summaryrefslogtreecommitdiffstats
path: root/src/prompt_toolkit/layout/margins.py
diff options
context:
space:
mode:
Diffstat (limited to 'src/prompt_toolkit/layout/margins.py')
-rw-r--r--src/prompt_toolkit/layout/margins.py305
1 files changed, 305 insertions, 0 deletions
diff --git a/src/prompt_toolkit/layout/margins.py b/src/prompt_toolkit/layout/margins.py
new file mode 100644
index 0000000..7c46819
--- /dev/null
+++ b/src/prompt_toolkit/layout/margins.py
@@ -0,0 +1,305 @@
+"""
+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