Restoring authorship annotation for <shadchin@yandex-team.ru>. Commit 1 of 2.

1 files changed, 947 insertions, 947 deletions

diff --git a/contrib/python/prompt-toolkit/py3/prompt_toolkit/widgets/base.py b/contrib/python/prompt-toolkit/py3/prompt_toolkit/widgets/base.py
index 728190b54c..c059872793 100644
--- a/contrib/python/prompt-toolkit/py3/prompt_toolkit/widgets/base.py
+++ b/contrib/python/prompt-toolkit/py3/prompt_toolkit/widgets/base.py
@@ -1,949 +1,949 @@
-"""
-Collection of reusable components for building full screen applications.
-
-All of these widgets implement the ``__pt_container__`` method, which makes
-them usable in any situation where we are expecting a `prompt_toolkit`
-container object.
-
-.. warning::
-
-    At this point, the API for these widgets is considered unstable, and can
-    potentially change between minor releases (we try not too, but no
-    guarantees are made yet). The public API in
-    `prompt_toolkit.shortcuts.dialogs` on the other hand is considered stable.
-"""
-from functools import partial
-from typing import Callable, Generic, List, Optional, Sequence, Tuple, TypeVar, Union
-
-from prompt_toolkit.application.current import get_app
-from prompt_toolkit.auto_suggest import AutoSuggest, DynamicAutoSuggest
-from prompt_toolkit.buffer import Buffer, BufferAcceptHandler
-from prompt_toolkit.completion import Completer, DynamicCompleter
-from prompt_toolkit.document import Document
-from prompt_toolkit.filters import (
-    Condition,
-    FilterOrBool,
-    has_focus,
-    is_done,
-    is_true,
-    to_filter,
-)
-from prompt_toolkit.formatted_text import (
-    AnyFormattedText,
-    StyleAndTextTuples,
-    Template,
-    to_formatted_text,
-)
-from prompt_toolkit.formatted_text.utils import fragment_list_to_text
-from prompt_toolkit.history import History
-from prompt_toolkit.key_binding.key_bindings import KeyBindings
-from prompt_toolkit.key_binding.key_processor import KeyPressEvent
-from prompt_toolkit.keys import Keys
-from prompt_toolkit.layout.containers import (
-    AnyContainer,
-    ConditionalContainer,
-    Container,
-    DynamicContainer,
-    Float,
-    FloatContainer,
-    HSplit,
-    VSplit,
-    Window,
-    WindowAlign,
-)
-from prompt_toolkit.layout.controls import (
-    BufferControl,
-    FormattedTextControl,
-    GetLinePrefixCallable,
-)
-from prompt_toolkit.layout.dimension import AnyDimension
-from prompt_toolkit.layout.dimension import Dimension as D
-from prompt_toolkit.layout.dimension import to_dimension
-from prompt_toolkit.layout.margins import (
-    ConditionalMargin,
-    NumberedMargin,
-    ScrollbarMargin,
-)
-from prompt_toolkit.layout.processors import (
-    AppendAutoSuggestion,
-    BeforeInput,
-    ConditionalProcessor,
-    PasswordProcessor,
-    Processor,
-)
-from prompt_toolkit.lexers import DynamicLexer, Lexer
-from prompt_toolkit.mouse_events import MouseEvent, MouseEventType
-from prompt_toolkit.utils import get_cwidth
-from prompt_toolkit.validation import DynamicValidator, Validator
-
-from .toolbars import SearchToolbar
-
-__all__ = [
-    "TextArea",
-    "Label",
-    "Button",
-    "Frame",
-    "Shadow",
-    "Box",
-    "VerticalLine",
-    "HorizontalLine",
-    "RadioList",
-    "CheckboxList",
-    "Checkbox",  # backward compatibility
-    "ProgressBar",
-]
-
-E = KeyPressEvent
-
-
-class Border:
-    "Box drawing characters. (Thin)"
-    HORIZONTAL = "\u2500"
-    VERTICAL = "\u2502"
-    TOP_LEFT = "\u250c"
-    TOP_RIGHT = "\u2510"
-    BOTTOM_LEFT = "\u2514"
-    BOTTOM_RIGHT = "\u2518"
-
-
-class TextArea:
-    """
-    A simple input field.
-
-    This is a higher level abstraction on top of several other classes with
-    sane defaults.
-
-    This widget does have the most common options, but it does not intend to
-    cover every single use case. For more configurations options, you can
-    always build a text area manually, using a
-    :class:`~prompt_toolkit.buffer.Buffer`,
-    :class:`~prompt_toolkit.layout.BufferControl` and
-    :class:`~prompt_toolkit.layout.Window`.
-
-    Buffer attributes:
-
-    :param text: The initial text.
-    :param multiline: If True, allow multiline input.
-    :param completer: :class:`~prompt_toolkit.completion.Completer` instance
-        for auto completion.
-    :param complete_while_typing: Boolean.
-    :param accept_handler: Called when `Enter` is pressed (This should be a
-        callable that takes a buffer as input).
-    :param history: :class:`~prompt_toolkit.history.History` instance.
-    :param auto_suggest: :class:`~prompt_toolkit.auto_suggest.AutoSuggest`
-        instance for input suggestions.
-
-    BufferControl attributes:
-
-    :param password: When `True`, display using asterisks.
-    :param focusable: When `True`, allow this widget to receive the focus.
-    :param focus_on_click: When `True`, focus after mouse click.
-    :param input_processors: `None` or a list of
-        :class:`~prompt_toolkit.layout.Processor` objects.
-    :param validator: `None` or a :class:`~prompt_toolkit.validation.Validator`
-        object.
-
-    Window attributes:
-
-    :param lexer: :class:`~prompt_toolkit.lexers.Lexer` instance for syntax
-        highlighting.
-    :param wrap_lines: When `True`, don't scroll horizontally, but wrap lines.
-    :param width: Window width. (:class:`~prompt_toolkit.layout.Dimension` object.)
-    :param height: Window height. (:class:`~prompt_toolkit.layout.Dimension` object.)
-    :param scrollbar: When `True`, display a scroll bar.
-    :param style: A style string.
-    :param dont_extend_width: When `True`, don't take up more width then the
-                              preferred width reported by the control.
-    :param dont_extend_height: When `True`, don't take up more width then the
-                               preferred height reported by the control.
-    :param get_line_prefix: None or a callable that returns formatted text to
-        be inserted before a line. It takes a line number (int) and a
-        wrap_count and returns formatted text. This can be used for
-        implementation of line continuations, things like Vim "breakindent" and
-        so on.
-
-    Other attributes:
-
-    :param search_field: An optional `SearchToolbar` object.
-    """
-
-    def __init__(
-        self,
-        text: str = "",
-        multiline: FilterOrBool = True,
-        password: FilterOrBool = False,
-        lexer: Optional[Lexer] = None,
-        auto_suggest: Optional[AutoSuggest] = None,
-        completer: Optional[Completer] = None,
-        complete_while_typing: FilterOrBool = True,
-        validator: Optional[Validator] = None,
-        accept_handler: Optional[BufferAcceptHandler] = None,
-        history: Optional[History] = None,
-        focusable: FilterOrBool = True,
-        focus_on_click: FilterOrBool = False,
-        wrap_lines: FilterOrBool = True,
-        read_only: FilterOrBool = False,
-        width: AnyDimension = None,
-        height: AnyDimension = None,
-        dont_extend_height: FilterOrBool = False,
-        dont_extend_width: FilterOrBool = False,
-        line_numbers: bool = False,
-        get_line_prefix: Optional[GetLinePrefixCallable] = None,
-        scrollbar: bool = False,
-        style: str = "",
-        search_field: Optional[SearchToolbar] = None,
-        preview_search: FilterOrBool = True,
-        prompt: AnyFormattedText = "",
-        input_processors: Optional[List[Processor]] = None,
-    ) -> None:
-
-        if search_field is None:
-            search_control = None
-        elif isinstance(search_field, SearchToolbar):
-            search_control = search_field.control
-
-        if input_processors is None:
-            input_processors = []
-
-        # Writeable attributes.
-        self.completer = completer
-        self.complete_while_typing = complete_while_typing
-        self.lexer = lexer
-        self.auto_suggest = auto_suggest
-        self.read_only = read_only
-        self.wrap_lines = wrap_lines
-        self.validator = validator
-
-        self.buffer = Buffer(
-            document=Document(text, 0),
-            multiline=multiline,
-            read_only=Condition(lambda: is_true(self.read_only)),
-            completer=DynamicCompleter(lambda: self.completer),
-            complete_while_typing=Condition(
-                lambda: is_true(self.complete_while_typing)
-            ),
-            validator=DynamicValidator(lambda: self.validator),
-            auto_suggest=DynamicAutoSuggest(lambda: self.auto_suggest),
-            accept_handler=accept_handler,
-            history=history,
-        )
-
-        self.control = BufferControl(
-            buffer=self.buffer,
-            lexer=DynamicLexer(lambda: self.lexer),
-            input_processors=[
-                ConditionalProcessor(
-                    AppendAutoSuggestion(), has_focus(self.buffer) & ~is_done
-                ),
-                ConditionalProcessor(
-                    processor=PasswordProcessor(), filter=to_filter(password)
-                ),
-                BeforeInput(prompt, style="class:text-area.prompt"),
-            ]
-            + input_processors,
-            search_buffer_control=search_control,
-            preview_search=preview_search,
-            focusable=focusable,
-            focus_on_click=focus_on_click,
-        )
-
-        if multiline:
-            if scrollbar:
-                right_margins = [ScrollbarMargin(display_arrows=True)]
-            else:
-                right_margins = []
-            if line_numbers:
-                left_margins = [NumberedMargin()]
-            else:
-                left_margins = []
-        else:
-            height = D.exact(1)
-            left_margins = []
-            right_margins = []
-
-        style = "class:text-area " + style
-
-        # If no height was given, guarantee height of at least 1.
-        if height is None:
-            height = D(min=1)
-
-        self.window = Window(
-            height=height,
-            width=width,
-            dont_extend_height=dont_extend_height,
-            dont_extend_width=dont_extend_width,
-            content=self.control,
-            style=style,
-            wrap_lines=Condition(lambda: is_true(self.wrap_lines)),
-            left_margins=left_margins,
-            right_margins=right_margins,
-            get_line_prefix=get_line_prefix,
-        )
-
-    @property
-    def text(self) -> str:
-        """
-        The `Buffer` text.
-        """
-        return self.buffer.text
-
-    @text.setter
-    def text(self, value: str) -> None:
-        self.document = Document(value, 0)
-
-    @property
-    def document(self) -> Document:
-        """
-        The `Buffer` document (text + cursor position).
-        """
-        return self.buffer.document
-
-    @document.setter
-    def document(self, value: Document) -> None:
-        self.buffer.set_document(value, bypass_readonly=True)
-
-    @property
-    def accept_handler(self) -> Optional[BufferAcceptHandler]:
-        """
-        The accept handler. Called when the user accepts the input.
-        """
-        return self.buffer.accept_handler
-
-    @accept_handler.setter
-    def accept_handler(self, value: BufferAcceptHandler) -> None:
-        self.buffer.accept_handler = value
-
-    def __pt_container__(self) -> Container:
-        return self.window
-
-
-class Label:
-    """
-    Widget that displays the given text. It is not editable or focusable.
-
-    :param text: Text to display. Can be multiline. All value types accepted by
-        :class:`prompt_toolkit.layout.FormattedTextControl` are allowed,
-        including a callable.
-    :param style: A style string.
-    :param width: When given, use this width, rather than calculating it from
-        the text size.
-    :param dont_extend_width: When `True`, don't take up more width than
-                              preferred, i.e. the length of the longest line of
-                              the text, or value of `width` parameter, if
-                              given. `True` by default
-    :param dont_extend_height: When `True`, don't take up more width than the
-                               preferred height, i.e. the number of lines of
-                               the text. `False` by default.
-    """
-
-    def __init__(
-        self,
-        text: AnyFormattedText,
-        style: str = "",
-        width: AnyDimension = None,
-        dont_extend_height: bool = True,
-        dont_extend_width: bool = False,
+""" 
+Collection of reusable components for building full screen applications. 
+ 
+All of these widgets implement the ``__pt_container__`` method, which makes 
+them usable in any situation where we are expecting a `prompt_toolkit` 
+container object. 
+ 
+.. warning:: 
+ 
+    At this point, the API for these widgets is considered unstable, and can 
+    potentially change between minor releases (we try not too, but no 
+    guarantees are made yet). The public API in 
+    `prompt_toolkit.shortcuts.dialogs` on the other hand is considered stable. 
+""" 
+from functools import partial 
+from typing import Callable, Generic, List, Optional, Sequence, Tuple, TypeVar, Union 
+ 
+from prompt_toolkit.application.current import get_app 
+from prompt_toolkit.auto_suggest import AutoSuggest, DynamicAutoSuggest 
+from prompt_toolkit.buffer import Buffer, BufferAcceptHandler 
+from prompt_toolkit.completion import Completer, DynamicCompleter 
+from prompt_toolkit.document import Document 
+from prompt_toolkit.filters import ( 
+    Condition, 
+    FilterOrBool, 
+    has_focus, 
+    is_done, 
+    is_true, 
+    to_filter, 
+) 
+from prompt_toolkit.formatted_text import ( 
+    AnyFormattedText, 
+    StyleAndTextTuples, 
+    Template, 
+    to_formatted_text, 
+) 
+from prompt_toolkit.formatted_text.utils import fragment_list_to_text 
+from prompt_toolkit.history import History 
+from prompt_toolkit.key_binding.key_bindings import KeyBindings 
+from prompt_toolkit.key_binding.key_processor import KeyPressEvent 
+from prompt_toolkit.keys import Keys 
+from prompt_toolkit.layout.containers import ( 
+    AnyContainer, 
+    ConditionalContainer, 
+    Container, 
+    DynamicContainer, 
+    Float, 
+    FloatContainer, 
+    HSplit, 
+    VSplit, 
+    Window, 
+    WindowAlign, 
+) 
+from prompt_toolkit.layout.controls import ( 
+    BufferControl, 
+    FormattedTextControl, 
+    GetLinePrefixCallable, 
+) 
+from prompt_toolkit.layout.dimension import AnyDimension 
+from prompt_toolkit.layout.dimension import Dimension as D 
+from prompt_toolkit.layout.dimension import to_dimension 
+from prompt_toolkit.layout.margins import ( 
+    ConditionalMargin, 
+    NumberedMargin, 
+    ScrollbarMargin, 
+) 
+from prompt_toolkit.layout.processors import ( 
+    AppendAutoSuggestion, 
+    BeforeInput, 
+    ConditionalProcessor, 
+    PasswordProcessor, 
+    Processor, 
+) 
+from prompt_toolkit.lexers import DynamicLexer, Lexer 
+from prompt_toolkit.mouse_events import MouseEvent, MouseEventType 
+from prompt_toolkit.utils import get_cwidth 
+from prompt_toolkit.validation import DynamicValidator, Validator 
+ 
+from .toolbars import SearchToolbar 
+ 
+__all__ = [ 
+    "TextArea", 
+    "Label", 
+    "Button", 
+    "Frame", 
+    "Shadow", 
+    "Box", 
+    "VerticalLine", 
+    "HorizontalLine", 
+    "RadioList", 
+    "CheckboxList", 
+    "Checkbox",  # backward compatibility 
+    "ProgressBar", 
+] 
+ 
+E = KeyPressEvent 
+ 
+ 
+class Border: 
+    "Box drawing characters. (Thin)" 
+    HORIZONTAL = "\u2500" 
+    VERTICAL = "\u2502" 
+    TOP_LEFT = "\u250c" 
+    TOP_RIGHT = "\u2510" 
+    BOTTOM_LEFT = "\u2514" 
+    BOTTOM_RIGHT = "\u2518" 
+ 
+ 
+class TextArea: 
+    """ 
+    A simple input field. 
+ 
+    This is a higher level abstraction on top of several other classes with 
+    sane defaults. 
+ 
+    This widget does have the most common options, but it does not intend to 
+    cover every single use case. For more configurations options, you can 
+    always build a text area manually, using a 
+    :class:`~prompt_toolkit.buffer.Buffer`, 
+    :class:`~prompt_toolkit.layout.BufferControl` and 
+    :class:`~prompt_toolkit.layout.Window`. 
+ 
+    Buffer attributes: 
+ 
+    :param text: The initial text. 
+    :param multiline: If True, allow multiline input. 
+    :param completer: :class:`~prompt_toolkit.completion.Completer` instance 
+        for auto completion. 
+    :param complete_while_typing: Boolean. 
+    :param accept_handler: Called when `Enter` is pressed (This should be a 
+        callable that takes a buffer as input). 
+    :param history: :class:`~prompt_toolkit.history.History` instance. 
+    :param auto_suggest: :class:`~prompt_toolkit.auto_suggest.AutoSuggest` 
+        instance for input suggestions. 
+ 
+    BufferControl attributes: 
+ 
+    :param password: When `True`, display using asterisks. 
+    :param focusable: When `True`, allow this widget to receive the focus. 
+    :param focus_on_click: When `True`, focus after mouse click. 
+    :param input_processors: `None` or a list of 
+        :class:`~prompt_toolkit.layout.Processor` objects. 
+    :param validator: `None` or a :class:`~prompt_toolkit.validation.Validator` 
+        object. 
+ 
+    Window attributes: 
+ 
+    :param lexer: :class:`~prompt_toolkit.lexers.Lexer` instance for syntax 
+        highlighting. 
+    :param wrap_lines: When `True`, don't scroll horizontally, but wrap lines. 
+    :param width: Window width. (:class:`~prompt_toolkit.layout.Dimension` object.) 
+    :param height: Window height. (:class:`~prompt_toolkit.layout.Dimension` object.) 
+    :param scrollbar: When `True`, display a scroll bar. 
+    :param style: A style string. 
+    :param dont_extend_width: When `True`, don't take up more width then the 
+                              preferred width reported by the control. 
+    :param dont_extend_height: When `True`, don't take up more width then the 
+                               preferred height reported by the control. 
+    :param get_line_prefix: None or a callable that returns formatted text to 
+        be inserted before a line. It takes a line number (int) and a 
+        wrap_count and returns formatted text. This can be used for 
+        implementation of line continuations, things like Vim "breakindent" and 
+        so on. 
+ 
+    Other attributes: 
+ 
+    :param search_field: An optional `SearchToolbar` object. 
+    """ 
+ 
+    def __init__( 
+        self, 
+        text: str = "", 
+        multiline: FilterOrBool = True, 
+        password: FilterOrBool = False, 
+        lexer: Optional[Lexer] = None, 
+        auto_suggest: Optional[AutoSuggest] = None, 
+        completer: Optional[Completer] = None, 
+        complete_while_typing: FilterOrBool = True, 
+        validator: Optional[Validator] = None, 
+        accept_handler: Optional[BufferAcceptHandler] = None, 
+        history: Optional[History] = None, 
+        focusable: FilterOrBool = True, 
+        focus_on_click: FilterOrBool = False, 
+        wrap_lines: FilterOrBool = True, 
+        read_only: FilterOrBool = False, 
+        width: AnyDimension = None, 
+        height: AnyDimension = None, 
+        dont_extend_height: FilterOrBool = False, 
+        dont_extend_width: FilterOrBool = False, 
+        line_numbers: bool = False, 
+        get_line_prefix: Optional[GetLinePrefixCallable] = None, 
+        scrollbar: bool = False, 
+        style: str = "", 
+        search_field: Optional[SearchToolbar] = None, 
+        preview_search: FilterOrBool = True, 
+        prompt: AnyFormattedText = "", 
+        input_processors: Optional[List[Processor]] = None, 
+    ) -> None: 
+ 
+        if search_field is None: 
+            search_control = None 
+        elif isinstance(search_field, SearchToolbar): 
+            search_control = search_field.control 
+ 
+        if input_processors is None: 
+            input_processors = [] 
+ 
+        # Writeable attributes. 
+        self.completer = completer 
+        self.complete_while_typing = complete_while_typing 
+        self.lexer = lexer 
+        self.auto_suggest = auto_suggest 
+        self.read_only = read_only 
+        self.wrap_lines = wrap_lines 
+        self.validator = validator 
+ 
+        self.buffer = Buffer( 
+            document=Document(text, 0), 
+            multiline=multiline, 
+            read_only=Condition(lambda: is_true(self.read_only)), 
+            completer=DynamicCompleter(lambda: self.completer), 
+            complete_while_typing=Condition( 
+                lambda: is_true(self.complete_while_typing) 
+            ), 
+            validator=DynamicValidator(lambda: self.validator), 
+            auto_suggest=DynamicAutoSuggest(lambda: self.auto_suggest), 
+            accept_handler=accept_handler, 
+            history=history, 
+        ) 
+ 
+        self.control = BufferControl( 
+            buffer=self.buffer, 
+            lexer=DynamicLexer(lambda: self.lexer), 
+            input_processors=[ 
+                ConditionalProcessor( 
+                    AppendAutoSuggestion(), has_focus(self.buffer) & ~is_done 
+                ), 
+                ConditionalProcessor( 
+                    processor=PasswordProcessor(), filter=to_filter(password) 
+                ), 
+                BeforeInput(prompt, style="class:text-area.prompt"), 
+            ] 
+            + input_processors, 
+            search_buffer_control=search_control, 
+            preview_search=preview_search, 
+            focusable=focusable, 
+            focus_on_click=focus_on_click, 
+        ) 
+ 
+        if multiline: 
+            if scrollbar: 
+                right_margins = [ScrollbarMargin(display_arrows=True)] 
+            else: 
+                right_margins = [] 
+            if line_numbers: 
+                left_margins = [NumberedMargin()] 
+            else: 
+                left_margins = [] 
+        else: 
+            height = D.exact(1) 
+            left_margins = [] 
+            right_margins = [] 
+ 
+        style = "class:text-area " + style 
+ 
+        # If no height was given, guarantee height of at least 1. 
+        if height is None: 
+            height = D(min=1) 
+ 
+        self.window = Window( 
+            height=height, 
+            width=width, 
+            dont_extend_height=dont_extend_height, 
+            dont_extend_width=dont_extend_width, 
+            content=self.control, 
+            style=style, 
+            wrap_lines=Condition(lambda: is_true(self.wrap_lines)), 
+            left_margins=left_margins, 
+            right_margins=right_margins, 
+            get_line_prefix=get_line_prefix, 
+        ) 
+ 
+    @property 
+    def text(self) -> str: 
+        """ 
+        The `Buffer` text. 
+        """ 
+        return self.buffer.text 
+ 
+    @text.setter 
+    def text(self, value: str) -> None: 
+        self.document = Document(value, 0) 
+ 
+    @property 
+    def document(self) -> Document: 
+        """ 
+        The `Buffer` document (text + cursor position). 
+        """ 
+        return self.buffer.document 
+ 
+    @document.setter 
+    def document(self, value: Document) -> None: 
+        self.buffer.set_document(value, bypass_readonly=True) 
+ 
+    @property 
+    def accept_handler(self) -> Optional[BufferAcceptHandler]: 
+        """ 
+        The accept handler. Called when the user accepts the input. 
+        """ 
+        return self.buffer.accept_handler 
+ 
+    @accept_handler.setter 
+    def accept_handler(self, value: BufferAcceptHandler) -> None: 
+        self.buffer.accept_handler = value 
+ 
+    def __pt_container__(self) -> Container: 
+        return self.window 
+ 
+ 
+class Label: 
+    """ 
+    Widget that displays the given text. It is not editable or focusable. 
+ 
+    :param text: Text to display. Can be multiline. All value types accepted by 
+        :class:`prompt_toolkit.layout.FormattedTextControl` are allowed, 
+        including a callable. 
+    :param style: A style string. 
+    :param width: When given, use this width, rather than calculating it from 
+        the text size. 
+    :param dont_extend_width: When `True`, don't take up more width than 
+                              preferred, i.e. the length of the longest line of 
+                              the text, or value of `width` parameter, if 
+                              given. `True` by default 
+    :param dont_extend_height: When `True`, don't take up more width than the 
+                               preferred height, i.e. the number of lines of 
+                               the text. `False` by default. 
+    """ 
+ 
+    def __init__( 
+        self, 
+        text: AnyFormattedText, 
+        style: str = "", 
+        width: AnyDimension = None, 
+        dont_extend_height: bool = True, 
+        dont_extend_width: bool = False, 
         align: Union[WindowAlign, Callable[[], WindowAlign]] = WindowAlign.LEFT,
-    ) -> None:
-
-        self.text = text
-
-        def get_width() -> AnyDimension:
-            if width is None:
-                text_fragments = to_formatted_text(self.text)
-                text = fragment_list_to_text(text_fragments)
-                if text:
-                    longest_line = max(get_cwidth(line) for line in text.splitlines())
-                else:
-                    return D(preferred=0)
-                return D(preferred=longest_line)
-            else:
-                return width
-
-        self.formatted_text_control = FormattedTextControl(text=lambda: self.text)
-
-        self.window = Window(
-            content=self.formatted_text_control,
-            width=get_width,
-            height=D(min=1),
-            style="class:label " + style,
-            dont_extend_height=dont_extend_height,
-            dont_extend_width=dont_extend_width,
+    ) -> None: 
+ 
+        self.text = text 
+ 
+        def get_width() -> AnyDimension: 
+            if width is None: 
+                text_fragments = to_formatted_text(self.text) 
+                text = fragment_list_to_text(text_fragments) 
+                if text: 
+                    longest_line = max(get_cwidth(line) for line in text.splitlines()) 
+                else: 
+                    return D(preferred=0) 
+                return D(preferred=longest_line) 
+            else: 
+                return width 
+ 
+        self.formatted_text_control = FormattedTextControl(text=lambda: self.text) 
+ 
+        self.window = Window( 
+            content=self.formatted_text_control, 
+            width=get_width, 
+            height=D(min=1), 
+            style="class:label " + style, 
+            dont_extend_height=dont_extend_height, 
+            dont_extend_width=dont_extend_width, 
             align=align,
-        )
-
-    def __pt_container__(self) -> Container:
-        return self.window
-
-
-class Button:
-    """
-    Clickable button.
-
-    :param text: The caption for the button.
-    :param handler: `None` or callable. Called when the button is clicked. No
-        parameters are passed to this callable. Use for instance Python's
-        `functools.partial` to pass parameters to this callable if needed.
-    :param width: Width of the button.
-    """
-
-    def __init__(
-        self,
-        text: str,
-        handler: Optional[Callable[[], None]] = None,
-        width: int = 12,
-        left_symbol: str = "<",
-        right_symbol: str = ">",
-    ) -> None:
-
-        self.text = text
-        self.left_symbol = left_symbol
-        self.right_symbol = right_symbol
-        self.handler = handler
-        self.width = width
-        self.control = FormattedTextControl(
-            self._get_text_fragments,
-            key_bindings=self._get_key_bindings(),
-            focusable=True,
-        )
-
-        def get_style() -> str:
-            if get_app().layout.has_focus(self):
-                return "class:button.focused"
-            else:
-                return "class:button"
-
-        # Note: `dont_extend_width` is False, because we want to allow buttons
-        #       to take more space if the parent container provides more space.
-        #       Otherwise, we will also truncate the text.
-        #       Probably we need a better way here to adjust to width of the
-        #       button to the text.
-
-        self.window = Window(
-            self.control,
-            align=WindowAlign.CENTER,
-            height=1,
-            width=width,
-            style=get_style,
-            dont_extend_width=False,
-            dont_extend_height=True,
-        )
-
-    def _get_text_fragments(self) -> StyleAndTextTuples:
-        width = self.width - (
-            get_cwidth(self.left_symbol) + get_cwidth(self.right_symbol)
-        )
-        text = ("{{:^{}}}".format(width)).format(self.text)
-
-        def handler(mouse_event: MouseEvent) -> None:
-            if (
-                self.handler is not None
-                and mouse_event.event_type == MouseEventType.MOUSE_UP
-            ):
-                self.handler()
-
-        return [
-            ("class:button.arrow", self.left_symbol, handler),
-            ("[SetCursorPosition]", ""),
-            ("class:button.text", text, handler),
-            ("class:button.arrow", self.right_symbol, handler),
-        ]
-
-    def _get_key_bindings(self) -> KeyBindings:
-        "Key bindings for the Button."
-        kb = KeyBindings()
-
-        @kb.add(" ")
-        @kb.add("enter")
-        def _(event: E) -> None:
-            if self.handler is not None:
-                self.handler()
-
-        return kb
-
-    def __pt_container__(self) -> Container:
-        return self.window
-
-
-class Frame:
-    """
-    Draw a border around any container, optionally with a title text.
-
-    Changing the title and body of the frame is possible at runtime by
-    assigning to the `body` and `title` attributes of this class.
-
-    :param body: Another container object.
-    :param title: Text to be displayed in the top of the frame (can be formatted text).
-    :param style: Style string to be applied to this widget.
-    """
-
-    def __init__(
-        self,
-        body: AnyContainer,
-        title: AnyFormattedText = "",
-        style: str = "",
-        width: AnyDimension = None,
-        height: AnyDimension = None,
-        key_bindings: Optional[KeyBindings] = None,
-        modal: bool = False,
-    ) -> None:
-
-        self.title = title
-        self.body = body
-
-        fill = partial(Window, style="class:frame.border")
-        style = "class:frame " + style
-
-        top_row_with_title = VSplit(
-            [
-                fill(width=1, height=1, char=Border.TOP_LEFT),
-                fill(char=Border.HORIZONTAL),
-                fill(width=1, height=1, char="|"),
-                # Notice: we use `Template` here, because `self.title` can be an
-                # `HTML` object for instance.
-                Label(
-                    lambda: Template(" {} ").format(self.title),
-                    style="class:frame.label",
-                    dont_extend_width=True,
-                ),
-                fill(width=1, height=1, char="|"),
-                fill(char=Border.HORIZONTAL),
-                fill(width=1, height=1, char=Border.TOP_RIGHT),
-            ],
-            height=1,
-        )
-
-        top_row_without_title = VSplit(
-            [
-                fill(width=1, height=1, char=Border.TOP_LEFT),
-                fill(char=Border.HORIZONTAL),
-                fill(width=1, height=1, char=Border.TOP_RIGHT),
-            ],
-            height=1,
-        )
-
-        @Condition
-        def has_title() -> bool:
-            return bool(self.title)
-
-        self.container = HSplit(
-            [
-                ConditionalContainer(content=top_row_with_title, filter=has_title),
-                ConditionalContainer(content=top_row_without_title, filter=~has_title),
-                VSplit(
-                    [
-                        fill(width=1, char=Border.VERTICAL),
-                        DynamicContainer(lambda: self.body),
-                        fill(width=1, char=Border.VERTICAL),
-                        # Padding is required to make sure that if the content is
-                        # too small, the right frame border is still aligned.
-                    ],
-                    padding=0,
-                ),
-                VSplit(
-                    [
-                        fill(width=1, height=1, char=Border.BOTTOM_LEFT),
-                        fill(char=Border.HORIZONTAL),
-                        fill(width=1, height=1, char=Border.BOTTOM_RIGHT),
-                    ],
-                    # specifying height here will increase the rendering speed.
-                    height=1,
-                ),
-            ],
-            width=width,
-            height=height,
-            style=style,
-            key_bindings=key_bindings,
-            modal=modal,
-        )
-
-    def __pt_container__(self) -> Container:
-        return self.container
-
-
-class Shadow:
-    """
-    Draw a shadow underneath/behind this container.
-    (This applies `class:shadow` the the cells under the shadow. The Style
-    should define the colors for the shadow.)
-
-    :param body: Another container object.
-    """
-
-    def __init__(self, body: AnyContainer) -> None:
-        self.container = FloatContainer(
-            content=body,
-            floats=[
-                Float(
-                    bottom=-1,
-                    height=1,
-                    left=1,
-                    right=-1,
-                    transparent=True,
-                    content=Window(style="class:shadow"),
-                ),
-                Float(
-                    bottom=-1,
-                    top=1,
-                    width=1,
-                    right=-1,
-                    transparent=True,
-                    content=Window(style="class:shadow"),
-                ),
-            ],
-        )
-
-    def __pt_container__(self) -> Container:
-        return self.container
-
-
-class Box:
-    """
-    Add padding around a container.
-
-    This also makes sure that the parent can provide more space than required by
-    the child. This is very useful when wrapping a small element with a fixed
-    size into a ``VSplit`` or ``HSplit`` object. The ``HSplit`` and ``VSplit``
-    try to make sure to adapt respectively the width and height, possibly
-    shrinking other elements. Wrapping something in a ``Box`` makes it flexible.
-
-    :param body: Another container object.
-    :param padding: The margin to be used around the body. This can be
-        overridden by `padding_left`, padding_right`, `padding_top` and
-        `padding_bottom`.
-    :param style: A style string.
-    :param char: Character to be used for filling the space around the body.
-        (This is supposed to be a character with a terminal width of 1.)
-    """
-
-    def __init__(
-        self,
-        body: AnyContainer,
-        padding: AnyDimension = None,
-        padding_left: AnyDimension = None,
-        padding_right: AnyDimension = None,
-        padding_top: AnyDimension = None,
-        padding_bottom: AnyDimension = None,
-        width: AnyDimension = None,
-        height: AnyDimension = None,
-        style: str = "",
-        char: Union[None, str, Callable[[], str]] = None,
-        modal: bool = False,
-        key_bindings: Optional[KeyBindings] = None,
-    ) -> None:
-
-        if padding is None:
-            padding = D(preferred=0)
-
-        def get(value: AnyDimension) -> D:
-            if value is None:
-                value = padding
-            return to_dimension(value)
-
-        self.padding_left = get(padding_left)
-        self.padding_right = get(padding_right)
-        self.padding_top = get(padding_top)
-        self.padding_bottom = get(padding_bottom)
-        self.body = body
-
-        self.container = HSplit(
-            [
-                Window(height=self.padding_top, char=char),
-                VSplit(
-                    [
-                        Window(width=self.padding_left, char=char),
-                        body,
-                        Window(width=self.padding_right, char=char),
-                    ]
-                ),
-                Window(height=self.padding_bottom, char=char),
-            ],
-            width=width,
-            height=height,
-            style=style,
-            modal=modal,
-            key_bindings=None,
-        )
-
-    def __pt_container__(self) -> Container:
-        return self.container
-
-
-_T = TypeVar("_T")
-
-
-class _DialogList(Generic[_T]):
-    """
-    Common code for `RadioList` and `CheckboxList`.
-    """
-
-    open_character: str = ""
-    close_character: str = ""
-    container_style: str = ""
-    default_style: str = ""
-    selected_style: str = ""
-    checked_style: str = ""
-    multiple_selection: bool = False
-    show_scrollbar: bool = True
-
-    def __init__(self, values: Sequence[Tuple[_T, AnyFormattedText]]) -> None:
-        assert len(values) > 0
-
-        self.values = values
-        # current_values will be used in multiple_selection,
-        # current_value will be used otherwise.
-        self.current_values: List[_T] = []
-        self.current_value: _T = values[0][0]
-        self._selected_index = 0
-
-        # Key bindings.
-        kb = KeyBindings()
-
-        @kb.add("up")
-        def _up(event: E) -> None:
-            self._selected_index = max(0, self._selected_index - 1)
-
-        @kb.add("down")
-        def _down(event: E) -> None:
-            self._selected_index = min(len(self.values) - 1, self._selected_index + 1)
-
-        @kb.add("pageup")
-        def _pageup(event: E) -> None:
-            w = event.app.layout.current_window
-            if w.render_info:
-                self._selected_index = max(
-                    0, self._selected_index - len(w.render_info.displayed_lines)
-                )
-
-        @kb.add("pagedown")
-        def _pagedown(event: E) -> None:
-            w = event.app.layout.current_window
-            if w.render_info:
-                self._selected_index = min(
-                    len(self.values) - 1,
-                    self._selected_index + len(w.render_info.displayed_lines),
-                )
-
-        @kb.add("enter")
-        @kb.add(" ")
-        def _click(event: E) -> None:
-            self._handle_enter()
-
-        @kb.add(Keys.Any)
-        def _find(event: E) -> None:
-            # We first check values after the selected value, then all values.
-            values = list(self.values)
-            for value in values[self._selected_index + 1 :] + values:
-                text = fragment_list_to_text(to_formatted_text(value[1])).lower()
-
-                if text.startswith(event.data.lower()):
-                    self._selected_index = self.values.index(value)
-                    return
-
-        # Control and window.
-        self.control = FormattedTextControl(
-            self._get_text_fragments, key_bindings=kb, focusable=True
-        )
-
-        self.window = Window(
-            content=self.control,
-            style=self.container_style,
-            right_margins=[
-                ConditionalMargin(
-                    margin=ScrollbarMargin(display_arrows=True),
-                    filter=Condition(lambda: self.show_scrollbar),
-                ),
-            ],
-            dont_extend_height=True,
-        )
-
-    def _handle_enter(self) -> None:
-        if self.multiple_selection:
-            val = self.values[self._selected_index][0]
-            if val in self.current_values:
-                self.current_values.remove(val)
-            else:
-                self.current_values.append(val)
-        else:
-            self.current_value = self.values[self._selected_index][0]
-
-    def _get_text_fragments(self) -> StyleAndTextTuples:
-        def mouse_handler(mouse_event: MouseEvent) -> None:
-            """
-            Set `_selected_index` and `current_value` according to the y
-            position of the mouse click event.
-            """
-            if mouse_event.event_type == MouseEventType.MOUSE_UP:
-                self._selected_index = mouse_event.position.y
-                self._handle_enter()
-
-        result: StyleAndTextTuples = []
-        for i, value in enumerate(self.values):
-            if self.multiple_selection:
-                checked = value[0] in self.current_values
-            else:
-                checked = value[0] == self.current_value
-            selected = i == self._selected_index
-
-            style = ""
-            if checked:
-                style += " " + self.checked_style
-            if selected:
-                style += " " + self.selected_style
-
-            result.append((style, self.open_character))
-
-            if selected:
-                result.append(("[SetCursorPosition]", ""))
-
-            if checked:
-                result.append((style, "*"))
-            else:
-                result.append((style, " "))
-
-            result.append((style, self.close_character))
-            result.append((self.default_style, " "))
-            result.extend(to_formatted_text(value[1], style=self.default_style))
-            result.append(("", "\n"))
-
-        # Add mouse handler to all fragments.
-        for i in range(len(result)):
-            result[i] = (result[i][0], result[i][1], mouse_handler)
-
-        result.pop()  # Remove last newline.
-        return result
-
-    def __pt_container__(self) -> Container:
-        return self.window
-
-
-class RadioList(_DialogList[_T]):
-    """
-    List of radio buttons. Only one can be checked at the same time.
-
-    :param values: List of (value, label) tuples.
-    """
-
-    open_character = "("
-    close_character = ")"
-    container_style = "class:radio-list"
-    default_style = "class:radio"
-    selected_style = "class:radio-selected"
-    checked_style = "class:radio-checked"
-    multiple_selection = False
-
-
-class CheckboxList(_DialogList[_T]):
-    """
-    List of checkbox buttons. Several can be checked at the same time.
-
-    :param values: List of (value, label) tuples.
-    """
-
-    open_character = "["
-    close_character = "]"
-    container_style = "class:checkbox-list"
-    default_style = "class:checkbox"
-    selected_style = "class:checkbox-selected"
-    checked_style = "class:checkbox-checked"
-    multiple_selection = True
-
-
-class Checkbox(CheckboxList[str]):
-    """Backward compatibility util: creates a 1-sized CheckboxList
-
-    :param text: the text
-    """
-
-    show_scrollbar = False
-
-    def __init__(self, text: AnyFormattedText = "", checked: bool = False) -> None:
-        values = [("value", text)]
-        CheckboxList.__init__(self, values)
-        self.checked = checked
-
-    @property
-    def checked(self) -> bool:
-        return "value" in self.current_values
-
-    @checked.setter
-    def checked(self, value: bool) -> None:
-        if value:
-            self.current_values = ["value"]
-        else:
-            self.current_values = []
-
-
-class VerticalLine(object):
-    """
-    A simple vertical line with a width of 1.
-    """
-
-    def __init__(self) -> None:
-        self.window = Window(
-            char=Border.VERTICAL, style="class:line,vertical-line", width=1
-        )
-
-    def __pt_container__(self) -> Container:
-        return self.window
-
-
-class HorizontalLine:
-    """
-    A simple horizontal line with a height of 1.
-    """
-
-    def __init__(self) -> None:
-        self.window = Window(
-            char=Border.HORIZONTAL, style="class:line,horizontal-line", height=1
-        )
-
-    def __pt_container__(self) -> Container:
-        return self.window
-
-
-class ProgressBar:
-    def __init__(self) -> None:
-        self._percentage = 60
-
-        self.label = Label("60%")
-        self.container = FloatContainer(
-            content=Window(height=1),
-            floats=[
-                # We first draw the label, then the actual progress bar.  Right
-                # now, this is the only way to have the colors of the progress
-                # bar appear on top of the label. The problem is that our label
-                # can't be part of any `Window` below.
-                Float(content=self.label, top=0, bottom=0),
-                Float(
-                    left=0,
-                    top=0,
-                    right=0,
-                    bottom=0,
-                    content=VSplit(
-                        [
-                            Window(
-                                style="class:progress-bar.used",
-                                width=lambda: D(weight=int(self._percentage)),
-                            ),
-                            Window(
-                                style="class:progress-bar",
-                                width=lambda: D(weight=int(100 - self._percentage)),
-                            ),
-                        ]
-                    ),
-                ),
-            ],
-        )
-
-    @property
-    def percentage(self) -> int:
-        return self._percentage
-
-    @percentage.setter
-    def percentage(self, value: int) -> None:
-        self._percentage = value
-        self.label.text = "{0}%".format(value)
-
-    def __pt_container__(self) -> Container:
-        return self.container
+        ) 
+ 
+    def __pt_container__(self) -> Container: 
+        return self.window 
+ 
+ 
+class Button: 
+    """ 
+    Clickable button. 
+ 
+    :param text: The caption for the button. 
+    :param handler: `None` or callable. Called when the button is clicked. No 
+        parameters are passed to this callable. Use for instance Python's 
+        `functools.partial` to pass parameters to this callable if needed. 
+    :param width: Width of the button. 
+    """ 
+ 
+    def __init__( 
+        self, 
+        text: str, 
+        handler: Optional[Callable[[], None]] = None, 
+        width: int = 12, 
+        left_symbol: str = "<", 
+        right_symbol: str = ">", 
+    ) -> None: 
+ 
+        self.text = text 
+        self.left_symbol = left_symbol 
+        self.right_symbol = right_symbol 
+        self.handler = handler 
+        self.width = width 
+        self.control = FormattedTextControl( 
+            self._get_text_fragments, 
+            key_bindings=self._get_key_bindings(), 
+            focusable=True, 
+        ) 
+ 
+        def get_style() -> str: 
+            if get_app().layout.has_focus(self): 
+                return "class:button.focused" 
+            else: 
+                return "class:button" 
+ 
+        # Note: `dont_extend_width` is False, because we want to allow buttons 
+        #       to take more space if the parent container provides more space. 
+        #       Otherwise, we will also truncate the text. 
+        #       Probably we need a better way here to adjust to width of the 
+        #       button to the text. 
+ 
+        self.window = Window( 
+            self.control, 
+            align=WindowAlign.CENTER, 
+            height=1, 
+            width=width, 
+            style=get_style, 
+            dont_extend_width=False, 
+            dont_extend_height=True, 
+        ) 
+ 
+    def _get_text_fragments(self) -> StyleAndTextTuples: 
+        width = self.width - ( 
+            get_cwidth(self.left_symbol) + get_cwidth(self.right_symbol) 
+        ) 
+        text = ("{{:^{}}}".format(width)).format(self.text) 
+ 
+        def handler(mouse_event: MouseEvent) -> None: 
+            if ( 
+                self.handler is not None 
+                and mouse_event.event_type == MouseEventType.MOUSE_UP 
+            ): 
+                self.handler() 
+ 
+        return [ 
+            ("class:button.arrow", self.left_symbol, handler), 
+            ("[SetCursorPosition]", ""), 
+            ("class:button.text", text, handler), 
+            ("class:button.arrow", self.right_symbol, handler), 
+        ] 
+ 
+    def _get_key_bindings(self) -> KeyBindings: 
+        "Key bindings for the Button." 
+        kb = KeyBindings() 
+ 
+        @kb.add(" ") 
+        @kb.add("enter") 
+        def _(event: E) -> None: 
+            if self.handler is not None: 
+                self.handler() 
+ 
+        return kb 
+ 
+    def __pt_container__(self) -> Container: 
+        return self.window 
+ 
+ 
+class Frame: 
+    """ 
+    Draw a border around any container, optionally with a title text. 
+ 
+    Changing the title and body of the frame is possible at runtime by 
+    assigning to the `body` and `title` attributes of this class. 
+ 
+    :param body: Another container object. 
+    :param title: Text to be displayed in the top of the frame (can be formatted text). 
+    :param style: Style string to be applied to this widget. 
+    """ 
+ 
+    def __init__( 
+        self, 
+        body: AnyContainer, 
+        title: AnyFormattedText = "", 
+        style: str = "", 
+        width: AnyDimension = None, 
+        height: AnyDimension = None, 
+        key_bindings: Optional[KeyBindings] = None, 
+        modal: bool = False, 
+    ) -> None: 
+ 
+        self.title = title 
+        self.body = body 
+ 
+        fill = partial(Window, style="class:frame.border") 
+        style = "class:frame " + style 
+ 
+        top_row_with_title = VSplit( 
+            [ 
+                fill(width=1, height=1, char=Border.TOP_LEFT), 
+                fill(char=Border.HORIZONTAL), 
+                fill(width=1, height=1, char="|"), 
+                # Notice: we use `Template` here, because `self.title` can be an 
+                # `HTML` object for instance. 
+                Label( 
+                    lambda: Template(" {} ").format(self.title), 
+                    style="class:frame.label", 
+                    dont_extend_width=True, 
+                ), 
+                fill(width=1, height=1, char="|"), 
+                fill(char=Border.HORIZONTAL), 
+                fill(width=1, height=1, char=Border.TOP_RIGHT), 
+            ], 
+            height=1, 
+        ) 
+ 
+        top_row_without_title = VSplit( 
+            [ 
+                fill(width=1, height=1, char=Border.TOP_LEFT), 
+                fill(char=Border.HORIZONTAL), 
+                fill(width=1, height=1, char=Border.TOP_RIGHT), 
+            ], 
+            height=1, 
+        ) 
+ 
+        @Condition 
+        def has_title() -> bool: 
+            return bool(self.title) 
+ 
+        self.container = HSplit( 
+            [ 
+                ConditionalContainer(content=top_row_with_title, filter=has_title), 
+                ConditionalContainer(content=top_row_without_title, filter=~has_title), 
+                VSplit( 
+                    [ 
+                        fill(width=1, char=Border.VERTICAL), 
+                        DynamicContainer(lambda: self.body), 
+                        fill(width=1, char=Border.VERTICAL), 
+                        # Padding is required to make sure that if the content is 
+                        # too small, the right frame border is still aligned. 
+                    ], 
+                    padding=0, 
+                ), 
+                VSplit( 
+                    [ 
+                        fill(width=1, height=1, char=Border.BOTTOM_LEFT), 
+                        fill(char=Border.HORIZONTAL), 
+                        fill(width=1, height=1, char=Border.BOTTOM_RIGHT), 
+                    ], 
+                    # specifying height here will increase the rendering speed. 
+                    height=1, 
+                ), 
+            ], 
+            width=width, 
+            height=height, 
+            style=style, 
+            key_bindings=key_bindings, 
+            modal=modal, 
+        ) 
+ 
+    def __pt_container__(self) -> Container: 
+        return self.container 
+ 
+ 
+class Shadow: 
+    """ 
+    Draw a shadow underneath/behind this container. 
+    (This applies `class:shadow` the the cells under the shadow. The Style 
+    should define the colors for the shadow.) 
+ 
+    :param body: Another container object. 
+    """ 
+ 
+    def __init__(self, body: AnyContainer) -> None: 
+        self.container = FloatContainer( 
+            content=body, 
+            floats=[ 
+                Float( 
+                    bottom=-1, 
+                    height=1, 
+                    left=1, 
+                    right=-1, 
+                    transparent=True, 
+                    content=Window(style="class:shadow"), 
+                ), 
+                Float( 
+                    bottom=-1, 
+                    top=1, 
+                    width=1, 
+                    right=-1, 
+                    transparent=True, 
+                    content=Window(style="class:shadow"), 
+                ), 
+            ], 
+        ) 
+ 
+    def __pt_container__(self) -> Container: 
+        return self.container 
+ 
+ 
+class Box: 
+    """ 
+    Add padding around a container. 
+ 
+    This also makes sure that the parent can provide more space than required by 
+    the child. This is very useful when wrapping a small element with a fixed 
+    size into a ``VSplit`` or ``HSplit`` object. The ``HSplit`` and ``VSplit`` 
+    try to make sure to adapt respectively the width and height, possibly 
+    shrinking other elements. Wrapping something in a ``Box`` makes it flexible. 
+ 
+    :param body: Another container object. 
+    :param padding: The margin to be used around the body. This can be 
+        overridden by `padding_left`, padding_right`, `padding_top` and 
+        `padding_bottom`. 
+    :param style: A style string. 
+    :param char: Character to be used for filling the space around the body. 
+        (This is supposed to be a character with a terminal width of 1.) 
+    """ 
+ 
+    def __init__( 
+        self, 
+        body: AnyContainer, 
+        padding: AnyDimension = None, 
+        padding_left: AnyDimension = None, 
+        padding_right: AnyDimension = None, 
+        padding_top: AnyDimension = None, 
+        padding_bottom: AnyDimension = None, 
+        width: AnyDimension = None, 
+        height: AnyDimension = None, 
+        style: str = "", 
+        char: Union[None, str, Callable[[], str]] = None, 
+        modal: bool = False, 
+        key_bindings: Optional[KeyBindings] = None, 
+    ) -> None: 
+ 
+        if padding is None: 
+            padding = D(preferred=0) 
+ 
+        def get(value: AnyDimension) -> D: 
+            if value is None: 
+                value = padding 
+            return to_dimension(value) 
+ 
+        self.padding_left = get(padding_left) 
+        self.padding_right = get(padding_right) 
+        self.padding_top = get(padding_top) 
+        self.padding_bottom = get(padding_bottom) 
+        self.body = body 
+ 
+        self.container = HSplit( 
+            [ 
+                Window(height=self.padding_top, char=char), 
+                VSplit( 
+                    [ 
+                        Window(width=self.padding_left, char=char), 
+                        body, 
+                        Window(width=self.padding_right, char=char), 
+                    ] 
+                ), 
+                Window(height=self.padding_bottom, char=char), 
+            ], 
+            width=width, 
+            height=height, 
+            style=style, 
+            modal=modal, 
+            key_bindings=None, 
+        ) 
+ 
+    def __pt_container__(self) -> Container: 
+        return self.container 
+ 
+ 
+_T = TypeVar("_T") 
+ 
+ 
+class _DialogList(Generic[_T]): 
+    """ 
+    Common code for `RadioList` and `CheckboxList`. 
+    """ 
+ 
+    open_character: str = "" 
+    close_character: str = "" 
+    container_style: str = "" 
+    default_style: str = "" 
+    selected_style: str = "" 
+    checked_style: str = "" 
+    multiple_selection: bool = False 
+    show_scrollbar: bool = True 
+ 
+    def __init__(self, values: Sequence[Tuple[_T, AnyFormattedText]]) -> None: 
+        assert len(values) > 0 
+ 
+        self.values = values 
+        # current_values will be used in multiple_selection, 
+        # current_value will be used otherwise. 
+        self.current_values: List[_T] = [] 
+        self.current_value: _T = values[0][0] 
+        self._selected_index = 0 
+ 
+        # Key bindings. 
+        kb = KeyBindings() 
+ 
+        @kb.add("up") 
+        def _up(event: E) -> None: 
+            self._selected_index = max(0, self._selected_index - 1) 
+ 
+        @kb.add("down") 
+        def _down(event: E) -> None: 
+            self._selected_index = min(len(self.values) - 1, self._selected_index + 1) 
+ 
+        @kb.add("pageup") 
+        def _pageup(event: E) -> None: 
+            w = event.app.layout.current_window 
+            if w.render_info: 
+                self._selected_index = max( 
+                    0, self._selected_index - len(w.render_info.displayed_lines) 
+                ) 
+ 
+        @kb.add("pagedown") 
+        def _pagedown(event: E) -> None: 
+            w = event.app.layout.current_window 
+            if w.render_info: 
+                self._selected_index = min( 
+                    len(self.values) - 1, 
+                    self._selected_index + len(w.render_info.displayed_lines), 
+                ) 
+ 
+        @kb.add("enter") 
+        @kb.add(" ") 
+        def _click(event: E) -> None: 
+            self._handle_enter() 
+ 
+        @kb.add(Keys.Any) 
+        def _find(event: E) -> None: 
+            # We first check values after the selected value, then all values. 
+            values = list(self.values) 
+            for value in values[self._selected_index + 1 :] + values: 
+                text = fragment_list_to_text(to_formatted_text(value[1])).lower() 
+ 
+                if text.startswith(event.data.lower()): 
+                    self._selected_index = self.values.index(value) 
+                    return 
+ 
+        # Control and window. 
+        self.control = FormattedTextControl( 
+            self._get_text_fragments, key_bindings=kb, focusable=True 
+        ) 
+ 
+        self.window = Window( 
+            content=self.control, 
+            style=self.container_style, 
+            right_margins=[ 
+                ConditionalMargin( 
+                    margin=ScrollbarMargin(display_arrows=True), 
+                    filter=Condition(lambda: self.show_scrollbar), 
+                ), 
+            ], 
+            dont_extend_height=True, 
+        ) 
+ 
+    def _handle_enter(self) -> None: 
+        if self.multiple_selection: 
+            val = self.values[self._selected_index][0] 
+            if val in self.current_values: 
+                self.current_values.remove(val) 
+            else: 
+                self.current_values.append(val) 
+        else: 
+            self.current_value = self.values[self._selected_index][0] 
+ 
+    def _get_text_fragments(self) -> StyleAndTextTuples: 
+        def mouse_handler(mouse_event: MouseEvent) -> None: 
+            """ 
+            Set `_selected_index` and `current_value` according to the y 
+            position of the mouse click event. 
+            """ 
+            if mouse_event.event_type == MouseEventType.MOUSE_UP: 
+                self._selected_index = mouse_event.position.y 
+                self._handle_enter() 
+ 
+        result: StyleAndTextTuples = [] 
+        for i, value in enumerate(self.values): 
+            if self.multiple_selection: 
+                checked = value[0] in self.current_values 
+            else: 
+                checked = value[0] == self.current_value 
+            selected = i == self._selected_index 
+ 
+            style = "" 
+            if checked: 
+                style += " " + self.checked_style 
+            if selected: 
+                style += " " + self.selected_style 
+ 
+            result.append((style, self.open_character)) 
+ 
+            if selected: 
+                result.append(("[SetCursorPosition]", "")) 
+ 
+            if checked: 
+                result.append((style, "*")) 
+            else: 
+                result.append((style, " ")) 
+ 
+            result.append((style, self.close_character)) 
+            result.append((self.default_style, " ")) 
+            result.extend(to_formatted_text(value[1], style=self.default_style)) 
+            result.append(("", "\n")) 
+ 
+        # Add mouse handler to all fragments. 
+        for i in range(len(result)): 
+            result[i] = (result[i][0], result[i][1], mouse_handler) 
+ 
+        result.pop()  # Remove last newline. 
+        return result 
+ 
+    def __pt_container__(self) -> Container: 
+        return self.window 
+ 
+ 
+class RadioList(_DialogList[_T]): 
+    """ 
+    List of radio buttons. Only one can be checked at the same time. 
+ 
+    :param values: List of (value, label) tuples. 
+    """ 
+ 
+    open_character = "(" 
+    close_character = ")" 
+    container_style = "class:radio-list" 
+    default_style = "class:radio" 
+    selected_style = "class:radio-selected" 
+    checked_style = "class:radio-checked" 
+    multiple_selection = False 
+ 
+ 
+class CheckboxList(_DialogList[_T]): 
+    """ 
+    List of checkbox buttons. Several can be checked at the same time. 
+ 
+    :param values: List of (value, label) tuples. 
+    """ 
+ 
+    open_character = "[" 
+    close_character = "]" 
+    container_style = "class:checkbox-list" 
+    default_style = "class:checkbox" 
+    selected_style = "class:checkbox-selected" 
+    checked_style = "class:checkbox-checked" 
+    multiple_selection = True 
+ 
+ 
+class Checkbox(CheckboxList[str]): 
+    """Backward compatibility util: creates a 1-sized CheckboxList 
+ 
+    :param text: the text 
+    """ 
+ 
+    show_scrollbar = False 
+ 
+    def __init__(self, text: AnyFormattedText = "", checked: bool = False) -> None: 
+        values = [("value", text)] 
+        CheckboxList.__init__(self, values) 
+        self.checked = checked 
+ 
+    @property 
+    def checked(self) -> bool: 
+        return "value" in self.current_values 
+ 
+    @checked.setter 
+    def checked(self, value: bool) -> None: 
+        if value: 
+            self.current_values = ["value"] 
+        else: 
+            self.current_values = [] 
+ 
+ 
+class VerticalLine(object): 
+    """ 
+    A simple vertical line with a width of 1. 
+    """ 
+ 
+    def __init__(self) -> None: 
+        self.window = Window( 
+            char=Border.VERTICAL, style="class:line,vertical-line", width=1 
+        ) 
+ 
+    def __pt_container__(self) -> Container: 
+        return self.window 
+ 
+ 
+class HorizontalLine: 
+    """ 
+    A simple horizontal line with a height of 1. 
+    """ 
+ 
+    def __init__(self) -> None: 
+        self.window = Window( 
+            char=Border.HORIZONTAL, style="class:line,horizontal-line", height=1 
+        ) 
+ 
+    def __pt_container__(self) -> Container: 
+        return self.window 
+ 
+ 
+class ProgressBar: 
+    def __init__(self) -> None: 
+        self._percentage = 60 
+ 
+        self.label = Label("60%") 
+        self.container = FloatContainer( 
+            content=Window(height=1), 
+            floats=[ 
+                # We first draw the label, then the actual progress bar.  Right 
+                # now, this is the only way to have the colors of the progress 
+                # bar appear on top of the label. The problem is that our label 
+                # can't be part of any `Window` below. 
+                Float(content=self.label, top=0, bottom=0), 
+                Float( 
+                    left=0, 
+                    top=0, 
+                    right=0, 
+                    bottom=0, 
+                    content=VSplit( 
+                        [ 
+                            Window( 
+                                style="class:progress-bar.used", 
+                                width=lambda: D(weight=int(self._percentage)), 
+                            ), 
+                            Window( 
+                                style="class:progress-bar", 
+                                width=lambda: D(weight=int(100 - self._percentage)), 
+                            ), 
+                        ] 
+                    ), 
+                ), 
+            ], 
+        ) 
+ 
+    @property 
+    def percentage(self) -> int: 
+        return self._percentage 
+ 
+    @percentage.setter 
+    def percentage(self, value: int) -> None: 
+        self._percentage = value 
+        self.label.text = "{0}%".format(value) 
+ 
+    def __pt_container__(self) -> Container: 
+        return self.container