pyedit_wrap_paragraph.py

from __future__ import nested_scopes # for Jython 2.1 compatibility
""" Wrap Paragraph by Don Taylor.

A Pydev script for rewrapping the current paragraph to fit inside the print
margin preference in Eclipse (defaults to 80 columns).  A paragraph is a block
of lines with a common leading string such as '# ' or a number of spaces. The
lines in the newly wrapped paragraph will all have the same leading string as
the original paragraph.

Usage: Position cursor inside paragraph to be rewrapped and hit <ctrl+2>, w

Caveats:  Embedded tabs are always replaced by single spaces.
          Does not wrap if the cursor is within the first line of a docstring.
          Wrap Paragraph makes simple assumptions about paragraphs.  Check your
          results, <ctrl-Z> will undo the last rewrap.

Note: Activates with 'w' by default. Edit the constants ACTIVATION_STRING
      and WAIT_FOR_ENTER near the end of this file if this does not suit your
      needs.
      
Version: 0.1.1 - alpha

Date:    May 2006

License: Available under the same conditions as PyDev.  See PyDev license for
         details: http://pydev.sourceforge.net
         
Support: Contact the author for bug reports/feature requests via the Pydev
         users list (or use the source).

History: 20 May 2006 - Initial release.
         21 May 2006 - Changed no of columns wrapped from 80 to the Eclipse
         setting for the print margin preference.

"""
#===============================================================================
# The following is a copy of textwrap.py from the CPython 2.4 standard library
# - slightly modified for Jython 2.1 compatibility.  Included here directly
# instead of as an imported module so that the Wrap Paragraph Jython Pydev
# extension can consist of a single file.  The extension code starts at around
# line 400.
#===============================================================================
"""Text wrapping and filling.
"""

# Copyright (C) 1999-2001 Gregory P. Ward.
# Copyright (C) 2002, 2003 Python Software Foundation.
# Written by Greg Ward <gward@python.net>

__revision__ = "$Id$"

import string, re, textwrap

# Do the right thing with boolean values for all known Python versions (so this
# module can be copied to projects that don't depend on Python 2.3, e.g. Optik
# and Docutils).
try:
    True, False #@UndefinedVariable
except NameError:
    (True, False) = (1, 0)


#===============================================================================
# Pydev Extensions in Jython code protocol
#=============================================================================== 
if False:
    from org.python.pydev.editor import PyEdit #@UnresolvedImport
    cmd = 'command string'
    editor = PyEdit

#---------------------------- REQUIRED LOCALS-----------------------------------
# interface: String indicating which command will be executed As this script
# will be watching the PyEdit (that is the actual editor in Pydev), and this
# script will be listening to it, this string can indicate any of the methods of
# org.python.pydev.editor.IPyEditListener
assert cmd is not None 

# interface: PyEdit object: this is the actual editor that we will act upon
assert editor is not None
     
if cmd == 'onCreateActions':
    from org.eclipse.jface.action import Action #@UnresolvedImport
    from org.python.pydev.core.docutils import PySelection #@UnresolvedImport
    from org.eclipse.ui.texteditor import IEditorStatusLine #@UnresolvedImport
    from org.eclipse.swt.widgets import Display #@UnresolvedImport
    from java.lang import Runnable #@UnresolvedImport
    from org.python.pydev.plugin.preferences import PydevPrefs #@UnresolvedImport
    from org.eclipse.ui.texteditor import AbstractDecoratedTextEditorPreferenceConstants #@UnresolvedImport
#------------------------ HELPER TO RUN THINGS IN THE UI -----------------------

    class RunInUi(Runnable):
        '''Helper class that implements a Runnable (just so that we
        can pass it to the Java side). It simply calls some callable.
        '''
       
        def __init__(self, c):
            self.callable = c
        def run(self):
            self.callable ()
           
    def runInUi(callable):
        '''
        @param callable: the callable that will be run in the UI
        '''
        Display.getDefault().asyncExec(RunInUi(callable))
       
#---------------------- END HELPER TO RUN THINGS IN THE UI ---------------------    


#----------------------------------Paragrapher----------------------------------
    class Paragrapher:
        ''' Provides tools to process a paragraph of text in the Pydev editor. 
        
        '''
        def __init__(self):
          
            self.selection = PySelection(editor)
            self.document = editor.getDocument()
            
            self.offset = self.selection.getAbsoluteCursorOffset()
            self.currentLineNo = self.selection.getLineOfOffset(self.offset)

            self.docDelimiter = self.selection.getDelimiter(self.document) 
            self.currentLine = self.selection.getLine(self.currentLineNo)
            
            self.pattern = r'''(\s*#\s*|\s*"""\s*|''' \
                    + r"""\s*'''\s*|""" \
                    + r'''\s*"\s*|''' \
                    + r"""\s*'\s*|\s*)"""
            self.compiledRe = re.compile(self.pattern)
                                
            self.leadingString, self.mainText = \
                self._splitLine(self.currentLine)
            
            self.offsetOfOriginalParagraph = 0
            self.lengthOfOriginalParagraph = 0
            
            self.numberOfLinesInDocument = self.document.getNumberOfLines()
                                
        def _splitLine(self, line):
            ''' _splitLine(string: line) -> (string: leadingString,\
                                            string: mainText)
            
            Split the line into two parts - a leading string and the remaining
            text.
            '''

            matched = self.compiledRe.match(line)
            leadingString = line[0:matched.end()]
            mainText = line[matched.end():]
                            
            return (leadingString, mainText)
                         
        def getCurrentLine(self):
            ''' getCurrentLine() -> string
            
            Return the main part of the text of the current line as a string.            
            '''

            self.currentLine = self.selection.getLine(self.currentLineNo)
            self.mainText = self._splitLine(self.currentLine)[1]               
            return self.mainText
    
        def previousLineIsInParagraph(self):    
            ''' previousLineIsInParagraph() -> bool '''
            
            previousLine = self.selection.getLine(self.currentLineNo - 1)
            leadingStringOfPreviousLine, mainTextOfPreviousLine = \
                 self._splitLine(previousLine)
                           
            if (self.currentLineNo == 0) |\
            (mainTextOfPreviousLine.strip() == "") | \
            (leadingStringOfPreviousLine != self.leadingString): # diff para [1]
                line = self.selection.getLine(self.currentLineNo)
                lineEndsAt = self.selection.getEndLineOffset(self.currentLineNo)
                self.offsetOfOriginalParagraph = lineEndsAt - len(line)
                return False 
            else:
                return True # same para
           
            # [1]  The current line is the first line of a paragraph. Calculate
            # starting offset of the first character of the original paragraph.
           
        def nextLineIsInParagraph(self):    
            ''' nextLineIsInParagraph() -> bool '''
                        
            nextLine = self.selection.getLine(self.currentLineNo + 1)
            leadingStringOfNextLine, mainTextOfNextLine = \
                self._splitLine(nextLine)
            
            if (self.currentLineNo + 1 == self.numberOfLinesInDocument) | \
            (mainTextOfNextLine.strip() == "") | \
            (leadingStringOfNextLine != self.leadingString): # diff para [1]        
                self.lengthOfOriginalParagraph = \
                    self.selection.getEndLineOffset(self.currentLineNo) - \
                    self.offsetOfOriginalParagraph                         
                return False               
            else:
                return True # same para

            # [1]  The current line is the last line of a paragraph. Calculate
            # the length of the original paragraph.
                    
#------------------------------end of Paragrapher------------------------------- 
    
    class wrapParagraph(Action):
        ''' Rewrap the text of the current paragraph.
        
        wrapParagraph searches for the beginning and end of the paragraph that
        contains the selection, rewraps it to fit into 79 character lines and
        replaces the original paragraph with the newly wrapped paragraph.
            
        The current paragraph is the text surrounding the current selection
        point.  
        
        Only one paragraph at a time is wrapped.
        
        A paragraph is a consecutive block of lines whose alphanumeric text all
        begins at the same column position.  Any constant leading string will be
        retained in the newly wrapped paragraph.  This handles indented
        paragraphs and # comment blocks, and avoids wrapping indented code
        examples - but not code samples that are not indented.
        
        The first, or only, line of a docstring is handled as a special case and
        is not wrapped at all.
        
        '''
        def run(self):
                                
            def displayStatusMessage():
                ''' Displays the message in 'statusMessage' in the Eclipse
                status area.
                
                Uses runInUi so that it runs in the Eclispe UI thread otherwise
                it won't show up.  Called thus:
                    statusMessage = "Cannot rewrap docstrings"
                    runInUi(displayStatusMessage)
                                
                '''
                
                statusLine = editor.getAdapter(IEditorStatusLine)
                if statusLine is not None:
                    statusLine.setMessage(False, statusMessage, None)
                                                               
            p = Paragrapher()
 
            # Start building a list of lines of text in paragraph
            paragraph = [p.getCurrentLine()] 
                                
            isDocstring = (p.leadingString.find('"""') != -1) |\
                    (p.leadingString.find("'") != -1) |\
                    (p.leadingString.find('"') != -1)
            if isDocstring:
                statusMessage = "Cannot rewrap docstrings"
                runInUi(displayStatusMessage)
                                
            # Don't wrap empty lines or docstrings.                    
            if ((paragraph[0].strip() != "") & (not isDocstring)):
                startingLineNo = p.currentLineNo
                # Add the lines before the line containing the selection.
                while p.previousLineIsInParagraph():
                    p.currentLineNo -= 1
                    paragraph.insert(0, p.getCurrentLine())
                    
                # Add the lines after the line containing the selection.    
                p.currentLineNo = startingLineNo
                while p.nextLineIsInParagraph():
                    p.currentLineNo += 1
                    paragraph.append(p.getCurrentLine())
                                          
                # paragraph now contains all of the lines so rewrap it [1].
                noCols = PydevPrefs.getChainedPrefStore().\
                         getInt(AbstractDecoratedTextEditorPreferenceConstants.\
                         EDITOR_PRINT_MARGIN_COLUMN )
                paragraph = [line.rstrip() + " "  for line in paragraph]
                paragraph = textwrap.wrap("".join(paragraph), \
                                 width = noCols - len(p.leadingString), \
                                 expand_tabs = False, \
                                 )
                # Add line terminators.
                paragraph = map((lambda aLine: p.leadingString + aLine + \
                                 p.docDelimiter), paragraph)
                paragraph[-1] = paragraph[-1].replace(p.docDelimiter,"") # [2]

                # Replace original paragraph.
                p.document.replace(p.offsetOfOriginalParagraph, \
                                   p.lengthOfOriginalParagraph, \
                                   "".join(paragraph))         
                # and we are done.
                

        # [1]  paragraph now contains all of the lines of the paragraph to be
        # rewrapped and the lines have all been stripped of their leading
        # strings.
        #
        # Rewrap the paragraph allowing space to insert the leading strings back
        # in again after the wrapping is done. But first we need to make sure
        # that there is at least one space at the end of each line otherwise the
        # wrap routine will combine the last word of one line with the first
        # word of the next line.  We cannot just add a space as this will be
        # kept if there is one there already so strip off any trailing white
        # space first and add back just a single space character.
        #
        # [2]  Add line terminators to the end of every line in paragraph except
        # the last line otherwise the new paragraph will have an extra line
        # terminator at the end.
        
    # Change these constants if the default does not suit your needs
    ACTIVATION_STRING = 'w'
    WAIT_FOR_ENTER = False
    
    # Register the extension as an ActionListener.    
    editor.addOfflineActionListener(ACTIVATION_STRING, wrapParagraph(),\
                                    'Wrap paragraph',\
                                    WAIT_FOR_ENTER)