hub/venv/lib/python3.7/site-packages/prompt_toolkit/layout/margins.py

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"""
Margin implementations for a :class:`~prompt_toolkit.layout.containers.Window`.
"""
from abc import ABCMeta, abstractmethod
from typing import TYPE_CHECKING, Callable, Optional
from prompt_toolkit.filters import FilterOrBool, to_filter
from prompt_toolkit.formatted_text import (
StyleAndTextTuples,
fragment_list_to_text,
to_formatted_text,
)
from prompt_toolkit.utils import get_cwidth
from .controls import UIContent
if TYPE_CHECKING:
from .containers import WindowRenderInfo
__all__ = [
"Margin",
"NumberedMargin",
"ScrollbarMargin",
"ConditionalMargin",
"PromptMargin",
]
class Margin(metaclass=ABCMeta):
"""
Base interface for a margin.
"""
@abstractmethod
def get_width(self, get_ui_content: Callable[[], UIContent]) -> int:
"""
Return the width that this margin is going to consume.
:param get_ui_content: Callable that asks the user control to create
a :class:`.UIContent` instance. This can be used for instance to
obtain the number of lines.
"""
return 0
@abstractmethod
def create_margin(
self, window_render_info: "WindowRenderInfo", width: int, height: int
) -> StyleAndTextTuples:
"""
Creates a margin.
This should return a list of (style_str, text) tuples.
:param window_render_info:
:class:`~prompt_toolkit.layout.containers.WindowRenderInfo`
instance, generated after rendering and copying the visible part of
the :class:`~prompt_toolkit.layout.controls.UIControl` into the
:class:`~prompt_toolkit.layout.containers.Window`.
:param width: The width that's available for this margin. (As reported
by :meth:`.get_width`.)
:param height: The height that's available for this margin. (The height
of the :class:`~prompt_toolkit.layout.containers.Window`.)
"""
return []
class NumberedMargin(Margin):
"""
Margin that displays the line numbers.
:param relative: Number relative to the cursor position. Similar to the Vi
'relativenumber' option.
:param display_tildes: Display tildes after the end of the document, just
like Vi does.
"""
def __init__(
self, relative: FilterOrBool = False, display_tildes: FilterOrBool = False
) -> None:
self.relative = to_filter(relative)
self.display_tildes = to_filter(display_tildes)
def get_width(self, get_ui_content: Callable[[], UIContent]) -> int:
line_count = get_ui_content().line_count
return max(3, len("%s" % line_count) + 1)
def create_margin(
self, window_render_info: "WindowRenderInfo", width: int, height: int
) -> StyleAndTextTuples:
relative = self.relative()
style = "class:line-number"
style_current = "class:line-number.current"
# Get current line number.
current_lineno = window_render_info.ui_content.cursor_position.y
# Construct margin.
result: StyleAndTextTuples = []
last_lineno = None
for y, lineno in enumerate(window_render_info.displayed_lines):
# Only display line number if this line is not a continuation of the previous line.
if lineno != last_lineno:
if lineno is None:
pass
elif lineno == current_lineno:
# Current line.
if relative:
# Left align current number in relative mode.
result.append((style_current, "%i" % (lineno + 1)))
else:
result.append(
(style_current, ("%i " % (lineno + 1)).rjust(width))
)
else:
# Other lines.
if relative:
lineno = abs(lineno - current_lineno) - 1
result.append((style, ("%i " % (lineno + 1)).rjust(width)))
last_lineno = lineno
result.append(("", "\n"))
# Fill with tildes.
if self.display_tildes():
while y < window_render_info.window_height:
result.append(("class:tilde", "~\n"))
y += 1
return result
class ConditionalMargin(Margin):
"""
Wrapper around other :class:`.Margin` classes to show/hide them.
"""
def __init__(self, margin: Margin, filter: FilterOrBool) -> None:
self.margin = margin
self.filter = to_filter(filter)
def get_width(self, get_ui_content: Callable[[], UIContent]) -> int:
if self.filter():
return self.margin.get_width(get_ui_content)
else:
return 0
def create_margin(
self, window_render_info: "WindowRenderInfo", width: int, height: int
) -> StyleAndTextTuples:
if width and self.filter():
return self.margin.create_margin(window_render_info, width, height)
else:
return []
class ScrollbarMargin(Margin):
"""
Margin displaying a scrollbar.
:param display_arrows: Display scroll up/down arrows.
"""
def __init__(
self,
display_arrows: FilterOrBool = False,
up_arrow_symbol: str = "^",
down_arrow_symbol: str = "v",
) -> None:
self.display_arrows = to_filter(display_arrows)
self.up_arrow_symbol = up_arrow_symbol
self.down_arrow_symbol = down_arrow_symbol
def get_width(self, get_ui_content: Callable[[], UIContent]) -> int:
return 1
def create_margin(
self, window_render_info: "WindowRenderInfo", width: int, height: int
) -> StyleAndTextTuples:
content_height = window_render_info.content_height
window_height = window_render_info.window_height
display_arrows = self.display_arrows()
if display_arrows:
window_height -= 2
try:
fraction_visible = len(window_render_info.displayed_lines) / float(
content_height
)
fraction_above = window_render_info.vertical_scroll / float(content_height)
scrollbar_height = int(
min(window_height, max(1, window_height * fraction_visible))
)
scrollbar_top = int(window_height * fraction_above)
except ZeroDivisionError:
return []
else:
def is_scroll_button(row: int) -> bool:
" True if we should display a button on this row. "
return scrollbar_top <= row <= scrollbar_top + scrollbar_height
# Up arrow.
result: StyleAndTextTuples = []
if display_arrows:
result.extend(
[
("class:scrollbar.arrow", self.up_arrow_symbol),
("class:scrollbar", "\n"),
]
)
# Scrollbar body.
scrollbar_background = "class:scrollbar.background"
scrollbar_background_start = "class:scrollbar.background,scrollbar.start"
scrollbar_button = "class:scrollbar.button"
scrollbar_button_end = "class:scrollbar.button,scrollbar.end"
for i in range(window_height):
if is_scroll_button(i):
if not is_scroll_button(i + 1):
# Give the last cell a different style, because we
# want to underline this.
result.append((scrollbar_button_end, " "))
else:
result.append((scrollbar_button, " "))
else:
if is_scroll_button(i + 1):
result.append((scrollbar_background_start, " "))
else:
result.append((scrollbar_background, " "))
result.append(("", "\n"))
# Down arrow
if display_arrows:
result.append(("class:scrollbar.arrow", self.down_arrow_symbol))
return result
class PromptMargin(Margin):
"""
[Deprecated]
Create margin that displays a prompt.
This can display one prompt at the first line, and a continuation prompt
(e.g, just dots) on all the following lines.
This `PromptMargin` implementation has been largely superseded in favor of
the `get_line_prefix` attribute of `Window`. The reason is that a margin is
always a fixed width, while `get_line_prefix` can return a variable width
prefix in front of every line, making it more powerful, especially for line
continuations.
:param get_prompt: Callable returns formatted text or a list of
`(style_str, type)` tuples to be shown as the prompt at the first line.
:param get_continuation: Callable that takes three inputs. The width (int),
line_number (int), and is_soft_wrap (bool). It should return formatted
text or a list of `(style_str, type)` tuples for the next lines of the
input.
"""
def __init__(
self,
get_prompt: Callable[[], StyleAndTextTuples],
get_continuation: Optional[
Callable[[int, int, bool], StyleAndTextTuples]
] = None,
) -> None:
self.get_prompt = get_prompt
self.get_continuation = get_continuation
def get_width(self, get_ui_content: Callable[[], UIContent]) -> int:
" Width to report to the `Window`. "
# Take the width from the first line.
text = fragment_list_to_text(self.get_prompt())
return get_cwidth(text)
def create_margin(
self, window_render_info: "WindowRenderInfo", width: int, height: int
) -> StyleAndTextTuples:
get_continuation = self.get_continuation
result: StyleAndTextTuples = []
# First line.
result.extend(to_formatted_text(self.get_prompt()))
# Next lines.
if get_continuation:
last_y = None
for y in window_render_info.displayed_lines[1:]:
result.append(("", "\n"))
result.extend(
to_formatted_text(get_continuation(width, y, y == last_y))
)
last_y = y
return result