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	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			attrs["title"] = layer.title
127			attrs["filename"] = relative_filename(self.dir, layer.filename)
128	jonathan	773	attrs["visible"] = ("false", "true")[int(layer.Visible())]
129	bh	268
130	jonathan	932	if isinstance(layer, Layer):
131	jonathan	740
132	jonathan	932	lc = layer.GetClassification()
133			attrs["stroke"] = lc.GetDefaultLineColor().hex()
134			attrs["stroke_width"] = str(lc.GetDefaultLineWidth())
135			attrs["fill"] = lc.GetDefaultFill().hex()
136	jonathan	740
137	jonathan	932	self.open_element("layer", attrs)
138			self.write_projection(layer.GetProjection())
139			self.write_classification(layer)
140			self.close_element("layer")
141	jonathan	740
142	jonathan	932	elif isinstance(layer, RasterLayer):
143	jonathan	366
144	jonathan	932	self.open_element("rasterlayer", attrs)
145			self.write_projection(layer.GetProjection())
146			self.close_element("rasterlayer")
147
148	jonathan	366	def write_classification(self, layer, attrs = None):
149			if attrs is None:
150			attrs = {}
151
152	jonathan	414	lc = layer.GetClassification()
153	jonathan	366
154	jonathan	429	field = lc.GetField()
155	jonathan	366
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	jonathan	466	attrs["field_type"] = str(lc.GetFieldType())
164	jonathan	366	self.open_element("classification", attrs)
165
166	jonathan	429
167	jonathan	876	types = [[lambda p: 'clnull label="%s"' % self.encode(p.GetLabel()),
168	jonathan	440	lambda p: 'clnull'],
169	jonathan	683	[lambda p: 'clpoint label="%s" value="%s"' %
170	jonathan	876	(self.encode(p.GetLabel()), str(p.GetValue())),
171	jonathan	440	lambda p: 'clpoint'],
172	jonathan	876	[lambda p: 'clrange label="%s" range="%s"' %
173			(self.encode(p.GetLabel()),
174			str(p.GetRange())),
175	jonathan	440	lambda p: 'clrange']]
176	jonathan	429
177	jonathan	440	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	jonathan	605	assert type >= 0
184	jonathan	366
185	jonathan	440	if type <= 2:
186			data = group.GetProperties()
187	jonathan	466	dict = {'stroke' : data.GetLineColor().hex(),
188			'stroke_width': str(data.GetLineWidth()),
189	jonathan	440	'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	jonathan	429	for i in lc:
197	jonathan	440	write_class_group(i)
198	jonathan	429
199	jonathan	366	self.close_element("classification")
200
201	bh	268	def write_label_layer(self, layer):
202			"""Write the label layer.
203			"""
204			labels = layer.Labels()
205	bh	6	if labels:
206	jonathan	366	self.open_element('labellayer')
207	bh	6	for label in labels:
208	jonathan	366	self.write_element(('label x="%g" y="%g" text="%s"'
209			' halign="%s" valign="%s"')
210	jonathan	876	% (label.x, label.y,
211			self.encode(label.text),
212			label.halign,
213	bh	268	label.valign))
214	jonathan	366	self.close_element('labellayer')
215	bh	6
216	bh	268
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	jonathan	697	SessionSaver.
226	bh	268
227			If writing the session is successful call the session's
228			UnsetModified method
229			"""
230			if saver_class is None:
231	jonathan	697	saver_class = SessionSaver
232	bh	268	saver = saver_class(session)
233			saver.write(file)
234
235	bh	6	# after a successful save consider the session unmodified.
236			session.UnsetModified()
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