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()

    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.
    """

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