# -*- coding: utf-8 -*-
import inspect
from prompt_toolkit import PromptSession
from prompt_toolkit.filters import IsDone, Always
from prompt_toolkit.layout import (
FormattedTextControl,
Layout,
HSplit,
ConditionalContainer,
Window,
)
from prompt_toolkit.validation import Validator, ValidationError
from typing import Optional, Any, List, Text, Dict, Union, Callable, Tuple
from questionary.constants import (
SELECTED_POINTER,
INDICATOR_SELECTED,
INDICATOR_UNSELECTED,
)
class Choice(object):
"""One choice in a select, rawselect or checkbox."""
def __init__(
self,
title: Text,
value: Optional[Any] = None,
disabled: Optional[Text] = None,
checked: bool = False,
shortcut_key: Optional[Text] = None,
) -> None:
"""Create a new choice.
Args:
title: Text shown in the selection list.
value: Value returned, when the choice is selected.
disabled: If set, the choice can not be selected by the user. The
provided text is used to explain, why the selection is
disabled.
checked: Preselect this choice when displaying the options.
shortcut_key: Key shortcut used to select this item.
"""
self.disabled = disabled
self.title = title
self.checked = checked
if value is not None:
self.value = value
elif isinstance(title, list):
self.value = "".join([token[1] for token in title])
else:
self.value = title
if shortcut_key is not None:
self.shortcut_key = str(shortcut_key)
else:
self.shortcut_key = None
@staticmethod
def build(c: Union[Text, "Choice", Dict[Text, Any]]) -> "Choice":
"""Create a choice object from different representations."""
if isinstance(c, Choice):
return c
elif isinstance(c, str):
return Choice(c, c)
else:
return Choice(
c.get("name"),
c.get("value"),
c.get("disabled", None),
c.get("checked"),
c.get("key"),
)
class Separator(Choice):
"""Used to space/separate choices group."""
default_separator = "-" * 15
def __init__(self, line: Optional[Text] = None):
"""Create a separator in a list.
Args:
line: Text to be displayed in the list, by default uses `---`.
"""
self.line = line or self.default_separator
super(Separator, self).__init__(self.line, None, "-")
class InquirerControl(FormattedTextControl):
SHORTCUT_KEYS = [
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"8",
"9",
"0",
"a",
"b",
"c",
"d",
"e",
"f",
"g",
"h",
"i",
"j",
"k",
"l",
"m",
"n",
"o",
"p",
"q",
"r",
"s",
"t",
"u",
"v",
"w",
"x",
"y",
"z",
]
def __init__(
self,
choices: List[Union[Text, Choice, Dict[Text, Any]]],
default: Optional[Any] = None,
use_indicator: bool = True,
use_shortcuts: bool = False,
use_pointer: bool = True,
**kwargs
):
self.use_indicator = use_indicator
self.use_shortcuts = use_shortcuts
self.use_pointer = use_pointer
self.default = default
self.pointed_at = None
self.is_answered = False
self.choices = []
self.selected_options = []
self._init_choices(choices)
self._assign_shortcut_keys()
super(InquirerControl, self).__init__(self._get_choice_tokens, **kwargs)
def _is_selected(self, choice):
return (
choice.checked or choice.value == self.default and self.default is not None
) and not choice.disabled
def _assign_shortcut_keys(self):
available_shortcuts = self.SHORTCUT_KEYS[:]
# first, make sure we do not double assign a shortcut
for c in self.choices:
if c.shortcut_key is not None:
if c.shortcut_key in available_shortcuts:
available_shortcuts.remove(c.shortcut_key)
else:
raise ValueError(
"Invalid shortcut '{}'"
"for choice '{}'. Shortcuts "
"should be single characters or numbers. "
"Make sure that all your shortcuts are "
"unique.".format(c.shortcut_key, c.title)
)
shortcut_idx = 0
for c in self.choices:
if c.shortcut_key is None and not c.disabled:
c.shortcut_key = available_shortcuts[shortcut_idx]
shortcut_idx += 1
if shortcut_idx == len(available_shortcuts):
break # fail gracefully if we run out of shortcuts
def _init_choices(self, choices):
# helper to convert from question format to internal format
self.choices = []
for i, c in enumerate(choices):
choice = Choice.build(c)
if self._is_selected(choice):
self.selected_options.append(choice.value)
if self.pointed_at is None and not choice.disabled:
# find the first (available) choice
self.pointed_at = i
self.choices.append(choice)
@property
def choice_count(self):
return len(self.choices)
def _get_choice_tokens(self):
tokens = []
def append(index, choice):
# use value to check if option has been selected
selected = choice.value in self.selected_options
if index == self.pointed_at:
if self.use_pointer:
tokens.append(("class:pointer", " {} ".format(SELECTED_POINTER)))
else:
tokens.append(("class:text", " "))
tokens.append(("[SetCursorPosition]", ""))
else:
tokens.append(("class:text", " "))
if isinstance(choice, Separator):
tokens.append(("class:separator", "{}".format(choice.title)))
elif choice.disabled: # disabled
if isinstance(choice.title, list):
tokens.append(
("class:selected" if selected else "class:disabled", "- ")
)
tokens.extend(choice.title)
else:
tokens.append(
(
"class:selected" if selected else "class:disabled",
"- {}".format(choice.title),
)
)
tokens.append(
(
"class:selected" if selected else "class:disabled",
"{}".format(
""
if isinstance(choice.disabled, bool)
else " ({})".format(choice.disabled)
),
)
)
else:
if self.use_shortcuts and choice.shortcut_key is not None:
shortcut = "{}) ".format(choice.shortcut_key)
else:
shortcut = ""
if selected:
if self.use_indicator:
indicator = INDICATOR_SELECTED + " "
else:
indicator = ""
tokens.append(("class:selected", "{}".format(indicator)))
else:
if self.use_indicator:
indicator = INDICATOR_UNSELECTED + " "
else:
indicator = ""
tokens.append(("class:text", "{}".format(indicator)))
if isinstance(choice.title, list):
tokens.extend(choice.title)
elif selected:
tokens.append(
("class:selected", "{}{}".format(shortcut, choice.title))
)
elif index == self.pointed_at:
tokens.append(
("class:highlighted", "{}{}".format(shortcut, choice.title))
)
else:
tokens.append(("class:text", "{}{}".format(shortcut, choice.title)))
tokens.append(("", "\n"))
# prepare the select choices
for i, c in enumerate(self.choices):
append(i, c)
if self.use_shortcuts:
tokens.append(
(
"class:text",
" Answer: {}" "".format(self.get_pointed_at().shortcut_key),
)
)
else:
tokens.pop() # Remove last newline.
return tokens
def is_selection_a_separator(self):
selected = self.choices[self.pointed_at]
return isinstance(selected, Separator)
def is_selection_disabled(self):
return self.choices[self.pointed_at].disabled
def is_selection_valid(self):
return not self.is_selection_disabled() and not self.is_selection_a_separator()
def select_previous(self):
self.pointed_at = (self.pointed_at - 1) % self.choice_count
def select_next(self):
self.pointed_at = (self.pointed_at + 1) % self.choice_count
def get_pointed_at(self):
return self.choices[self.pointed_at]
def get_selected_values(self):
# get values not labels
return [
c
for c in self.choices
if (not isinstance(c, Separator) and c.value in self.selected_options)
]
def build_validator(validate: Any) -> Optional[Validator]:
if validate:
if inspect.isclass(validate) and issubclass(validate, Validator):
return validate()
elif isinstance(validate, Validator):
return validate
elif callable(validate):
class _InputValidator(Validator):
def validate(self, document):
verdict = validate(document.text)
if verdict is not True:
if verdict is False:
verdict = "invalid input"
raise ValidationError(
message=verdict, cursor_position=len(document.text)
)
return _InputValidator()
return None
def _fix_unecessary_blank_lines(ps: PromptSession) -> None:
"""This is a fix for additional empty lines added by prompt toolkit.
This assumes the layout of the default session doesn't change, if it
does, this needs an update."""
default_container = ps.layout.container
default_buffer_window = (
default_container.get_children()[0].content.get_children()[1].content
)
assert isinstance(default_buffer_window, Window)
# this forces the main window to stay as small as possible, avoiding
# empty lines in selections
default_buffer_window.dont_extend_height = Always()
def create_inquirer_layout(
ic: InquirerControl,
get_prompt_tokens: Callable[[], List[Tuple[Text, Text]]],
**kwargs
) -> Layout:
"""Create a layout combining question and inquirer selection."""
ps = PromptSession(get_prompt_tokens, reserve_space_for_menu=0, **kwargs)
_fix_unecessary_blank_lines(ps)
return Layout(
HSplit(
[ps.layout.container, ConditionalContainer(Window(ic), filter=~IsDone())]
)
)
