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	# 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
svn:eol-style	native
svn:keywords	Author Date Id Revision