'Draw everything (from scratch).'

def draw(self):

    if self._tree_canvas:
        self._tree_canvas.delete('all')
        self.draw_tree()
    if self._sentence_canvas:
        self._sentence_canvas.delete('all')
        self._draw_sentence()
    self._chart_canvas.delete('all')
    self._edgetags = {}
    for lvl in range(len(self._edgelevels)):
        for edge in self._edgelevels[lvl]:
            self._draw_edge(edge, lvl)
    for edge in self._chart:
        self._add_edge(edge)
    self._draw_loclines()
