48			self.ury = max(ys)
49
50	jonathan	828	self.bbox = (self.llx, self.lly, self.urx, self.ury)
51
52			return self.bbox
53
54	bh	6	def Points(self):
55			return self.points
56
57
58
59			# Shape type constants
60			SHAPETYPE_POLYGON = "polygon"
61			SHAPETYPE_ARC = "arc"
62			SHAPETYPE_POINT = "point"
63
64			# mapping from shapelib shapetype constants to our constants
65			shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
66			shapelib.SHPT_ARC: SHAPETYPE_ARC,
67			shapelib.SHPT_POINT: SHAPETYPE_POINT}
68
69			shapetype_names = {SHAPETYPE_POINT: "Point",
70			SHAPETYPE_ARC: "Arc",
71			SHAPETYPE_POLYGON: "Polygon"}
72
73			class BaseLayer(TitledObject, Modifiable):
74
75			"""Base class for the layers."""
76
77	jonathan	771	def __init__(self, title, visible = True):
78	bh	6	"""Initialize the layer.
79
80			title -- the title
81			visible -- boolean. If true the layer is visible.
82			"""
83			TitledObject.__init__(self, title)
84			Modifiable.__init__(self)
85			self.visible = visible
86
87			def Visible(self):
88			"""Return true if layer is visible"""
89			return self.visible
90
91			def SetVisible(self, visible):
92			"""Set the layer's visibility."""
93			self.visible = visible
94			self.issue(LAYER_VISIBILITY_CHANGED, self)
95	bh	276
96
97	bh	6	class Layer(BaseLayer):
98
99			"""Represent the information of one geodata file (currently a shapefile)
100
101			All children of the layer have the same type.
102
103			A layer has fill and stroke colors. Colors should be instances of
104			Color. They can also be None, indicating no fill or no stroke.
105
106			The layer objects send the following events, all of which have the
107			layer object as parameter:
108
109			TITLE_CHANGED -- The title has changed.
110			LAYER_PROJECTION_CHANGED -- the projection has changed.
111			"""
112
113	bh	723	def __init__(self, title, data, projection = None,
114	jonathan	610	fill = Color.Transparent,
115	jonathan	412	stroke = Color.Black,
116	jonathan	464	lineWidth = 1,
117	jonathan	771	visible = True):
118	bh	6	"""Initialize the layer.
119
120			title -- the title
121	bh	723	data -- datastore object for the shape data shown by the layer
122	bh	6	projection -- the projection object. Its Inverse method is
123			assumed to map the layer's coordinates to lat/long
124			coordinates
125	jonathan	610	fill -- the fill color or Color.Transparent if the shapes are
126			not filled
127			stroke -- the stroke color or Color.Transparent if the shapes
128			are not stroked
129	bh	6	visible -- boolean. If true the layer is visible.
130
131			colors are expected to be instances of Color class
132			"""
133			BaseLayer.__init__(self, title, visible = visible)
134	bh	276
135	bh	6	self.projection = projection
136
137	jonathan	481	#
138			# this is really important so that when the classification class
139			# tries to set its parent layer the variable will exist
140			#
141	bh	723	self.__classification = None
142	jonathan	529	self.__setClassLock = False
143	jonathan	481
144	bh	723	self.SetShapeStore(data)
145	jonathan	492
146			self.SetClassification(None)
147
148	jonathan	464	self.__classification.SetDefaultLineColor(stroke)
149			self.__classification.SetDefaultLineWidth(lineWidth)
150	jonathan	412	self.__classification.SetDefaultFill(fill)
151	jonathan	492	self.__classification.SetLayer(self)
152	jonathan	364
153	jonathan	389	self.UnsetModified()
154
155	bh	6
156	bh	723	def SetShapeStore(self, store):
157			self.store = store
158			self.shapefile = self.store.Shapefile()
159			self.shapetable = self.store.Table()
160			self.filename = self.store.filename
161			self.table = self.shapetable
162	bh	179
163	bh	723	numshapes, shapetype, mins, maxs = self.shapefile.info()
164			self.numshapes = numshapes
165			self.shapetype = shapelib_shapetypes[shapetype]
166	bh	171
167	bh	723	# if there are shapes, set the bbox accordingly. Otherwise
168			# set it to None.
169			if self.numshapes:
170			self.bbox = mins[:2] + maxs[:2]
171			else:
172			self.bbox = None
173	bh	171
174	bh	723	# estimate a good depth for the quad tree. Each depth
175			# multiplies the number of nodes by four, therefore we
176			# basically take the base 4 logarithm of the number of
177			# shapes.
178			if self.numshapes < 4:
179			maxdepth = 1
180			else:
181			maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
182
183			self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
184			maxdepth)
185			if self.__classification is not None:
186			fieldname = self.__classification.GetField()
187	jan	791	if fieldname is not None and \
188	bh	839	not self.store.Table().HasColumn(fieldname):
189	bh	723	self.SetClassification(None)
190			self.changed(LAYER_CHANGED, self)
191
192			def ShapeStore(self):
193			return self.store
194
195	bh	258	def Destroy(self):
196	bh	260	BaseLayer.Destroy(self)
197	jonathan	529	self.SetClassification(None)
198	bh	258
199	bh	6	def BoundingBox(self):
200	bh	179	"""Return the layer's bounding box in the intrinsic coordinate system.
201
202			If the layer has no shapes, return None.
203			"""
204	bh	6	return self.bbox
205
206			def LatLongBoundingBox(self):
207	bh	179	"""Return the layer's bounding box in lat/long coordinates.
208	bh	6
209	bh	179	Return None, if the layer doesn't contain any shapes.
210			"""
211			bbox = self.BoundingBox()
212			if bbox is not None:
213			llx, lly, urx, ury = bbox
214			if self.projection is not None:
215			llx, lly = self.projection.Inverse(llx, lly)
216			urx, ury = self.projection.Inverse(urx, ury)
217			return llx, lly, urx, ury
218			else:
219			return None
220
221	jonathan	828	def ShapesBoundingBox(self, shapes):
222			"""Return a bounding box in lat/long coordinates for the given
223			list of shape ids.
224
225			If shapes is None or empty, return None.
226			"""
227
228			if shapes is None or len(shapes) == 0: return None
229
230			llx = []
231			lly = []
232			urx = []
233			ury = []
234
235			if self.projection is not None:
236			inverse = lambda x, y: self.projection.Inverse(x, y)
237			else:
238			inverse = lambda x, y: (x, y)
239
240			for id in shapes:
241			left, bottom, right, top = self.Shape(id).compute_bbox()
242
243			left, bottom = inverse(left, bottom)
244			right, top = inverse(right, top)
245
246			llx.append(left)
247			lly.append(bottom)
248			urx.append(right)
249			ury.append(top)
250
251			return (min(llx), min(lly), max(urx), max(ury))
252
253	jonathan	464	def GetFieldType(self, fieldName):
254	bh	839	if self.table.HasColumn(fieldName):
255			return self.table.Column(fieldName).type
256			return None
257	jonathan	464
258	bh	6	def NumShapes(self):
259			"""Return the number of shapes in the layer"""
260			return self.numshapes
261
262			def ShapeType(self):
263			"""Return the type of the shapes in the layer.
264			This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
265			"""
266			return self.shapetype
267
268			def Shape(self, index):
269			"""Return the shape with index index"""
270			shape = self.shapefile.read_object(index)
271	jonathan	364
272	bh	6	if self.shapetype == SHAPETYPE_POINT:
273			points = shape.vertices()
274			else:
275			#for poly in shape.vertices():
276			poly = shape.vertices()[0]
277			points = []
278			for x, y in poly:
279	bh	82	points.append((x, y))
280	jonathan	364
281	bh	6	return Shape(points)
282
283	bh	143	def ShapesInRegion(self, box):
284			"""Return the ids of the shapes that overlap the box.
285
286	jonathan	794	Box is a tuple (left, bottom, right, top) in unprojected coordinates.
287	bh	143	"""
288			left, bottom, right, top = box
289	jonathan	794
290			if self.projection is not None:
291			left, bottom = self.projection.Forward(left, bottom)
292			right, top = self.projection.Forward(right, top)
293
294	bh	147	return self.shapetree.find_shapes((left, bottom), (right, top))
295	bh	143
296	jonathan	725	def GetProjection(self):
297			return self.projection
298
299	bh	6	def SetProjection(self, projection):
300			"""Set the layer's projection"""
301			self.projection = projection
302			self.changed(LAYER_PROJECTION_CHANGED, self)
303
304	jonathan	412	def GetClassification(self):
305			return self.__classification
306
307			def SetClassification(self, clazz):
308	jonathan	492	"""Set the classification to 'clazz'
309	jonathan	481
310	jonathan	492	If 'clazz' is None a default classification is created
311			"""
312	jonathan	481
313	jonathan	529	# prevent infinite recursion when calling SetLayer()
314			if self.__setClassLock: return
315
316			self.__setClassLock = True
317
318	jonathan	492	if clazz is None:
319	jonathan	529	if self.__classification is not None:
320			self.__classification.SetLayer(None)
321	jonathan	492	self.__classification = classification.Classification()
322			else:
323			self.__classification = clazz
324	jonathan	529	try:
325			self.__classification.SetLayer(self)
326			except ValueError:
327			self.__setClassLock = False
328			raise ValueError
329	jonathan	492
330	jonathan	545	self.changed(LAYER_CHANGED, self)
331	jonathan	412
332	jonathan	529	self.__setClassLock = False
333
334	jonathan	492	def ClassChanged(self):
335			"""Called from the classification object when it has changed."""
336	jonathan	558	self.changed(LAYER_CHANGED, self)
337	jonathan	492
338	bh	217	def TreeInfo(self):
339			items = []
340
341			if self.Visible():
342	jan	374	items.append(_("Shown"))
343	bh	217	else:
344	jan	374	items.append(_("Hidden"))
345			items.append(_("Shapes: %d") % self.NumShapes())
346	bh	217
347			bbox = self.LatLongBoundingBox()
348			if bbox is not None:
349	jan	374	items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
350	bh	217	else:
351	jan	374	items.append(_("Extent (lat-lon):"))
352			items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
353	bh	217
354	jonathan	736	if self.projection and len(self.projection.params) > 0:
355			items.append((_("Projection"),
356			[str(param) for param in self.projection.params]))
357
358	jonathan	412	items.append(self.__classification)
359	bh	217
360	jan	374	return (_("Layer '%s'") % self.Title(), items)
361	jonathan	382
362	jonathan	736
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision