avatar.css

img.avatar {
 max-width: 40px;
 max-height: 40px;
 vertical-align: bottom;
}

avatar.js

jQuery(document).ready(function($) {
  var usernames = [];
  var elements = $('.report').find("td.owner, td.reporter, td.担当者, td.報告者");
  var uniq_username = {};
  var data = {username: [], __FORM_TOKEN: form_token};
  elements.each(function() {
    var text = $(this).text();
    usernames.push(text);
    if (!text || text == 'anonymous' || text == 'somebody' || text == 'trac')
      return;
    if (!(text in uniq_username)) {
      uniq_username[text] = true;
      data.username.push(text);
    }
  });

  if (data.username.length == 0)
    return;

  $.ajax({
    url: avatar_request_path,
    data: data,
    traditional: true,
    dataType: 'json',
    type: 'POST',
    success: function(json) {
      var images = {};
      $.each(json, function(username, href) {
        var image = new Image();
        image.className = 'avatar';
        image.src = href;
        images[username] = image;
      });
      var curr = 0;
      var length = elements.length;
      function step() {
        var n = Math.min(length - curr, 25);
        for (var i = 0; i < n; i++) {
          var index = curr + i;
          var username = usernames[index];
          if (username in images)
            $(elements[index]).prepend(images[username].cloneNode(false));
        };
        curr += n;
        if (curr < length)
          setTimeout(step, 50);
      }
      step();
    }
  });
});

web_ui.py

# -*- coding: utf-8 -*-
from genshi.builder import tag

from trac.core import Component, implements
from trac.web.chrome import Chrome, add_stylesheet, add_script, \
                            add_script_data, ITemplateProvider
from trac.web.main import IRequestHandler, IRequestFilter
from trac.util.compat import partial
from trac.util.presentation import to_json

class TracAvatarModule(Component):
    implements(IRequestHandler, IRequestFilter, ITemplateProvider)

    # IRequestFilter methods
    def pre_process_request(self, req, handler):
        return handler
        
    def post_process_request(self, req, template, data, content_type):
        if data:
            req.callbacks['avatars'] = self._get_avatars
            if template == 'ticket.html':
                if data['owner_link']:
                    ticket = data['ticket']
                    data['owner_link'] = tag(
                        self._avatar_image(req, ticket['owner']),
                        data['owner_link'])
                if data['reporter_link']:
                    data['reporter_link'] = tag(
                        self._avatar_image(req, ticket['reporter']),
                        data['reporter_link'])
            data['authorinfo'] = partial(self.authorinfo, req)
            data['format_author'] = partial(self.format_author, req)
        add_script_data(req, {'avatar_request_path': req.href.tracavatar(),
                              'form_token': req.form_token})
        add_stylesheet(req, 'tracavatar/css/avatar.css')
        add_script(req, 'tracavatar/js/avatar.js')
        return (template, data, content_type)

    def _get_avatars(self, req):
        db = self.env.get_read_db()
        cursor = db.cursor()
        cursor.execute("SELECT sid, value FROM session_attribute"
                       " WHERE authenticated=1 AND name='picture_href'")
        avatars = dict((sid, value) for sid, value in cursor)
        # default avatar
        avatars[None] = req.href.chrome('tracusermanager/img/no_picture.png')
        return avatars

    def _avatar_image(self, req, author):
        src = req.avatars.get(author) or req.avatars[None]
        return tag.img(src=src, class_='avatar')

    def authorinfo(self, req, author, email_map=None):
        return tag(self._avatar_image(req, author),
                   Chrome(self.env).authorinfo(req, author,
                                               email_map=email_map))

    def format_author(self, req, author):
        return tag(self._avatar_image(req, author),
                   Chrome(self.env).format_author(req, author))

    # IRequestHandler methods
    def match_request(self, req):
        if req.path_info in ('/login/tracavatar', '/tracavatar'):
            self.log.debug("%s matches %s" % (req.path_info, True))
            return True
        return False

    def process_request(self, req):
        sids = req.args.getlist('username')
        avatars = {}
        if sids:
            default = req.href.chrome('tracusermanager/img/no_picture.png')
            avatars = dict((sid, default) for sid in sids)
            query = "SELECT sid, value FROM session_attribute" + \
                    " WHERE sid IN(" + ','.join(['%s'] * len(sids)) + ")" + \
                    " AND authenticated=1 AND name='picture_href'"
            db = self.env.get_read_db()
            cursor = db.cursor()
            cursor.execute(query, sids)
            for sid, value in cursor:
                avatars[sid] = value

        response = to_json(avatars)
        if isinstance(response, unicode):
            response = response.encode('utf-8')
        req.send(response, 'application/json')

    # ITemplateProvider methods
    def get_templates_dirs(self):
        return []

    def get_htdocs_dirs(self):
        from pkg_resources import resource_filename
        return [('tracavatar', resource_filename(__name__, 'htdocs'))]