'Add the current figure to the stack of views and positions'

def add_figure(self, figure):

    if (figure not in self.views):
        self.views[figure] = cbook.Stack()
        self.positions[figure] = cbook.Stack()
        self.home_views[figure] = WeakKeyDictionary()
        self.push_current(figure)
        figure.add_axobserver((lambda fig: self.update_home_views(fig)))
