class LineItem(urwid.WidgetWrap):

    def __init__(self, user, content):
        self.user = urwid.Text(user)
        self.content = urwid.Text(content)
        self.item = [
            ('fixed', 10, urwid.Padding(
                urwid.AttrMap(self.user, 'text'), left=2)),
            urwid.AttrMap(self.content, 'text')
        ]
        self.info = '%s: %s' % (user, content)
        w = urwid.Columns(self.item)
        self.__super.__init__(w)

    def selectable(self):
        return True
    def keypress(self, size, key):
        return key

class ExtenedEdit(urwid.Edit):
    __metaclass = urwid.signals.MetaSignals
    signals = ['done']

    def keypress(self, size, key):

        if key is 'enter':
            urwid.emit_signal(self, 'done', self, self.get_edit_text())
            super(ExtenedEdit, self).set_edit_text('')
            return
        elif key is 'esc':
            urwid.emit_signal(self, 'done', None)
            super(ExtenedEdit, self).set_edit_text('')
            return
        urwid.Edit.keypress(self, size, key)

    def selectable(self):
        return True

class MainWindow(object):

    """
     -------context-------
    | --inner context---- |
    || HEADER            ||
    ||                   ||
    || BODY              ||
    ||                   ||
    || DIVIDER           ||
    | ------------------- |
    | FOOTER              |
     ---------------------
    """
    _palette = [
        ('divider', 'black', 'dark cyan', 'standout'),
        ('text', 'light gray', 'default'),
        ('body', 'text'),
        ('footer', 'text'),
        ('header', 'text'), ]

    def __init__(self):
        self.items = []

    def input_cb(key):
        if key is 'f8':
            raise urwid.ExitMainLoop()
        if key is 'enter':
            text = self.txt_footer.get_edit_text()
            self.items.append(LineItem('user:', text))

    def run(self):
        self.build_interface()

        self.main_loop = urwid.MainLoop(
            self.context,
            palette=self._palette,
            handle_mouse=False,
            unhandled_input=self.input_cb,
        )

        self.main_loop.run()

    def _create_widget(self):
        """ create the UI widgets """
        self.header = urwid.Text("HEADER")
        self.txt_footer = ExtenedEdit(">> ")
        self.divider = urwid.Text("Initializing.")
        item = LineItem('bavan', 'Hello')
        self.items.append(item)
        self.generic_output_walker = urwid.SimpleListWalker(self.items)
        self.lst_body = urwid.ListBox(
            self.generic_output_walker)

    def _setup_widgets(self):
        self.header = urwid.AttrMap(self.header, 'divider')
        self.footer = urwid.AttrMap(self.txt_footer, 'footer')
        self.divider = urwid.AttrMap(self.divider, 'divider')
        self.body = urwid.AttrMap(self.lst_body, 'body')

    def _setup_context(self):
        self.context = urwid.Frame(self.body, header=self.header,
                                   footer=self.divider)
        self.context = urwid.Frame(self.context, footer=self.footer)
        self.context.set_focus('footer')

    def build_interface(self):
        self._create_widget()
        self._setup_widgets()
        self._setup_context()

if __name__ == '__main__':
    import sys
    try:
        main_win = MainWindow()
        main_win.run()
    except KeyboardInterrupt:
        sys.exit(0)