| """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): |
| """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. |
| """ |
| maxformatwidth = idleConf.GetOption( |
| 'main', 'FormatParagraph', 'paragraph', type='int') |
| 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, maxformatwidth, comment_header) |
| else: |
| newdata = reformat_paragraph(data, maxformatwidth) |
| 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__": |
| from test import support; support.use_resources = ['gui'] |
| import unittest |
| unittest.main('idlelib.idle_test.test_formatparagraph', |
| verbosity=2, exit=False) |
