main.py 文件源码

def kve_preview(self):
        r'''Editor?text??Widget???????Preview

        Builder.load_string?
        1. ?????Kv????????????????
        2. ?????Kv????root rule?????None???
        ?????????????????????????????????????
        Label???????????
        '''

        editor = self.ids.editor  # Editor???Widget(CodeInput)
        preview = self.ids.preview  # Preview??????Widget
        editor.text = tab2spaces(editor.text)
        preview.clear_widgets()  # ???Preview???
        Builder.unload_file(self.KV_FILENAME)  # ???Kv???????

        widget = None
        try:
            widget = Builder.load_string(
                editor.text,
                filename=self.KV_FILENAME
            )
        except Exception as e:
            temp = [str(e.__class__)]
            temp.extend([str(arg) for arg in e.args])
            error_msg = '\n'.join(temp)
        else:
            if widget is None:
                error_msg = r'No root rules.'
        if widget is None:
            # Widget????????????????????????????Label
            # ??????
            preview.add_widget(Factory.Label(text=error_msg))
        else:
            preview.add_widget(widget)