Thuban/Model/save.py

# Copyright (c) 2001, 2002, 2003 by Intevation GmbH
# Authors:
# Jan-Oliver Wagner <[email protected]>
# Bernhard Herzog <[email protected]>
# Jonathan Coles <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

"""
Functions to save a session to a file
"""

__version__ = "$Revision$"

import os

import Thuban.Lib.fileutil

from Thuban.Model.color import Color 
from Thuban.Model.layer import Layer, RasterLayer

from Thuban.Model.classification import \
    ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap

from Thuban.Model.xmlwriter import XMLWriter

def relative_filename(dir, filename):
    """Return a filename relative to dir for the absolute file name absname.

    This is almost the same as the function in fileutil, except that dir
    can be an empty string in which case filename will be returned
    unchanged.
    """
    if dir:
        return Thuban.Lib.fileutil.relative_filename(dir, filename)
    else:
        return filename

class SessionSaver(XMLWriter):

    """Class to serialize a session into an XML file.

    Applications built on top of Thuban may derive from this class and
    override or extend the methods to save additional information. This
    additional information should take the form of additional attributes
    or elements whose names are prefixed with a namespace. To define a
    namespace derived classes should extend the write_session method to
    pass the namespaces to the default implementation.
    """


    def __init__(self, session):
        XMLWriter.__init__(self)
        self.session = session

    def write(self, file_or_filename):
        XMLWriter.write(self, file_or_filename)

        self.write_header("session", "thuban.dtd")
        self.write_session(self.session)
        self.close()

    def write_session(self, session, attrs = None, namespaces = ()):
        """Write the session and its contents

        By default, write a session element with the title attribute and
        call write_map for each map contained in the session.

        The optional argument attrs is for additional attributes and, if
        given, should be a mapping from attribute names to attribute
        values. The values should not be XML-escaped yet.

        The optional argument namespaces, if given, should be a sequence
        of (name, URI) pairs. The namespaces are written as namespace
        attributes into the session element. This is mainly useful for
        derived classes that need to store additional information in a
        thuban session file.
        """
        if attrs is None:
            attrs = {}
        attrs["title"] = session.title
        for name, uri in namespaces:
            attrs["xmlns:" + name] = uri
        self.open_element("session", attrs)
        for map in session.Maps():
            self.write_map(map)
        self.close_element("session")

    def write_map(self, map):
        """Write the map and its contents.

        By default, write a map element element with the title
        attribute, call write_projection to write the projection
        element, call write_layer for each layer contained in the map
        and finally call write_label_layer to write the label layer.
        """
        self.open_element('map title="%s"' % self.encode(map.title))
        self.write_projection(map.projection)
        for layer in map.Layers():
            self.write_layer(layer)
        self.write_label_layer(map.LabelLayer())
        self.close_element('map')

    def write_projection(self, projection):
        """Write the projection.
        """
        if projection and len(projection.params) > 0:
            self.open_element("projection", {"name": projection.GetName()})
            for param in projection.params:
                self.write_element('parameter value="%s"' % 
                                   self.encode(param))
            self.close_element("projection")

    def write_layer(self, layer, attrs = None):
        """Write the layer.

        The optional argument attrs is for additional attributes and, if
        given, should be a mapping from attribute names to attribute
        values. The values should not be XML-escaped yet.
        """

        if attrs is None:
            attrs = {}

        attrs["title"]   = layer.title
        attrs["visible"] = ("false", "true")[int(layer.Visible())]

        if isinstance(layer, Layer):
            attrs["filename"] = relative_filename(self.dir,
                                                layer.ShapeStore().FileName())

            lc = layer.GetClassification()
            attrs["stroke"]       = lc.GetDefaultLineColor().hex()
            attrs["stroke_width"] = str(lc.GetDefaultLineWidth())
            attrs["fill"]         = lc.GetDefaultFill().hex()

            self.open_element("layer", attrs)
            self.write_projection(layer.GetProjection())
            self.write_classification(layer)
            self.close_element("layer")

        elif isinstance(layer, RasterLayer):
            attrs["filename"] = relative_filename(self.dir, layer.filename)
            self.open_element("rasterlayer", attrs)
            self.write_projection(layer.GetProjection())
            self.close_element("rasterlayer")

    def write_classification(self, layer, attrs = None):
        """Write Classification information."""

        if attrs is None:
            attrs = {}

        lc = layer.GetClassification()

        field = lc.GetField()
 
        #
        # there isn't a classification of anything so do nothing
        #
        if field is None: return

        attrs["field"] = field
        attrs["field_type"] = str(lc.GetFieldType())
        self.open_element("classification", attrs)

        for g in lc:
            if isinstance(g, ClassGroupDefault):
                open_el  = 'clnull label="%s"' % self.encode(g.GetLabel())
                close_el = 'clnull'
            elif isinstance(g, ClassGroupSingleton): 
                open_el  = 'clpoint label="%s" value="%s"' \
                           % (self.encode(g.GetLabel()), str(g.GetValue()))
                close_el = 'clpoint'
            elif isinstance(g, ClassGroupRange):
                open_el  = 'clrange label="%s" range="%s"' \
                          % (self.encode(g.GetLabel()), str(g.GetRange()))
                close_el = 'clrange'
            else:
                assert False, _("Unsupported group type in classification")
                continue

            data = g.GetProperties()
            dict = {'stroke'      : data.GetLineColor().hex(),
                    'stroke_width': str(data.GetLineWidth()),
                    'fill'        : data.GetFill().hex()}

            self.open_element(open_el)
            self.write_element("cldata", dict)
            self.close_element(close_el)

        self.close_element("classification")

    def write_label_layer(self, layer):
        """Write the label layer.
        """
        labels = layer.Labels()
        if labels:
            self.open_element('labellayer')
            for label in labels:
                self.write_element(('label x="%g" y="%g" text="%s"'
                                    ' halign="%s" valign="%s"')
                                % (label.x, label.y, 
                                   self.encode(label.text), 
                                   label.halign,
                                   label.valign))
            self.close_element('labellayer')


def save_session(session, file, saver_class = None):
    """Save the session session to a file.

    The file argument may either be a filename or an open file object.

    The optional argument saver_class is the class to use to serialize
    the session. By default or if it's None, the saver class will be
    SessionSaver.

    If writing the session is successful call the session's
    UnsetModified method
    """
    if saver_class is None:
        saver_class = SessionSaver
    saver = saver_class(session)
    saver.write(file)

    # after a successful save consider the session unmodified.
    session.UnsetModified()
1	bh	454	# Copyright (c) 2001, 2002, 2003 by Intevation GmbH
2	bh	6	# Authors:
3			# Jan-Oliver Wagner <[email protected]>
4			# Bernhard Herzog <[email protected]>
5	jonathan	414	# Jonathan Coles <[email protected]>
6	bh	6	#
7			# This program is free software under the GPL (>=v2)
8			# Read the file COPYING coming with Thuban for details.
9
10			"""
11			Functions to save a session to a file
12			"""
13
14			__version__ = "$Revision$"
15
16			import os
17
18	bh	201	import Thuban.Lib.fileutil
19	bh	6
20	jonathan	932	from Thuban.Model.color import Color
21			from Thuban.Model.layer import Layer, RasterLayer
22
23	jonathan	876	from Thuban.Model.classification import \
24			ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap
25	jonathan	429
26	jonathan	1160	from Thuban.Model.xmlwriter import XMLWriter
27	jonathan	366
28	bh	201	def relative_filename(dir, filename):
29			"""Return a filename relative to dir for the absolute file name absname.
30
31			This is almost the same as the function in fileutil, except that dir
32			can be an empty string in which case filename will be returned
33			unchanged.
34			"""
35			if dir:
36			return Thuban.Lib.fileutil.relative_filename(dir, filename)
37			else:
38			return filename
39
40	jonathan	710	class SessionSaver(XMLWriter):
41	bh	268
42	jonathan	697	"""Class to serialize a session into an XML file.
43
44			Applications built on top of Thuban may derive from this class and
45			override or extend the methods to save additional information. This
46			additional information should take the form of additional attributes
47			or elements whose names are prefixed with a namespace. To define a
48			namespace derived classes should extend the write_session method to
49			pass the namespaces to the default implementation.
50			"""
51
52
53			def __init__(self, session):
54	jonathan	710	XMLWriter.__init__(self)
55	jonathan	697	self.session = session
56
57			def write(self, file_or_filename):
58	jonathan	710	XMLWriter.write(self, file_or_filename)
59	jonathan	697
60			self.write_header("session", "thuban.dtd")
61			self.write_session(self.session)
62			self.close()
63
64	bh	268	def write_session(self, session, attrs = None, namespaces = ()):
65			"""Write the session and its contents
66
67			By default, write a session element with the title attribute and
68			call write_map for each map contained in the session.
69
70			The optional argument attrs is for additional attributes and, if
71			given, should be a mapping from attribute names to attribute
72			values. The values should not be XML-escaped yet.
73
74			The optional argument namespaces, if given, should be a sequence
75			of (name, URI) pairs. The namespaces are written as namespace
76			attributes into the session element. This is mainly useful for
77			derived classes that need to store additional information in a
78			thuban session file.
79			"""
80			if attrs is None:
81			attrs = {}
82			attrs["title"] = session.title
83			for name, uri in namespaces:
84			attrs["xmlns:" + name] = uri
85	jonathan	366	self.open_element("session", attrs)
86	bh	268	for map in session.Maps():
87			self.write_map(map)
88	jonathan	366	self.close_element("session")
89	bh	268
90			def write_map(self, map):
91			"""Write the map and its contents.
92
93			By default, write a map element element with the title
94			attribute, call write_projection to write the projection
95			element, call write_layer for each layer contained in the map
96			and finally call write_label_layer to write the label layer.
97			"""
98	jonathan	876	self.open_element('map title="%s"' % self.encode(map.title))
99	bh	268	self.write_projection(map.projection)
100			for layer in map.Layers():
101			self.write_layer(layer)
102			self.write_label_layer(map.LabelLayer())
103	jonathan	366	self.close_element('map')
104	bh	6
105	bh	268	def write_projection(self, projection):
106			"""Write the projection.
107			"""
108			if projection and len(projection.params) > 0:
109	jonathan	876	self.open_element("projection", {"name": projection.GetName()})
110	bh	268	for param in projection.params:
111	jonathan	876	self.write_element('parameter value="%s"' %
112			self.encode(param))
113	jonathan	366	self.close_element("projection")
114	bh	268
115			def write_layer(self, layer, attrs = None):
116			"""Write the layer.
117
118			The optional argument attrs is for additional attributes and, if
119			given, should be a mapping from attribute names to attribute
120			values. The values should not be XML-escaped yet.
121			"""
122	jonathan	391
123	bh	268	if attrs is None:
124			attrs = {}
125	jonathan	429
126	jonathan	1251	attrs["title"] = layer.title
127			attrs["visible"] = ("false", "true")[int(layer.Visible())]
128	bh	268
129	jonathan	932	if isinstance(layer, Layer):
130	bh	1219	attrs["filename"] = relative_filename(self.dir,
131			layer.ShapeStore().FileName())
132	jonathan	740
133	jonathan	932	lc = layer.GetClassification()
134			attrs["stroke"] = lc.GetDefaultLineColor().hex()
135			attrs["stroke_width"] = str(lc.GetDefaultLineWidth())
136			attrs["fill"] = lc.GetDefaultFill().hex()
137	jonathan	740
138	jonathan	932	self.open_element("layer", attrs)
139			self.write_projection(layer.GetProjection())
140			self.write_classification(layer)
141			self.close_element("layer")
142	jonathan	740
143	jonathan	932	elif isinstance(layer, RasterLayer):
144	bh	1219	attrs["filename"] = relative_filename(self.dir, layer.filename)
145	jonathan	932	self.open_element("rasterlayer", attrs)
146			self.write_projection(layer.GetProjection())
147			self.close_element("rasterlayer")
148
149	jonathan	366	def write_classification(self, layer, attrs = None):
150	jonathan	1251	"""Write Classification information."""
151
152	jonathan	366	if attrs is None:
153			attrs = {}
154
155	jonathan	414	lc = layer.GetClassification()
156	jonathan	366
157	jonathan	429	field = lc.GetField()
158	jonathan	366
159			#
160	jonathan	1251	# there isn't a classification of anything so do nothing
161	jonathan	366	#
162			if field is None: return
163
164			attrs["field"] = field
165	jonathan	466	attrs["field_type"] = str(lc.GetFieldType())
166	jonathan	366	self.open_element("classification", attrs)
167
168	jonathan	1251	for g in lc:
169			if isinstance(g, ClassGroupDefault):
170			open_el = 'clnull label="%s"' % self.encode(g.GetLabel())
171			close_el = 'clnull'
172			elif isinstance(g, ClassGroupSingleton):
173			open_el = 'clpoint label="%s" value="%s"' \
174			% (self.encode(g.GetLabel()), str(g.GetValue()))
175			close_el = 'clpoint'
176			elif isinstance(g, ClassGroupRange):
177			open_el = 'clrange label="%s" range="%s"' \
178			% (self.encode(g.GetLabel()), str(g.GetRange()))
179			close_el = 'clrange'
180			else:
181			assert False, _("Unsupported group type in classification")
182			continue
183	jonathan	429
184	jonathan	1251	data = g.GetProperties()
185			dict = {'stroke' : data.GetLineColor().hex(),
186			'stroke_width': str(data.GetLineWidth()),
187			'fill' : data.GetFill().hex()}
188	jonathan	429
189	jonathan	1251	self.open_element(open_el)
190			self.write_element("cldata", dict)
191			self.close_element(close_el)
192	jonathan	366
193			self.close_element("classification")
194
195	bh	268	def write_label_layer(self, layer):
196			"""Write the label layer.
197			"""
198			labels = layer.Labels()
199	bh	6	if labels:
200	jonathan	366	self.open_element('labellayer')
201	bh	6	for label in labels:
202	jonathan	366	self.write_element(('label x="%g" y="%g" text="%s"'
203			' halign="%s" valign="%s"')
204	jonathan	876	% (label.x, label.y,
205			self.encode(label.text),
206			label.halign,
207	bh	268	label.valign))
208	jonathan	366	self.close_element('labellayer')
209	bh	6
210	bh	268
211
212			def save_session(session, file, saver_class = None):
213			"""Save the session session to a file.
214
215			The file argument may either be a filename or an open file object.
216
217			The optional argument saver_class is the class to use to serialize
218			the session. By default or if it's None, the saver class will be
219	jonathan	697	SessionSaver.
220	bh	268
221			If writing the session is successful call the session's
222			UnsetModified method
223			"""
224			if saver_class is None:
225	jonathan	697	saver_class = SessionSaver
226	bh	268	saver = saver_class(session)
227			saver.write(file)
228
229	bh	6	# after a successful save consider the session unmodified.
230			session.UnsetModified()
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