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	bh	73	# Copyright (c) 2001, 2002 by Intevation GmbH
2	bh	6	# 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	bh	276	import os
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			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	jonathan	364	from classification import Classification
25	bh	6
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	bh	276
91
92	bh	6	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	bh	73	fill = None, stroke = _black, stroke_width = 1, visible = 1):
112	bh	6	"""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	bh	276
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	bh	6	self.projection = projection
134			self.fill = fill
135			self.stroke = stroke
136	bh	73	self.stroke_width = stroke_width
137	bh	6	self.shapefile = None
138	bh	143	self.shapetree = None
139	bh	21	self.open_shapefile()
140	bh	6	# 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	jonathan	389	self.classification = Classification(self)
147			self.classification.SetDefaultStroke(stroke)
148			self.classification.SetDefaultStrokeWidth(stroke_width)
149			self.classification.SetDefaultFill(fill)
150	jonathan	364
151	jonathan	389	self.UnsetModified()
152
153	bh	6	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	bh	179	# 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	bh	171	# 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	bh	258	def Destroy(self):
180	bh	260	BaseLayer.Destroy(self)
181	bh	258	if self.shapefile is not None:
182			self.shapefile.close()
183			self.shapefile = None
184			self.shapetree = None
185			self.table.Destroy()
186
187	bh	6	def BoundingBox(self):
188	bh	179	"""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	bh	6	self.open_shapefile()
195			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	bh	6	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	jonathan	364
229	bh	6	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	bh	82	points.append((x, y))
237	jonathan	364
238	bh	6	return Shape(points)
239
240	bh	143	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	bh	147	return self.shapetree.find_shapes((left, bottom), (right, top))
248	bh	143
249	bh	6	def SetProjection(self, projection):
250			"""Set the layer's projection"""
251			self.projection = projection
252			self.changed(LAYER_PROJECTION_CHANGED, self)
253
254	bh	217	def TreeInfo(self):
255			items = []
256
257			if self.Visible():
258	jan	374	items.append(_("Shown"))
259	bh	217	else:
260	jan	374	items.append(_("Hidden"))
261			items.append(_("Shapes: %d") % self.NumShapes())
262	bh	217
263			bbox = self.LatLongBoundingBox()
264			if bbox is not None:
265	jan	374	items.append(_("Extent (lat-lon): (%g, %g, %g, %g)") % bbox)
266	bh	217	else:
267	jan	374	items.append(_("Extent (lat-lon):"))
268			items.append(_("Shapetype: %s") % shapetype_names[self.ShapeType()])
269	bh	217
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	jonathan	382	# 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	jan	374	return (_("Layer '%s'") % self.Title(), items)
283	jonathan	382
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision