diff options
Diffstat (limited to 'cmd2/ansi.py')
| -rw-r--r-- | cmd2/ansi.py | 50 |
1 files changed, 27 insertions, 23 deletions
diff --git a/cmd2/ansi.py b/cmd2/ansi.py index c875a9d1..57b204ca 100644 --- a/cmd2/ansi.py +++ b/cmd2/ansi.py @@ -1,5 +1,8 @@ # coding=utf-8 -"""Support for ANSI escape sequences which are used for things like applying style to text""" +""" +Support for ANSI escape sequences which are used for things like applying style to text, +setting the window title, and asynchronous alerts. + """ import functools import re from typing import Any, IO @@ -11,16 +14,17 @@ from wcwidth import wcswidth # On Windows, filter ANSI escape codes out of text sent to stdout/stderr, and replace them with equivalent Win32 calls colorama.init(strip=False) -# Values for allow_ansi setting -ANSI_NEVER = 'Never' -ANSI_TERMINAL = 'Terminal' -ANSI_ALWAYS = 'Always' +# Values for allow_style setting +STYLE_NEVER = 'Never' +STYLE_TERMINAL = 'Terminal' +STYLE_ALWAYS = 'Always' -# Controls when ANSI escape sequences are allowed in output -allow_ansi = ANSI_TERMINAL +# Controls when ANSI style style sequences are allowed in output +allow_style = STYLE_TERMINAL -# Regular expression to match ANSI escape sequences -ANSI_ESCAPE_RE = re.compile(r'\x1b[^m]*m') +# Regular expression to match ANSI style sequences +# This matches: colorama.ansi.CSI + digit(s) + m +ANSI_STYLE_RE = re.compile(r'\033\[[0-9]+m') # Foreground color presets FG_COLORS = { @@ -71,41 +75,41 @@ RESET_ALL = Style.RESET_ALL BRIGHT = Style.BRIGHT NORMAL = Style.NORMAL -# ANSI escape sequences not provided by colorama +# ANSI style sequences not provided by colorama UNDERLINE_ENABLE = colorama.ansi.code_to_chars(4) UNDERLINE_DISABLE = colorama.ansi.code_to_chars(24) -def strip_ansi(text: str) -> str: +def strip_style(text: str) -> str: """ - Strip ANSI escape sequences from a string. + Strip ANSI style sequences from a string. - :param text: string which may contain ANSI escape sequences - :return: the same string with any ANSI escape sequences removed + :param text: string which may contain ANSI style sequences + :return: the same string with any ANSI style sequences removed """ - return ANSI_ESCAPE_RE.sub('', text) + return ANSI_STYLE_RE.sub('', text) def ansi_safe_wcswidth(text: str) -> int: """ - Wrap wcswidth to make it compatible with strings that contains ANSI escape sequences + Wrap wcswidth to make it compatible with strings that contains ANSI style sequences :param text: the string being measured """ - # Strip ANSI escape sequences since they cause wcswidth to return -1 - return wcswidth(strip_ansi(text)) + # Strip ANSI style sequences since they cause wcswidth to return -1 + return wcswidth(strip_style(text)) def ansi_aware_write(fileobj: IO, msg: str) -> None: """ - Write a string to a fileobject and strip its ANSI escape sequences if required by allow_ansi setting + Write a string to a fileobject and strip its ANSI style sequences if required by allow_style setting :param fileobj: the file object being written to :param msg: the string being written """ - if allow_ansi.lower() == ANSI_NEVER.lower() or \ - (allow_ansi.lower() == ANSI_TERMINAL.lower() and not fileobj.isatty()): - msg = strip_ansi(msg) + if allow_style.lower() == STYLE_NEVER.lower() or \ + (allow_style.lower() == STYLE_TERMINAL.lower() and not fileobj.isatty()): + msg = strip_style(msg) fileobj.write(msg) @@ -176,7 +180,7 @@ def style(text: Any, *, fg: str = '', bg: str = '', bold: bool = False, underlin additions.append(UNDERLINE_ENABLE) removals.append(UNDERLINE_DISABLE) - # Combine the ANSI escape sequences with the text + # Combine the ANSI style sequences with the text return "".join(additions) + text + "".join(removals) |