path: root/prompt_toolkit/shortcuts/prompt.py

"""
Line editing functionality.
---------------------------

This provides a UI for a line input, similar to GNU Readline, libedit and
linenoise.

Either call the `prompt` function for every line input. Or create an instance
of the :class:`.PromptSession` class and call the `prompt` method from that
class. In the second case, we'll have a 'session' that keeps all the state like
the history in between several calls.

There is a lot of overlap between the arguments taken by the `prompt` function
and the `PromptSession` (like `completer`, `style`, etcetera). There we have
the freedom to decide which settings we want for the whole 'session', and which
we want for an individual `prompt`.

Example::

        # Simple `prompt` call.
        result = prompt('Say something: ')

        # Using a 'session'.
        s = PromptSession()
        result = s.prompt('Say something: ')
"""
from __future__ import unicode_literals

from prompt_toolkit.application import Application
from prompt_toolkit.application.current import get_app
from prompt_toolkit.auto_suggest import DynamicAutoSuggest
from prompt_toolkit.buffer import Buffer
from prompt_toolkit.clipboard import DynamicClipboard, InMemoryClipboard
from prompt_toolkit.completion import DynamicCompleter, ThreadedCompleter
from prompt_toolkit.document import Document
from prompt_toolkit.enums import DEFAULT_BUFFER, SEARCH_BUFFER, EditingMode
from prompt_toolkit.eventloop import ensure_future, Return, From
from prompt_toolkit.filters import is_done, has_focus, renderer_height_is_known, to_filter, Condition, has_arg
from prompt_toolkit.formatted_text import to_formatted_text
from prompt_toolkit.history import InMemoryHistory
from prompt_toolkit.input.defaults import get_default_input
from prompt_toolkit.key_binding.bindings.auto_suggest import load_auto_suggest_bindings
from prompt_toolkit.key_binding.bindings.completion import display_completions_like_readline
from prompt_toolkit.key_binding.bindings.open_in_editor import load_open_in_editor_bindings
from prompt_toolkit.key_binding.key_bindings import KeyBindings, DynamicKeyBindings, merge_key_bindings, ConditionalKeyBindings, KeyBindingsBase
from prompt_toolkit.keys import Keys
from prompt_toolkit.layout import Window, HSplit, FloatContainer, Float
from prompt_toolkit.layout.containers import ConditionalContainer, WindowAlign
from prompt_toolkit.layout.controls import BufferControl, SearchBufferControl, FormattedTextControl
from prompt_toolkit.layout.dimension import Dimension
from prompt_toolkit.layout.layout import Layout
from prompt_toolkit.layout.margins import PromptMargin, ConditionalMargin
from prompt_toolkit.layout.menus import CompletionsMenu, MultiColumnCompletionsMenu
from prompt_toolkit.layout.processors import DynamicProcessor, PasswordProcessor, ConditionalProcessor, AppendAutoSuggestion, HighlightIncrementalSearchProcessor, HighlightSelectionProcessor, DisplayMultipleCursors, BeforeInput, ReverseSearchProcessor, ShowArg, merge_processors
from prompt_toolkit.layout.utils import explode_text_fragments
from prompt_toolkit.lexers import DynamicLexer
from prompt_toolkit.output.defaults import get_default_output
from prompt_toolkit.styles import BaseStyle, DynamicStyle
from prompt_toolkit.utils import suspend_to_background_supported
from prompt_toolkit.validation import DynamicValidator
from prompt_toolkit.widgets.toolbars import ValidationToolbar, SystemToolbar, SearchToolbar
from six import text_type

import contextlib
import threading
import time

__all__ = [
    'PromptSession',
    'prompt',
    'confirm',
    'create_confirm_session',  # Used by '_display_completions_like_readline'.
    'CompleteStyle',
]


def _split_multiline_prompt(get_prompt_text):
    """
    Take a `get_prompt_text` function and return three new functions instead.
    One that tells whether this prompt consists of multiple lines; one that
    returns the fragments to be shown on the lines above the input; and another
    one with the fragments to be shown at the first line of the input.
    """
    def has_before_fragments():
        for fragment, char in get_prompt_text():
            if '\n' in char:
                return True
        return False

    def before():
        result = []
        found_nl = False
        for fragment, char in reversed(explode_text_fragments(get_prompt_text())):
            if found_nl:
                result.insert(0, (fragment, char))
            elif char == '\n':
                found_nl = True
        return result

    def first_input_line():
        result = []
        for fragment, char in reversed(explode_text_fragments(get_prompt_text())):
            if char == '\n':
                break
            else:
                result.insert(0, (fragment, char))
        return result

    return has_before_fragments, before, first_input_line


class _RPrompt(Window):
    " The prompt that is displayed on the right side of the Window. "
    def __init__(self, get_formatted_text):
        super(_RPrompt, self).__init__(
            FormattedTextControl(get_formatted_text),
            align=WindowAlign.RIGHT,
            style='class:rprompt')


def _true(value):
    " Test whether `value` is True. In case of a Filter, call it. "
    return to_filter(value)()


class CompleteStyle:
    " How to display autocompletions for the prompt. "
    COLUMN = 'COLUMN'
    MULTI_COLUMN = 'MULTI_COLUMN'
    READLINE_LIKE = 'READLINE_LIKE'


class PromptSession(object):
    """
    PromptSession for a prompt application, which can be used as a GNU Readline
    replacement.

    This is a wrapper around a lot of ``prompt_toolkit`` functionality and can
    be a replacement for `raw_input`.

    All parameters that expect "formatted text" can take either just plain text
    (a unicode object), a list of ``(style_str, text)`` tuples or an HTML object.

    Example usage::

        s = PromptSession(message='>')
        text = s.prompt()

    :param message: Plain text or formatted text to be shown before the prompt.
        This can also be a callable that returns formatted text.
    :param multiline: `bool` or :class:`~prompt_toolkit.filters.Filter`.
        When True, prefer a layout that is more adapted for multiline input.
        Text after newlines is automatically indented, and search/arg input is
        shown below the input, instead of replacing the prompt.
    :param wrap_lines: `bool` or :class:`~prompt_toolkit.filters.Filter`.
        When True (the default), automatically wrap long lines instead of
        scrolling horizontally.
    :param is_password: Show asterisks instead of the actual typed characters.
    :param editing_mode: ``EditingMode.VI`` or ``EditingMode.EMACS``.
    :param vi_mode: `bool`, if True, Identical to ``editing_mode=EditingMode.VI``.
    :param complete_while_typing: `bool` or
        :class:`~prompt_toolkit.filters.Filter`. Enable autocompletion while
        typing.
    :param validate_while_typing: `bool` or
        :class:`~prompt_toolkit.filters.Filter`. Enable input validation while
        typing.
    :param enable_history_search: `bool` or
        :class:`~prompt_toolkit.filters.Filter`. Enable up-arrow parting
        string matching.
    :param search_ignore_case:
        :class:`~prompt_toolkit.filters.Filter`. Search case insensitive.
    :param lexer: :class:`~prompt_toolkit.lexers.Lexer` to be used for the
        syntax highlighting.
    :param validator: :class:`~prompt_toolkit.validation.Validator` instance
        for input validation.
    :param completer: :class:`~prompt_toolkit.completion.Completer` instance
        for input completion.
    :param complete_in_thread: `bool` or
        :class:`~prompt_toolkit.filters.Filter`. Run the completer code in a
        background thread in order to avoid blocking the user interface.
        For ``CompleteStyle.READLINE_LIKE``, this setting has no effect. There
        we always run the completions in the main thread.
    :param reserve_space_for_menu: Space to be reserved for displaying the menu.
        (0 means that no space needs to be reserved.)
    :param auto_suggest: :class:`~prompt_toolkit.auto_suggest.AutoSuggest`
        instance for input suggestions.
    :param style: :class:`.Style` instance for the color scheme.
    :param include_default_pygments_style: `bool` or
        :class:`~prompt_toolkit.filters.Filter`. Tell whether the default
        styling for Pygments lexers has to be included. By default, this is
        true, but it is recommended to be disabled if another Pygments style is
        passed as the `style` argument, otherwise, two Pygments styles will be
        merged.
    :param enable_system_prompt: `bool` or
        :class:`~prompt_toolkit.filters.Filter`. Pressing Meta+'!' will show
        a system prompt.
    :param enable_suspend: `bool` or :class:`~prompt_toolkit.filters.Filter`.
        Enable Control-Z style suspension.
    :param enable_open_in_editor: `bool` or
        :class:`~prompt_toolkit.filters.Filter`. Pressing 'v' in Vi mode or
        C-X C-E in emacs mode will open an external editor.
    :param history: :class:`~prompt_toolkit.history.History` instance.
    :param clipboard: :class:`~prompt_toolkit.clipboard.Clipboard` instance.
        (e.g. :class:`~prompt_toolkit.clipboard.InMemoryClipboard`)
    :param rprompt: Text or formatted text to be displayed on the right side.
        This can also be a callable that returns (formatted) text.
    :param bottom_toolbar: Formatted text or callable which is supposed to
        return formatted text.
    :param prompt_continuation: Text that needs to be displayed for a multiline
        prompt continuation. This can either be formatted text or a callable
        that the width as input and returns formatted text.
    :param complete_style: ``CompleteStyle.COLUMN``,
        ``CompleteStyle.MULTI_COLUMN`` or ``CompleteStyle.READLINE_LIKE``.
    :param mouse_support: `bool` or :class:`~prompt_toolkit.filters.Filter`
        to enable mouse support.
    :param default: The default input text to be shown. (This can be edited by
        the user).
    :param refresh_interval: (number; in seconds) When given, refresh the UI
        every so many seconds.
    :param inputhook: None or an Inputhook callable that takes an
        `InputHookContext` object.
    """
    _fields = (
        'message', 'lexer', 'completer', 'complete_in_thread', 'is_password',
        'editing_mode', 'key_bindings', 'is_password', 'bottom_toolbar',
        'style', 'color_depth', 'include_default_pygments_style', 'rprompt',
        'multiline', 'prompt_continuation', 'wrap_lines',
        'enable_history_search', 'search_ignore_case', 'complete_while_typing',
        'validate_while_typing', 'complete_style', 'mouse_support',
        'auto_suggest', 'clipboard', 'validator', 'refresh_interval',
        'input_processors', 'default', 'enable_system_prompt',
        'enable_suspend', 'enable_open_in_editor', 'reserve_space_for_menu',
        'tempfile_suffix', 'inputhook')

    def __init__(
            self,
            message='',
            default='',
            multiline=False,
            wrap_lines=True,
            is_password=False,
            vi_mode=False,
            editing_mode=EditingMode.EMACS,
            complete_while_typing=True,
            validate_while_typing=True,
            enable_history_search=False,
            search_ignore_case=False,
            lexer=None,
            enable_system_prompt=False,
            enable_suspend=False,
            enable_open_in_editor=False,
            validator=