Thuban/Model/layer.py

# Copyright (c) 2001 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 shapelib

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, 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)
        self.filename = filename
        self.projection = projection
        self.fill = fill
        self.stroke = stroke
        self.shapefile = None
        # 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]
            self.bbox = mins[:2] + maxs[:2]

    def BoundingBox(self):
        """Return the bounding box of the layer's shapes in their default
        coordinate system"""
        self.open_shapefile()
        return self.bbox

    def LatLongBoundingBox(self):
        """Return the layer's bounding box in lat/long coordinates"""
        llx, lly, urx, ury = self.BoundingBox()
        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

    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 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)
1	bh	6	# Copyright (c) 2001 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 shapelib
11
12			from messages import LAYER_PROJECTION_CHANGED, LAYER_LEGEND_CHANGED, \
13			LAYER_VISIBILITY_CHANGED
14
15			from color import Color
16			# Some predefined colors for internal use
17			_black = Color(0, 0, 0)
18
19
20			from table import Table
21
22			from base import TitledObject, Modifiable
23
24			class Shape:
25
26			"""Represent one shape"""
27
28			def __init__(self, points):
29			self.points = points
30			#self.compute_bbox()
31
32			def compute_bbox(self):
33			xs = []
34			ys = []
35			for x, y in self.points:
36			xs.append(x)
37			ys.append(y)
38			self.llx = min(xs)
39			self.lly = min(ys)
40			self.urx = max(xs)
41			self.ury = max(ys)
42
43			def Points(self):
44			return self.points
45
46
47
48			# Shape type constants
49			SHAPETYPE_POLYGON = "polygon"
50			SHAPETYPE_ARC = "arc"
51			SHAPETYPE_POINT = "point"
52
53			# mapping from shapelib shapetype constants to our constants
54			shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
55			shapelib.SHPT_ARC: SHAPETYPE_ARC,
56			shapelib.SHPT_POINT: SHAPETYPE_POINT}
57
58			shapetype_names = {SHAPETYPE_POINT: "Point",
59			SHAPETYPE_ARC: "Arc",
60			SHAPETYPE_POLYGON: "Polygon"}
61
62			class BaseLayer(TitledObject, Modifiable):
63
64			"""Base class for the layers."""
65
66			def __init__(self, title, visible = 1):
67			"""Initialize the layer.
68
69			title -- the title
70			visible -- boolean. If true the layer is visible.
71			"""
72			TitledObject.__init__(self, title)
73			Modifiable.__init__(self)
74			self.visible = visible
75
76			def Visible(self):
77			"""Return true if layer is visible"""
78			return self.visible
79
80			def SetVisible(self, visible):
81			"""Set the layer's visibility."""
82			self.visible = visible
83			self.issue(LAYER_VISIBILITY_CHANGED, self)
84
85
86			class Layer(BaseLayer):
87
88			"""Represent the information of one geodata file (currently a shapefile)
89
90			All children of the layer have the same type.
91
92			A layer has fill and stroke colors. Colors should be instances of
93			Color. They can also be None, indicating no fill or no stroke.
94
95			The layer objects send the following events, all of which have the
96			layer object as parameter:
97
98			TITLE_CHANGED -- The title has changed.
99			LAYER_PROJECTION_CHANGED -- the projection has changed.
100			LAYER_LEGEND_CHANGED -- the fill or stroke attributes have changed
101
102			"""
103
104			def __init__(self, title, filename, projection = None,
105			fill = None, stroke = _black, visible = 1):
106			"""Initialize the layer.
107
108			title -- the title
109			filename -- the name of the shapefile
110			projection -- the projection object. Its Inverse method is
111			assumed to map the layer's coordinates to lat/long
112			coordinates
113			fill -- the fill color or None if the shapes are not filled
114			stroke -- the stroke color or None if the shapes are not stroked
115			visible -- boolean. If true the layer is visible.
116
117			colors are expected to be instances of Color class
118			"""
119			BaseLayer.__init__(self, title, visible = visible)
120			self.filename = filename
121			self.projection = projection
122			self.fill = fill
123			self.stroke = stroke
124			self.shapefile = None
125			# shapetable is the table associated with the shapefile, while
126			# table is the default table used to look up attributes for
127			# display
128			self.shapetable = Table(filename)
129			self.table = self.shapetable
130
131			def open_shapefile(self):
132			if self.shapefile is None:
133			self.shapefile = shapelib.ShapeFile(self.filename)
134			numshapes, shapetype, mins, maxs = self.shapefile.info()
135			self.numshapes = numshapes
136			self.shapetype = shapelib_shapetypes[shapetype]
137			self.bbox = mins[:2] + maxs[:2]
138
139			def BoundingBox(self):
140			"""Return the bounding box of the layer's shapes in their default
141			coordinate system"""
142			self.open_shapefile()
143			return self.bbox
144
145			def LatLongBoundingBox(self):
146			"""Return the layer's bounding box in lat/long coordinates"""
147			llx, lly, urx, ury = self.BoundingBox()
148			if self.projection is not None:
149			llx, lly = self.projection.Inverse(llx, lly)
150			urx, ury = self.projection.Inverse(urx, ury)
151			return llx, lly, urx, ury
152
153			def NumShapes(self):
154			"""Return the number of shapes in the layer"""
155			self.open_shapefile()
156			return self.numshapes
157
158			def ShapeType(self):
159			"""Return the type of the shapes in the layer.
160			This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
161			"""
162			self.open_shapefile()
163			return self.shapetype
164
165			def Shape(self, index):
166			"""Return the shape with index index"""
167			self.open_shapefile()
168			shape = self.shapefile.read_object(index)
169			if self.shapetype == SHAPETYPE_POINT:
170			points = shape.vertices()
171			else:
172			#for poly in shape.vertices():
173			poly = shape.vertices()[0]
174			points = []
175			for x, y in poly:
176			points.append(x, y)
177			return Shape(points)
178
179			def SetProjection(self, projection):
180			"""Set the layer's projection"""
181			self.projection = projection
182			self.changed(LAYER_PROJECTION_CHANGED, self)
183
184			def SetFill(self, fill):
185			"""Set the layer's fill color. None means the shapes are not filled"""
186			self.fill = fill
187			self.changed(LAYER_LEGEND_CHANGED, self)
188
189			def SetStroke(self, stroke):
190			"""Set the layer's stroke color. None means the shapes are not
191			stroked."""
192			self.stroke = stroke
193			self.changed(LAYER_LEGEND_CHANGED, self)
Name	Value
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svn:keywords	Author Date Id Revision