bad workaround QClipboard::dataChanged()

#I write the slot of QClipboard::dataChanged() as this  to avoid the bug,
@pyqtSlot()
def detectClipboardUrl(self):
    clipboardText = self.clipboard.text()
    if getattr(self.clipboard, 'lastClipboardUrl', None) != clipboardText:
        url = clipboardText
        setattr(self.clipboard, 'lastClipboardUrl', url)
       #会造成不能连续复制同样的url

self.on_autodownloadEnable_triggered()  # 立即断开 Clipboard的信号联系，# 为了防止chrome造成signal call twice的bug
QTimer.singleShot(400, self.on_autodownloadEnable_triggered)  # #会造成400ms内无法连续复制的url