Thuban/Model/layer.py

# Copyright (c) 2001, 2002 by Intevation GmbH
# Authors:
# Bernhard Herzog <[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

import shapelib, shptree

from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
     LAYER_VISIBILITY_CHANGED

from color import Color
# Some predefined colors for internal use
_black = Color(0, 0, 0)


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 = None, stroke = _black, stroke_width = 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 None if the shapes are not filled
        stroke -- the stroke color or 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.fill = fill
        self.stroke = stroke
        self.stroke_width = stroke_width
        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

    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.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 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 SetFill(self, fill):
        """Set the layer's fill color. None means the shapes are not filled"""
        self.fill = fill
        self.changed(LAYER_LEGEND_CHANGED, self)

    def SetStroke(self, stroke):
        """Set the layer's stroke color. None means the shapes are not
        stroked."""
        self.stroke = stroke
        self.changed(LAYER_LEGEND_CHANGED, self)

    def SetStrokeWidth(self, width):
        """Set the layer's stroke width."""
        self.stroke_width = width
        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()])

        def color_string(color):
            if color is None:
                return "None"
            return "(%.3f, %.3f, %.3f)" % (color.red, color.green, color.blue)
        items.append("Fill: " + color_string(self.fill))
        items.append("Outline: " + color_string(self.stroke))

        return ("Layer '%s'" % self.Title(), items)
1	# Copyright (c) 2001, 2002 by Intevation GmbH
2	# Authors:
3	# Bernhard Herzog <[email protected]>
4	#
5	# This program is free software under the GPL (>=v2)
6	# Read the file COPYING coming with Thuban for details.
7
8	__version__ = "$Revision$"
9
10	import os
11	from math import log, ceil
12
13	import shapelib, shptree
14
15	from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
16	LAYER_VISIBILITY_CHANGED
17
18	from color import Color
19	# Some predefined colors for internal use
20	_black = Color(0, 0, 0)
21
22
23	from table import Table
24
25	from base import TitledObject, Modifiable
26
27	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
88
89	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	LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed
104
105	"""
106
107	def __init__(self, title, filename, projection = None,
108	fill = None, stroke = _black, stroke_width = 1, visible = 1):
109	"""Initialize the layer.
110
111	title -- the title
112	filename -- the name of the shapefile
113	projection -- the projection object. Its Inverse method is
114	assumed to map the layer's coordinates to lat/long
115	coordinates
116	fill -- the fill color or None if the shapes are not filled
117	stroke -- the stroke color or None if the shapes are not stroked
118	visible -- boolean. If true the layer is visible.
119
120	colors are expected to be instances of Color class
121	"""
122	BaseLayer.__init__(self, title, visible = visible)
123
124	# Make the filename absolute. The filename will be
125	# interpreted relative to that anyway, but when saving a
126	# session we need to compare absolute paths and it's usually
127	# safer to always work with absolute paths.
128	self.filename = os.path.abspath(filename)
129
130	self.projection = projection
131	self.fill = fill
132	self.stroke = stroke
133	self.stroke_width = stroke_width
134	self.shapefile = None
135	self.shapetree = None
136	self.open_shapefile()
137	# shapetable is the table associated with the shapefile, while
138	# table is the default table used to look up attributes for
139	# display
140	self.shapetable = Table(filename)
141	self.table = self.shapetable
142
143	def open_shapefile(self):
144	if self.shapefile is None:
145	self.shapefile = shapelib.ShapeFile(self.filename)
146	numshapes, shapetype, mins, maxs = self.shapefile.info()
147	self.numshapes = numshapes
148	self.shapetype = shapelib_shapetypes[shapetype]
149
150	# if there are shapes, set the bbox accordinly. Otherwise
151	# set it to None.
152	if self.numshapes:
153	self.bbox = mins[:2] + maxs[:2]
154	else:
155	self.bbox = None
156
157	# estimate a good depth for the quad tree. Each depth
158	# multiplies the number of nodes by four, therefore we
159	# basically take the base 4 logarithm of the number of
160	# shapes.
161	if self.numshapes < 4:
162	maxdepth = 1
163	else:
164	maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
165
166	self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
167	maxdepth)
168
169	def Destroy(self):
170	BaseLayer.Destroy(self)
171	if self.shapefile is not None:
172	self.shapefile.close()
173	self.shapefile = None
174	self.shapetree = None
175	self.table.Destroy()
176
177	def BoundingBox(self):
178	"""Return the layer's bounding box in the intrinsic coordinate system.
179
180	If the layer has no shapes, return None.
181	"""
182	# The bbox will be set by open_shapefile just as we need it
183	# here.
184	self.open_shapefile()
185	return self.bbox
186
187	def LatLongBoundingBox(self):
188	"""Return the layer's bounding box in lat/long coordinates.
189
190	Return None, if the layer doesn't contain any shapes.
191	"""
192	bbox = self.BoundingBox()
193	if bbox is not None:
194	llx, lly, urx, ury = bbox
195	if self.projection is not None:
196	llx, lly = self.projection.Inverse(llx, lly)
197	urx, ury = self.projection.Inverse(urx, ury)
198	return llx, lly, urx, ury
199	else:
200	return None
201
202	def NumShapes(self):
203	"""Return the number of shapes in the layer"""
204	self.open_shapefile()
205	return self.numshapes
206
207	def ShapeType(self):
208	"""Return the type of the shapes in the layer.
209	This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
210	"""
211	self.open_shapefile()
212	return self.shapetype
213
214	def Shape(self, index):
215	"""Return the shape with index index"""
216	self.open_shapefile()
217	shape = self.shapefile.read_object(index)
218	if self.shapetype == SHAPETYPE_POINT:
219	points = shape.vertices()
220	else:
221	#for poly in shape.vertices():
222	poly = shape.vertices()[0]
223	points = []
224	for x, y in poly:
225	points.append((x, y))
226	return Shape(points)
227
228	def ShapesInRegion(self, box):
229	"""Return the ids of the shapes that overlap the box.
230
231	Box is a tuple (left, bottom, right, top) in the coordinate
232	system used by the layer's shapefile.
233	"""
234	left, bottom, right, top = box
235	return self.shapetree.find_shapes((left, bottom), (right, top))
236
237	def SetProjection(self, projection):
238	"""Set the layer's projection"""
239	self.projection = projection
240	self.changed(LAYER_PROJECTION_CHANGED, self)
241
242	def SetFill(self, fill):
243	"""Set the layer's fill color. None means the shapes are not filled"""
244	self.fill = fill
245	self.changed(LAYER_LEGEND_CHANGED, self)
246
247	def SetStroke(self, stroke):
248	"""Set the layer's stroke color. None means the shapes are not
249	stroked."""
250	self.stroke = stroke
251	self.changed(LAYER_LEGEND_CHANGED, self)
252
253	def SetStrokeWidth(self, width):
254	"""Set the layer's stroke width."""
255	self.stroke_width = width
256	self.changed(LAYER_LEGEND_CHANGED, self)
257
258	def TreeInfo(self):
259	items = []
260
261	if self.Visible():
262	items.append("Shown")
263	else:
264	items.append("Hidden")
265	items.append("Shapes: %d" % self.NumShapes())
266
267	bbox = self.LatLongBoundingBox()
268	if bbox is not None:
269	items.append("Extent (lat-lon): (%g, %g, %g, %g)" % bbox)
270	else:
271	items.append("Extent (lat-lon):")
272	items.append("Shapetype: %s" % shapetype_names[self.ShapeType()])
273
274	def color_string(color):
275	if color is None:
276	return "None"
277	return "(%.3f, %.3f, %.3f)" % (color.red, color.green, color.blue)
278	items.append("Fill: " + color_string(self.fill))
279	items.append("Outline: " + color_string(self.stroke))
280
281	return ("Layer '%s'" % self.Title(), items)
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision