# Copyright (C) 2005-2010 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
"""Abstraction for interacting with the user.
Applications can choose different types of UI, and they deal with displaying
messages or progress to the user, and with gathering different types of input.
Several levels are supported, and you can also register new factories such as
for a GUI.
bzrlib.ui.UIFactory
Semi-abstract base class
bzrlib.ui.SilentUIFactory
Produces no output and cannot take any input; useful for programs using
bzrlib in batch mode or for programs such as loggerhead.
bzrlib.ui.CannedInputUIFactory
For use in testing; the input values to be returned are provided
at construction.
bzrlib.ui.text.TextUIFactory
Standard text command-line interface, with stdin, stdout, stderr.
May make more or less advanced use of them, eg in drawing progress bars,
depending on the detected capabilities of the terminal.
GUIs may choose to subclass this so that unimplemented methods fall
back to working through the terminal.
"""
import os
import sys
import warnings
from bzrlib.lazy_import import lazy_import
lazy_import(globals(), """
import getpass
from bzrlib import (
errors,
osutils,
progress,
trace,
)
""")
from bzrlib.symbol_versioning import (
deprecated_function,
deprecated_in,
deprecated_method,
)
_valid_boolean_strings = dict(yes=True, no=False,
y=True, n=False,
on=True, off=False,
true=True, false=False)
_valid_boolean_strings['1'] = True
_valid_boolean_strings['0'] = False
def bool_from_string(s, accepted_values=None):
"""Returns a boolean if the string can be interpreted as such.
Interpret case insensitive strings as booleans. The default values
includes: 'yes', 'no, 'y', 'n', 'true', 'false', '0', '1', 'on',
'off'. Alternative values can be provided with the 'accepted_values'
parameter.
:param s: A string that should be interpreted as a boolean. It should be of
type string or unicode.
:param accepted_values: An optional dict with accepted strings as keys and
True/False as values. The strings will be tested against a lowered
version of 's'.
:return: True or False for accepted strings, None otherwise.
"""
if accepted_values is None:
accepted_values = _valid_boolean_strings
val = None
if type(s) in (str, unicode):
try:
val = accepted_values[s.lower()]
except KeyError:
pass
return val
class UIFactory(object):
"""UI abstraction.
This tells the library how to display things to the user. Through this
layer different applications can choose the style of UI.
:ivar suppressed_warnings: Identifiers for user warnings that should
no be emitted.
"""
_user_warning_templates = dict(
cross_format_fetch=("Doing on-the-fly conversion from "
"%(from_format)s to %(to_format)s.\n"
"This may take some time. Upgrade the repositories to the "
"same format for better performance."
)
)
def __init__(self):
self._task_stack = []
self.suppressed_warnings = set()
self._quiet = False
def be_quiet(self, state):
"""Tell the UI to be more quiet, or not.
Typically this suppresses progress bars; the application may also look
at ui_factory.is_quiet().
"""
self._quiet = state
def get_password(self, prompt='', **kwargs):
"""Prompt the user for a password.
:param prompt: The prompt to present the user
:param kwargs: Arguments which will be expanded into the prompt.
This lets front ends display different things if
they so choose.
:return: The password string, return None if the user canceled the
request. Note that we do not touch the encoding, users may
have whatever they see fit and the password should be
transported as is.
"""
raise NotImplementedError(self.get_password)
def is_quiet(self):
return self._quiet
def make_output_stream(self, encoding=None, encoding_type=None):
"""Get a stream for sending out bulk text data.
This is used for commands that produce bulk text, such as log or diff
output, as opposed to user interaction. This should work even for
non-interactive user interfaces. Typically this goes to a decorated
version of stdout, but in a GUI it might be appropriate to send it to a
window displaying the text.
:param encoding: Unicode encoding for output; default is the
terminal encoding, which may be different from the user encoding.
(See get_terminal_encoding.)
:param encoding_type: How to handle encoding errors:
replace/strict/escape/exact. Default is replace.
"""
# XXX: is the caller supposed to close the resulting object?
if encoding is None:
encoding = osutils.get_terminal_encoding()
if encoding_type is None:
encoding_type = 'replace'
out_stream = self._make_output_stream_explicit(encoding, encoding_type)
return out_stream
def _make_output_stream_explicit(self, encoding, encoding_type):
raise NotImplementedError("%s doesn't support make_output_stream"
% (self.__class__.__name__))
def nested_progress_bar(self):
"""Return a nested progress bar.
When the bar has been finished with, it should be released by calling
bar.finished().
"""
if self._task_stack:
t = progress.ProgressTask(self._task_stack[-1], self)
else:
t = progress.ProgressTask(None, self)
self._task_stack.append(t)
return t
def _progress_finished(self, task):
"""Called by the ProgressTask when it finishes"""
if not self._task_stack:
warnings.warn("%r finished but nothing is active"
% (task,))
if task in self._task_stack:
self._task_stack.remove(task)
else:
warnings.warn("%r is not in active stack %r"
% (task, self._task_stack))
if not self._task_stack:
self._progress_all_finished()
def _progress_all_finished(self):
"""Called when the top-level progress task finished"""
pass
def _progress_updated(self, task):
"""Called by the ProgressTask when it changes.
Should be specialized to draw the progress.
"""
pass
def clear_term(self):
"""Prepare the terminal for output.
This will, for example, clear text progress bars, and leave the
cursor at the leftmost position.
"""
pass
def format_user_warning(self, warning_id, message_args):
try:
template = self._user_warning_templates[warning_id]
except KeyError:
fail = "failed to format warning %r, %r" % (warning_id, message_args)
warnings.warn(fail) # so tests will fail etc
return fail
try:
return template % message_args
except ValueError, e:
fail = "failed to format warning %r, %r: %s" % (
warning_id, message_args, e)
warnings.warn(fail) # so tests will fail etc
return fail
def get_boolean(self, prompt):
"""Get a boolean question answered from the user.
:param prompt: a message to prompt the user with. Should be a single
line without terminating \n.
:return: True or False for y/yes or n/no.
"""
raise NotImplementedError(self.get_boolean)
def get_integer(self, prompt):
"""Get an integer from the user.
:param prompt: a message to prompt the user with. Could be a multi-line
prompt but without a terminating \n.
:return: A signed integer.
"""
raise NotImplementedError(self.get_integer)
def make_progress_view(self):
"""Construct a new ProgressView object for this UI.
Application code should normally not call this but instead
nested_progress_bar().
"""
return NullProgressView()
def recommend_upgrade(self,
current_format_name,
basedir):
# XXX: this should perhaps be in the TextUIFactory and the default can do
# nothing
#
# XXX: Change to show_user_warning - that will accomplish the previous
# xxx. -- mbp 2010-02-25
trace.warning("%s is deprecated "
"and a better format is available.\n"
"It is recommended that you upgrade by "
"running the command\n"
" bzr upgrade %s",
current_format_name,
basedir)
def report_transport_activity(self, transport, byte_count, direction):
"""Called by transports as they do IO.
This may update a progress bar, spinner, or similar display.
By default it does nothing.
"""
pass
def log_transport_activity(self, display=False):
"""Write out whatever transport activity has been measured.
Implementations are allowed to do nothing, but it is useful if they can
write a line to the log file.
:param display: If False, only log to disk, if True also try to display
a message to the user.
:return: None
"""
# Default implementation just does nothing
pass
def show_user_warning(self, warning_id, **message_args):
"""Show a warning to the user.
This is specifically for things that are under the user's control (eg
outdated formats), not for internal program warnings like deprecated
APIs.
This can be overridden by UIFactory subclasses to show it in some
appropriate way; the default UIFactory is noninteractive and does
nothing. format_user_warning maps it to a string, though other
presentations can be used for particular UIs.
:param warning_id: An identifier like 'cross_format_fetch' used to
check if the message is suppressed and to look up the string.
:param message_args: Arguments to be interpolated into the message.
"""
pass
def show_error(self, msg):
"""Show an error message (not an exception) to the user.
The message should not have an error prefix or trailing newline. That
will be added by the factory if appropriate.
"""
raise NotImplementedError(self.show_error)
def show_message(self, msg):
"""Show a message to the user."""
raise NotImplementedError(self.show_message)
def show_warning(self, msg):
"""Show a warning to the user."""
raise NotImplementedError(self.show_warning)
def warn_cross_format_fetch(self, from_format, to_format):
"""Warn about a potentially slow cross-format transfer.
This is deprecated in favor of show_user_warning, but retained for api
compatibility in 2.0 and 2.1.
"""
self.show_user_warning('cross_format_fetch', from_format=from_format,
to_format=to_format)
def warn_experimental_format_fetch(self, inter):
"""Warn about fetching into experimental repository formats."""
if inter.target._format.experimental:
trace.warning("Fetching into experimental format %s.\n"
"This format may be unreliable or change in the future "
"without an upgrade path.\n" % (inter.target._format,))
class SilentUIFactory(UIFactory):
"""A UI Factory which never prints anything.
This is the default UI, if another one is never registered by a program
using bzrlib, and it's also active for example inside 'bzr serve'.
Methods that try to read from the user raise an error; methods that do
output do nothing.
"""
def __init__(self):
UIFactory.__init__(self)
def note(self, msg):
pass
def get_username(self, prompt, **kwargs):
return None
def _make_output_stream_explicit(self, encoding, encoding_type):
return NullOutputStream(encoding)
def show_error(self, msg):
pass
def show_message(self, msg):
pass
def show_warning(self, msg):
pass
class CannedInputUIFactory(SilentUIFactory):
"""A silent UI that return canned input."""
def __init__(self, responses):
self.responses = responses
def __repr__(self):
return "%s(%r)" % (self.__class__.__name__, self.responses)
def get_boolean(self, prompt):
return self.responses.pop(0)
def get_integer(self, prompt):
return self.responses.pop(0)
def get_password(self, prompt='', **kwargs):
return self.responses.pop(0)
def get_username(self, prompt, **kwargs):
return self.responses.pop(0)
def assert_all_input_consumed(self):
if self.responses:
raise AssertionError("expected all input in %r to be consumed"
% (self,))
ui_factory = SilentUIFactory()
# IMPORTANT: never import this symbol directly. ONLY ever access it as
# ui.ui_factory, so that you refer to the current value.
def make_ui_for_terminal(stdin, stdout, stderr):
"""Construct and return a suitable UIFactory for a text mode program.
"""
# this is now always TextUIFactory, which in turn decides whether it
# should display progress bars etc
from bzrlib.ui.text import TextUIFactory
return TextUIFactory(stdin, stdout, stderr)
class NullProgressView(object):
"""Soak up and ignore progress information."""
def clear(self):
pass
def show_progress(self, task):
pass
def show_transport_activity(self, transport, direction, byte_count):
pass
def log_transport_activity(self, display=False):
pass
class NullOutputStream(object):
"""Acts like a file, but discard all output."""
def __init__(self, encoding):
self.encoding = encoding
def write(self, data):
pass
def writelines(self, data):
pass
def close(self):
pass
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