    """WebKit page template class for pages with a sidebar."""

    from Page import Page

    class SidebarPage(Page):
        """WebKit page template class for pages with a sidebar.

        SidebarPage is an abstract superclass for pages that have a sidebar
        (as well as a header and "content well"). Sidebars are normally used
        for navigation (e.g., a menu or list of links), showing small bits
        of info and occasionally a simple form (such as login or search).

        Subclasses should override cornerTitle(), writeSidebar() and
        writeContent() (and title() if necessary; see Page).

        The utility methods menuHeading() and menuItem() can be used by
        subclasses, typically in their implementation of writeSidebar().

        WebKit itself uses this class: Examples/ExamplePage and Admin/AdminPage
        both inherit from it.

        TO DO
          * More consequent use style sheets; get rid of tables completely.
          * The header, corner and colors are not easy to customize via subclasses.

        """

        ## StyleSheet ##

        _styleSheet = '''
    <!--
    body {
        background-color: white;
        color: #080810;
        font-size: 11pt;
        font-family: Tahoma,Verdana,Arial,Helvetica,sans-serif;
        margin: 0pt;
        padding: 0pt;
    }

    h1 { font-size: 18pt; }
    h2 { font-size: 16pt; }
    h3 { font-size: 14pt; }
    h4 { font-size: 12pt; }
    h5 { font-size: 11pt; }
    table#PageTable {
        border-collapse: collapse;
    }
    td#CornerTitle {
        background-color: #101040;
        color: white;
        padding: 6pt 6pt;
        font-size: 14pt;
        text-align: center;
        vertical-align: middle;
    }
    td#Banner {
        background-color: #202080;
        color: white;
        padding: 8pt 6pt;
        font-size: 16pt;
        font-weight: bold;
        text-align: center;
        vertical-align: middle;
    }
    td#Sidebar {
        background-color: #E8E8F0;
        padding: 4pt;
        font-size: 10pt;
        line-height: 13pt;
        vertical-align: top;
        white-space: nowrap;
        height: 100%;
    }
    td#Sidebar div {
        margin-bottom: 1pt;
    }
    td#Sidebar div.MenuHeading {
        font-weight: bold;
        margin-top: 6pt;
        margin-bottom: 3pt;
        width: 12em;
    }
    td#Content {
        padding: 8pt;
        vertical-align: top;
        width: 100%;
    }
    table.NiceTable {
        margin-bottom: 4pt;
    }
    table.NiceTable td, .Data {
        background-color: #EEE;
        color: #111;
    }
    table tr th, .SubHeading {
        background-color: #CCC;
        color: black;
    }
    table tr.TopHeading th, .TopHeading {
    background-color: #555;
    color: white;
    }
    td#Content table tr.NoTable td {
        background-color: white;
        color: #080810;
    }
    table.NiceTable th a:link, table.NiceTable th a:visited {
        color: #101040;
    }
    -->
    '''

        def writeStyleSheet(self):
            """We're using a simple internal style sheet.

            This way we avoid having to care about where an external style
            sheet should be located when this class is used in another context.

            """
            self.writeln('<style type="text/css">%s</style>' % self._styleSheet)

        ## Content methods ##

        def writeBodyParts(self):
            wr = self.writeln
            wr('<table id="PageTable">')
            self.writeBanner()
            wr('<tr><td id="Sidebar">')
            self.writeSidebar()
            wr('</td>')
            wr('<td id="Content">')
            self.writeContent()
            wr('</td>')
            wr('</tr></table>')

        def writeBanner(self):
            self.writeln('<tr><td id="CornerTitle">%s</td>' % self.cornerTitle(),
                '<td id="Banner">%s</td></tr>' % self.title())

        def writeSidebar(self):
            self.writeWebKitSidebarSections()

        @staticmethod
        def cornerTitle():
            return ''

        ## Menu ##

        def menuHeading(self, title):
            self.writeln('<div class="MenuHeading">%s</div>' % title)

        def menuItem(self, title, url=None, suffix=None, indentLevel=1):
            if suffix:
                suffix = ' ' + suffix
            else:
                suffix = ''
            if url is not None:
                title = '<a href="%s">%s</a>' % (url, title)
            self.writeln('<div style="margin-left:%dpt">%s%s</div>'
                % (4*indentLevel, title, suffix))

        ## WebKit sidebar sections ##

        def writeWebKitSidebarSections(self):
            """Write sidebar sections.

            This method (and consequently the methods it invokes)
            are provided for WebKit's example and admin pages.
            It writes sections such as contexts, e-mails, exits and versions.

            """
            self.writeContextsMenu()
            self.writeWebwareEmailMenu()
            self.writeWebwareExitsMenu()
            self.writeVersions()

        def writeContextsMenu(self):
            self.menuHeading('Contexts')
            servletPath = self.request().servletPath()
            for ctx in sorted(ctx for ctx in self.application().contexts()
                    if ctx != 'default' and not '/' in ctx):
                self.menuItem(ctx, '%s/%s/' % (servletPath, ctx))

        def writeWebwareEmailMenu(self):
            self.menuHeading('E-mail')
            self.menuItem('webware-discuss',
                'mailto:webware-discuss@lists.sourceforge.net')

        def writeWebwareExitsMenu(self):
            self.menuHeading('Exits')
            self.menuItem('Webware', 'http://www.webwareforpython.org')
            self.menuItem('Python', 'http://www.python.org')

        def writeVersions(self):
            app = self.application()
            self.menuHeading('Versions')
            self.menuItem('WebKit ' + app.webKitVersionString())
            self.menuItem('Webware ' + app.webwareVersionString())
            from sys import version
            self.menuItem('Python ' + version.split(None, 1)[0])

        def writeContent(self):
            self.writeln('Woops, someone forgot to override writeContent().')