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

1 files changed, 720 insertions, 720 deletions

diff --git a/contrib/python/prompt-toolkit/py3/prompt_toolkit/layout/menus.py b/contrib/python/prompt-toolkit/py3/prompt_toolkit/layout/menus.py
index 8998f5ed1d..557450c000 100644
--- a/contrib/python/prompt-toolkit/py3/prompt_toolkit/layout/menus.py
+++ b/contrib/python/prompt-toolkit/py3/prompt_toolkit/layout/menus.py
@@ -1,722 +1,722 @@
-import math 
-from itertools import zip_longest 
-from typing import ( 
-    TYPE_CHECKING, 
-    Callable, 
-    Dict, 
-    Iterable, 
-    List, 
-    Optional, 
-    Tuple, 
-    TypeVar, 
-    Union, 
-    cast, 
-) 
- 
-from prompt_toolkit.application.current import get_app 
-from prompt_toolkit.buffer import CompletionState 
-from prompt_toolkit.completion import Completion 
-from prompt_toolkit.data_structures import Point 
-from prompt_toolkit.filters import ( 
-    Condition, 
-    FilterOrBool, 
-    has_completions, 
-    is_done, 
-    to_filter, 
-) 
-from prompt_toolkit.formatted_text import ( 
-    StyleAndTextTuples, 
-    fragment_list_width, 
-    to_formatted_text, 
-) 
-from prompt_toolkit.key_binding.key_processor import KeyPressEvent 
-from prompt_toolkit.layout.utils import explode_text_fragments 
-from prompt_toolkit.mouse_events import MouseEvent, MouseEventType 
-from prompt_toolkit.utils import get_cwidth 
- 
-from .containers import ConditionalContainer, HSplit, ScrollOffsets, Window 
-from .controls import GetLinePrefixCallable, UIContent, UIControl 
-from .dimension import Dimension 
-from .margins import ScrollbarMargin 
- 
-if TYPE_CHECKING: 
-    from prompt_toolkit.key_binding.key_bindings import ( 
-        KeyBindings, 
-        NotImplementedOrNone, 
-    ) 
- 
- 
-__all__ = [ 
-    "CompletionsMenu", 
-    "MultiColumnCompletionsMenu", 
-] 
- 
-E = KeyPressEvent 
- 
- 
-class CompletionsMenuControl(UIControl): 
-    """ 
-    Helper for drawing the complete menu to the screen. 
- 
-    :param scroll_offset: Number (integer) representing the preferred amount of 
-        completions to be displayed before and after the current one. When this 
-        is a very high number, the current completion will be shown in the 
-        middle most of the time. 
-    """ 
- 
-    # Preferred minimum size of the menu control. 
-    # The CompletionsMenu class defines a width of 8, and there is a scrollbar 
-    # of 1.) 
-    MIN_WIDTH = 7 
- 
-    def has_focus(self) -> bool: 
-        return False 
- 
-    def preferred_width(self, max_available_width: int) -> Optional[int]: 
-        complete_state = get_app().current_buffer.complete_state 
-        if complete_state: 
-            menu_width = self._get_menu_width(500, complete_state) 
-            menu_meta_width = self._get_menu_meta_width(500, complete_state) 
- 
-            return menu_width + menu_meta_width 
-        else: 
-            return 0 
- 
-    def preferred_height( 
-        self, 
-        width: int, 
-        max_available_height: int, 
-        wrap_lines: bool, 
-        get_line_prefix: Optional[GetLinePrefixCallable], 
-    ) -> Optional[int]: 
- 
-        complete_state = get_app().current_buffer.complete_state 
-        if complete_state: 
-            return len(complete_state.completions) 
-        else: 
-            return 0 
- 
-    def create_content(self, width: int, height: int) -> UIContent: 
-        """ 
-        Create a UIContent object for this control. 
-        """ 
-        complete_state = get_app().current_buffer.complete_state 
-        if complete_state: 
-            completions = complete_state.completions 
-            index = complete_state.complete_index  # Can be None! 
- 
-            # Calculate width of completions menu. 
-            menu_width = self._get_menu_width(width, complete_state) 
-            menu_meta_width = self._get_menu_meta_width( 
-                width - menu_width, complete_state 
-            ) 
-            show_meta = self._show_meta(complete_state) 
- 
-            def get_line(i: int) -> StyleAndTextTuples: 
-                c = completions[i] 
-                is_current_completion = i == index 
-                result = _get_menu_item_fragments( 
-                    c, is_current_completion, menu_width, space_after=True 
-                ) 
- 
-                if show_meta: 
-                    result += self._get_menu_item_meta_fragments( 
-                        c, is_current_completion, menu_meta_width 
-                    ) 
-                return result 
- 
-            return UIContent( 
-                get_line=get_line, 
-                cursor_position=Point(x=0, y=index or 0), 
-                line_count=len(completions), 
-            ) 
- 
-        return UIContent() 
- 
-    def _show_meta(self, complete_state: CompletionState) -> bool: 
-        """ 
-        Return ``True`` if we need to show a column with meta information. 
-        """ 
-        return any(c.display_meta_text for c in complete_state.completions) 
- 
-    def _get_menu_width(self, max_width: int, complete_state: CompletionState) -> int: 
-        """ 
-        Return the width of the main column. 
-        """ 
-        return min( 
-            max_width, 
-            max( 
-                self.MIN_WIDTH, 
-                max(get_cwidth(c.display_text) for c in complete_state.completions) + 2, 
-            ), 
-        ) 
- 
-    def _get_menu_meta_width( 
-        self, max_width: int, complete_state: CompletionState 
-    ) -> int: 
-        """ 
-        Return the width of the meta column. 
-        """ 
- 
-        def meta_width(completion: Completion) -> int: 
-            return get_cwidth(completion.display_meta_text) 
- 
-        if self._show_meta(complete_state): 
-            return min( 
-                max_width, max(meta_width(c) for c in complete_state.completions) + 2 
-            ) 
-        else: 
-            return 0 
- 
-    def _get_menu_item_meta_fragments( 
-        self, completion: Completion, is_current_completion: bool, width: int 
-    ) -> StyleAndTextTuples: 
- 
-        if is_current_completion: 
-            style_str = "class:completion-menu.meta.completion.current" 
-        else: 
-            style_str = "class:completion-menu.meta.completion" 
- 
-        text, tw = _trim_formatted_text(completion.display_meta, width - 2) 
-        padding = " " * (width - 1 - tw) 
- 
-        return to_formatted_text( 
-            cast(StyleAndTextTuples, []) + [("", " ")] + text + [("", padding)], 
-            style=style_str, 
-        ) 
- 
-    def mouse_handler(self, mouse_event: MouseEvent) -> "NotImplementedOrNone": 
-        """ 
-        Handle mouse events: clicking and scrolling. 
-        """ 
-        b = get_app().current_buffer 
- 
-        if mouse_event.event_type == MouseEventType.MOUSE_UP: 
-            # Select completion. 
-            b.go_to_completion(mouse_event.position.y) 
-            b.complete_state = None 
- 
-        elif mouse_event.event_type == MouseEventType.SCROLL_DOWN: 
-            # Scroll up. 
-            b.complete_next(count=3, disable_wrap_around=True) 
- 
-        elif mouse_event.event_type == MouseEventType.SCROLL_UP: 
-            # Scroll down. 
-            b.complete_previous(count=3, disable_wrap_around=True) 
- 
-        return None 
- 
- 
-def _get_menu_item_fragments( 
-    completion: Completion, 
-    is_current_completion: bool, 
-    width: int, 
-    space_after: bool = False, 
-) -> StyleAndTextTuples: 
-    """ 
-    Get the style/text tuples for a menu item, styled and trimmed to the given 
-    width. 
-    """ 
-    if is_current_completion: 
-        style_str = "class:completion-menu.completion.current %s %s" % ( 
-            completion.style, 
-            completion.selected_style, 
-        ) 
-    else: 
-        style_str = "class:completion-menu.completion " + completion.style 
- 
-    text, tw = _trim_formatted_text( 
-        completion.display, (width - 2 if space_after else width - 1) 
-    ) 
- 
-    padding = " " * (width - 1 - tw) 
- 
-    return to_formatted_text( 
-        cast(StyleAndTextTuples, []) + [("", " ")] + text + [("", padding)], 
-        style=style_str, 
-    ) 
- 
- 
-def _trim_formatted_text( 
-    formatted_text: StyleAndTextTuples, max_width: int 
-) -> Tuple[StyleAndTextTuples, int]: 
-    """ 
-    Trim the text to `max_width`, append dots when the text is too long. 
-    Returns (text, width) tuple. 
-    """ 
-    width = fragment_list_width(formatted_text) 
- 
-    # When the text is too wide, trim it. 
-    if width > max_width: 
-        result = []  # Text fragments. 
-        remaining_width = max_width - 3 
- 
-        for style_and_ch in explode_text_fragments(formatted_text): 
-            ch_width = get_cwidth(style_and_ch[1]) 
- 
-            if ch_width <= remaining_width: 
-                result.append(style_and_ch) 
-                remaining_width -= ch_width 
-            else: 
-                break 
- 
-        result.append(("", "...")) 
- 
-        return result, max_width - remaining_width 
-    else: 
-        return formatted_text, width 
- 
- 
-class CompletionsMenu(ConditionalContainer): 
-    # NOTE: We use a pretty big z_index by default. Menus are supposed to be 
-    #       above anything else. We also want to make sure that the content is 
-    #       visible at the point where we draw this menu. 
-    def __init__( 
-        self, 
-        max_height: Optional[int] = None, 
-        scroll_offset: Union[int, Callable[[], int]] = 0, 
-        extra_filter: FilterOrBool = True, 
-        display_arrows: FilterOrBool = False, 
+import math
+from itertools import zip_longest
+from typing import (
+    TYPE_CHECKING,
+    Callable,
+    Dict,
+    Iterable,
+    List,
+    Optional,
+    Tuple,
+    TypeVar,
+    Union,
+    cast,
+)
+
+from prompt_toolkit.application.current import get_app
+from prompt_toolkit.buffer import CompletionState
+from prompt_toolkit.completion import Completion
+from prompt_toolkit.data_structures import Point
+from prompt_toolkit.filters import (
+    Condition,
+    FilterOrBool,
+    has_completions,
+    is_done,
+    to_filter,
+)
+from prompt_toolkit.formatted_text import (
+    StyleAndTextTuples,
+    fragment_list_width,
+    to_formatted_text,
+)
+from prompt_toolkit.key_binding.key_processor import KeyPressEvent
+from prompt_toolkit.layout.utils import explode_text_fragments
+from prompt_toolkit.mouse_events import MouseEvent, MouseEventType
+from prompt_toolkit.utils import get_cwidth
+
+from .containers import ConditionalContainer, HSplit, ScrollOffsets, Window
+from .controls import GetLinePrefixCallable, UIContent, UIControl
+from .dimension import Dimension
+from .margins import ScrollbarMargin
+
+if TYPE_CHECKING:
+    from prompt_toolkit.key_binding.key_bindings import (
+        KeyBindings,
+        NotImplementedOrNone,
+    )
+
+
+__all__ = [
+    "CompletionsMenu",
+    "MultiColumnCompletionsMenu",
+]
+
+E = KeyPressEvent
+
+
+class CompletionsMenuControl(UIControl):
+    """
+    Helper for drawing the complete menu to the screen.
+
+    :param scroll_offset: Number (integer) representing the preferred amount of
+        completions to be displayed before and after the current one. When this
+        is a very high number, the current completion will be shown in the
+        middle most of the time.
+    """
+
+    # Preferred minimum size of the menu control.
+    # The CompletionsMenu class defines a width of 8, and there is a scrollbar
+    # of 1.)
+    MIN_WIDTH = 7
+
+    def has_focus(self) -> bool:
+        return False
+
+    def preferred_width(self, max_available_width: int) -> Optional[int]:
+        complete_state = get_app().current_buffer.complete_state
+        if complete_state:
+            menu_width = self._get_menu_width(500, complete_state)
+            menu_meta_width = self._get_menu_meta_width(500, complete_state)
+
+            return menu_width + menu_meta_width
+        else:
+            return 0
+
+    def preferred_height(
+        self,
+        width: int,
+        max_available_height: int,
+        wrap_lines: bool,
+        get_line_prefix: Optional[GetLinePrefixCallable],
+    ) -> Optional[int]:
+
+        complete_state = get_app().current_buffer.complete_state
+        if complete_state:
+            return len(complete_state.completions)
+        else:
+            return 0
+
+    def create_content(self, width: int, height: int) -> UIContent:
+        """
+        Create a UIContent object for this control.
+        """
+        complete_state = get_app().current_buffer.complete_state
+        if complete_state:
+            completions = complete_state.completions
+            index = complete_state.complete_index  # Can be None!
+
+            # Calculate width of completions menu.
+            menu_width = self._get_menu_width(width, complete_state)
+            menu_meta_width = self._get_menu_meta_width(
+                width - menu_width, complete_state
+            )
+            show_meta = self._show_meta(complete_state)
+
+            def get_line(i: int) -> StyleAndTextTuples:
+                c = completions[i]
+                is_current_completion = i == index
+                result = _get_menu_item_fragments(
+                    c, is_current_completion, menu_width, space_after=True
+                )
+
+                if show_meta:
+                    result += self._get_menu_item_meta_fragments(
+                        c, is_current_completion, menu_meta_width
+                    )
+                return result
+
+            return UIContent(
+                get_line=get_line,
+                cursor_position=Point(x=0, y=index or 0),
+                line_count=len(completions),
+            )
+
+        return UIContent()
+
+    def _show_meta(self, complete_state: CompletionState) -> bool:
+        """
+        Return ``True`` if we need to show a column with meta information.
+        """
+        return any(c.display_meta_text for c in complete_state.completions)
+
+    def _get_menu_width(self, max_width: int, complete_state: CompletionState) -> int:
+        """
+        Return the width of the main column.
+        """
+        return min(
+            max_width,
+            max(
+                self.MIN_WIDTH,
+                max(get_cwidth(c.display_text) for c in complete_state.completions) + 2,
+            ),
+        )
+
+    def _get_menu_meta_width(
+        self, max_width: int, complete_state: CompletionState
+    ) -> int:
+        """
+        Return the width of the meta column.
+        """
+
+        def meta_width(completion: Completion) -> int:
+            return get_cwidth(completion.display_meta_text)
+
+        if self._show_meta(complete_state):
+            return min(
+                max_width, max(meta_width(c) for c in complete_state.completions) + 2
+            )
+        else:
+            return 0
+
+    def _get_menu_item_meta_fragments(
+        self, completion: Completion, is_current_completion: bool, width: int
+    ) -> StyleAndTextTuples:
+
+        if is_current_completion:
+            style_str = "class:completion-menu.meta.completion.current"
+        else:
+            style_str = "class:completion-menu.meta.completion"
+
+        text, tw = _trim_formatted_text(completion.display_meta, width - 2)
+        padding = " " * (width - 1 - tw)
+
+        return to_formatted_text(
+            cast(StyleAndTextTuples, []) + [("", " ")] + text + [("", padding)],
+            style=style_str,
+        )
+
+    def mouse_handler(self, mouse_event: MouseEvent) -> "NotImplementedOrNone":
+        """
+        Handle mouse events: clicking and scrolling.
+        """
+        b = get_app().current_buffer
+
+        if mouse_event.event_type == MouseEventType.MOUSE_UP:
+            # Select completion.
+            b.go_to_completion(mouse_event.position.y)
+            b.complete_state = None
+
+        elif mouse_event.event_type == MouseEventType.SCROLL_DOWN:
+            # Scroll up.
+            b.complete_next(count=3, disable_wrap_around=True)
+
+        elif mouse_event.event_type == MouseEventType.SCROLL_UP:
+            # Scroll down.
+            b.complete_previous(count=3, disable_wrap_around=True)
+
+        return None
+
+
+def _get_menu_item_fragments(
+    completion: Completion,
+    is_current_completion: bool,
+    width: int,
+    space_after: bool = False,
+) -> StyleAndTextTuples:
+    """
+    Get the style/text tuples for a menu item, styled and trimmed to the given
+    width.
+    """
+    if is_current_completion:
+        style_str = "class:completion-menu.completion.current %s %s" % (
+            completion.style,
+            completion.selected_style,
+        )
+    else:
+        style_str = "class:completion-menu.completion " + completion.style
+
+    text, tw = _trim_formatted_text(
+        completion.display, (width - 2 if space_after else width - 1)
+    )
+
+    padding = " " * (width - 1 - tw)
+
+    return to_formatted_text(
+        cast(StyleAndTextTuples, []) + [("", " ")] + text + [("", padding)],
+        style=style_str,
+    )
+
+
+def _trim_formatted_text(
+    formatted_text: StyleAndTextTuples, max_width: int
+) -> Tuple[StyleAndTextTuples, int]:
+    """
+    Trim the text to `max_width`, append dots when the text is too long.
+    Returns (text, width) tuple.
+    """
+    width = fragment_list_width(formatted_text)
+
+    # When the text is too wide, trim it.
+    if width > max_width:
+        result = []  # Text fragments.
+        remaining_width = max_width - 3
+
+        for style_and_ch in explode_text_fragments(formatted_text):
+            ch_width = get_cwidth(style_and_ch[1])
+
+            if ch_width <= remaining_width:
+                result.append(style_and_ch)
+                remaining_width -= ch_width
+            else:
+                break
+
+        result.append(("", "..."))
+
+        return result, max_width - remaining_width
+    else:
+        return formatted_text, width
+
+
+class CompletionsMenu(ConditionalContainer):
+    # NOTE: We use a pretty big z_index by default. Menus are supposed to be
+    #       above anything else. We also want to make sure that the content is
+    #       visible at the point where we draw this menu.
+    def __init__(
+        self,
+        max_height: Optional[int] = None,
+        scroll_offset: Union[int, Callable[[], int]] = 0,
+        extra_filter: FilterOrBool = True,
+        display_arrows: FilterOrBool = False,
         z_index: int = 10**8,
-    ) -> None: 
- 
-        extra_filter = to_filter(extra_filter) 
-        display_arrows = to_filter(display_arrows) 
- 
-        super().__init__( 
-            content=Window( 
-                content=CompletionsMenuControl(), 
-                width=Dimension(min=8), 
-                height=Dimension(min=1, max=max_height), 
-                scroll_offsets=ScrollOffsets(top=scroll_offset, bottom=scroll_offset), 
-                right_margins=[ScrollbarMargin(display_arrows=display_arrows)], 
-                dont_extend_width=True, 
-                style="class:completion-menu", 
-                z_index=z_index, 
-            ), 
-            # Show when there are completions but not at the point we are 
-            # returning the input. 
-            filter=has_completions & ~is_done & extra_filter, 
-        ) 
- 
- 
-class MultiColumnCompletionMenuControl(UIControl): 
-    """ 
-    Completion menu that displays all the completions in several columns. 
-    When there are more completions than space for them to be displayed, an 
-    arrow is shown on the left or right side. 
- 
-    `min_rows` indicates how many rows will be available in any possible case. 
-    When this is larger than one, it will try to use less columns and more 
-    rows until this value is reached. 
-    Be careful passing in a too big value, if less than the given amount of 
-    rows are available, more columns would have been required, but 
-    `preferred_width` doesn't know about that and reports a too small value. 
-    This results in less completions displayed and additional scrolling. 
-    (It's a limitation of how the layout engine currently works: first the 
-    widths are calculated, then the heights.) 
- 
-    :param suggested_max_column_width: The suggested max width of a column. 
-        The column can still be bigger than this, but if there is place for two 
-        columns of this width, we will display two columns. This to avoid that 
-        if there is one very wide completion, that it doesn't significantly 
-        reduce the amount of columns. 
-    """ 
- 
-    _required_margin = 3  # One extra padding on the right + space for arrows. 
- 
-    def __init__(self, min_rows: int = 3, suggested_max_column_width: int = 30) -> None: 
-        assert min_rows >= 1 
- 
-        self.min_rows = min_rows 
-        self.suggested_max_column_width = suggested_max_column_width 
-        self.scroll = 0 
- 
-        # Info of last rendering. 
-        self._rendered_rows = 0 
-        self._rendered_columns = 0 
-        self._total_columns = 0 
-        self._render_pos_to_completion: Dict[Tuple[int, int], Completion] = {} 
-        self._render_left_arrow = False 
-        self._render_right_arrow = False 
-        self._render_width = 0 
- 
-    def reset(self) -> None: 
-        self.scroll = 0 
- 
-    def has_focus(self) -> bool: 
-        return False 
- 
-    def preferred_width(self, max_available_width: int) -> Optional[int]: 
-        """ 
-        Preferred width: prefer to use at least min_rows, but otherwise as much 
-        as possible horizontally. 
-        """ 
-        complete_state = get_app().current_buffer.complete_state 
-        if complete_state is None: 
-            return 0 
- 
-        column_width = self._get_column_width(complete_state) 
-        result = int( 
-            column_width 
-            * math.ceil(len(complete_state.completions) / float(self.min_rows)) 
-        ) 
- 
-        # When the desired width is still more than the maximum available, 
-        # reduce by removing columns until we are less than the available 
-        # width. 
-        while ( 
-            result > column_width 
-            and result > max_available_width - self._required_margin 
-        ): 
-            result -= column_width 
-        return result + self._required_margin 
- 
-    def preferred_height( 
-        self, 
-        width: int, 
-        max_available_height: int, 
-        wrap_lines: bool, 
-        get_line_prefix: Optional[GetLinePrefixCallable], 
-    ) -> Optional[int]: 
-        """ 
-        Preferred height: as much as needed in order to display all the completions. 
-        """ 
-        complete_state = get_app().current_buffer.complete_state 
-        if complete_state is None: 
-            return 0 
- 
-        column_width = self._get_column_width(complete_state) 
-        column_count = max(1, (width - self._required_margin) // column_width) 
- 
-        return int(math.ceil(len(complete_state.completions) / float(column_count))) 
- 
-    def create_content(self, width: int, height: int) -> UIContent: 
-        """ 
-        Create a UIContent object for this menu. 
-        """ 
-        complete_state = get_app().current_buffer.complete_state 
-        if complete_state is None: 
-            return UIContent() 
- 
-        column_width = self._get_column_width(complete_state) 
-        self._render_pos_to_completion = {} 
- 
-        _T = TypeVar("_T") 
- 
-        def grouper( 
-            n: int, iterable: Iterable[_T], fillvalue: Optional[_T] = None 
-        ) -> Iterable[List[_T]]: 
-            "grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx" 
-            args = [iter(iterable)] * n 
-            return zip_longest(fillvalue=fillvalue, *args) 
- 
-        def is_current_completion(completion: Completion) -> bool: 
-            "Returns True when this completion is the currently selected one." 
-            return ( 
-                complete_state is not None 
-                and complete_state.complete_index is not None 
-                and c == complete_state.current_completion 
-            ) 
- 
-        # Space required outside of the regular columns, for displaying the 
-        # left and right arrow. 
-        HORIZONTAL_MARGIN_REQUIRED = 3 
- 
-        # There should be at least one column, but it cannot be wider than 
-        # the available width. 
-        column_width = min(width - HORIZONTAL_MARGIN_REQUIRED, column_width) 
- 
-        # However, when the columns tend to be very wide, because there are 
-        # some very wide entries, shrink it anyway. 
-        if column_width > self.suggested_max_column_width: 
-            # `column_width` can still be bigger that `suggested_max_column_width`, 
-            # but if there is place for two columns, we divide by two. 
-            column_width //= column_width // self.suggested_max_column_width 
- 
-        visible_columns = max(1, (width - self._required_margin) // column_width) 
- 
-        columns_ = list(grouper(height, complete_state.completions)) 
-        rows_ = list(zip(*columns_)) 
- 
-        # Make sure the current completion is always visible: update scroll offset. 
-        selected_column = (complete_state.complete_index or 0) // height 
-        self.scroll = min( 
-            selected_column, max(self.scroll, selected_column - visible_columns + 1) 
-        ) 
- 
-        render_left_arrow = self.scroll > 0 
-        render_right_arrow = self.scroll < len(rows_[0]) - visible_columns 
- 
-        # Write completions to screen. 
-        fragments_for_line = [] 
- 
-        for row_index, row in enumerate(rows_): 
-            fragments: StyleAndTextTuples = [] 
-            middle_row = row_index == len(rows_) // 2 
- 
-            # Draw left arrow if we have hidden completions on the left. 
-            if render_left_arrow: 
-                fragments.append(("class:scrollbar", "<" if middle_row else " ")) 
-            elif render_right_arrow: 
-                # Reserve one column empty space. (If there is a right 
-                # arrow right now, there can be a left arrow as well.) 
-                fragments.append(("", " ")) 
- 
-            # Draw row content. 
-            for column_index, c in enumerate(row[self.scroll :][:visible_columns]): 
-                if c is not None: 
-                    fragments += _get_menu_item_fragments( 
-                        c, is_current_completion(c), column_width, space_after=False 
-                    ) 
- 
-                    # Remember render position for mouse click handler. 
-                    for x in range(column_width): 
-                        self._render_pos_to_completion[ 
-                            (column_index * column_width + x, row_index) 
-                        ] = c 
-                else: 
-                    fragments.append(("class:completion", " " * column_width)) 
- 
-            # Draw trailing padding for this row. 
-            # (_get_menu_item_fragments only returns padding on the left.) 
-            if render_left_arrow or render_right_arrow: 
-                fragments.append(("class:completion", " ")) 
- 
-            # Draw right arrow if we have hidden completions on the right. 
-            if render_right_arrow: 
-                fragments.append(("class:scrollbar", ">" if middle_row else " ")) 
-            elif render_left_arrow: 
-                fragments.append(("class:completion", " ")) 
- 
-            # Add line. 
-            fragments_for_line.append( 
-                to_formatted_text(fragments, style="class:completion-menu") 
-            ) 
- 
-        self._rendered_rows = height 
-        self._rendered_columns = visible_columns 
-        self._total_columns = len(columns_) 
-        self._render_left_arrow = render_left_arrow 
-        self._render_right_arrow = render_right_arrow 
-        self._render_width = ( 
-            column_width * visible_columns + render_left_arrow + render_right_arrow + 1 
-        ) 
- 
-        def get_line(i: int) -> StyleAndTextTuples: 
-            return fragments_for_line[i] 
- 
-        return UIContent(get_line=get_line, line_count=len(rows_)) 
- 
-    def _get_column_width(self, complete_state: CompletionState) -> int: 
-        """ 
-        Return the width of each column. 
-        """ 
-        return max(get_cwidth(c.display_text) for c in complete_state.completions) + 1 
- 
-    def mouse_handler(self, mouse_event: MouseEvent) -> "NotImplementedOrNone": 
-        """ 
-        Handle scroll and click events. 
-        """ 
-        b = get_app().current_buffer 
- 
-        def scroll_left() -> None: 
-            b.complete_previous(count=self._rendered_rows, disable_wrap_around=True) 
-            self.scroll = max(0, self.scroll - 1) 
- 
-        def scroll_right() -> None: 
-            b.complete_next(count=self._rendered_rows, disable_wrap_around=True) 
-            self.scroll = min( 
-                self._total_columns - self._rendered_columns, self.scroll + 1 
-            ) 
- 
-        if mouse_event.event_type == MouseEventType.SCROLL_DOWN: 
-            scroll_right() 
- 
-        elif mouse_event.event_type == MouseEventType.SCROLL_UP: 
-            scroll_left() 
- 
-        elif mouse_event.event_type == MouseEventType.MOUSE_UP: 
-            x = mouse_event.position.x 
-            y = mouse_event.position.y 
- 
-            # Mouse click on left arrow. 
-            if x == 0: 
-                if self._render_left_arrow: 
-                    scroll_left() 
- 
-            # Mouse click on right arrow. 
-            elif x == self._render_width - 1: 
-                if self._render_right_arrow: 
-                    scroll_right() 
- 
-            # Mouse click on completion. 
-            else: 
-                completion = self._render_pos_to_completion.get((x, y)) 
-                if completion: 
-                    b.apply_completion(completion) 
- 
-        return None 
- 
-    def get_key_bindings(self) -> "KeyBindings": 
-        """ 
-        Expose key bindings that handle the left/right arrow keys when the menu 
-        is displayed. 
-        """ 
-        from prompt_toolkit.key_binding.key_bindings import KeyBindings 
- 
-        kb = KeyBindings() 
- 
-        @Condition 
-        def filter() -> bool: 
-            "Only handle key bindings if this menu is visible." 
-            app = get_app() 
-            complete_state = app.current_buffer.complete_state 
- 
-            # There need to be completions, and one needs to be selected. 
-            if complete_state is None or complete_state.complete_index is None: 
-                return False 
- 
-            # This menu needs to be visible. 
-            return any(window.content == self for window in app.layout.visible_windows) 
- 
-        def move(right: bool = False) -> None: 
-            buff = get_app().current_buffer 
-            complete_state = buff.complete_state 
- 
-            if complete_state is not None and complete_state.complete_index is not None: 
-                # Calculate new complete index. 
-                new_index = complete_state.complete_index 
-                if right: 
-                    new_index += self._rendered_rows 
-                else: 
-                    new_index -= self._rendered_rows 
- 
-                if 0 <= new_index < len(complete_state.completions): 
-                    buff.go_to_completion(new_index) 
- 
-        # NOTE: the is_global is required because the completion menu will 
-        #       never be focussed. 
- 
-        @kb.add("left", is_global=True, filter=filter) 
-        def _left(event: E) -> None: 
-            move() 
- 
-        @kb.add("right", is_global=True, filter=filter) 
-        def _right(event: E) -> None: 
-            move(True) 
- 
-        return kb 
- 
- 
-class MultiColumnCompletionsMenu(HSplit): 
-    """ 
-    Container that displays the completions in several columns. 
-    When `show_meta` (a :class:`~prompt_toolkit.filters.Filter`) evaluates 
-    to True, it shows the meta information at the bottom. 
-    """ 
- 
-    def __init__( 
-        self, 
-        min_rows: int = 3, 
-        suggested_max_column_width: int = 30, 
-        show_meta: FilterOrBool = True, 
-        extra_filter: FilterOrBool = True, 
+    ) -> None:
+
+        extra_filter = to_filter(extra_filter)
+        display_arrows = to_filter(display_arrows)
+
+        super().__init__(
+            content=Window(
+                content=CompletionsMenuControl(),
+                width=Dimension(min=8),
+                height=Dimension(min=1, max=max_height),
+                scroll_offsets=ScrollOffsets(top=scroll_offset, bottom=scroll_offset),
+                right_margins=[ScrollbarMargin(display_arrows=display_arrows)],
+                dont_extend_width=True,
+                style="class:completion-menu",
+                z_index=z_index,
+            ),
+            # Show when there are completions but not at the point we are
+            # returning the input.
+            filter=has_completions & ~is_done & extra_filter,
+        )
+
+
+class MultiColumnCompletionMenuControl(UIControl):
+    """
+    Completion menu that displays all the completions in several columns.
+    When there are more completions than space for them to be displayed, an
+    arrow is shown on the left or right side.
+
+    `min_rows` indicates how many rows will be available in any possible case.
+    When this is larger than one, it will try to use less columns and more
+    rows until this value is reached.
+    Be careful passing in a too big value, if less than the given amount of
+    rows are available, more columns would have been required, but
+    `preferred_width` doesn't know about that and reports a too small value.
+    This results in less completions displayed and additional scrolling.
+    (It's a limitation of how the layout engine currently works: first the
+    widths are calculated, then the heights.)
+
+    :param suggested_max_column_width: The suggested max width of a column.
+        The column can still be bigger than this, but if there is place for two
+        columns of this width, we will display two columns. This to avoid that
+        if there is one very wide completion, that it doesn't significantly
+        reduce the amount of columns.
+    """
+
+    _required_margin = 3  # One extra padding on the right + space for arrows.
+
+    def __init__(self, min_rows: int = 3, suggested_max_column_width: int = 30) -> None:
+        assert min_rows >= 1
+
+        self.min_rows = min_rows
+        self.suggested_max_column_width = suggested_max_column_width
+        self.scroll = 0
+
+        # Info of last rendering.
+        self._rendered_rows = 0
+        self._rendered_columns = 0
+        self._total_columns = 0
+        self._render_pos_to_completion: Dict[Tuple[int, int], Completion] = {}
+        self._render_left_arrow = False
+        self._render_right_arrow = False
+        self._render_width = 0
+
+    def reset(self) -> None:
+        self.scroll = 0
+
+    def has_focus(self) -> bool:
+        return False
+
+    def preferred_width(self, max_available_width: int) -> Optional[int]:
+        """
+        Preferred width: prefer to use at least min_rows, but otherwise as much
+        as possible horizontally.
+        """
+        complete_state = get_app().current_buffer.complete_state
+        if complete_state is None:
+            return 0
+
+        column_width = self._get_column_width(complete_state)
+        result = int(
+            column_width
+            * math.ceil(len(complete_state.completions) / float(self.min_rows))
+        )
+
+        # When the desired width is still more than the maximum available,
+        # reduce by removing columns until we are less than the available
+        # width.
+        while (
+            result > column_width
+            and result > max_available_width - self._required_margin
+        ):
+            result -= column_width
+        return result + self._required_margin
+
+    def preferred_height(
+        self,
+        width: int,
+        max_available_height: int,
+        wrap_lines: bool,
+        get_line_prefix: Optional[GetLinePrefixCallable],
+    ) -> Optional[int]:
+        """
+        Preferred height: as much as needed in order to display all the completions.
+        """
+        complete_state = get_app().current_buffer.complete_state
+        if complete_state is None:
+            return 0
+
+        column_width = self._get_column_width(complete_state)
+        column_count = max(1, (width - self._required_margin) // column_width)
+
+        return int(math.ceil(len(complete_state.completions) / float(column_count)))
+
+    def create_content(self, width: int, height: int) -> UIContent:
+        """
+        Create a UIContent object for this menu.
+        """
+        complete_state = get_app().current_buffer.complete_state
+        if complete_state is None:
+            return UIContent()
+
+        column_width = self._get_column_width(complete_state)
+        self._render_pos_to_completion = {}
+
+        _T = TypeVar("_T")
+
+        def grouper(
+            n: int, iterable: Iterable[_T], fillvalue: Optional[_T] = None
+        ) -> Iterable[List[_T]]:
+            "grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx"
+            args = [iter(iterable)] * n
+            return zip_longest(fillvalue=fillvalue, *args)
+
+        def is_current_completion(completion: Completion) -> bool:
+            "Returns True when this completion is the currently selected one."
+            return (
+                complete_state is not None
+                and complete_state.complete_index is not None
+                and c == complete_state.current_completion
+            )
+
+        # Space required outside of the regular columns, for displaying the
+        # left and right arrow.
+        HORIZONTAL_MARGIN_REQUIRED = 3
+
+        # There should be at least one column, but it cannot be wider than
+        # the available width.
+        column_width = min(width - HORIZONTAL_MARGIN_REQUIRED, column_width)
+
+        # However, when the columns tend to be very wide, because there are
+        # some very wide entries, shrink it anyway.
+        if column_width > self.suggested_max_column_width:
+            # `column_width` can still be bigger that `suggested_max_column_width`,
+            # but if there is place for two columns, we divide by two.
+            column_width //= column_width // self.suggested_max_column_width
+
+        visible_columns = max(1, (width - self._required_margin) // column_width)
+
+        columns_ = list(grouper(height, complete_state.completions))
+        rows_ = list(zip(*columns_))
+
+        # Make sure the current completion is always visible: update scroll offset.
+        selected_column = (complete_state.complete_index or 0) // height
+        self.scroll = min(
+            selected_column, max(self.scroll, selected_column - visible_columns + 1)
+        )
+
+        render_left_arrow = self.scroll > 0
+        render_right_arrow = self.scroll < len(rows_[0]) - visible_columns
+
+        # Write completions to screen.
+        fragments_for_line = []
+
+        for row_index, row in enumerate(rows_):
+            fragments: StyleAndTextTuples = []
+            middle_row = row_index == len(rows_) // 2
+
+            # Draw left arrow if we have hidden completions on the left.
+            if render_left_arrow:
+                fragments.append(("class:scrollbar", "<" if middle_row else " "))
+            elif render_right_arrow:
+                # Reserve one column empty space. (If there is a right
+                # arrow right now, there can be a left arrow as well.)
+                fragments.append(("", " "))
+
+            # Draw row content.
+            for column_index, c in enumerate(row[self.scroll :][:visible_columns]):
+                if c is not None:
+                    fragments += _get_menu_item_fragments(
+                        c, is_current_completion(c), column_width, space_after=False
+                    )
+
+                    # Remember render position for mouse click handler.
+                    for x in range(column_width):
+                        self._render_pos_to_completion[
+                            (column_index * column_width + x, row_index)
+                        ] = c
+                else:
+                    fragments.append(("class:completion", " " * column_width))
+
+            # Draw trailing padding for this row.
+            # (_get_menu_item_fragments only returns padding on the left.)
+            if render_left_arrow or render_right_arrow:
+                fragments.append(("class:completion", " "))
+
+            # Draw right arrow if we have hidden completions on the right.
+            if render_right_arrow:
+                fragments.append(("class:scrollbar", ">" if middle_row else " "))
+            elif render_left_arrow:
+                fragments.append(("class:completion", " "))
+
+            # Add line.
+            fragments_for_line.append(
+                to_formatted_text(fragments, style="class:completion-menu")
+            )
+
+        self._rendered_rows = height
+        self._rendered_columns = visible_columns
+        self._total_columns = len(columns_)
+        self._render_left_arrow = render_left_arrow
+        self._render_right_arrow = render_right_arrow
+        self._render_width = (
+            column_width * visible_columns + render_left_arrow + render_right_arrow + 1
+        )
+
+        def get_line(i: int) -> StyleAndTextTuples:
+            return fragments_for_line[i]
+
+        return UIContent(get_line=get_line, line_count=len(rows_))
+
+    def _get_column_width(self, complete_state: CompletionState) -> int:
+        """
+        Return the width of each column.
+        """
+        return max(get_cwidth(c.display_text) for c in complete_state.completions) + 1
+
+    def mouse_handler(self, mouse_event: MouseEvent) -> "NotImplementedOrNone":
+        """
+        Handle scroll and click events.
+        """
+        b = get_app().current_buffer
+
+        def scroll_left() -> None:
+            b.complete_previous(count=self._rendered_rows, disable_wrap_around=True)
+            self.scroll = max(0, self.scroll - 1)
+
+        def scroll_right() -> None:
+            b.complete_next(count=self._rendered_rows, disable_wrap_around=True)
+            self.scroll = min(
+                self._total_columns - self._rendered_columns, self.scroll + 1
+            )
+
+        if mouse_event.event_type == MouseEventType.SCROLL_DOWN:
+            scroll_right()
+
+        elif mouse_event.event_type == MouseEventType.SCROLL_UP:
+            scroll_left()
+
+        elif mouse_event.event_type == MouseEventType.MOUSE_UP:
+            x = mouse_event.position.x
+            y = mouse_event.position.y
+
+            # Mouse click on left arrow.
+            if x == 0:
+                if self._render_left_arrow:
+                    scroll_left()
+
+            # Mouse click on right arrow.
+            elif x == self._render_width - 1:
+                if self._render_right_arrow:
+                    scroll_right()
+
+            # Mouse click on completion.
+            else:
+                completion = self._render_pos_to_completion.get((x, y))
+                if completion:
+                    b.apply_completion(completion)
+
+        return None
+
+    def get_key_bindings(self) -> "KeyBindings":
+        """
+        Expose key bindings that handle the left/right arrow keys when the menu
+        is displayed.
+        """
+        from prompt_toolkit.key_binding.key_bindings import KeyBindings
+
+        kb = KeyBindings()
+
+        @Condition
+        def filter() -> bool:
+            "Only handle key bindings if this menu is visible."
+            app = get_app()
+            complete_state = app.current_buffer.complete_state
+
+            # There need to be completions, and one needs to be selected.
+            if complete_state is None or complete_state.complete_index is None:
+                return False
+
+            # This menu needs to be visible.
+            return any(window.content == self for window in app.layout.visible_windows)
+
+        def move(right: bool = False) -> None:
+            buff = get_app().current_buffer
+            complete_state = buff.complete_state
+
+            if complete_state is not None and complete_state.complete_index is not None:
+                # Calculate new complete index.
+                new_index = complete_state.complete_index
+                if right:
+                    new_index += self._rendered_rows
+                else:
+                    new_index -= self._rendered_rows
+
+                if 0 <= new_index < len(complete_state.completions):
+                    buff.go_to_completion(new_index)
+
+        # NOTE: the is_global is required because the completion menu will
+        #       never be focussed.
+
+        @kb.add("left", is_global=True, filter=filter)
+        def _left(event: E) -> None:
+            move()
+
+        @kb.add("right", is_global=True, filter=filter)
+        def _right(event: E) -> None:
+            move(True)
+
+        return kb
+
+
+class MultiColumnCompletionsMenu(HSplit):
+    """
+    Container that displays the completions in several columns.
+    When `show_meta` (a :class:`~prompt_toolkit.filters.Filter`) evaluates
+    to True, it shows the meta information at the bottom.
+    """
+
+    def __init__(
+        self,
+        min_rows: int = 3,
+        suggested_max_column_width: int = 30,
+        show_meta: FilterOrBool = True,
+        extra_filter: FilterOrBool = True,
         z_index: int = 10**8,
-    ) -> None: 
- 
-        show_meta = to_filter(show_meta) 
-        extra_filter = to_filter(extra_filter) 
- 
-        # Display filter: show when there are completions but not at the point 
-        # we are returning the input. 
-        full_filter = has_completions & ~is_done & extra_filter 
- 
-        @Condition 
-        def any_completion_has_meta() -> bool: 
-            complete_state = get_app().current_buffer.complete_state 
-            return complete_state is not None and any( 
-                c.display_meta for c in complete_state.completions 
-            ) 
- 
-        # Create child windows. 
-        # NOTE: We don't set style='class:completion-menu' to the 
-        #       `MultiColumnCompletionMenuControl`, because this is used in a 
-        #       Float that is made transparent, and the size of the control 
-        #       doesn't always correspond exactly with the size of the 
-        #       generated content. 
-        completions_window = ConditionalContainer( 
-            content=Window( 
-                content=MultiColumnCompletionMenuControl( 
-                    min_rows=min_rows, 
-                    suggested_max_column_width=suggested_max_column_width, 
-                ), 
-                width=Dimension(min=8), 
-                height=Dimension(min=1), 
-            ), 
-            filter=full_filter, 
-        ) 
- 
-        meta_window = ConditionalContainer( 
-            content=Window(content=_SelectedCompletionMetaControl()), 
-            filter=show_meta & full_filter & any_completion_has_meta, 
-        ) 
- 
-        # Initialise split. 
-        super().__init__([completions_window, meta_window], z_index=z_index) 
- 
- 
-class _SelectedCompletionMetaControl(UIControl): 
-    """ 
-    Control that shows the meta information of the selected completion. 
-    """ 
- 
-    def preferred_width(self, max_available_width: int) -> Optional[int]: 
-        """ 
-        Report the width of the longest meta text as the preferred width of this control. 
- 
-        It could be that we use less width, but this way, we're sure that the 
-        layout doesn't change when we select another completion (E.g. that 
-        completions are suddenly shown in more or fewer columns.) 
-        """ 
-        app = get_app() 
-        if app.current_buffer.complete_state: 
-            state = app.current_buffer.complete_state 
-            return 2 + max(get_cwidth(c.display_meta_text) for c in state.completions) 
-        else: 
-            return 0 
- 
-    def preferred_height( 
-        self, 
-        width: int, 
-        max_available_height: int, 
-        wrap_lines: bool, 
-        get_line_prefix: Optional[GetLinePrefixCallable], 
-    ) -> Optional[int]: 
-        return 1 
- 
-    def create_content(self, width: int, height: int) -> UIContent: 
-        fragments = self._get_text_fragments() 
- 
-        def get_line(i: int) -> StyleAndTextTuples: 
-            return fragments 
- 
-        return UIContent(get_line=get_line, line_count=1 if fragments else 0) 
- 
-    def _get_text_fragments(self) -> StyleAndTextTuples: 
-        style = "class:completion-menu.multi-column-meta" 
-        state = get_app().current_buffer.complete_state 
- 
-        if ( 
-            state 
-            and state.current_completion 
-            and state.current_completion.display_meta_text 
-        ): 
-            return to_formatted_text( 
-                cast(StyleAndTextTuples, [("", " ")]) 
-                + state.current_completion.display_meta 
-                + [("", " ")], 
-                style=style, 
-            ) 
- 
-        return [] 
+    ) -> None:
+
+        show_meta = to_filter(show_meta)
+        extra_filter = to_filter(extra_filter)
+
+        # Display filter: show when there are completions but not at the point
+        # we are returning the input.
+        full_filter = has_completions & ~is_done & extra_filter
+
+        @Condition
+        def any_completion_has_meta() -> bool:
+            complete_state = get_app().current_buffer.complete_state
+            return complete_state is not None and any(
+                c.display_meta for c in complete_state.completions
+            )
+
+        # Create child windows.
+        # NOTE: We don't set style='class:completion-menu' to the
+        #       `MultiColumnCompletionMenuControl`, because this is used in a
+        #       Float that is made transparent, and the size of the control
+        #       doesn't always correspond exactly with the size of the
+        #       generated content.
+        completions_window = ConditionalContainer(
+            content=Window(
+                content=MultiColumnCompletionMenuControl(
+                    min_rows=min_rows,
+                    suggested_max_column_width=suggested_max_column_width,
+                ),
+                width=Dimension(min=8),
+                height=Dimension(min=1),
+            ),
+            filter=full_filter,
+        )
+
+        meta_window = ConditionalContainer(
+            content=Window(content=_SelectedCompletionMetaControl()),
+            filter=show_meta & full_filter & any_completion_has_meta,
+        )
+
+        # Initialise split.
+        super().__init__([completions_window, meta_window], z_index=z_index)
+
+
+class _SelectedCompletionMetaControl(UIControl):
+    """
+    Control that shows the meta information of the selected completion.
+    """
+
+    def preferred_width(self, max_available_width: int) -> Optional[int]:
+        """
+        Report the width of the longest meta text as the preferred width of this control.
+
+        It could be that we use less width, but this way, we're sure that the
+        layout doesn't change when we select another completion (E.g. that
+        completions are suddenly shown in more or fewer columns.)
+        """
+        app = get_app()
+        if app.current_buffer.complete_state:
+            state = app.current_buffer.complete_state
+            return 2 + max(get_cwidth(c.display_meta_text) for c in state.completions)
+        else:
+            return 0
+
+    def preferred_height(
+        self,
+        width: int,
+        max_available_height: int,
+        wrap_lines: bool,
+        get_line_prefix: Optional[GetLinePrefixCallable],
+    ) -> Optional[int]:
+        return 1
+
+    def create_content(self, width: int, height: int) -> UIContent:
+        fragments = self._get_text_fragments()
+
+        def get_line(i: int) -> StyleAndTextTuples:
+            return fragments
+
+        return UIContent(get_line=get_line, line_count=1 if fragments else 0)
+
+    def _get_text_fragments(self) -> StyleAndTextTuples:
+        style = "class:completion-menu.multi-column-meta"
+        state = get_app().current_buffer.complete_state
+
+        if (
+            state
+            and state.current_completion
+            and state.current_completion.display_meta_text
+        ):
+            return to_formatted_text(
+                cast(StyleAndTextTuples, [("", " ")])
+                + state.current_completion.display_meta
+                + [("", " ")],
+                style=style,
+            )
+
+        return []