Re: [PATCH 1/4] python/utils: add enboxify() text decoration utility

[Eric Blake]

On Tue, Feb 15, 2022 at 05:08:50PM -0500, John Snow wrote:
> >>> print(enboxify(msg, width=72, name="commit message"))
> ┏━ commit message ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
> ┃ enboxify() takes a chunk of text and wraps it in a text art box that ┃
> ┃  adheres to a specified width. An optional title label may be given, ┃
> ┃  and any of the individual glyphs used to draw the box may be        ┃

Why do these two lines have a leading space,

> ┃ replaced or specified as well.                                       ┃

but this one doesn't?  It must be an off-by-one corner case when your
choice of space to wrap on is exactly at the wrap column.

> ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
> 
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  python/qemu/utils/__init__.py | 58 +++++++++++++++++++++++++++++++++++
>  1 file changed, 58 insertions(+)
> 
> diff --git a/python/qemu/utils/__init__.py b/python/qemu/utils/__init__.py
> index 7f1a5138c4b..f785316f230 100644
> --- a/python/qemu/utils/__init__.py
> +++ b/python/qemu/utils/__init__.py
> @@ -15,7 +15,10 @@
>  # the COPYING file in the top-level directory.
>  #
>  
> +import os
>  import re
> +import shutil
> +import textwrap
>  from typing import Optional
>  
>  # pylint: disable=import-error
> @@ -23,6 +26,7 @@
>  
>  
>  __all__ = (
> +    'enboxify',
>      'get_info_usernet_hostfwd_port',
>      'kvm_available',
>      'list_accel',
> @@ -43,3 +47,57 @@ def get_info_usernet_hostfwd_port(info_usernet_output: 
> str) -> Optional[int]:
>          if match is not None:
>              return int(match[1])
>      return None
> +
> +
> +# pylint: disable=too-many-arguments
> +def enboxify(
> +        content: str = '',
> +        width: Optional[int] = None,
> +        name: Optional[str] = None,
> +        padding: int = 1,
> +        upper_left: str = '┏',
> +        upper_right: str = '┓',
> +        lower_left: str = '┗',
> +        lower_right: str = '┛',
> +        horizontal: str = '━',
> +        vertical: str = '┃',
> +) -> str:
> +    """
> +    Wrap some text into a text art box of a given width.
> +
> +    :param content: The text to wrap into a box.
> +    :param width: The number of columns (including the box itself).
> +    :param name: A label to apply to the upper-left of the box.
> +    :param padding: How many columns of padding to apply inside.
> +    """

Where's theh :param docs for the 6 custom glyphs?

> +    if width is None:
> +        width = shutil.get_terminal_size()[0]
> +    prefix = vertical + (' ' * padding)
> +    suffix = (' ' * padding) + vertical
> +    lwidth = width - len(suffix)
> +
> +    def _bar(name: Optional[str], top: bool = True) -> str:
> +        ret = upper_left if top else lower_left
> +        right = upper_right if top else lower_right
> +        if name is not None:
> +            ret += f"{horizontal} {name} "
> +
> +        assert width is not None
> +        filler_len = width - len(ret) - len(right)
> +        ret += f"{horizontal * filler_len}{right}"
> +        return ret
> +
> +    def _wrap(line: str) -> str:
> +        return os.linesep.join([
> +            wrapped_line.ljust(lwidth) + suffix
> +            for wrapped_line in textwrap.wrap(
> +                    line, width=lwidth, initial_indent=prefix,
> +                    subsequent_indent=prefix, replace_whitespace=False,
> +                    drop_whitespace=False, break_on_hyphens=False)

Always nice when someone else has written the cool library function to
do all the hard work for you ;)  But this is probably where you have the 
off-by-one I called out above.

> +        ])
> +
> +    return os.linesep.join((
> +        _bar(name, top=True),
> +        os.linesep.join(_wrap(line) for line in content.splitlines()),
> +        _bar(None, top=False),
> +    ))
> -- 
> 2.34.1
> 
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org