WIP-pyshapelib-bramz/Thuban/__init__.py

# Copyright (c) 2001, 2003, 2005 by Intevation GmbH
# Authors:
# Bernhard Herzog <[email protected]>
# Jan-Oliver Wagner <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

import os

# Thuban Message Translation
#
# This is somewhat tricky. On the one hand we want to use the wx
# facilities because that way the standard wx messages are also
# translated and we get automatic conversion of encodings so the we can
# use e.g. an UTF po/mo file in a Latin 1 environment. OTOH, we do not
# want to import the wxPython modules at all when running the test suite
# because otherwise the test suite would require a working X server
# connection.
#
# Therefore this module only provides the hooks for installing the
# correct translation function with a default translation function that
# does nothing and simply returns the string it gets as argument.
#
# The front end to the installed translation function is _ (see it's
# doc-string).
#
# The Thuban.UI module is responsible for installing the wx translation
# function. It must take care to install the translation function as
# early as possible, i.e. when Thuban/UI/__init__.py is executed so that
# strings translated at module import time are translated (this also
# means that a program built on top of Thuban and which uses Thuban.UI
# should start by importing Thuban.UI before any other Thuban module.
#
# At the same time Thuban/UI/__init__.py should not import any wxPython
# module unless it really has to install the translation function, i.e.
# when no other translation function has already been installed. That
# way the test suite can override the wx translation by installing its
# own translation function before importing anything from Thuban.UI and
# actually before importing anything but the Thuban module itself.

# Thedirectory holding the translation files (actually they're in
# language specific subdirectories of _message_dir)
_message_dir = os.path.join(os.path.dirname(__file__), os.pardir, "Resources",
                            "Locale")

def _(s):
    """Return a localized version of the the string s

    This is the function to use in the sources to translate strings and
    it simply delegates the translation to the installable translation
    function. It's done this way so that _ may be imported with 'from
    Thuban import _' even when the correct translation function hasn't
    been installed yet.
    """
    return _translation_function(s)

def gettext_identity(s):
    """Default gettext implementation which returns the string as is"""
    return s

_translation_function = gettext_identity

def translation_function_installed():
    """Return whether a translation function has been installed."""
    return _translation_function is not gettext_identity

def install_translation_function(function):
    """Install function as the translation function

    If a translation has already been installed that is not the default
    implementation (gettext_identity) do nothing.
    """
    global _translation_function
    if not translation_function_installed():
        _translation_function = function


# String representation in Thuban
#
# Thuban has an internal representation for textual data that all text
# that comes into Thuban has to be converted into.  Any text written by
# Thuban has to be converted to whatever is needed by the output device.
#
# Currently, the internal representation is usually a byte-string in a
# particuler encoding.  For more details see the file
# Doc/technotes/string_representation.txt.

# The encoding to use for the internal string representation.  Usually
# it's a string with the encoding name to use when converting between
# Python byte-strings and unicode objects.  The special value "unicode"
# means the use unicode objects as the internal representation.
_internal_encoding = None

def internal_from_unicode(unistr):
    """Return Thuban's internal representation for the unicode object unistr"""
    if _internal_encoding != "unicode":
        # we use replace so that we don't get exceptions when the
        # conversion can't be done properly.
        return unistr.encode(_internal_encoding, "replace")
    else:
        return unistr

def unicode_from_internal(s):
    """Return the unicode object for the string s in internal representation"""
    if _internal_encoding != "unicode":
        return unicode(s, _internal_encoding)
    else:
        return s


def set_internal_encoding(encoding):
    """Set the encoding to use for the internal string representation

    The parameter should be the name of an encoding known to Python so
    that it can be used with e.g. the encode method of unicode objects.
    As a special case it can be the string 'unicode' to indicate that
    the internal representation are unicode objects.
    """
    global _internal_encoding
    _internal_encoding = encoding

    # and now let us test, if we can go back and forth
    # it is better to complain now than to have runtime problems later
    unicode_from_internal(internal_from_unicode(u''))
1	bh	2642	# Copyright (c) 2001, 2003, 2005 by Intevation GmbH
2	bh	6	# Authors:
3			# Bernhard Herzog <[email protected]>
4	jan	373	# Jan-Oliver Wagner <[email protected]>
5	bh	6	#
6			# This program is free software under the GPL (>=v2)
7			# Read the file COPYING coming with Thuban for details.
8	jan	373
9	bh	671	import os
10
11	bh	1871	# Thuban Message Translation
12	bh	671	#
13	bh	1871	# This is somewhat tricky. On the one hand we want to use the wx
14			# facilities because that way the standard wx messages are also
15			# translated and we get automatic conversion of encodings so the we can
16			# use e.g. an UTF po/mo file in a Latin 1 environment. OTOH, we do not
17			# want to import the wxPython modules at all when running the test suite
18			# because otherwise the test suite would require a working X server
19			# connection.
20	bh	671	#
21	bh	1871	# Therefore this module only provides the hooks for installing the
22			# correct translation function with a default translation function that
23			# does nothing and simply returns the string it gets as argument.
24			#
25			# The front end to the installed translation function is _ (see it's
26			# doc-string).
27			#
28			# The Thuban.UI module is responsible for installing the wx translation
29			# function. It must take care to install the translation function as
30			# early as possible, i.e. when Thuban/UI/__init__.py is executed so that
31			# strings translated at module import time are translated (this also
32			# means that a program built on top of Thuban and which uses Thuban.UI
33			# should start by importing Thuban.UI before any other Thuban module.
34			#
35			# At the same time Thuban/UI/__init__.py should not import any wxPython
36			# module unless it really has to install the translation function, i.e.
37			# when no other translation function has already been installed. That
38			# way the test suite can override the wx translation by installing its
39			# own translation function before importing anything from Thuban.UI and
40			# actually before importing anything but the Thuban module itself.
41
42			# Thedirectory holding the translation files (actually they're in
43			# language specific subdirectories of _message_dir)
44	bh	671	_message_dir = os.path.join(os.path.dirname(__file__), os.pardir, "Resources",
45			"Locale")
46
47	bh	1871	def _(s):
48			"""Return a localized version of the the string s
49	bh	671
50	bh	1871	This is the function to use in the sources to translate strings and
51			it simply delegates the translation to the installable translation
52			function. It's done this way so that _ may be imported with 'from
53			Thuban import _' even when the correct translation function hasn't
54			been installed yet.
55			"""
56			return _translation_function(s)
57
58			def gettext_identity(s):
59			"""Default gettext implementation which returns the string as is"""
60			return s
61
62			_translation_function = gettext_identity
63
64			def translation_function_installed():
65			"""Return whether a translation function has been installed."""
66			return _translation_function is not gettext_identity
67
68			def install_translation_function(function):
69			"""Install function as the translation function
70
71			If a translation has already been installed that is not the default
72			implementation (gettext_identity) do nothing.
73			"""
74			global _translation_function
75			if not translation_function_installed():
76			_translation_function = function
77	bh	2642
78
79
80			# String representation in Thuban
81			#
82			# Thuban has an internal representation for textual data that all text
83			# that comes into Thuban has to be converted into. Any text written by
84			# Thuban has to be converted to whatever is needed by the output device.
85			#
86			# Currently, the internal representation is usually a byte-string in a
87			# particuler encoding. For more details see the file
88			# Doc/technotes/string_representation.txt.
89
90			# The encoding to use for the internal string representation. Usually
91			# it's a string with the encoding name to use when converting between
92			# Python byte-strings and unicode objects. The special value "unicode"
93			# means the use unicode objects as the internal representation.
94			_internal_encoding = None
95
96			def internal_from_unicode(unistr):
97			"""Return Thuban's internal representation for the unicode object unistr"""
98			if _internal_encoding != "unicode":
99			# we use replace so that we don't get exceptions when the
100			# conversion can't be done properly.
101			return unistr.encode(_internal_encoding, "replace")
102			else:
103			return unistr
104
105			def unicode_from_internal(s):
106			"""Return the unicode object for the string s in internal representation"""
107			if _internal_encoding != "unicode":
108			return unicode(s, _internal_encoding)
109			else:
110			return s
111
112
113			def set_internal_encoding(encoding):
114			"""Set the encoding to use for the internal string representation
115
116			The parameter should be the name of an encoding known to Python so
117			that it can be used with e.g. the encode method of unicode objects.
118			As a special case it can be the string 'unicode' to indicate that
119			the internal representation are unicode objects.
120			"""
121			global _internal_encoding
122			_internal_encoding = encoding
123	bernhard	2672
124			# and now let us test, if we can go back and forth
125			# it is better to complain now than to have runtime problems later
126			unicode_from_internal(internal_from_unicode(u''))
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