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

from Thuban import _

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 classification 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 = 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

        self.classification = Classification(self)
        self.classification.SetDefaultStroke(stroke)
        self.classification.SetDefaultStrokeWidth(stroke_width)
        self.classification.SetDefaultFill(fill)

        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.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 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)

        # layers will always have a classification with at least a NULL data set

        #items.append((_("Fill: %s") % color_string(self.fill), self.fill))
        #items.append((_("Outline: %s") % color_string(self.stroke), self.stroke))

        items.append(self.classification)

        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	from Thuban import _
14
15	import shapelib, shptree
16
17	from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
18	LAYER_VISIBILITY_CHANGED
19
20	from color import Color
21	# Some predefined colors for internal use
22	_black = Color(0, 0, 0)
23
24	from classification import Classification
25
26	from table import Table
27
28	from base import TitledObject, Modifiable
29
30	class Shape:
31
32	"""Represent one shape"""
33
34	def __init__(self, points):
35	self.points = points
36	#self.compute_bbox()
37
38	def compute_bbox(self):
39	xs = []
40	ys = []
41	for x, y in self.points:
42	xs.append(x)
43	ys.append(y)
44	self.llx = min(xs)
45	self.lly = min(ys)
46	self.urx = max(xs)
47	self.ury = max(ys)
48
49	def Points(self):
50	return self.points
51
52
53
54	# Shape type constants
55	SHAPETYPE_POLYGON = "polygon"
56	SHAPETYPE_ARC = "arc"
57	SHAPETYPE_POINT = "point"
58
59	# mapping from shapelib shapetype constants to our constants
60	shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
61	shapelib.SHPT_ARC: SHAPETYPE_ARC,
62	shapelib.SHPT_POINT: SHAPETYPE_POINT}
63
64	shapetype_names = {SHAPETYPE_POINT: "Point",
65	SHAPETYPE_ARC: "Arc",
66	SHAPETYPE_POLYGON: "Polygon"}
67
68	class BaseLayer(TitledObject, Modifiable):
69
70	"""Base class for the layers."""
71
72	def __init__(self, title, visible = 1):
73	"""Initialize the layer.
74
75	title -- the title
76	visible -- boolean. If true the layer is visible.
77	"""
78	TitledObject.__init__(self, title)
79	Modifiable.__init__(self)
80	self.visible = visible
81
82	def Visible(self):
83	"""Return true if layer is visible"""
84	return self.visible
85
86	def SetVisible(self, visible):
87	"""Set the layer's visibility."""
88	self.visible = visible
89	self.issue(LAYER_VISIBILITY_CHANGED, self)
90
91
92	class Layer(BaseLayer):
93
94	"""Represent the information of one geodata file (currently a shapefile)
95
96	All children of the layer have the same type.
97
98	A layer has fill and stroke colors. Colors should be instances of
99	Color. They can also be None, indicating no fill or no stroke.
100
101	The layer objects send the following events, all of which have the
102	layer object as parameter:
103
104	TITLE_CHANGED -- The title has changed.
105	LAYER_PROJECTION_CHANGED -- the projection has changed.
106	LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed
107
108	"""
109
110	def __init__(self, title, filename, projection = None,
111	fill = None, stroke = _black, stroke_width = 1, visible = 1):
112	"""Initialize the layer.
113
114	title -- the title
115	filename -- the name of the shapefile
116	projection -- the projection object. Its Inverse method is
117	assumed to map the layer's coordinates to lat/long
118	coordinates
119	fill -- the fill color or None if the shapes are not filled
120	stroke -- the stroke color or None if the shapes are not stroked
121	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
127	# Make the filename absolute. The filename will be
128	# interpreted relative to that anyway, but when saving a
129	# session we need to compare absolute paths and it's usually
130	# safer to always work with absolute paths.
131	self.filename = os.path.abspath(filename)
132
133	self.projection = projection
134	self.fill = fill
135	self.stroke = stroke
136	self.stroke_width = stroke_width
137	self.shapefile = None
138	self.shapetree = None
139	self.open_shapefile()
140	# shapetable is the table associated with the shapefile, while
141	# table is the default table used to look up attributes for
142	# display
143	self.shapetable = Table(filename)
144	self.table = self.shapetable
145
146	self.classification = Classification(self)
147	self.classification.SetDefaultStroke(stroke)
148	self.classification.SetDefaultStrokeWidth(stroke_width)
149	self.classification.SetDefaultFill(fill)
150
151	self.UnsetModified()
152
153	def open_shapefile(self):
154	if self.shapefile is None:
155	self.shapefile = shapelib.ShapeFile(self.filename)
156	numshapes, shapetype, mins, maxs = self.shapefile.info()
157	self.numshapes = numshapes
158	self.shapetype = shapelib_shapetypes[shapetype]
159
160	# if there are shapes, set the bbox accordinly. Otherwise
161	# set it to None.
162	if self.numshapes:
163	self.bbox = mins[:2] + maxs[:2]
164	else:
165	self.bbox = None
166
167	# estimate a good depth for the quad tree. Each depth
168	# multiplies the number of nodes by four, therefore we
169	# basically take the base 4 logarithm of the number of
170	# shapes.
171	if self.numshapes < 4:
172	maxdepth = 1
173	else:
174	maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
175
176	self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
177	maxdepth)
178
179	def Destroy(self):
180	BaseLayer.Destroy(self)
181	if self.shapefile is not None:
182	self.shapefile.close()
183	self.shapefile = None
184	self.shapetree = None
185	self.table.Destroy()
186
187	def BoundingBox(self):
188	"""Return the layer's bounding box in the intrinsic coordinate system.
189
190	If the layer has no shapes, return None.
191	"""
192	# The bbox will be set by open_shapefile just as we need it
193	# here.
194	self.open_shapefile()
195	return self.bbox
196
197	def LatLongBoundingBox(self):
198	"""Return the layer's bounding box in lat/long coordinates.
199
200	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	def NumShapes(self):
213	"""Return the number of shapes in the layer"""
214	self.open_shapefile()
215	return self.numshapes
216
217	def ShapeType(self):
218	"""Return the type of the shapes in the layer.
219	This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
220	"""
221	self.open_shapefile()
222	return self.shapetype
223
224	def Shape(self, index):
225	"""Return the shape with index index"""
226	self.open_shapefile()
227	shape = self.shapefile.read_object(index)
228
229	if self.shapetype == SHAPETYPE_POINT:
230	points = shape.vertices()
231	else:
232	#for poly in shape.vertices():
233	poly = shape.vertices()[0]
234	points = []
235	for x, y in poly:
236	points.append((x, y))
237
238	return Shape(points)
239
240	def ShapesInRegion(self, box):
241	"""Return the ids of the shapes that overlap the box.
242
243	Box is a tuple (left, bottom, right, top) in the coordinate
244	system used by the layer's shapefile.
245	"""
246	left, bottom, right, top = box
247	return self.shapetree.find_shapes((left, bottom), (right, top))
248
249	def SetProjection(self, projection):
250	"""Set the layer's projection"""
251	self.projection = projection
252	self.changed(LAYER_PROJECTION_CHANGED, self)
253
254	def TreeInfo(self):
255	items = []
256
257	if self.Visible():
258	items.append(_("Shown"))
259	else:
260	items.append(_("Hidden"))
261	items.append(_("Shapes: %d") % self.NumShapes())
262
263	bbox = self.LatLongBoundingBox()
264	if bbox is not None:
265	items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
266	else:
267	items.append(_("Extent (lat-lon):"))
268	items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
269
270	def color_string(color):
271	if color is None:
272	return "None"
273	return "(%.3f, %.3f, %.3f)" % (color.red, color.green, color.blue)
274
275	# layers will always have a classification with at least a NULL data set
276
277	#items.append((_("Fill: %s") % color_string(self.fill), self.fill))
278	#items.append((_("Outline: %s") % color_string(self.stroke), self.stroke))
279
280	items.append(self.classification)
281
282	return (_("Layer '%s'") % self.Title(), items)
283
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision