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authorTerry Jan Reedy <tjreedy@udel.edu>2016-05-22 23:10:31 (GMT)
committerTerry Jan Reedy <tjreedy@udel.edu>2016-05-22 23:10:31 (GMT)
commit0d9220e162f1e5f8caa3d7ebaa54665776d361a1 (patch)
treea4fa9f7cafdfc93fde86b8ffd6088d739bb93e01 /Lib/idlelib/paragraph.py
parentdc4f7c09cc934524a763498250e30123a0d9d2c5 (diff)
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Issue #24225: Rename many idlelib/*.py and idlelib/idle_test/test_*.py files.
Diffstat (limited to 'Lib/idlelib/paragraph.py')
-rw-r--r--Lib/idlelib/paragraph.py195
1 files changed, 195 insertions, 0 deletions
diff --git a/Lib/idlelib/paragraph.py b/Lib/idlelib/paragraph.py
new file mode 100644
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+++ b/Lib/idlelib/paragraph.py
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+"""Extension to format a paragraph or selection to a max width.
+
+Does basic, standard text formatting, and also understands Python
+comment blocks. Thus, for editing Python source code, this
+extension is really only suitable for reformatting these comment
+blocks or triple-quoted strings.
+
+Known problems with comment reformatting:
+* If there is a selection marked, and the first line of the
+ selection is not complete, the block will probably not be detected
+ as comments, and will have the normal "text formatting" rules
+ applied.
+* If a comment block has leading whitespace that mixes tabs and
+ spaces, they will not be considered part of the same block.
+* Fancy comments, like this bulleted list, aren't handled :-)
+"""
+
+import re
+from idlelib.configHandler import idleConf
+
+class FormatParagraph:
+
+ menudefs = [
+ ('format', [ # /s/edit/format dscherer@cmu.edu
+ ('Format Paragraph', '<<format-paragraph>>'),
+ ])
+ ]
+
+ def __init__(self, editwin):
+ self.editwin = editwin
+
+ def close(self):
+ self.editwin = None
+
+ def format_paragraph_event(self, event, limit=None):
+ """Formats paragraph to a max width specified in idleConf.
+
+ If text is selected, format_paragraph_event will start breaking lines
+ at the max width, starting from the beginning selection.
+
+ If no text is selected, format_paragraph_event uses the current
+ cursor location to determine the paragraph (lines of text surrounded
+ by blank lines) and formats it.
+
+ The length limit parameter is for testing with a known value.
+ """
+ if limit is None:
+ # The default length limit is that defined by pep8
+ limit = idleConf.GetOption(
+ 'extensions', 'FormatParagraph', 'max-width',
+ type='int', default=72)
+ text = self.editwin.text
+ first, last = self.editwin.get_selection_indices()
+ if first and last:
+ data = text.get(first, last)
+ comment_header = get_comment_header(data)
+ else:
+ first, last, comment_header, data = \
+ find_paragraph(text, text.index("insert"))
+ if comment_header:
+ newdata = reformat_comment(data, limit, comment_header)
+ else:
+ newdata = reformat_paragraph(data, limit)
+ text.tag_remove("sel", "1.0", "end")
+
+ if newdata != data:
+ text.mark_set("insert", first)
+ text.undo_block_start()
+ text.delete(first, last)
+ text.insert(first, newdata)
+ text.undo_block_stop()
+ else:
+ text.mark_set("insert", last)
+ text.see("insert")
+ return "break"
+
+def find_paragraph(text, mark):
+ """Returns the start/stop indices enclosing the paragraph that mark is in.
+
+ Also returns the comment format string, if any, and paragraph of text
+ between the start/stop indices.
+ """
+ lineno, col = map(int, mark.split("."))
+ line = text.get("%d.0" % lineno, "%d.end" % lineno)
+
+ # Look for start of next paragraph if the index passed in is a blank line
+ while text.compare("%d.0" % lineno, "<", "end") and is_all_white(line):
+ lineno = lineno + 1
+ line = text.get("%d.0" % lineno, "%d.end" % lineno)
+ first_lineno = lineno
+ comment_header = get_comment_header(line)
+ comment_header_len = len(comment_header)
+
+ # Once start line found, search for end of paragraph (a blank line)
+ while get_comment_header(line)==comment_header and \
+ not is_all_white(line[comment_header_len:]):
+ lineno = lineno + 1
+ line = text.get("%d.0" % lineno, "%d.end" % lineno)
+ last = "%d.0" % lineno
+
+ # Search back to beginning of paragraph (first blank line before)
+ lineno = first_lineno - 1
+ line = text.get("%d.0" % lineno, "%d.end" % lineno)
+ while lineno > 0 and \
+ get_comment_header(line)==comment_header and \
+ not is_all_white(line[comment_header_len:]):
+ lineno = lineno - 1
+ line = text.get("%d.0" % lineno, "%d.end" % lineno)
+ first = "%d.0" % (lineno+1)
+
+ return first, last, comment_header, text.get(first, last)
+
+# This should perhaps be replaced with textwrap.wrap
+def reformat_paragraph(data, limit):
+ """Return data reformatted to specified width (limit)."""
+ lines = data.split("\n")
+ i = 0
+ n = len(lines)
+ while i < n and is_all_white(lines[i]):
+ i = i+1
+ if i >= n:
+ return data
+ indent1 = get_indent(lines[i])
+ if i+1 < n and not is_all_white(lines[i+1]):
+ indent2 = get_indent(lines[i+1])
+ else:
+ indent2 = indent1
+ new = lines[:i]
+ partial = indent1
+ while i < n and not is_all_white(lines[i]):
+ # XXX Should take double space after period (etc.) into account
+ words = re.split("(\s+)", lines[i])
+ for j in range(0, len(words), 2):
+ word = words[j]
+ if not word:
+ continue # Can happen when line ends in whitespace
+ if len((partial + word).expandtabs()) > limit and \
+ partial != indent1:
+ new.append(partial.rstrip())
+ partial = indent2
+ partial = partial + word + " "
+ if j+1 < len(words) and words[j+1] != " ":
+ partial = partial + " "
+ i = i+1
+ new.append(partial.rstrip())
+ # XXX Should reformat remaining paragraphs as well
+ new.extend(lines[i:])
+ return "\n".join(new)
+
+def reformat_comment(data, limit, comment_header):
+ """Return data reformatted to specified width with comment header."""
+
+ # Remove header from the comment lines
+ lc = len(comment_header)
+ data = "\n".join(line[lc:] for line in data.split("\n"))
+ # Reformat to maxformatwidth chars or a 20 char width,
+ # whichever is greater.
+ format_width = max(limit - len(comment_header), 20)
+ newdata = reformat_paragraph(data, format_width)
+ # re-split and re-insert the comment header.
+ newdata = newdata.split("\n")
+ # If the block ends in a \n, we dont want the comment prefix
+ # inserted after it. (Im not sure it makes sense to reformat a
+ # comment block that is not made of complete lines, but whatever!)
+ # Can't think of a clean solution, so we hack away
+ block_suffix = ""
+ if not newdata[-1]:
+ block_suffix = "\n"
+ newdata = newdata[:-1]
+ return '\n'.join(comment_header+line for line in newdata) + block_suffix
+
+def is_all_white(line):
+ """Return True if line is empty or all whitespace."""
+
+ return re.match(r"^\s*$", line) is not None
+
+def get_indent(line):
+ """Return the initial space or tab indent of line."""
+ return re.match(r"^([ \t]*)", line).group()
+
+def get_comment_header(line):
+ """Return string with leading whitespace and '#' from line or ''.
+
+ A null return indicates that the line is not a comment line. A non-
+ null return, such as ' #', will be used to find the other lines of
+ a comment block with the same indent.
+ """
+ m = re.match(r"^([ \t]*#*)", line)
+ if m is None: return ""
+ return m.group(1)
+
+if __name__ == "__main__":
+ import unittest
+ unittest.main('idlelib.idle_test.test_formatparagraph',
+ verbosity=2, exit=False)