hgext/highlight/highlight.py

hgweb: add a "URL breadcrumb" to the index and repository pages

The purpose of this change is to make it much easier to navigate up the
repository tree when the hg web server is used to serve more than one
repository.

A "URL breadcrumb" is a path where each of the path items can be clicked to go
to the corresponding path page.

This lets you go up the folder hierarchy very quickly. For example, when showing
the list of repositories in http://myserver/myteams/myprojects, the following
"breadcrumb" will be shown:

Mercurial > myteams > myprojects

Clicking on "myprojects" reloads the page. Clicking on "myteams" goes up one
folder. Clicking on the leftmost "Mercurial" goes to the server root.

This "breadcrumb" also appears on all repository pages. For example on the
summary page of the repository at http://myserver/myteams/myprojects/myrepo the
following will be shown:

Mercurial > myteams > myprojects > myrepo / summary

This change has been applied to all templates that already had a link to the
main repository page (i.e. gitweb, monoblue, paper and coal) plus to the index
page of the spartan template.

In order to make the breadcumb links stand out the some of the template styles
have been customized.

# highlight.py - highlight extension implementation file
#
#  Copyright 2007-2009 Adam Hupp <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
#
# The original module was split in an interface and an implementation
# file to defer pygments loading and speedup extension setup.

from mercurial import demandimport
demandimport.ignore.extend(['pkgutil', 'pkg_resources', '__main__'])
from mercurial import util, encoding

from pygments import highlight
from pygments.util import ClassNotFound
from pygments.lexers import guess_lexer, guess_lexer_for_filename, TextLexer
from pygments.formatters import HtmlFormatter

SYNTAX_CSS = ('\n<link rel="stylesheet" href="{url}highlightcss" '
              'type="text/css" />')

def pygmentize(field, fctx, style, tmpl):

    # append a <link ...> to the syntax highlighting css
    old_header = tmpl.load('header')
    if SYNTAX_CSS not in old_header:
        new_header =  old_header + SYNTAX_CSS
        tmpl.cache['header'] = new_header

    text = fctx.data()
    if util.binary(text):
        return

    # Pygments is best used with Unicode strings:
    # <http://pygments.org/docs/unicode/>
    text = text.decode(encoding.encoding, 'replace')

    # To get multi-line strings right, we can't format line-by-line
    try:
        lexer = guess_lexer_for_filename(fctx.path(), text[:1024])
    except (ClassNotFound, ValueError):
        try:
            lexer = guess_lexer(text[:1024])
        except (ClassNotFound, ValueError):
            lexer = TextLexer()

    formatter = HtmlFormatter(style=style)

    colorized = highlight(text, lexer, formatter)
    # strip wrapping div
    colorized = colorized[:colorized.find('\n</pre>')]
    colorized = colorized[colorized.find('<pre>') + 5:]
    coloriter = (s.encode(encoding.encoding, 'replace')
                 for s in colorized.splitlines())

    tmpl.filters['colorize'] = lambda x: coloriter.next()

    oldl = tmpl.cache[field]
    newl = oldl.replace('line|escape', 'line|colorize')
    tmpl.cache[field] = newl