code: # -*- coding: utf-8 -*-
  #
  # Copyright (C) 2004-2010 Edgewall Software
  # Copyright (C) 2004 Daniel Lundin dummy@email.com
  # Copyright (C) 2005-2006 Christopher Lenz dummy@email.com
  # Copyright (C) 2006-2007 Christian Boos dummy@email.com
  # All rights reserved.
  #
  # This software is licensed as described in the file COPYING, which
  # you should have received as part of this distribution. The terms
  # are also available at http://trac.edgewall.org/wiki/TracLicense.
  #
  # This software consists of voluntary contributions made by many
  # individuals. For the exact contribution history, see the revision
  # history and logs, available at http://trac.edgewall.org/log/.
  #
  # Author: Daniel Lundin dummy@email.com
  #         Christopher Lenz dummy@email.com
  #         Christian Boos dummy@email.com
  
  """
  File metadata management
  ------------------------
  
  The `trac.mimeview` package centralizes the intelligence related to
  file metadata, principally concerning the `type` (MIME type) of the
  content and, if relevant, concerning the text encoding (charset) used
  by the content.
  
  There are primarily two approaches for getting the MIME type of a
  given file, either taking advantage of existing conventions for the
  file name, or examining the file content and applying various
  heuristics.
  
  The module also knows how to convert the file content from one type to
  another type.
  
  In some cases, only the `url` pointing to the file's content is
  actually needed, that's why we avoid to read the file's content when
  it's not needed.
  
  The actual `content` to be converted might be a `unicode` object, but
  it can also be the raw byte string (`str`) object, or simply an object
  that can be `read()`.
  
  .. note:: (for plugin developers)
  
    The Mimeview API is quite complex and many things there are
    currently a bit difficult to work with (e.g. what an actual
    `content` might be, see the last paragraph of this description).
  
    So this area is mainly in a ''work in progress'' state, which will
    be improved along the lines described in :teo:`#3332`.
  
    In particular, if you are interested in writing `IContentConverter`
    and `IHTMLPreviewRenderer` components, note that those interfaces
    will be merged into a new style `IContentConverter`.  Feel free to
    contribute remarks and suggestions for improvements to the
    corresponding ticket (#3332 as well).
  """
  
  import re
  from StringIO import StringIO
  
  from genshi import Markup, Stream
  from genshi.core import TEXT, START, END, START_NS, END_NS
  from genshi.builder import Fragment, tag
  from genshi.input import HTMLParser
  
  from trac.config import IntOption, ListOption, Option
  from trac.core import *
  from trac.resource import Resource
  from trac.util import Ranges, content_disposition
  from trac.util.text import exception_to_unicode, to_utf8, to_unicode
  from trac.util.translation import _, tag_
  
  
  __all__ = ['Context', 'Mimeview', 'RenderingContext', 'get_mimetype',
             'is_binary', 'detect_unicode', 'content_to_unicode', 'ct_mimetype']
  
  class RenderingContext(object):
      """
      A rendering context specifies ''how'' the content should be rendered.
  
      It holds together all the needed contextual information that will be
      needed by individual renderer components.
  
      To that end, a context keeps track of the Href instance (`.href`) which
      should be used as a base for building URLs.
      
      It also provides a `PermissionCache`  (`.perm`) which can be used to
      restrict the output so that only the authorized information is shown.
      
      A rendering context may also be associated to some Trac resource which
      will be used as the implicit reference when rendering relative links
      or for retrieving relative content and can be used to retrieve related
      metadata.
  
      Rendering contexts can be nested, and a new context can be created from 
      an existing context using the call syntax. The previous context can be
      retrieved using the `.parent` attribute.
      
      For example, when rendering a wiki text of a wiki page, the context will
      be associated to a resource identifying that wiki page.
      
      If that wiki text contains a `[[TicketQuery]]` wiki macro, the macro will
      set up nested contexts for each matching ticket that will be used for
      rendering the ticket descriptions.
  
      :since: version 0.11
      """
  
      def __init__(self, resource, href=None, perm=None):
          """Directly create a `RenderingContext`.
  
          :param resource: the associated resource
          :type resource: `Resource`
          :param href: an `Href` object suitable for creating URLs
          :param perm: a `PermissionCache` object used for restricting the
                       generated output to "authorized" information only.
  
          The actual `.perm` attribute of the rendering context will be bound
          to the given `resource` so that fine-grained permission checks will
          apply to that.
          """
          self.parent = None #: The parent context, if any
          self.resource = resource
          self.href = href
          self.perm = perm(resource) if perm and resource else perm
          self._hints = None
  
      @staticmethod
      def from_request(*args, **kwargs):
          """:deprecated: since 1.0, use `web_context` instead."""
          from trac.web.chrome import web_context
          return web_context(*args, **kwargs)
  
      def __repr__(self):
          path = []
          context = self
          while context:
              if context.resource.realm: # skip toplevel resource 
                  path.append(repr(context.resource))
              context = context.parent
          return '<%s %s>' % (type(self).__name__, ' - '.join(reversed(path)))
  
      def child(self, resource=None, id=False, version=False, parent=False):
          """Create a nested rendering context.
  
          `self` will be the parent for the new nested context.
  
          :param resource: either a `Resource` object or the realm string for a
                           resource specification to be associated to the new
                           context. If `None`, the resource will be the same
                           as the resource of the parent context.
          :param id: the identifier part of the resource specification
          :param version: the version of the resource specification
          :return: the new context object
          :rtype: `RenderingContext`
  
          >>> context = RenderingContext('wiki', 'WikiStart')
          >>> ticket1 = Resource('ticket', 1)
          >>> context.child('ticket', 1).resource == ticket1
          True
          >>> context.child(ticket1).resource is ticket1
          True
          >>> context.child(ticket1)().resource is ticket1
          True
          """
          if resource:
              resource = Resource(resource, id=id, version=version,
                                  parent=parent)
          else:
              resource = self.resource
          context = RenderingContext(resource, href=self.href, perm=self.perm)
          context.parent = self
  
          # hack for context instances created by from_request()
          # this is needed because various parts of the code rely on a request
          # object being available, but that will hopefully improve in the
          # future
          if hasattr(self, 'req'):
              context.req = self.req
  
          return context
  
      __call__ = child
  
      def __contains__(self, resource):
          """Check whether a resource is in the rendering path.
  
          The primary use for this check is to avoid to render the content of a
          resource if we're already embedded in a context associated to that
          resource.
  
          :param resource: a `Resource` specification which will be checked for
          """
          context = self
          while context:
              if context.resource and \
                     context.resource.realm == resource.realm and \
                     context.resource.id == resource.id:
                  # we don't care about version here
                  return True
              context = context.parent
  
      # Rendering hints 
      #
      # A rendering hint is a key/value pairs that can influence renderers,
      # wiki formatters and processors in the way they produce their output.
      # The keys are strings, but the values could be anything.
      #
      # In nested contexts, the hints are inherited from their parent context,
      # unless overriden locally.
  
      def set_hints(self, **keyvalues):
          """Set rendering hints for this rendering context.
  
          >>> ctx = RenderingContext('timeline')
          >>> ctx.set_hints(wiki_flavor='oneliner', shorten_lines=True)
          >>> t_ctx = ctx('ticket', 1)
          >>> t_ctx.set_hints(wiki_flavor='html', preserve_newlines=True)
          >>> (t_ctx.get_hint('wiki_flavor'), t_ctx.get_hint('shorten_lines'), \
               t_ctx.get_hint('preserve_newlines'))
          ('html', True, True)
          >>> (ctx.get_hint('wiki_flavor'), ctx.get_hint('shorten_lines'), \
               ctx.get_hint('preserve_newlines'))
          ('oneliner', True, None)
          """
          if self._hints is None:
              self._hints = {}
              hints = self._parent_hints()
              if hints is not None:
                  self._hints.update(hints)
          self._hints.update(keyvalues)
  
      def get_hint(self, hint, default=None):
          """Retrieve a rendering hint from this context or an ancestor context.
  
          >>> ctx = RenderingContext('timeline')
          >>> ctx.set_hints(wiki_flavor='oneliner')
          >>> t_ctx = ctx('ticket', 1)
          >>> t_ctx.get_hint('wiki_flavor')
          'oneliner'
          >>> t_ctx.get_hint('preserve_newlines', True)
          True
          """
          hints = self._hints
          if hints is None:
              hints = self._parent_hints()
              if hints is None:
                  return default
          return hints.get(hint, default)
  
      def has_hint(self, hint):
          """Test whether a rendering hint is defined in this context or in some
          ancestor context.
  
          >>> ctx = RenderingContext('timeline')
          >>> ctx.set_hints(wiki_flavor='oneliner')
          >>> t_ctx = ctx('ticket', 1)
          >>> t_ctx.has_hint('wiki_flavor')
          True
          >>> t_ctx.has_hint('preserve_newlines')
          False
          """
          hints = self._hints
          if hints is None:
              hints = self._parent_hints()
              if hints is None:
                  return False
          return hint in hints
  
      def _parent_hints(self):
          p = self.parent
          while p and p._hints is None:
              p = p.parent
          return p and p._hints
  
  
  class Context(RenderingContext):
      """:deprecated: old name kept for compatibility, use `RenderingContext`."""
  
  
  # Some common MIME types and their associated keywords and/or file extensions
  
  KNOWN_MIME_TYPES = {
      'application/javascript': 'js',
      'application/msword':     'doc dot',
      'application/pdf':        'pdf',
      'application/postscript': 'ps',
      'application/rtf':        'rtf',
      'application/x-sh':       'sh',
      'application/x-csh':      'csh',
      'application/x-troff':    'nroff roff troff',
      'application/x-yaml':     'yml yaml',
      
      'application/rss+xml':    'rss',
      'application/xsl+xml':    'xsl',
      'application/xslt+xml':   'xslt',
      
      'image/x-icon':           'ico',
      'image/svg+xml':          'svg',
      
      'model/vrml':             'vrml wrl',
      
      'text/css':               'css',
      'text/html':              'html htm',
      'text/plain':             'txt TXT text README INSTALL '
                                'AUTHORS COPYING ChangeLog RELEASE',
      'text/xml':               'xml',
      
      # see also TEXT_X_TYPES below
      'text/x-csrc':            'c xs',
      'text/x-chdr':            'h',
      'text/x-c++src':          'cc CC cpp C c++ C++',
      'text/x-c++hdr':          'hh HH hpp H',
      'text/x-csharp':          'cs c# C#',
      'text/x-diff':            'patch',
      'text/x-eiffel':          'e',
      'text/x-elisp':           'el',
      'text/x-fortran':         'f',
      'text/x-haskell':         'hs',
      'text/x-ini':             'ini cfg',
      'text/x-objc':            'm mm',
      'text/x-ocaml':           'ml mli',
      'text/x-makefile':        'make mk Makefile GNUMakefile',
      'text/x-pascal':          'pas',
      'text/x-perl':            'pl pm PL',
      'text/x-php':             'php3 php4',
      'text/x-python':          'py',
      'text/x-pyrex':           'pyx',
      'text/x-ruby':            'rb',
      'text/x-scheme':          'scm',
      'text/x-textile':         'txtl',
      'text/x-vba':             'vb vba bas',
      'text/x-verilog':         'v',
      'text/x-vhdl':            'vhd',
  }
  for t in KNOWN_MIME_TYPES.keys():
      types = KNOWN_MIME_TYPES[t].split()
      if t.startswith('text/x-'):
          types.append(t[len('text/x-'):])
      KNOWN_MIME_TYPES[t] = types
  
  # extend the above with simple (text/x-<something>: <something>) mappings
  
  TEXT_X_TYPES = """
      ada asm asp awk idl inf java ksh lua m4 mail psp rfc rst sql tcl tex zsh
  """
  for x in TEXT_X_TYPES.split():
      KNOWN_MIME_TYPES.setdefault('text/x-%s' % x, []).append(x)
  
  
  # Default mapping from keywords/extensions to known MIME types:
  
  MIME_MAP = {}
  for t, exts in KNOWN_MIME_TYPES.items():
      MIME_MAP[t] = t
      for e in exts:
          MIME_MAP[e] = t
  
  # Simple builtin autodetection from the content using a regexp
  MODE_RE = re.compile(r"""
        \#!.+?env\s+(\w+)                     # 1. look for shebang with env
      | \#!(?:[/\w.-_]+/)?(\w+)               # 2. look for regular shebang
      | -\*-\s*(?:mode:\s*)?([\w+-]+)\s*-\*-  # 3. look for Emacs' -*- mode -*-
      | vim:.*?(?:syntax|filetype|ft)=(\w+)   # 4. look for VIM's syntax=<n>
      """, re.VERBOSE)
  
  def get_mimetype(filename, content=None, mime_map=MIME_MAP):
      """Guess the most probable MIME type of a file with the given name.
  
      `filename` is either a filename (the lookup will then use the suffix)
      or some arbitrary keyword.
      
      `content` is either a `str` or an `unicode` string.
      """
      suffix = filename.split('.')[-1]
      if suffix in mime_map:
          # 1) mimetype from the suffix, using the `mime_map`
          return mime_map[suffix]
      else:
          mimetype = None
          try:
              import mimetypes
              # 2) mimetype from the suffix, using the `mimetypes` module
              mimetype = mimetypes.guess_type(filename)[0]
          except Exception:
              pass
          if not mimetype and content:
              match = re.search(MODE_RE, content[:1000] + content[-1000:])
              if match:
                  mode = match.group(1) or match.group(2) or match.group(4) or \
                      match.group(3).lower()
                  if mode in mime_map:
                      # 3) mimetype from the content, using the `MODE_RE`
                      return mime_map[mode]
              else:
                  if is_binary(content):
                      # 4) mimetype from the content, using`is_binary`
                      return 'application/octet-stream'
          return mimetype
  
  def ct_mimetype(content_type):
      """Return the mimetype part of a content type."""
      return (content_type or '').split(';')[0].strip()
  
  def is_binary(data):
      """Detect binary content by checking the first thousand bytes for zeroes.
  
      Operate on either `str` or `unicode` strings.
      """
      if isinstance(data, str) and detect_unicode(data):
          return False
      return '\0' in data[:1000]
  
  def detect_unicode(data):
      """Detect different unicode charsets by looking for BOMs (Byte Order Mark).
  
      Operate obviously only on `str` objects.
      """
      if data.startswith('\xff\xfe'):
          return 'utf-16-le'
      elif data.startswith('\xfe\xff'):
          return 'utf-16-be'
      elif data.startswith('\xef\xbb\xbf'):
          return 'utf-8'
      else:
          return None
  
  def content_to_unicode(env, content, mimetype):
      """Retrieve an `unicode` object from a `content` to be previewed.
  
      In case the raw content had an unicode BOM, we remove it.
  
      >>> from trac.test import EnvironmentStub
      >>> env = EnvironmentStub()
      >>> content_to_unicode(env, u"\ufeffNo BOM! h\u00e9 !", '')
      u'No BOM! h\\xe9 !'
      >>> content_to_unicode(env, "\xef\xbb\xbfNo BOM! h\xc3\xa9 !", '')
      u'No BOM! h\\xe9 !'
  
      """
      mimeview = Mimeview(env)
      if hasattr(content, 'read'):
          content = content.read(mimeview.max_preview_size)
      u = mimeview.to_unicode(content, mimetype)
      if u and u[0] == u'\ufeff':
          u = u[1:]
      return u
  
  
  class IHTMLPreviewRenderer(Interface):
      """Extension point interface for components that add HTML renderers of
      specific content types to the `Mimeview` component.
  
      .. note::
  
        This interface will be merged with IContentConverter, as
        conversion to text/html will simply be a particular content
        conversion.
  
        Note however that the IHTMLPreviewRenderer will still be
        supported for a while through an adapter, whereas the
        IContentConverter interface itself will be changed.
  
        So if all you want to do is convert to HTML and don't feel like
        following the API changes, you should rather implement this
        interface for the time being.
      """
  
      #: implementing classes should set this property to True if they
      #: support text content where Trac should expand tabs into spaces
      expand_tabs = False
  
      #: indicate whether the output of this renderer is source code that can
      #: be decorated with annotations
      returns_source = False
  
      def get_quality_ratio(mimetype):
          """Return the level of support this renderer provides for the `content`
          of the specified MIME type. The return value must be a number between
          0 and 9, where 0 means no support and 9 means "perfect" support.
          """
  
      def render(context, mimetype, content, filename=None, url=None):
          """Render an XHTML preview of the raw `content` in a RenderingContext.
  
          The `content` might be:
           * a `str` object
           * an `unicode` string
           * any object with a `read` method, returning one of the above
  
          It is assumed that the content will correspond to the given `mimetype`.
  
          Besides the `content` value, the same content may eventually
          be available through the `filename` or `url` parameters.
          This is useful for renderers that embed objects, using <object> or
          <img> instead of including the content inline.
          
          Can return the generated XHTML text as a single string or as an
          iterable that yields strings. In the latter case, the list will
          be considered to correspond to lines of text in the original content.
          """
  
  
  class IHTMLPreviewAnnotator(Interface):
      """Extension point interface for components that can annotate an XHTML
      representation of file contents with additional information."""
  
      def get_annotation_type():
          """Return a (type, label, description) tuple
          that defines the type of annotation and provides human readable names.
          The `type` element should be unique to the annotator.
          The `label` element is used as column heading for the table,
          while `description` is used as a display name to let the user
          toggle the appearance of the annotation type.
          """
          
      def get_annotation_data(context):
          """Return some metadata to be used by the `annotate_row` method below.
  
          This will be called only once, before lines are processed.
          If this raises an error, that annotator won't be used.
          """
  
      def annotate_row(context, row, number, line, data):
          """Return the XHTML markup for the table cell that contains the
          annotation data.
  
          `context` is the context corresponding to the content being annotated,
          `row` is the tr Element being built, `number` is the line number being
          processed and `line` is the line's actual content.
          `data` is whatever additional data the `get_annotation_data` method
          decided to provide.
          """
  
  
  class IContentConverter(Interface):
      """An extension point interface for generic MIME based content
      conversion.
  
      .. note:: This api will likely change in the future (see :teo:`#3332`)
  
      """
  
      def get_supported_conversions():
          """Return an iterable of tuples in the form (key, name, extension,
          in_mimetype, out_mimetype, quality) representing the MIME conversions
          supported and
          the quality ratio of the conversion in the range 0 to 9, where 0 means
          no support and 9 means "perfect" support. eg. ('latex', 'LaTeX', 'tex',
          'text/x-trac-wiki', 'text/plain', 8)"""
  
      def convert_content(req, mimetype, content, key):
          """Convert the given content from mimetype to the output MIME type
          represented by key. Returns a tuple in the form (content,
          output_mime_type) or None if conversion is not possible."""
  
  
  class Content(object):
      """A lazy file-like object that only reads `input` if necessary."""
      def __init__(self, input, max_size):
          self.input = input
          self.max_size = max_size
          self.content = None
      
      def read(self, size=-1):
          if size == 0:
              return ''
          if self.content is None:
              self.content = StringIO(self.input.read(self.max_size))
          return self.content.read(size)
      
      def reset(self):
          if self.content is not None:
              self.content.seek(0)
  
  
  class Mimeview(Component):
      """Generic HTML renderer for data, typically source code."""
  
      required = True
  
      renderers = ExtensionPoint(IHTMLPreviewRenderer)
      annotators = ExtensionPoint(IHTMLPreviewAnnotator)
      converters = ExtensionPoint(IContentConverter)
  
      default_charset = Option('trac', 'default_charset', 'utf-8',
          """Charset to be used when in doubt.""")
  
      tab_width = IntOption('mimeviewer', 'tab_width', 8,
          """Displayed tab width in file preview. (''since 0.9'')""")
  
      max_preview_size = IntOption('mimeviewer', 'max_preview_size', 262144,
          """Maximum file size for HTML preview. (''since 0.9'')""")
  
      mime_map = ListOption('mimeviewer', 'mime_map',
          'text/x-dylan:dylan, text/x-idl:ice, text/x-ada:ads:adb',
          doc="""List of additional MIME types and keyword mappings.
          Mappings are comma-separated, and for each MIME type,
          there's a colon (":") separated list of associated keywords
          or file extensions. (''since 0.10'')""")
  
      treat_as_binary = ListOption('mimeviewer', 'treat_as_binary',
          'application/octet-stream, application/pdf, application/postscript, '
          'application/msword,application/rtf,',
          doc="""Comma-separated list of MIME types that should be treated as
          binary data. (''since 0.11.5'')""")
  
      def __init__(self):
          self._mime_map = None
  
      # Public API
  
      def get_supported_conversions(self, mimetype):
          """Return a list of target MIME types in same form as
          `IContentConverter.get_supported_conversions()`, but with the converter
          component appended. Output is ordered from best to worst quality."""
          converters = []
          for converter in self.converters:
              conversions = converter.get_supported_conversions() or []
              for k, n, e, im, om, q in conversions:
                  if im == mimetype and q > 0:
                      converters.append((k, n, e, im, om, q, converter))
          converters = sorted(converters, key=lambda i: i[-2], reverse=True)
          return converters
  
      def convert_content(self, req, mimetype, content, key, filename=None,
                          url=None):
          """Convert the given content to the target MIME type represented by
          `key`, which can be either a MIME type or a key. Returns a tuple of
          (content, output_mime_type, extension)."""
          if not content:
              return ('', 'text/plain;charset=utf-8', '.txt')
  
          # Ensure we have a MIME type for this content
          full_mimetype = mimetype
          if not full_mimetype:
              if hasattr(content, 'read'):
                  content = content.read(self.max_preview_size)
              full_mimetype = self.get_mimetype(filename, content)
          if full_mimetype:
              mimetype = ct_mimetype(full_mimetype)   # split off charset
          else:
              mimetype = full_mimetype = 'text/plain' # fallback if not binary
  
          # Choose best converter
          candidates = list(self.get_supported_conversions(mimetype) or [])
          candidates = [c for c in candidates if key in (c[0], c[4])]
          if not candidates:
              raise TracError(
                  _("No available MIME conversions from %(old)s to %(new)s",
                    old=mimetype, new=key))
  
          # First successful conversion wins
          for ck, name, ext, input_mimettype, output_mimetype, quality, \
                  converter in candidates:
              output = converter.convert_content(req, mimetype, content, ck)
              if output:
                  return (output[0], output[1], ext)
          raise TracError(
              _("No available MIME conversions from %(old)s to %(new)s",
                old=mimetype, new=key))
  
      def get_annotation_types(self):
          """Generator that returns all available annotation types."""
          for annotator in self.annotators:
              yield annotator.get_annotation_type()
  
      def render(self, context, mimetype, content, filename=None, url=None,
                 annotations=None, force_source=False):
          """Render an XHTML preview of the given `content`.
  
          `content` is the same as an `IHTMLPreviewRenderer.render`'s
          `content` argument.
  
          The specified `mimetype` will be used to select the most appropriate
          `IHTMLPreviewRenderer` implementation available for this MIME type.
          If not given, the MIME type will be infered from the filename or the
          content.
  
          Return a string containing the XHTML text.
          
          When rendering with an `IHTMLPreviewRenderer` fails, a warning is added
          to the request associated with the context (if any), unless the
          `disable_warnings` hint is set to `True`.
          """
          if not content:
              return ''
          if not isinstance(context, RenderingContext):
              raise TypeError("RenderingContext expected (since 0.11)")
  
          # Ensure we have a MIME type for this content
          full_mimetype = mimetype
          if not full_mimetype:
              if hasattr(content, 'read'):
                  content = content.read(self.max_preview_size)
              full_mimetype = self.get_mimetype(filename, content)
          if full_mimetype:
              mimetype = ct_mimetype(full_mimetype)   # split off charset
          else:
              mimetype = full_mimetype = 'text/plain' # fallback if not binary
  
          # Determine candidate `IHTMLPreviewRenderer`s
          candidates = []
          for renderer in self.renderers:
              qr = renderer.get_quality_ratio(mimetype)
              if qr > 0:
                  candidates.append((qr, renderer))
          candidates.sort(lambda x, y: cmp(y[0], x[0]))
          
          # Wrap file-like object so that it can be read multiple times
          if hasattr(content, 'read'):
              content = Content(content, self.max_preview_size)
  
          # First candidate which renders successfully wins.
          # Also, we don't want to expand tabs more than once.
          expanded_content = None
          for qr, renderer in candidates:
              if force_source and not getattr(renderer, 'returns_source', False):
                  continue # skip non-source renderers in force_source mode
              if isinstance(content, Content):
                  content.reset()
              try:
                  ann_names = ', '.join(annotations) if annotations else \
                             'no annotations'
                  self.log.debug('Trying to render HTML preview using %s [%s]',
                                 renderer.__class__.__name__, ann_names)
  
                  # check if we need to perform a tab expansion
                  rendered_content = content
                  if getattr(renderer, 'expand_tabs', False):
                      if expanded_content is None:
                          content = content_to_unicode(self.env, content,
                                                       full_mimetype)
                          expanded_content = content.expandtabs(self.tab_width)
                      rendered_content = expanded_content
  
                  result = renderer.render(context, full_mimetype,
                                           rendered_content, filename, url)
                  if not result:
                      continue
  
                  if not (force_source or getattr(renderer, 'returns_source',
                                                  False)):
                      # Direct rendering of content
                      if isinstance(result, basestring):
                          if not isinstance(result, unicode):
                              result = to_unicode(result)
                          return Markup(to_unicode(result))
                      elif isinstance(result, Fragment):
                          return result.generate()
                      else:
                          return result
  
                  # Render content as source code
                  if annotations:
                      m = context.req.args.get('marks') if context.req else None
                      return self._render_source(context, result, annotations,
                                                 m and Ranges(m))
                  else:
                      if isinstance(result, list):
                          result = Markup('\n').join(result)
                      return tag.div(class_='code')(tag.pre(result)).generate()
  
              except Exception, e:
                  self.log.warning('HTML preview using %s failed: %s',
                                   renderer.__class__.__name__,
                                   exception_to_unicode(e, traceback=True))
                  if context.req and not context.get_hint('disable_warnings'):
                      from trac.web.chrome import add_warning
                      add_warning(context.req,
                          _("HTML preview using %(renderer)s failed (%(err)s)",
                            renderer=renderer.__class__.__name__,
                            err=exception_to_unicode(e)))
  
      def _render_source(self, context, stream, annotations, marks=None):
          from trac.web.chrome import add_warning
          annotators, labels, titles = {}, {}, {}
          for annotator in self.annotators:
              atype, alabel, atitle = annotator.get_annotation_type()
              if atype in annotations:
                  labels[atype] = alabel
                  titles[atype] = atitle
                  annotators[atype] = annotator
          annotations = [a for a in annotations if a in annotators]
  
          if isinstance(stream, list):
              stream = HTMLParser(StringIO(u'\n'.join(stream)))
          elif isinstance(stream, unicode):
              text = stream
              def linesplitter():
                  for line in text.splitlines(True):
                      yield TEXT, line, (None, -1, -1)
              stream = linesplitter()
  
          annotator_datas = []
          for a in annotations:
              annotator = annotators[a]
              try:
                  data = (annotator, annotator.get_annotation_data(context))
              except TracError, e:
                  self.log.warning("Can't use annotator '%s': %s", a, e.message)
                  add_warning(context.req, tag.strong(
                      tag_("Can't use %(annotator)s annotator: %(error)s",
                           annotator=tag.em(a), error=tag.pre(e.message))))
                  data = (None, None)
              annotator_datas.append(data)
  
          def _head_row():
              return tag.tr(
                  [tag.th(labels[a], class_=a, title=titles[a])
                   for a in annotations] +
                  [tag.th(u'\xa0', class_='content')]
              )
  
          def _body_rows():
              for idx, line in enumerate(_group_lines(stream)):
                  row = tag.tr()
                  if marks and idx + 1 in marks:
                      row(class_='hilite')
                  for annotator, data in annotator_datas:
                      if annotator:
                          annotator.annotate_row(context, row, idx+1, line, data)
                      else:
                          row.append(tag.td())
                  row.append(tag.td(line))
                  yield row
  
          return tag.table(class_='code')(
              tag.thead(_head_row()),
              tag.tbody(_body_rows())
          )
  
      def get_max_preview_size(self):
          """:deprecated: use `max_preview_size` attribute directly."""
          return self.max_preview_size
  
      def get_charset(self, content='', mimetype=None):
          """Infer the character encoding from the `content` or the `mimetype`.
  
          `content` is either a `str` or an `unicode` object.
          
          The charset will be determined using this order:
           * from the charset information present in the `mimetype` argument
           * auto-detection of the charset from the `content`
           * the configured `default_charset` 
          """
          if mimetype:
              ctpos = mimetype.find('charset=')
              if ctpos >= 0:
                  return mimetype[ctpos + 8:].strip()
          if isinstance(content, str):
              utf = detect_unicode(content)
              if utf is not None:
                  return utf
          return self.default_charset
  
      @property
      def mime_map(self):
          # Extend default extension to MIME type mappings with configured ones
          if not self._mime_map:
              self._mime_map = MIME_MAP.copy()
              for mapping in self.config['mimeviewer'].getlist('mime_map'):
                  if ':' in mapping:
                      assocations = mapping.split(':')
                      for keyword in assocations: # Note: [0] kept on purpose
                          self._mime_map[keyword] = assocations[0]
          return self._mime_map
  
      def get_mimetype(self, filename, content=None):
          """Infer the MIME type from the `filename` or the `content`.
  
          `content` is either a `str` or an `unicode` object.
  
          Return the detected MIME type, augmented by the
          charset information (i.e. "<mimetype>; charset=..."),
          or `None` if detection failed.
          """
  
          mimetype = get_mimetype(filename, content, self.mime_map)
          charset = None
          if mimetype:
              charset = self.get_charset(content, mimetype)
          if mimetype and charset and not 'charset' in mimetype:
              mimetype += '; charset=' + charset
          return mimetype
  
      def is_binary(self, mimetype=None, filename=None, content=None):
          """Check if a file must be considered as binary."""
          if not mimetype and filename:
              mimetype = self.get_mimetype(filename, content)
          if mimetype:
              mimetype = ct_mimetype(mimetype)
              if mimetype in self.treat_as_binary:
                  return True
          if content is not None and is_binary(content):
              return True
          return False
  
      def to_utf8(self, content, mimetype=None):
          """Convert an encoded `content` to utf-8.
  
          :deprecated: since 0.10, you should use `unicode` strings only.
          """
          return to_utf8(content, self.get_charset(content, mimetype))
  
      def to_unicode(self, content, mimetype=None, charset=None):
          """Convert `content` (an encoded `str` object) to an `unicode` object.
  
          This calls `trac.util.to_unicode` with the `charset` provided,
          or the one obtained by `Mimeview.get_charset()`.
          """
          if not charset:
              charset = self.get_charset(content, mimetype)
          return to_unicode(content, charset)
  
      def configured_modes_mapping(self, renderer):
          """Return a MIME type to `(mode,quality)` mapping for given `option`"""
          types, option = {}, '%s_modes' % renderer
          for mapping in self.config['mimeviewer'].getlist(option):
              if not mapping:
                  continue
              try:
                  mimetype, mode, quality = mapping.split(':')
                  types[mimetype] = (mode, int(quality))
              except (TypeError, ValueError):
                  self.log.warning("Invalid mapping '%s' specified in '%s' "
                                   "option.", mapping, option)
          return types
      
      def preview_data(self, context, content, length, mimetype, filename,
                       url=None, annotations=None, force_source=False):
          """Prepares a rendered preview of the given `content`.
  
          Note: `content` will usually be an object with a `read` method.
          """        
          data = {'raw_href': url, 'size': length,
                  'max_file_size': self.max_preview_size,
                  'max_file_size_reached': False,
                  'rendered': None,
                  }
          if length >= self.max_preview_size:
              data['max_file_size_reached'] = True
          else:
              result = self.render(context, mimetype, content, filename, url,
                                   annotations, force_source=force_source)
              data['rendered'] = result
          return data
  
      def send_converted(self, req, in_type, content, selector, filename='file'):
          """Helper method for converting `content` and sending it directly.
  
          `selector` can be either a key or a MIME Type."""
          from trac.web.api import RequestDone
          content, output_type, ext = self.convert_content(req, in_type,
                                                           content, selector)
          if isinstance(content, unicode):
              content = content.encode('utf-8')
          req.send_response(200)
          req.send_header('Content-Type', output_type)
          req.send_header('Content-Length', len(content))
          if filename:
              req.send_header('Content-Disposition',
                              content_disposition(filename='%s.%s' % 
                                                           (filename, ext)))
          req.end_headers()
          req.write(content)
          raise RequestDone
  
  
  def _group_lines(stream):
      space_re = re.compile('(?P<spaces> (?: +))|^(?P<tag><\w+.*?>)?( )')
      def pad_spaces(match):
          m = match.group('spaces')
          if m:
              div, mod = divmod(len(m), 2)
              return div * u'\xa0 ' + mod * u'\xa0'
          return (match.group('tag') or '') + u'\xa0'
  
      def _generate():
          stack = []
          def _reverse():
              for event in reversed(stack):
                  if event[0] is START:
                      yield END, event[1][0], event[2]
                  else:
                      yield END_NS, event[1][0], event[2]
  
          for kind, data, pos in stream:
              if kind is TEXT:
                  lines = data.split('\n')
                  if lines:
                      # First element
                      for e in stack:
                          yield e
                      yield kind, lines.pop(0), pos
                      for e in _reverse():
                          yield e
                      # Subsequent ones, prefix with \n
                      for line in lines:
                          yield TEXT, '\n', pos
                          for e in stack:
                              yield e
                          yield kind, line, pos
                          for e in _reverse():
                              yield e
              else:
                  if kind is START or kind is START_NS:
                      stack.append((kind, data, pos))
                  elif kind is END or kind is END_NS:
                      stack.pop()
                  else:
                      yield kind, data, pos
  
      buf = []
      
      # Fix the \n at EOF.
      if not isinstance(stream, list):
          stream = list(stream)
      found_text = False
      
      for i in range(len(stream)-1, -1, -1):
          if stream[i][0] is TEXT:
              e = stream[i]
              # One chance to strip a \n
              if not found_text and e[1].endswith('\n'):
                  stream[i] = (e[0], e[1][:-1], e[2])
              if len(e[1]):
                  found_text = True
                  break
      if not found_text:
          raise StopIteration
  
      for kind, data, pos in _generate():
          if kind is TEXT and data == '\n':
              yield Stream(buf[:])
              del buf[:]
          else:
              if kind is TEXT:
                  data = space_re.sub(pad_spaces, data)
              buf.append((kind, data, pos))
      if buf:
          yield Stream(buf[:])
  
  
  # -- Default annotators
  
  class LineNumberAnnotator(Component):
      """Text annotator that adds a column with line numbers."""
      implements(IHTMLPreviewAnnotator)
  
      # ITextAnnotator methods
  
      def get_annotation_type(self):
          return 'lineno', _('Line'), _('Line numbers')
  
      def get_annotation_data(self, context):
          return None
  
      def annotate_row(self, context, row, lineno, line, data):
          row.append(tag.th(id='L%s' % lineno)(
              tag.a(lineno, href='#L%s' % lineno)
          ))
  
  
  # -- Default renderers
  
  class PlainTextRenderer(Component):
      """HTML preview renderer for plain text, and fallback for any kind of text
      for which no more specific renderer is available.
      """
      implements(IHTMLPreviewRenderer)
  
      expand_tabs = True
      returns_source = True
  
      def get_quality_ratio(self, mimetype):
          if mimetype in Mimeview(self.env).treat_as_binary:
              return 0
          return 1
  
      def render(self, context, mimetype, content, filename=None, url=None):
          if is_binary(content):
              self.log.debug("Binary data; no preview available")
              return
  
          self.log.debug("Using default plain text mimeviewer")
          return content_to_unicode(self.env, content, mimetype)
  
  
  class ImageRenderer(Component):
      """Inline image display.
      
      This component doesn't need the `content` at all.
      """
      implements(IHTMLPreviewRenderer)
  
      def get_quality_ratio(self, mimetype):
          if mimetype.startswith('image/'):
              return 8
          return 0
  
      def render(self, context, mimetype, content, filename=None, url=None):
          if url:
              return tag.div(tag.img(src=url, alt=filename),
                             class_='image-file')
  
  
  class WikiTextRenderer(Component):
      """HTML renderer for files containing Trac's own Wiki formatting markup."""
      implements(IHTMLPreviewRenderer)
  
      def get_quality_ratio(self, mimetype):
          if mimetype in ('text/x-trac-wiki', 'application/x-trac-wiki'):
              return 8
          return 0
  
      def render(self, context, mimetype, content, filename=None, url=None):
          from trac.wiki.formatter import format_to_html
          return format_to_html(self.env, context,
                                content_to_unicode(self.env, content, mimetype))
  
entities: [['EMAIL_ADDRESS', 'dummy@email.com'], ['EMAIL_ADDRESS', 'dummy@email.com'], ['EMAIL_ADDRESS', 'dummy@email.com'], ['EMAIL_ADDRESS', 'dummy@email.com'], ['EMAIL_ADDRESS', 'dummy@email.com'], ['EMAIL_ADDRESS', 'dummy@email.com'], ['DATE_TIME', '2004-2010'], ['DATE_TIME', '2004'], ['PERSON', 'Daniel Lundin'], ['DATE_TIME', '2005-2006'], ['PERSON', 'Christopher Lenz'], ['DATE_TIME', '2006-2007'], ['NRP', 'Christian'], ['PERSON', 'Daniel Lundin'], ['PERSON', 'Christopher Lenz'], ['PERSON', 'Markup'], ['PERSON', 'Href'], ['LOCATION', 'self.resource'], ['PERSON', '1).resource'], ['PERSON', 'oneliner'], ['NRP', 'self._hints'], ['PERSON', 'msword'], ['PERSON', "roff troff'"], ['PERSON', "ini cfg'"], ['PERSON', 'vba'], ['PERSON', 'ada asm asp'], ['PERSON', 'ksh lua'], ['PERSON', 'tcl tex zsh'], ['PERSON', 'mimetype'], ['PERSON', 'Mark'], ['LOCATION', 'convert_content(req'], ['LOCATION', 'mimetype'], ['PERSON', 'dylan'], ['PERSON', 'msword'], ['NRP', 'input_mimettype'], ['LOCATION', 'mimetype'], ['NRP', 'force_source'], ['NRP', 'force_source'], ['NRP', 'force_source'], ['LOCATION', "self.log.debug('Trying"], ['NRP', 'force_source'], ['LOCATION', 'basestring'], ['PERSON', "context.get_hint('disable_warnings"], ['PERSON', 'atitle = annotator.get_annotation_type'], ['LOCATION', 'tag_("Can\'t'], ['PERSON', 'mimetype'], ['PERSON', 'mimetype'], ['NRP', 'force_source'], ['URL', 'self.ma'], ['PERSON', 'lineno'], ['URL', 'self.log.de'], ['URL', 'tag.im'], ['URL', 'trac.wiki.fo'], ['URL', 'http://trac.edgewall.org/wiki/TracLicense.'], ['URL', 'http://trac.edgewall.org/log/.'], ['IP_ADDRESS', '\n\n      '], ['IP_ADDRESS', 'e:: '], ['URL', 'email.com'], ['URL', 'email.com'], ['URL', 'email.com'], ['URL', 'email.com'], ['URL', 'email.com'], ['URL', 'email.com'], ['URL', 'genshi.co'], ['URL', 'genshi.in'], ['URL', 'trac.co'], ['URL', 'trac.co'], ['URL', 'trac.re'], ['URL', 'trac.util.tr'], ['URL', 'self.pa'], ['URL', 'self.re'], ['URL', 'self.hr'], ['URL', 'self.pe'], ['URL', 'trac.web.ch'], ['URL', 'context.resource.re'], ['URL', 'context.re'], ['URL', 'context.pa'], ['URL', 'context.ch'], ['URL', 'context.ch'], ['URL', 'context.ch'], ['URL', 'self.re'], ['URL', 'self.hr'], ['URL', 'self.pe'], ['URL', 'context.pa'], ['URL', 'context.re'], ['URL', 'self.re'], ['URL', 'context.re'], ['URL', 'context.resource.re'], ['URL', 'resource.re'], ['URL', 'context.resource.id'], ['URL', 'resource.id'], ['URL', 'context.pa'], ['URL', 'ctx.se'], ['URL', 'ctx.se'], ['URL', 'ctx.ge'], ['URL', 'ctx.ge'], ['URL', 'ctx.ge'], ['URL', 'ctx.ge'], ['URL', 'ctx.ge'], ['URL', 'ctx.ge'], ['URL', 'ctx.se'], ['URL', 'ctx.ge'], ['URL', 'ctx.ge'], ['URL', 'hints.ge'], ['URL', 'ctx.se'], ['URL', 'self.pa'], ['URL', 'p.pa'], ['URL', 'TYPES.ke'], ['URL', 't.st'], ['URL', 'TYPES.se'], ['URL', 'TYPES.it'], ['URL', 're.com'], ['URL', 're.VE'], ['URL', 'mimetypes.gu'], ['URL', 're.se'], ['URL', 'match.gr'], ['URL', 'match.gr'], ['URL', 'match.gr'], ['URL', 'match.gr'], ['URL', 'data.st'], ['URL', 'data.st'], ['URL', 'data.st'], ['URL', 'content.re'], ['URL', 'mimeview.ma'], ['URL', 'mimeview.to'], ['URL', 'self.in'], ['URL', 'self.ma'], ['URL', 'self.co'], ['URL', 'self.co'], ['URL', 'self.co'], ['URL', 'self.input.re'], ['URL', 'self.ma'], ['URL', 'self.content.re'], ['URL', 'self.co'], ['URL', 'self.content.se'], ['URL', 'IContentConverter.ge'], ['URL', 'self.co'], ['URL', 'converter.ge'], ['URL', 'content.re'], ['URL', 'self.ma'], ['URL', 'self.ge'], ['URL', 'self.ge'], ['URL', 'converter.co'], ['URL', 'self.an'], ['URL', 'annotator.ge'], ['URL', 'IHTMLPreviewRenderer.re'], ['URL', 'content.re'], ['URL', 'self.ma'], ['URL', 'self.ge'], ['URL', 'self.re'], ['URL', 'renderer.ge'], ['URL', 'candidates.so'], ['URL', 'self.ma'], ['URL', 'content.re'], ['URL', 'self.log.de'], ['URL', 'renderer.re'], ['URL', 'result.ge'], ['URL', 'context.req.args.ge'], ['URL', 'context.re'], ['URL', 'tag.pr'], ['URL', 'context.re'], ['URL', 'context.ge'], ['URL', 'trac.web.ch'], ['URL', 'context.re'], ['URL', 'trac.web.ch'], ['URL', 'self.an'], ['URL', 'annotator.ge'], ['URL', 'annotator.ge'], ['URL', 'e.me'], ['URL', 'context.re'], ['URL', 'tag.st'], ['URL', 'tag.pr'], ['URL', 'e.me'], ['URL', 'tag.tr'], ['URL', 'tag.th'], ['URL', 'tag.th'], ['URL', 'tag.tr'], ['URL', 'annotator.an'], ['URL', 'tag.td'], ['URL', 'tag.td'], ['URL', 'tag.th'], ['URL', 'self.ma'], ['URL', 'mimetype.fi'], ['URL', 'self.de'], ['URL', 'MAP.co'], ['URL', 'self.co'], ['URL', 'self.ge'], ['URL', 'self.ge'], ['URL', 'self.tr'], ['URL', 'self.ge'], ['URL', 'trac.util.to'], ['URL', 'Mimeview.ge'], ['URL', 'self.ge'], ['URL', 'self.co'], ['URL', 'self.ma'], ['URL', 'self.re'], ['URL', 'self.co'], ['URL', 'req.se'], ['URL', 'req.se'], ['URL', 'req.se'], ['URL', 'req.se'], ['URL', 're.com'], ['URL', 'match.gr'], ['URL', 'match.gr'], ['URL', 're.su'], ['URL', 'tag.th'], ['URL', 'self.log.de'], ['URL', 'mimetype.st']]