Update font from Preferences

def update_font(self):
        """Update font from Preferences"""
        font = self.get_plugin_font()
        color_scheme = self.get_color_scheme()
        for editorstack in self.editorstacks:
            editorstack.set_default_font(font, color_scheme)
            completion_size = CONF.get('main', 'completion/size')
            for finfo in editorstack.data:
                comp_widget = finfo.editor.completion_widget
                comp_widget.setup_appearance(completion_size, font)