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["filename"]     = relative_filename(self.dir, layer.filename)
        attrs["visible"]      = ("false", "true")[int(layer.Visible())]

        if isinstance(layer, Layer):

            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):

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

    def write_classification(self, layer, attrs = None):
        if attrs is None:
            attrs = {}

        lc = layer.GetClassification()

        field = lc.GetField()
 
        #
        # there isn't a classification of anything 
        # so don't do anything
        #
        if field is None: return

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


        types = [[lambda p: 'clnull label="%s"' % self.encode(p.GetLabel()),
                  lambda p: 'clnull'],
                 [lambda p: 'clpoint label="%s" value="%s"' % 
                             (self.encode(p.GetLabel()), str(p.GetValue())),
                  lambda p: 'clpoint'],
                 [lambda p: 'clrange label="%s" range="%s"' % 
                             (self.encode(p.GetLabel()),
                              str(p.GetRange())),
                  lambda p: 'clrange']]

        def write_class_group(group):
            type = -1
            if isinstance(group, ClassGroupDefault): type = 0
            elif isinstance(group, ClassGroupSingleton): type = 1
            elif isinstance(group, ClassGroupRange): type = 2
            elif isinstance(group, ClassGroupMap):   type = 3
            assert type >= 0

            if type <= 2: 
                data = group.GetProperties()
                dict = {'stroke'      : data.GetLineColor().hex(),
                        'stroke_width': str(data.GetLineWidth()),
                        'fill'        : data.GetFill().hex()}

                self.open_element(types[type][0](group))
                self.write_element("cldata", dict)
                self.close_element(types[type][1](group))
            else: pass # XXX: we need to handle maps

        for i in lc:
            write_class_group(i)

        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	# Copyright (c) 2001, 2002, 2003 by Intevation GmbH
2	# Authors:
3	# Jan-Oliver Wagner <[email protected]>
4	# Bernhard Herzog <[email protected]>
5	# Jonathan Coles <[email protected]>
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	import Thuban.Lib.fileutil
19
20	from Thuban.Model.color import Color
21	from Thuban.Model.layer import Layer, RasterLayer
22
23	from Thuban.Model.classification import \
24	ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap
25
26	from Thuban.Model.xmlwriter import XMLWriter
27
28	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	class SessionSaver(XMLWriter):
41
42	"""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	XMLWriter.__init__(self)
55	self.session = session
56
57	def write(self, file_or_filename):
58	XMLWriter.write(self, file_or_filename)
59
60	self.write_header("session", "thuban.dtd")
61	self.write_session(self.session)
62	self.close()
63
64	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	self.open_element("session", attrs)
86	for map in session.Maps():
87	self.write_map(map)
88	self.close_element("session")
89
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	self.open_element('map title="%s"' % self.encode(map.title))
99	self.write_projection(map.projection)
100	for layer in map.Layers():
101	self.write_layer(layer)
102	self.write_label_layer(map.LabelLayer())
103	self.close_element('map')
104
105	def write_projection(self, projection):
106	"""Write the projection.
107	"""
108	if projection and len(projection.params) > 0:
109	self.open_element("projection", {"name": projection.GetName()})
110	for param in projection.params:
111	self.write_element('parameter value="%s"' %
112	self.encode(param))
113	self.close_element("projection")
114
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
123	if attrs is None:
124	attrs = {}
125
126	attrs["title"] = layer.title
127	attrs["filename"] = relative_filename(self.dir, layer.filename)
128	attrs["visible"] = ("false", "true")[int(layer.Visible())]
129
130	if isinstance(layer, Layer):
131
132	lc = layer.GetClassification()
133	attrs["stroke"] = lc.GetDefaultLineColor().hex()
134	attrs["stroke_width"] = str(lc.GetDefaultLineWidth())
135	attrs["fill"] = lc.GetDefaultFill().hex()
136
137	self.open_element("layer", attrs)
138	self.write_projection(layer.GetProjection())
139	self.write_classification(layer)
140	self.close_element("layer")
141
142	elif isinstance(layer, RasterLayer):
143
144	self.open_element("rasterlayer", attrs)
145	self.write_projection(layer.GetProjection())
146	self.close_element("rasterlayer")
147
148	def write_classification(self, layer, attrs = None):
149	if attrs is None:
150	attrs = {}
151
152	lc = layer.GetClassification()
153
154	field = lc.GetField()
155
156	#
157	# there isn't a classification of anything
158	# so don't do anything
159	#
160	if field is None: return
161
162	attrs["field"] = field
163	attrs["field_type"] = str(lc.GetFieldType())
164	self.open_element("classification", attrs)
165
166
167	types = [[lambda p: 'clnull label="%s"' % self.encode(p.GetLabel()),
168	lambda p: 'clnull'],
169	[lambda p: 'clpoint label="%s" value="%s"' %
170	(self.encode(p.GetLabel()), str(p.GetValue())),
171	lambda p: 'clpoint'],
172	[lambda p: 'clrange label="%s" range="%s"' %
173	(self.encode(p.GetLabel()),
174	str(p.GetRange())),
175	lambda p: 'clrange']]
176
177	def write_class_group(group):
178	type = -1
179	if isinstance(group, ClassGroupDefault): type = 0
180	elif isinstance(group, ClassGroupSingleton): type = 1
181	elif isinstance(group, ClassGroupRange): type = 2
182	elif isinstance(group, ClassGroupMap): type = 3
183	assert type >= 0
184
185	if type <= 2:
186	data = group.GetProperties()
187	dict = {'stroke' : data.GetLineColor().hex(),
188	'stroke_width': str(data.GetLineWidth()),
189	'fill' : data.GetFill().hex()}
190
191	self.open_element(types[type][0](group))
192	self.write_element("cldata", dict)
193	self.close_element(types[type][1](group))
194	else: pass # XXX: we need to handle maps
195
196	for i in lc:
197	write_class_group(i)
198
199	self.close_element("classification")
200
201	def write_label_layer(self, layer):
202	"""Write the label layer.
203	"""
204	labels = layer.Labels()
205	if labels:
206	self.open_element('labellayer')
207	for label in labels:
208	self.write_element(('label x="%g" y="%g" text="%s"'
209	' halign="%s" valign="%s"')
210	% (label.x, label.y,
211	self.encode(label.text),
212	label.halign,
213	label.valign))
214	self.close_element('labellayer')
215
216
217
218	def save_session(session, file, saver_class = None):
219	"""Save the session session to a file.
220
221	The file argument may either be a filename or an open file object.
222
223	The optional argument saver_class is the class to use to serialize
224	the session. By default or if it's None, the saver class will be
225	SessionSaver.
226
227	If writing the session is successful call the session's
228	UnsetModified method
229	"""
230	if saver_class is None:
231	saver_class = SessionSaver
232	saver = saver_class(session)
233	saver.write(file)
234
235	# after a successful save consider the session unmodified.
236	session.UnsetModified()
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