/brz/remove-bazaar

# Copyright (C) 2005, 2006, 2007, 2008, 2009 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""UI abstraction.

This tells the library how to display things to the user.  Through this

layer different applications can choose the style of UI.

At the moment this layer is almost trivial: the application can just

choose the style of progress bar.

Set the ui_factory member to define the behaviour.  The default

displays no output.

"""

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,

    )

""")

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.

    """

    def __init__(self):

        self._task_stack = []

    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 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,))

        elif task != self._task_stack[-1]:

            warnings.warn("%r is not the active task %r" 

                % (task, self._task_stack[-1]))

        else:

            del self._task_stack[-1]

        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 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 recommend_upgrade(self,

        current_format_name,

        basedir):

        # this should perhaps be in the TextUIFactory and the default can do

        # nothing

        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

class CLIUIFactory(UIFactory):

    """Common behaviour for command line UI factories.

    This is suitable for dumb terminals that can't repaint existing text."""

    def __init__(self, stdin=None, stdout=None, stderr=None):

        UIFactory.__init__(self)

        self.stdin = stdin or sys.stdin

        self.stdout = stdout or sys.stdout

        self.stderr = stderr or sys.stderr

    def get_boolean(self, prompt):

        self.clear_term()

        # FIXME: make a regexp and handle case variations as well.

        while True:

            self.prompt(prompt + "? [y/n]: ")

            line = self.stdin.readline()

            if line in ('y\n', 'yes\n'):

                return True

            if line in ('n\n', 'no\n'):

                return False

    def get_non_echoed_password(self, prompt):

        if not sys.stdin.isatty():

            raise errors.NotATerminal()

        encoding = osutils.get_terminal_encoding()

        return getpass.getpass(prompt.encode(encoding, 'replace'))

    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.

        """

        prompt += ': '

        prompt = (prompt % kwargs)

        # There's currently no way to say 'i decline to enter a password'

        # as opposed to 'my password is empty' -- does it matter?

        return self.get_non_echoed_password(prompt)

    def prompt(self, prompt):

        """Emit prompt on the CLI."""

        self.stdout.write(prompt)

    def note(self, msg):

        """Write an already-formatted message."""

        self.stdout.write(msg + '\n')

class SilentUIFactory(CLIUIFactory):

    """A UI Factory which never prints anything.

    This is the default UI, if another one is never registered.

    """

    def __init__(self):

        CLIUIFactory.__init__(self)

    def get_password(self, prompt='', **kwargs):

        return None

    def prompt(self, prompt):

        pass

    def note(self, msg):

        pass

def clear_decorator(func, *args, **kwargs):

    """Decorator that clears the term"""

    ui_factory.clear_term()

    func(*args, **kwargs)

ui_factory = SilentUIFactory()

"""IMPORTANT: never import this symbol directly. ONLY ever access it as 

ui.ui_factory."""

def make_ui_for_terminal(stdin, stdout, stderr):

    """Construct and return a suitable UIFactory for a text mode program.

    If stdout is a smart terminal, this gets a smart UIFactory with 

    progress indicators, etc.  If it's a dumb terminal, just plain text output.

    """

    cls = None

    isatty = getattr(stdin, 'isatty', None)

    if isatty is None:

        cls = CLIUIFactory

    elif not isatty():

        cls = CLIUIFactory

    elif os.environ.get('TERM') in (None, 'dumb', ''):

        # e.g. emacs compile window

        cls = CLIUIFactory

    # User may know better, otherwise default to TextUIFactory

    if (   os.environ.get('BZR_USE_TEXT_UI', None) is not None

        or cls is None):

        from bzrlib.ui.text import TextUIFactory

        cls = TextUIFactory

    return cls(stdin=stdin, stdout=stdout, stderr=stderr)