diff options
| -rw-r--r-- | CHANGELOG.md | 1 | ||||
| -rw-r--r-- | cmd2/constants.py | 1 | ||||
| -rw-r--r-- | cmd2/utils.py | 78 | ||||
| -rw-r--r-- | tests/test_utils.py | 43 |
4 files changed, 100 insertions, 23 deletions
diff --git a/CHANGELOG.md b/CHANGELOG.md index 0269d287..d4e3bc0b 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -2,6 +2,7 @@ * Bug Fixes * Corrected issue where the actual new value was not always being printed in do_set. This occurred in cases where the typed value differed from what the setter had converted it to. + * Fixed bug where ANSI style sequences were not correctly handled in `utils.truncate_line()`. * Enhancements * Renamed set command's `-l/--long` flag to `-v/--verbose` for consistency with help and history commands. diff --git a/cmd2/constants.py b/cmd2/constants.py index 9e8e7780..04042d4d 100644 --- a/cmd2/constants.py +++ b/cmd2/constants.py @@ -14,6 +14,7 @@ COMMENT_CHAR = '#' MULTILINE_TERMINATOR = ';' LINE_FEED = '\n' +HORIZONTAL_ELLIPSIS = '\N{HORIZONTAL ELLIPSIS}' DEFAULT_SHORTCUTS = {'?': 'help', '!': 'shell', '@': 'run_script', '@@': '_relative_run_script'} diff --git a/cmd2/utils.py b/cmd2/utils.py index cfe75f53..2add7c5e 100644 --- a/cmd2/utils.py +++ b/cmd2/utils.py @@ -682,8 +682,8 @@ def align_text(text: str, alignment: TextAlignment, *, fill_char: str = ' ', width: Optional[int] = None, tab_width: int = 4, truncate: bool = False) -> str: """ Align text for display within a given width. Supports characters with display widths greater than 1. - ANSI style sequences are safely ignored and do not count toward the display width. This means colored text is - supported. If text has line breaks, then each line is aligned independently. + ANSI style sequences do not count toward the display width. If text has line breaks, then each line is aligned + independently. There are convenience wrappers around this function: align_left(), align_center(), and align_right() @@ -777,8 +777,8 @@ def align_left(text: str, *, fill_char: str = ' ', width: Optional[int] = None, tab_width: int = 4, truncate: bool = False) -> str: """ Left align text for display within a given width. Supports characters with display widths greater than 1. - ANSI style sequences are safely ignored and do not count toward the display width. This means colored text is - supported. If text has line breaks, then each line is aligned independently. + ANSI style sequences do not count toward the display width. If text has line breaks, then each line is aligned + independently. :param text: text to left align (can contain multiple lines) :param fill_char: character that fills the alignment gap. Defaults to space. (Cannot be a line breaking character) @@ -800,8 +800,8 @@ def align_center(text: str, *, fill_char: str = ' ', width: Optional[int] = None tab_width: int = 4, truncate: bool = False) -> str: """ Center text for display within a given width. Supports characters with display widths greater than 1. - ANSI style sequences are safely ignored and do not count toward the display width. This means colored text is - supported. If text has line breaks, then each line is aligned independently. + ANSI style sequences do not count toward the display width. If text has line breaks, then each line is aligned + independently. :param text: text to center (can contain multiple lines) :param fill_char: character that fills the alignment gap. Defaults to space. (Cannot be a line breaking character) @@ -823,8 +823,8 @@ def align_right(text: str, *, fill_char: str = ' ', width: Optional[int] = None, tab_width: int = 4, truncate: bool = False) -> str: """ Right align text for display within a given width. Supports characters with display widths greater than 1. - ANSI style sequences are safely ignored and do not count toward the display width. This means colored text is - supported. If text has line breaks, then each line is aligned independently. + ANSI style sequences do not count toward the display width. If text has line breaks, then each line is aligned + independently. :param text: text to right align (can contain multiple lines) :param fill_char: character that fills the alignment gap. Defaults to space. (Cannot be a line breaking character) @@ -845,8 +845,15 @@ def align_right(text: str, *, fill_char: str = ' ', width: Optional[int] = None, def truncate_line(line: str, max_width: int, *, tab_width: int = 4) -> str: """ Truncate a single line to fit within a given display width. Any portion of the string that is truncated - is replaced by a '…' character. Supports characters with display widths greater than 1. ANSI style sequences are - safely ignored and do not count toward the display width. This means colored text is supported. + is replaced by a '…' character. Supports characters with display widths greater than 1. ANSI style sequences + do not count toward the display width. + + If there are ANSI style sequences in the string after where truncation occurs, this function will append them + to the returned string. + + This is done to prevent issues caused in cases like: truncate_string(fg.blue + hello + fg.reset, 3) + In this case, "hello" would be truncated before fg.reset resets the color from blue. Appending the remaining style + sequences makes sure the style is in the same state had the entire string been printed. :param line: text to truncate :param max_width: the maximum display width the resulting string is allowed to have @@ -855,6 +862,7 @@ def truncate_line(line: str, max_width: int, *, tab_width: int = 4) -> str: :raises: ValueError if text contains an unprintable character like a new line ValueError if max_width is less than 1 """ + import io from . import ansi # Handle tabs @@ -866,12 +874,48 @@ def truncate_line(line: str, max_width: int, *, tab_width: int = 4) -> str: if max_width < 1: raise ValueError("max_width must be at least 1") - if ansi.style_aware_wcswidth(line) > max_width: - # Remove characters until we fit. Leave room for the ellipsis. - line = line[:max_width - 1] - while ansi.style_aware_wcswidth(line) > max_width - 1: - line = line[:-1] + if ansi.style_aware_wcswidth(line) <= max_width: + return line + + # Find all style sequences in the line + start = 0 + styles = collections.OrderedDict() + while True: + match = ansi.ANSI_STYLE_RE.search(line, start) + if match is None: + break + styles[match.start()] = match.group() + start += len(match.group()) + + # Add characters one by one and preserve all style sequences + done = False + index = 0 + total_width = 0 + truncated_buf = io.StringIO() + + while not done: + # Check if a style sequence is at this index. These don't count toward display width. + if index in styles: + truncated_buf.write(styles[index]) + style_len = len(styles[index]) + styles.pop(index) + index += style_len + continue + + char = line[index] + char_width = ansi.style_aware_wcswidth(char) + + # This char will make the text too wide, add the ellipsis instead + if char_width + total_width >= max_width: + char = constants.HORIZONTAL_ELLIPSIS + char_width = ansi.style_aware_wcswidth(char) + done = True + + total_width += char_width + truncated_buf.write(char) + index += 1 - line += "\N{HORIZONTAL ELLIPSIS}" + # Append remaining style sequences from original string + truncated_buf.write(''.join(styles.values())) - return line + return truncated_buf.getvalue() diff --git a/tests/test_utils.py b/tests/test_utils.py index 5030ce0e..db432286 100644 --- a/tests/test_utils.py +++ b/tests/test_utils.py @@ -10,6 +10,7 @@ import time import pytest import cmd2.utils as cu +from cmd2.constants import HORIZONTAL_ELLIPSIS HELLO_WORLD = 'Hello, world!' @@ -297,7 +298,13 @@ def test_truncate_line(): line = 'long' max_width = 3 truncated = cu.truncate_line(line, max_width) - assert truncated == 'lo\N{HORIZONTAL ELLIPSIS}' + assert truncated == 'lo' + HORIZONTAL_ELLIPSIS + +def test_truncate_line_already_fits(): + line = 'long' + max_width = 4 + truncated = cu.truncate_line(line, max_width) + assert truncated == line def test_truncate_line_with_newline(): line = 'fo\no' @@ -315,20 +322,44 @@ def test_truncate_line_wide_text(): line = '苹苹other' max_width = 6 truncated = cu.truncate_line(line, max_width) - assert truncated == '苹苹o\N{HORIZONTAL ELLIPSIS}' + assert truncated == '苹苹o' + HORIZONTAL_ELLIPSIS def test_truncate_line_split_wide_text(): """Test when truncation results in a string which is shorter than max_width""" line = '1苹2苹' max_width = 3 truncated = cu.truncate_line(line, max_width) - assert truncated == '1\N{HORIZONTAL ELLIPSIS}' + assert truncated == '1' + HORIZONTAL_ELLIPSIS def test_truncate_line_tabs(): line = 'has\ttab' max_width = 9 truncated = cu.truncate_line(line, max_width) - assert truncated == 'has t\N{HORIZONTAL ELLIPSIS}' + assert truncated == 'has t' + HORIZONTAL_ELLIPSIS + +def test_truncate_with_style(): + from cmd2 import ansi + + before_style = ansi.fg.blue + ansi.UNDERLINE_ENABLE + after_style = ansi.fg.reset + ansi.UNDERLINE_DISABLE + + # Style only before truncated text + line = before_style + 'long' + max_width = 3 + truncated = cu.truncate_line(line, max_width) + assert truncated == before_style + 'lo' + HORIZONTAL_ELLIPSIS + + # Style before and after truncated text + line = before_style + 'long' + after_style + max_width = 3 + truncated = cu.truncate_line(line, max_width) + assert truncated == before_style + 'lo' + HORIZONTAL_ELLIPSIS + after_style + + # Style only after truncated text + line = 'long' + after_style + max_width = 3 + truncated = cu.truncate_line(line, max_width) + assert truncated == 'lo' + HORIZONTAL_ELLIPSIS + after_style def test_align_text_fill_char_is_tab(): text = 'foo' @@ -384,7 +415,7 @@ def test_align_text_wider_than_width_truncate(): fill_char = '-' width = 8 aligned = cu.align_text(text, cu.TextAlignment.LEFT, fill_char=fill_char, width=width, truncate=True) - assert aligned == 'long te\N{HORIZONTAL ELLIPSIS}' + assert aligned == 'long te' + HORIZONTAL_ELLIPSIS def test_align_text_wider_than_width_truncate_add_fill(): """Test when truncation results in a string which is shorter than width and align_text adds filler""" @@ -392,7 +423,7 @@ def test_align_text_wider_than_width_truncate_add_fill(): fill_char = '-' width = 3 aligned = cu.align_text(text, cu.TextAlignment.LEFT, fill_char=fill_char, width=width, truncate=True) - assert aligned == '1\N{HORIZONTAL ELLIPSIS}-' + assert aligned == '1' + HORIZONTAL_ELLIPSIS + fill_char def test_align_text_has_unprintable(): text = 'foo\x02' |